Buckeye Dairy News: VOLUME 23, ISSUE 4

  1. Milk Prices, Costs of Nutrients, Margins and Comparison of Feedstuffs Prices

    April F. White, Graduate Research Associate, Department of Animal Sciences, The Ohio State University

    Milk prices

    In the last issue, the Class III futures for May and June were at $18.93/cwt and $17.63/cwt, respectively. Class III closed slightly lower than predicted at $17.21/cwt in June, with protein continuing to decline in price from $2.81/lb in May to $2.51/lb in July. The Class III future for August is $16.50/cwt, followed by a slight increase to $16.66/cwt in September.

    Nutrient prices

    It can be helpful to compare the prices in Table 1 to the 5-year averages. The price of NEL and peNDF are about 37 and 41% higher than the 5-year averages ($0.08/Mcal and $0.08/lb), while MP is 2% below the 5-year average ($0.38/lb). The price of MP in the SESAME model using this week’s feed prices is very close to the 5-year average, although the prices of many feeds providing protein to the ration continue to be higher than they were this time last year.

    To estimate profitability at these nutrient prices, the Cow-Jones Index was used for average US cows weighing 1500 lb and producing milk with 3.9% fat and 3.2% protein. For July’s issue, the income over nutrient cost (IONC) for cows milking 70 lb/day and 85 lb/day is about $9.33 and $9.87/cwt, respectively. Both estimates are likely to be profitable, although they are lower than in May. As a word of caution, these estimates of IONC do not account for the cost of replacements or dry cows, or for profitability changes related to culling cows.

    Table 1. Prices of dairy nutrients for Ohio dairy farms, July 21, 2021.

    Economic Value of Feeds

    Results of the Sesame analysis for central Ohio on July 21, 2021 are presented in Table 2. Detailed results for all 26 feed commodities are reported. The lower and upper limits mark the 75% confidence range for the predicted (break-even) prices. Feeds in the “Appraisal Set” were those for which we didn’t have a local price or were adjusted to reflect their true (“Corrected”) value in a lactating diet. One must remember that SESAME™ compares all commodities at one specific point in time. Thus, the results do not imply that the bargain feeds are cheap on a historical basis. Feeds for which a price was not reported were added to the appraisal set for this issue.

    Table 2. Actual, breakeven (predicted) and 75% confidence limits of 26 feed commodities used on Ohio dairy farms, July 21, 2021.

    For convenience, Table 3 summarizes the economic classification of feeds according to their outcome in the SESAME™ analysis. Feedstuffs that have gone up in price based on current nutrient values or in other words moved a column to the right since the last issue are in oversized text. Conversely, feedstuffs that have moved to the left (i.e., decreased in value) are undersized text. These shifts (i.e., feeds moving columns to the left or right) in price are only temporary changes relative to other feedstuffs within the last two months and do not reflect historical prices. Feeds added to the appraisal set were removed from this table.

    Table 3. Partitioning of feedstuffs in Ohio, July 21, 2021.

    Bargains At Breakeven Overpriced
    Gluten meal Whole Cottonseed Mechanically extracted canola meal
    Corn, ground, dry

    Feather meal

    41% Cottonseed meal
    Corn silage Soybean hulls Soybean meal - expeller
    Distillers dried grains Wheat bran

    44% Soybean meal

    Hominy

    48% Soybean meal

    Solvent extracted canola meal
    Gluten feed Alfalfa hay - 40% NDF

    Meat meal

      Wheat middlings

    Whole, roasted soybeans

    As coined by Dr. St-Pierre, I must remind the readers that these results do not mean that you can formulate a balanced diet using only feeds in the “bargains” column. Feeds in the “bargains” column offer a savings opportunity, and their usage should be maximized within the limits of a properly balanced diet. In addition, prices within a commodity type can vary considerably because of quality differences as well as non-nutritional value added by some suppliers in the form of nutritional services, blending, terms of credit, etc. Also, there are reasons that a feed might be a very good fit in your feeding program while not appearing in the “bargains” column. For example, your nutritionist might be using some molasses in your rations for reasons other than its NEL and MP contents.

    Appendix

    For those of you who use the 5-nutrient group values (i.e., replace metabolizable protein by rumen degradable protein and digestible rumen undegradable protein), see the Table 4.

    Table 4. Prices of dairy nutrients using the 5-nutrient solution for Ohio dairy farms, July 21, 2021.

  2. USDA Releases July Dairy Outlook

    Chris Zoller, Extension Educator, Agriculture and Natural Resources, Tuscarawas County, Ohio State University Extension

    The United States Department of Agriculture Economic Research Service (USDA-ERS) released its monthly Livestock, Dairy, and Poultry Outlook (https://www.ers.usda.gov/webdocs/outlooks/101676/ldp-m-325.pdf?v=2053.7) on July 16, 2021. This monthly outlook provides supply and use projections based on the World Agricultural Supply and Demand Estimate (WASDE) report.  The WASDE report, also released monthly, is available here: https://www.usda.gov/oce/commodity/wasde.

    Production and Use Data

    According to data from the National Agricultural Statistics Service (NASS), milk cow numbers in the United States have increased each month since July 2020 (see graph below).  The number of dairy cattle slaughtered at federally inspected facilities has been comparable to a year ago levels; however, for the week ending June 27, 2021, slaughter numbers were 4,100 higher than the same week one year ago.

    Milk production in May was 0.5 lb less than April, averaging 67.4 lb/cow.  Over the last 20 years, the only larger decreases from April to May occurred in 2012 and 2020.  Possible reasons for this decrease, as described in the report, include:

    • Actions taken by some cooperatives and handlers may have discouraged higher production
    • Increased feed costs
    • Hot, dry weather in the western U.S.
    • The U.S. Agriculture Drought Monitor, as of July 13, reported 50% of milk cow inventory, 64% of alfalfa acres, 36% of corn acres, and 31% of soybean acres were in areas experiencing drought

    Dairy Price Forecast – 2021

    USDA projects 9.5 million head of dairy cows in 2021, 5,000 more than in the previous month’s forecast.  Per cow production for the year is estimated at 24,020 lb, a reduction of 45 lb from last month’s report.  Continued drought, high feed prices, and reduced milk prices result in the lowered forecast.

    Milk Class Price/cwt
    III $16.80
    IV $15.40
    All-milk $18.30

    Looking Ahead – Milk Production and Pricing - 2022

    The forecast for 2022 calls for an increase of 15,000 head compared to 2021, bringing the total estimated number for the year at 9,515 million head.  USDA is expecting milk production to increase to 24,335 lb/cow, about 315 lb higher than 2021. 

    Milk Class Price/cwt
    III $16.75
    IV $15.75
    All-milk $18.50

    Summary

    This forecast calls for an increase in cow numbers, a slight increase in production, and no real improvement in milk pricing.  Dairy producers are encouraged to evaluate inputs, monitor expenses closely, and consult with trusted advisors to develop plans.

    Dairy farmers and advisors are encouraged to consult the Ohio State University Extension Dairy Excel 15 Measures of Competitiveness bulletin available at: https://dairy.osu.edu/sites/dairy/files/imce/2019%2015%20Measures%20of%20Dairy%20Farm%20Competitiveness%20Final%20%281%29.pdf,  Ohio State University Extension Farm Budgets available at: https://farmoffice.osu.edu/farm-management/farm-budgets, and the Ohio State University Extension Ohio Farm Business Analysis and Benchmarking Program at:  https://farmprofitability.osu.edu/.

    Sources:

    USDA Economic Research Service Livestock, Dairy, and Poultry Outlook, July 2021 https://www.ers.usda.gov/webdocs/outlooks/101676/ldp-m-325.pdf?v=2053.7

    USDA Economic Research Service, World Agricultural Supply and Demand Estimate (WASDE), July 2021 https://www.usda.gov/oce/commodity/wasde/wasde0721.pdf

  3. Assessing Calf Death Losses in a Beef-Dairy Crossbreeding Program

    Dr. Gustavo M. Schuenemann, Professor and Extension Veterinarian, Department of Veterinary Preventive Medicine, The Ohio State University

    Many dairy herds are implementing a beef-dairy crossbreeding program for all or a portion of their lactating cows in order to add value to newborn calves. In beef cattle, there is a moderate to high correlation between heritability of growth traits and their genetic correlations with birth weight (e.g., yearling body weight has a heritability of 58% and a correlation with birth weight of 0.61). Although there are several considerations such as market for beef-dairy cross calves, replacement heifers needed, and calf death losses due to dystocia and the subsequent survival and performance of lactating cows, the potential for added value by implementing a beef-dairy crossbreeding program must not neglect the potential to increase calving difficulty due to increased birth weights.

    A case study using data from a beef-dairy crossbreeding program was developed to illustrate a systematic approach to assess calf death losses. The case study was developed for educational purposes; and the information may or may not be applicable to other situations. The overall objective was to assess calf death losses at calving for a 12-month period (March 2020 to March 2021). Therefore, the patterns of calf death losses were assessed on the following variables by:

    1. Length of dry period (primarily cows with <44 days),
    2. Gestation length and twin pregnancies,
    3. Parity (first calf heifer and multiparous cows),
    4. Sire (beef and Holstein bulls),
    5. Calendar week, and
    6. Calendar month.

    Background: A total of 6488 calvings during March 2020 to March 2021 from one Holstein dairy herd were assessed. All cows were housed in free-stall barns and fed a TMR to meet or exceed nutritional requirements. Prepartum cows and pregnant heifers were fed an anionic diet and postpartum cows were grouped for the first 21 days in milk. First calf-heifers were grouped separately from multiparous cows in both pre- and postpartum pens. All lactating cows were milked 3x per day (every 8-hour interval) with an average annual milk yield of 96 lb/day (3.3% milk protein and 3.5% milk fat, and ~160,000 SCC/mL). The reported voluntary waiting period was 60 days for lactating cows. All lactating cows were presynched (starting at 26 ± 3 DIM) and enrolled in Ovsynch 12 days later. Cows showing signs of estrus during Ovsynch were bred and the remaining animals were subjected to timed-AI (~60% of cows were bred on heat detection and ~40% of cows on timed-AI). Multiparous cows (lactation 2 or greater) were bred with beef bulls and lactation 1 cows were bred with sex-sorted semen for the first two services (3rd or greater services with beef bulls). Breeding heifers were bred with sex-sorted semen following a simple reproductive program consisting of PGF every 14 days plus heat detection. Pregnant first-calf heifers were moved to the farm ~45 days prior to calving. All replacement heifers were raised on-site at a different facility. Pregnancy diagnosis was performed weekly for cows (32 to 38 days post-AI) and first-calf heifers (42 to 48 post-AI). Regarding the reproductive performance, cows had an overall 42% conception rate (CR) with 28% 21-day pregnancy rate (PR) and replacement heifers had an overall 60% CR with 42% 21-day PR. The owners and their advising team requested an assessment of the maternity (overall calf death losses) to adjust, if necessary, their beef-dairy crossbreeding program. The dairy herd was enrolled in DHIA and maternity data available on calf losses were obtained from PCDART.  

    Case Study Outcomes:

    The overall calf death loss at the maternity was 5.4% (340 out of 6488 calvings). The pattern of calf death losses (n = 340) at calving were further analyzed to identify opportunities for improvement within the beef-dairy crossbreeding program (calving difficulty was not recorded):

    1.  What is the pattern of calf death losses by length of dry period?

    Pregnant cows experiencing short dry period length (≤44 days) accounted for 41.1% of all calf death losses (n=140/340; Table 1). Regardless of sires, male calves had ~37% more mortality (5.9%) compared to female calves (4.3%). When looking at length of dry period, keep in mind that there is an interaction with short gestation length and twin pregnancies. Pregnant cows and first-calf heifers with twin pregnancies have shorter gestation lengths.

    Table 1. Calf death losses by length of dry period.

    2.  What is the pattern of calf death losses by gestation length and birth of twins?

    Pregnant cows experiencing short gestation length (<270 days) accounted for 15% (n = 48) of the calf death losses (Table 2). In dairy cattle, successful pregnancy results in the birth of one calf. However, the birth of two or more calves could occur at a rate of 3 to 5%. Birth of twin calves has been associated with genetics, season, parity (1.2% in primiparous and 5.8% in multiparous), breeding program (timed-AI versus estrus detection), and high milk yield. It has been shown that high milk producing cows have reduced blood progesterone due to increased metabolism to support milk yield. This reduction of blood progesterone occurs at the time of peak milk yield and breeding during the selection of the preovulatory follicle around 60 days in milk. Cycling dairy cows inseminated following estrus detection are more likely to experience double ovulation resulting in twin pregnancies (10-15%) compared to cows bred following timed-AI (3-5%). Therefore, high milk producing cows bred following estrus detection increased the likelihood of twin pregnancies, and cows with twin pregnancies have shorter gestation length. In dairy cattle, the gestation length is 276±6 days, but pregnant cows/heifers could experience a short (255-269 days), average (270-283 days), or long gestation length (284-297 days). It is known that dairy cows experiencing short or long gestation length have more calf losses at calving.

    Table 2. Calf death losses by gestation length and twin pregnancies.

    3.  What is the pattern of calf losses by parity (first-calf heifers and multiparous cows)?

    First calf heifers had less calf death losses compared to multiparous cows (Table 3). This is due to the fact that all replacement heifers and the first two services of lactation=1 cows were bred using sex-sorted semen (Holstein bulls); thus, more females calves were born. About 52% of first-calf heifers calved with ≤21 months. Multiparous cows (lactation 2 or greater) were bred using semen from beef bulls. Also, it is important to note that about 60% of all multiparous cows were bred following observation of standing heat; thus, this increases the likelihood of double ovulation, resulting in twin pregnancies regardless of sires. The overall twining rate was ~1% for first-calf heifers, ~4% for lactation 1, and ~7% for multiparous cows. When removing calves born from twin pregnancies for multiparous cows (lactation=3 or greater), the overall calf death losses was 3.1%. Calf death losses appears to be associated with twin pregnancies, gender (male) and age at calving of heifers rather than type of sires.

    Table 3. Calf death losses by parity.

    Footnote: Lactation 1 cows became first-calf heifers after calving (bred with sex-sorted semen). Lactation 2 cows were bred with sex-sorted semen during lactation 1 and became lactation 2 after calving.  

    4.  What is the pattern of calf death losses by sire (beef and Holstein bulls)?

    A total of 111 bulls were assessed (8 beef and 103 Holsteins). Table 4 provides information for a subset of 17 bulls (3 beef and 14 Holsteins) with ~60% of the total calf death losses. Out of 8 beef bulls assessed, 3 beef bulls (Limousine, Simmental, and Simental-Angus cross) had 24% of all calvings (11-15% twin pregnancies) with ~39% of all death losses (n = 133). Also, the data reveled an important interaction between birth of twins and calf death losses, regardless of sires (beef or Holstein bulls). Cows with twin pregnancies from beef bulls likely had to deal with an added effect of increased calf birth weight (primarily for male calves) and delivery of multiple calves. Calf birth weight is the most important predictor for difficult calving. Calf mortality due to a dystocic birth increases by 0.35% for every increased pound of birth weight above the mean for the breed. When removing calves born from twin pregnancies from the analysis for cows with lactation=3 or greater, the overall calf death losses was 3.1%. Therefore, both beef and Holstein bulls had similar overall calf death losses.

    Table 4. Calf death losses by sires.

    5. What has been the pattern of calf death loss at birth by calendar week?

    In the calendar week, Monday had above mean calf death losses (Figure 1). Typically, Mondays are a busier workday for dairy farms because personnel are trying to catch up from any unfinished work from the previous weekend or week. This trend highlights the importance to review and adjust protocols and tasks to allow personnel sufficient time to monitor the maternity area.  


    Figure 1. Calf death losses by day of week.

    6.  What has been the pattern of calf death loss at birth by month?

    Overall, summer had above mean calf death losses compared with spring, winter and fall (Figure 2). This trend is likely due to a drop in prepartum DM intake experienced by heat stressed cows with the subsequent increase in blood non-esterified fatty acids (NEFA) prior to calving. The process of calving is an active process that requires energy (glucose) and calcium to support strong uterine and abdominal contractions for the successful delivery of one or more calves.  


    Figure 2. Calf death losses by month.

    For this case study, what are the top opportunities to reduce calf death losses?

    At a minimum, the confounding effect of twin pregnancies, gender (male vs female), and parity, season and calendar week should be considered when assessing calf death losses for a beef-dairy breeding program. The overall calf death losses for this case study (5.4%) are similar to the overall for the US (5.1%). However, the top 10% dairy herds in the US, in terms of calf survival, are achieving <2% calf losses at calving. To reduce calf losses at calving, consider the following points:

    1. Although beef bulls had similar proportion of calf death losses as Holstein bulls, select calving ease beef sires without neglecting growth traits for beef-dairy crossbred calves. Track the degree of calving difficulty using a 4-point scale and calf birth weights for all sires, including calves born from sex-sorted semen.
    2. Adjust management for twin pregnancies:
      1. Increase the proportion of multiparous cows bred on timed-AI by reducing heat detection. This reproductive strategy allows most high milk producing cows to develop the pre-ovulatory follicle under the influence of high blood progesterone, thus increasing the likelihood of single ovulation.
      2. Extend the voluntary waiting period from 60 to 70 DIM to allow cows more time to recover their uterine environment and start breeding cows right after the peak milk yield when DM intake supports production and liver metabolism.
      3. Cows confirmed pregnant with twins should be moved into the prepartum pen with an anionic diet 10 days earlier than the rest of the cows (at 245 ± 3 days of gestation). Because cows pregnant with twins had reduced gestation length, this management strategy allows enough exposure to the anionic diet to prevent hypocalcemia.
    3. Review and adjust the criteria for the replacement program: a) growth and development (e.g., double calf birth weight by 60 days of life, 1.9-2 lb/day of body weight gain from weaning to calving) and b) breeding criteria (age, body weight, and height). Calf death losses increase when first calf heifers are calving with ≤22 or >28 months of age and at <1200 lb of postpartum body wight (or <80% body weight of lactation 4 cows at 100-200 days in milk).
    4. Train calving personnel and adjust daily tasks to allow consistent handling of the maternity workload within the calendar week.
    5. Adjust the heat abatement system to overcome the negative effect of heat stress during summer.

    An ounce of prevention is worth a pound of cure! Please have this discussion with your veterinarian, nutritionist, and breeding team. These little details make the difference at the end of the day.

     

  4. Promising Vaccine Development to Control Johne’s Disease

    Dr. Gustavo M. Schuenemann and Dr. Jeffrey D. Workman, Department of Veterinary Preventive Medicine, Ohio State University Extension

    Johne’s disease is a chronic enteritis associated with ruminants caused by the intracellular pathogen Mycobacterium avium subsp. paratuberculosis (MAP). MAP is a highly prevalent and costly disease worldwide in large and small ruminant species, such as cattle, sheep, and goats. In the US, it is estimated that over 90% of dairy herds are infected with MAP. The clinical signs are characterized by chronic diarrhea with body weight loss in the later stages of infection. It has been shown that the subclinical stages of MAP were associated with decreased milk yield and higher risk for other common production diseases due to body weight loss and debilitating immune response. Infected animals with MAP are difficult to identify and segregate from the herd or flock due to: (1) long incubation period (it could take years), (2) the absence of clinical signs until advanced stages, and (3) the lack of reliable diagnostic methods. Newborn animals are infected at the time of parturition by ingesting MAP via colostrum and milk as well as environmental exposure to MAP in manure from infected cows. Identification of MAP in feces is performed by culture or PCR, or sometimes by serum ELISA to identify antibodies against MAP. Although these testing methods are rapid and cost-effective, the efficacy of MAP detection is almost entirely dependent on the immune status of the host.

    Vaccination is recognized as an effective method to prevent infections in livestock. There are a few commercially available vaccines for Johne’s disease worldwide (e.g., Gudair, Silirium); however, in the US, Mycopar® was the only USDA-licensed vaccine available for use (discontinued in the US in 2019).  Its use was restricted to cattle, and only under the supervision of a licensed veterinarian. The increasing prevalence of MAP requires new efficacious vaccines as an essential management tool to control MAP. A recent study assessed the effectiveness of pooled MAP recombinant proteins as a potential vaccine. Two separate studies were carried out: 1) In the first study, vaccinated two-week old calves were immunized with a total of 400 µg protein cocktail per dose and 2) the second study compared doses of 400 µg versus 800 µg of protein cocktail using another set of two-week old calves. Calves were vaccinated twice 14 days apart starting at two weeks of age, then vaccinated and nonvaccinated control calves were inoculated orally three times with live MAP isolated from infected cows. At the end of 12 months study period, the authors showed that vaccinated animals had significantly reduced tissue colonization with MAP compared to control animals. Calves immunized with the higher dose had improved protection with reduced MAP burden. Furthermore, there was a negligible level of cross-reactivity between M. avium and M. bovis antigens, suggesting that infection could be differentiated from vaccinated animals when using serology assays. The authors concluded that vaccination of calves with the pooled four recombinant MAP proteins was efficacious in reducing tissue colonization and fecal shedding. Although experimentally, this novel vaccine has the potential to prevent or reduce the spread of Johne’s disease in cattle.

    This study was conducted at the USDA-ARS, National Animal Disease Center located in Ames, IA. Please find below the reference for additional details:

    Stabel, J.R., and J.P. Bannantine. 2021. Reduced tissue colonization of Mycobacterium avium subsp. paratuberculosis in neonatal calves vaccinated with a cocktail of recombinant proteins. Vaccine 39:3131–3140.

  5. Key Mastitis Control Points for Best Milk Quality

    Dr. Luciana Bignardi da Costa, and Dr. Gustavo Schuenemann, Department of Veterinary Preventive Medicine, The Ohio State University

    Mastitis is the most common and costly disease affecting dairy cows, ranking within the top two reasons for early removal of cows within US dairy herds. This disease affects cow welfare and causes significant economic losses through decreased milk yield, reduced milk quality, early removal of cows from the milking herd, and increased treatments costs. Mastitis is caused by several pathogens which lead to mammary gland inflammation with the subsequent increase of somatic cell counts in milk. Somatic cell count (SCC) and standard plate count (SPC) are mandated by the federal Grade “A” Pasteurized Milk Ordinance (PMO), which specifies safety standards of Grade “A” milk. The quality of processed dairy products and fluid milk is greatly affected by the initial quality of the raw milk harvested at the farm level. Therefore, listed below are key points expanded from the National Mastitis Council control program to improve milk quality at the herd level:

    Point #1: Establishment of goals for udder health.

    The most important part of your mastitis control program is setting goals for udder health and milk quality (Tables 1 and 2).

    • Milk from uninfected mammary glands contains less than 100,000 somatic cells per mL. Research studies have shown that milk SCC of equal or more than 200,000 per mL is associated with an inflammatory response due to an infected or recovering mammary quarter, and that milk has reduced manufacturing quality properties.
    • The PMO requires the SPC to be less than 100,000 cfu/mL for Grade A farms and to be less than 300,000 cfu/mL for manufacturing grade milk. However, for being a critical control point for milk quality, some milk purchasers are more rigorous than the official regulations. Thus, realistic a goal for SPC can be set at <5,000 cfu/mL and usually a count of >10,000 cfu/mL is indicative of a problem.
    • The Preliminary Incubation Count (PIC) or PI counts recommended values are <10,000 cfu/mL but up to 20,000 cfu/mL is considered acceptable. Values higher than 50,000 cfu/mL suggest potential problems with cleaning and sanitation of the milking machine, poor pre-milking preparation (washing the teats with water, not using teat predip, and dirty teats) all known risk factors for mastitis.
    • The laboratory pasteurized count (LPC) is usually performed to distinguish organisms that survive pasteurization. High LPC numbers can be associated with improper sanitizing practices, unclean equipment, high water-hardness score, high alkalinity of alkaline detergent wash, or problems with cooling system/ plate cooler. The LPC values should be below 100 cfu/mL and values >200 cfu/mL are considered high.
    • Coliforms are fecal bacteria that are also commonly found in the environment. Thus, coliform count (CC) is an indication of the efficiency of procedures, such as cow’s milking preparation and cleanliness of the cows’ environment. The coliform count should be less than 10 cfu/mL. Coliform counts >50/ml suggest manure and soil on the teats, and counts higher than 100 cfu/mL usually indicate poor milking practices, dirty equipment, contaminated water, and/or cows presenting coliform cases of mastitis.

    Table 1. Criteria for bulk tank parameters.

    Parameter Low Medium High
    Bulk tank SCC (cells/mL) <200,000 200,000 - 400,000 >400,000
    Standard Plate Count (SPC; cfu/mL) <5,000 5,000 - 10,000 >10,000
    Preliminary Incubation Count (PIC; cfu/mL) <10,000 10,000 - 20,000 >20,000
    Lab Pasteurized Count (LPC; cfu/mL) <100 100-200 >200
    Coliform Count (cfu/mL) <50 50 - 100 >100

    Source: Oliver SP, Dairexnet, 2019.

    Table 2. Sources of Microbial Contamination as Detected by Bacteriological Procedures.

    Procedure Natural Flora Mastitis Dirty Cows Dirty Equipment Poor Cooling
    SPC>10,000 cfu/mL Not Likely Possible Possible Possible* Possible
    SPC>100,000 cfu/mL Not Likely Possible Not Likely Possible* Possible*
    LPC>200-300 cfu/mL Not Likely Not Likely Possible Possible* Not Likely
    PIC High vs SPC Not Likely Not Likely Possible Possible* Possible*
    SPC High/No Increase in PIC Not Likely Possible* Not Likely Not Likely, but Possible Not Likely
    CC High Not Likely Possible Possible Possible Not Likely

    * A more likely source.  
    Source: Murphy, SC. NMC Regional Meeting Proceedings, 1997.

    Point #2: Maintenance of clean and comfortable environment.

    The principles of best animal welfare are directly associated with cleanliness of housing and cow comfort (https://www.dcwcouncil.org/node/4006).

    • Keep bedding area dry and clean. Review frequently your bedding and grooming protocol, ensure appropriate ventilation, and avoid frequent social changes within transition cows (e.g. move groups of cows once per week)
    • A compacted bedding surface negatively affects laying time of cows. Dairy cows have strong behavioral need to rest, and this has a priority over dry matter intake, regardless of feed availability at the feed bunk.
    • Ensure adequate stocking density, feed availability within reach of cows, and water availability for pre- and postpartum cows. Transition cows should be less than 100% capacity relative to stalls available (1 stall per cow or less) and have a linear feed bank space of 30 inches per cow.
    • Water should not accumulate in alley ways and/or bedding area. A clogged flush line or leaky roof will flood alleys or add water to bedding surfaces, which in turn significantly increases the risk for environmental mastitis and lower milk quality.     
    • Think about cow comfort as a hotel which could range from 1 to 5 starts in terms of comfortable amenities. For a given cow, the difference in terms of consistent lying time (hours/day) is that the best dairy farm provides 2 to 2.5 hours per day more lying time compared with the average farm. For every 3 minutes of lost rest, the cow will sacrifice 1 minute of dry matter intake (DMI). Therefore, poor cow comfort will likely reduce eating to 40 to 50 minutes per day or a drop of 3.3 to 4.4 lb/day of DMI.    
    • Milk is 87% water and without sufficient water intake, milk production will suffer. An adequate ingestion of fresh, clean water promotes normal rumen function, high feed intake, digestion, and nutrient absorption - maximize water intake and you will maximize feed intake and consequently milk production. 
    • To improve mammary gland health: (1) Feed and manage dry and prepartum cows to maintain proper body condition and avoid a drop in feed intake prepartum and excessive body condition score (BCS) loss early lactation, (2) Proper mineral nutrition of prepartum cows to prevent hypocalcemia, and (3) formulate a diet considering your water quality (bacteria and mineral contribution) to feed adequate, but not excessive amounts of trace minerals and vitamins (selenium and vitamin E are critical for the immune system).

    Point #3: Proper milking procedures.

    • Allow milk to let-down properly by providing good practices on handling animals with care to the milking parlor and maintaining a calm (no yelling is necessary) and comfortable holding pen.
    • Strip 4-5 squirts of milk from each quarter before preparing the cow. Do a strip cup test routinely to identify the cases of mastitis at an early stage. Perform stripping correctly, avoiding spreading the milk skirts in other directions than the strip cup or floor.
    • Pre-dip teats with an effective germicide (iodine, chlorine dioxide, hydrogen peroxide, lactic acid, glycolic acid, or chlorhexidine) and allow 30 seconds contact time.
    • Dry teats thoroughly using individual paper towels or cloths.
    • After preparation starts, one should wait approximately 60-90 sec before attaching the unit that should be properly aligned on the udder.
    • Post milking teat disinfection remains a foundation for the prevention of contagious mastitis. The effectiveness of the various products offered is well documented in the scientific literature.
    • Discard teat dip contaminated with manure or dirt- it has lost its efficiency.
    • Milk last or segregate those cows with contagious mastitis (e.g., Staphylococcus aureus infections).

    Point #4: Proper maintenance and use of milking equipment.

    • With greater farm size, more herds are milking 3 – 4 times /day and adopting the use of robotic milking, thus the milking machine remains an important way of transfering contagious bacteria from infected to non-infected cows, particularly considering that more cows will be milked in the same milking unit.
    • Proper maintenance of milking equipment will assure proper vacuum to be applied to the teats, causing no damage to the cow’s teat-ends.
    • Make sure the cooling tank and any part or connection in the whole milk handling chain is cleaned. Water heating capacity must meet the requirements from the cleaning procedure.

    Point #5: Good record keeping.

    • When treatment is needed, record the necessary information, such as cow identification, drugs used, start of treatment day, dose, route of administration or how the drug was given (e.g. oral, injection, intramammary), name of the person who gave the drug, length of the treatment, withdrawal period, and results of culture, stripping and/or CMT.
    • To evaluate the effectiveness of your mastitis control during the dry period and to make decisions regarding mastitis prevention, it is important to record how many cows are infected and how many are not infected at dry-off and then compare those numbers after freshening. 

    Point #6: Appropriate management of clinical mastitis during lactation.

    • About 50 to 80% of clinical cases of mastitis may not benefit from an antibiotic treatment labeled for intramammary administration. If the pathogen is known and susceptible, an antibiotic is indicated BUT CANNOT be the ONLY approach to overcome limitations with environment and/or management. Note that dehydration and pain management should be top priorities for severe cases of mastitis.
    • Does antibiotic treatment increase her chance of cure? The short answer is “yes” but only for susceptible pathogens.
    • How long should I treat? Follow the label and your vet’s recommendations. Duration of 2 days should work, but some cases may require an extended therapy of 5-7 days. Extending duration may reduce clinical failure but may have no effect on cure rate, SCC, or new intramammary infection.
    • Will she get better on her own? “No” for contagious pathogens or toxic cases, but “yes” for minor pathogens. A milk culture will be needed to identify the pathogen(s) causing the infection. On most farms, mild and moderate cases of mastitis will resolve within 4-6 days, regardless of treatment. 
    • With the increased concern nowadays about the misuse of antibiotics in livestock, it is recommended to treat cases of clinical mastitis only after the identification of the causing organisms. This practice will not only reduce antibiotic usage, but also reduce the volume of milk withheld from the bulk tank because of antibiotic withdrawal. 

    Point #7: Effective dry cow therapy.

    • Mastitis disease is related to three major steps: 1) teat-end exposure to pathogens (environment), 2) pathogens entering the mammary gland (open teat-end); and 3) the ability of the pathogens to survive the host defenses and to invade the mammary gland epithelium (colonization).
    • Proper dry cow management is extremely important in maintaining and improving udder health, milk yield and milk quality.
    • Over 95% of new dry period infections occur in quarters with open teat canals.
    • Over 50% of clinical mastitis cases caused by environmental pathogens occurring in early lactation were acquired during the dry period.
    • High milk producing cows are very susceptible to new intramammary infections in the beginning and the end of the dry period (around calving).
    • In high milk producing dairy cows, reducing milk yield a week prior to dry-off (offering the dry cow ration would reduce milk yield by ~60% or milking 1x per day would reduce milk yield by ~40%) significantly enhances teat canal closure and formation of the keratin plug. It has been shown that lactating cows with >36 lb/day during the last week of lactation were over 7 times more likely to be infected at calving compared with lactating cows milking ≤24 lb/day.
    • New research showed that prepartum cows benefited by administering the mastitis vaccine at 28 days prior to parturition (dpp) followed by pen change with acidogenic diet at 21 dpp (greater serum glucose, ~46% reduction in subclinical hypocalcemia [from 31.9 to 17.3%], and 19% more colostral IgG at calving) compared to cows vaccinated plus pen change at 21 dpp.
    • Dairy cows confirmed with twin pregnancies almost always experience short gestation length and more hypocalcemia at calving. The transfer of IgG from blood into the mammary gland (colostrum and milk) is an active process that requires energy and calcium. Plan to vaccinate and move cows into the prepartum pen at least 7 days earlier than typically planned for cows confirmed with twin pregnancies.       
    • The usage of an intramammary antibiotic is indicated if a cow has a persistent infection from her previous lactation, while a proper application of a teat sealant aims to prevent new infections. Follow the label indications for safe and correct use.

    Point #8: Biosecurity for contagious pathogens and marketing of chronically infected cows.

    • Biosecurity refers to not just the management practices that reduce the chances of introduction of infectious diseases onto the farm (by animals or people) but also practices that prevents the spread of infectious disease on farms.
    • Keep the herd as closed as possible. If you purchase animals into your herd: 1) Ask for the somatic cell count information on milking cows and check the cow’s history on contagious mastitis in current and/or previous lactations; 2) Look for other health events; 3) When possible, test all purchased cattle for infection not just restricted to mastitis causing organisms, such as Staphylococcus aureus, Streptococcus agalactiae and Mycoplasma bovis, but others diseases such as BVD and Bovine leukosis; and 4) Immunization history.

    Point #9: Regular monitoring of udder health status.

    • Be enrolled in a system that provides you with individual SCC, such as DHIA. If not possible, perform regularly CMT tests to screen for clinical cases of mastitis.
    • Assess the success of your treatment protocols. Successful treatment could be defined based on: 1) Cure rate (return to normal appearance of milk, duration of milk discard or days in hospital pen) and/or 2) Bacteriological cure (absence of causative bacteria in follow up culture).
    • Work with your veterinarian on monitoring goals for SCC and clinical cases of mastitis. 

    Point #10: Periodic review of the mastitis control program.

    • Meet regularly with your veterinarian to review and discuss the points listed above to improve, adjust, or change your milk quality program. Small changes can lead to bigger benefits for the cow’s udder health and profitability of your farm.

    An ounce of prevention is worth a pound of cure! There is no magic bullet to solve milk quality issues at the farm level, and proactive management practices matter when it comes to controlling mastitis. How to remain competitive is the “big” question. Considering this 10-point mastitis control program, along with genetic selection of animals for improved udder health, can improve milk quality and reduce antimicrobial use at the herd level. Please share this discussion with your veterinarian and nutritionist. These little details make the difference at the end of the day!

  6. Forage Fertility: Where We Are and Why it Matters

    Garth Ruff, Beef Cattle Field Specialist and Greg LaBarge, Agronomic Crops Field Specialist, Ohio State University Extension

    Hay and haylage crops are grown on just over 1 million acres in Ohio (NASS, 2019) and are grown on more Ohio farms (44% of all farms) than any other crop (Becot et al., 2020). In addition, there are over 1.3 million acres of pastureland on nearly 39,000 farms (50% of all farms) in the state of Ohio (NASS, 2017). Fertilizer costs represent 40 to 60% of the variable input costs of forage hay production (Ward et al., 2016, 2018), and so managing these costs is key to an Ohio forage producers’ ability to stay competitive. Furthermore, water quality issues in the state underscore the need for Ohio farmers to manage on-farm nutrients as efficiently as possible. A farmer’s ability to find this optimal balance between meeting crop nutrient requirements without over-application is highly reliant on the best available information.

    In order to make better and up-to-date forage fertility recommendations, we want to hear back from producers as to what current practices are already implemented on farms across the state. Understanding current practices and limitations to forage fertility will guide us in determining the type and kind of related research to conduct in order to revise current recommendations.

    Please take this short voluntary survey regarding current forage fertility practices. This survey is part of a research effort conducted by The Ohio State University and should take 10 minutes or less to complete. Once again, your feedback is appreciated as we evaluate current forage fertility guidelines.

    Survey Link: https://osu.az1.qualtrics.com/jfe/form/SV_4JcgVRSdXM16pmK

    Results from this survey, in addition to forage fertility research, will allow for revision of current recommendations for forage crops, grasses and legumes that follow guidelines already established in the Tri-State Fertility Guide. If you have any questions regarding the survey, contact Garth Ruff at ruff.72@osu.edu.

  7. Creeping Towards Harvest

    Haley Zynda, Extension Educator, Agriculture and Natural Resources, Wayne County, Ohio State University Extension

    Silage harvest - it’s the most wonderful time of the year! And by that, I mean stressful and tiring. However, if you were to ask if corn planting or harvesting is more enjoyable, the answer of, “Well there’s no such thing as ‘re-harvesting’ is there?” would sum up my answer quite succinctly.

    Since there is only one shot to get it right, you have to make corn silage harvest count. The feed you make in a few days’ time will likely influence your milk yields for the next year. We need to not only be considering maximizing yield, but also maximizing quality. Corn moisture or dry matter, depending on which way you think about it, heavily influences silage yield and the quality of the fermentation and preservation once it is stored. Taking field samples will be essential in getting harvest timing right. You can start to sample for moisture when kernels begin to show denting (just before the appearance of the milkline), or 40 days after silking (for Ohio). Dry matter yield in tons/acre is maximized at a moisture content of 63% (37% DM) according to the University of Wisconsin. Furthermore, silage storage type will also determine how wet the crop should be prior to harvesting (Table 1). I think it’s safe to say that corn chopping will be occurring over the course of a couple days, so keep in mind that corn will lose 0.5-1.0% moisture per day. Therefore, do not start harvesting when the corn is of optimum moisture because the resulting average moisture will be drier than anticipated.

    Table 1. Silage storage type and recommended moisture content for corn silage harvest.

    Storage Type Moisture, %
    Upright silo 60-65
    Upright oxygen-eliminating silo 50-60
    Bunker 65-68
    Bag 62-68

    Chop height is another factor to consider when harvesting. Average height of chop is between 7 and 18 inches and can alter the digestibility and yield of silage. According to Pennsylvania State University, raising the cutter bar from 7” to 19” will decrease neutral detergent fiber (NDF) content by about 8% and increase starch content by about 2 percentage points. However, the increase in cutter height decreased yield by about 7%. The trade-off of quality and yield paid off – you can see in Figure 1 the estimated milk yield per ton and acre of silage. Two other research studies also concluded that raising the cutter bar height from 14 to 20 inches or 5 to 18 inches increased daily milk yield by an average of 3 lb/day.

    Chop length will also influence quality of silage. The theoretical length of cut (TLC) ranges from ½ to ¾ inch. Shorter cut silage will pack better but will not be as effective of a fiber source if it were longer. If you use a kernel processor, TLC is around the ¾ inch recommendation because the plant is being crushed and compaction in the bunk will be greater. Using a kernel processor will then not only increase digestibility and fermentation capacity of the silage, but indirectly increases the amount of physically effective fiber through increased TLC.


    Figure 1. Corn silage cutting height trade-off.

    Speaking of kernel processing, how can you tell if it’s working? First, take a dime and try to feed it through the rollers. If it won’t pass through, great! If it does, reset your roller clearance to a height of 0.08 to 0.12 inches. You can see how it affects the silage by taking a silage sample that fits in a 32 oz. cup (a freebie you may have gotten from a co-op or vendor show) and count the number of whole kernels you find in it. There should be no more than 2 to 3 whole or half kernels from silage that has been run through a kernel processor. By crushing the kernels, the starch is more readily accessed by rumen microbes during feeding, thus increasing the rumen starch digestibility.

    Before heading to the field, there are a couple of other items to check on.  First, make sure bunkers and silos are in proper condition. Clean out the old feed and scrape the edgesto remove any lingering or caked silage. You can also sweep out the dust using a push broom or broom attachment for a skid steer.  If you use a bunker or bag silo, check the plastic for holes. Patch any plastic that has been perforated with silage tape to prevent spoilage. Think about covering the sides of the bunker to prevent rain spoilage. Ensure the leachate drainage system isn't clogged and there is adequate storage volume.  Approximately 3 square yards of leachate will be produced for every 100 tons of silage stored with 70% moisture, not including any storm water that may interact with the silage (Michigan State University).

    Secondly, making sure your chopper is in top working order is an essential part of the equation. Check your knives and shear bar to make sure they don’t need replaced. While you’re taking care of the business end of the chopper, don’t forget to pay attention to bearings and belts that may need to be replaced. Taking care of 20-minute jobs as they come up is preferrable to leaving them until they evolve into a 3-day ordeal.

    Don’t forget, not only is harvest stressful and tiring, but it is also rewarding. Keep a log to track all the different aspects of silage harvest that you need to juggle. Knowing the knowledge and tools to make high quality feed not only sets YOU up for success, but also for your cows.  Happy harvest!

  8. Steps to Speed up Field Curing of Hay Crops

    Dr. Mark Sulc, Department of Horticulture and Crop Science; Jason Hartschuh, Agriculture and Natural Resources Extension Educator, Crawford County; and Allen Gahler, Agriculture and Natural Resources Extension Educator, Sandusky County, The Ohio State University

    The rainy weather in many regions of Ohio and surrounding states is making it difficult to harvest hay crops.  We usually wait for a clear forecast before cutting hay, and with good reason because hay does not dry in the rain! Cutting hay is certainly a gamble but waiting for the perfect stretch of weather can end up costing us through large reductions in forage quality as the crop matures.

    As we keep waiting for perfect haymaking weather, we will reach the point where the drop in quality becomes so great that the hay has little feeding value left. In such cases, it may be better to gamble more on the weather just to get the old crop off and a new one started. Some rain damage is not going to reduce the value much in that very mature forage.

    Before cutting though, keep in mind that the soil should be firm enough to support equipment. Compaction damage has long-lasting effects on hay crops. We’ve seen many fields where stand loss in wheel tracks led to lower forage yields, weed invasion, and frustrating attempts to “fill in” the stand later.

    This article summarizes proven techniques that can help speed up the process involved in storing good quality forage. While the weather limits how far we can push the limits, these techniques can help us improve the chances of success in those short windows of opportunity between rains, and hopefully avoid overly mature stored forages.

    Haylage vs. Hay

    Consider making haylage/silage or baleage instead of dry hay. Haylage is preserved at higher moisture contents, so it is a lot easier and quicker to get it to a proper dry matter content for safe preservation compared with dry hay. Proper dry matter content for chopping haylage or wrapping baleage can often be achieved within 24 hours or less as compared with 3 to 5 days for dry hay.

    “Hay in a day” is possible when making hay crop silage. The forage is mowed first thing in the morning and laid in wide swaths to be raked in the late afternoon and chopped as haylage starting in early evening. Proper dry matter content for haylage ranges from 30 to 50% (50 to 70% moisture), depending on the structure used.

    Wrapped baleage usually requires 24 hours to cure. Wrapped baleage should be dried to 40 to 55% dry matter (45 to 60% moisture).

    Dry hay should be baled at 80 to 85% dry matter (15 to 20% moisture), depending on the size of the bale package. The larger and the denser the dry hay package, the drier it must be to avoid spoilage. For example, safe baling moistures for dry hay without preservatives are 18-20% for small square bales (80 to 82% dry matter), 18% or less for large round bales, and less than 17% for large square bales. See below for more information on baling with preservatives.

    Mechanically Condition the Forage

    Faster drying of cut forage begins with using a well-adjusted mower-conditioner to cause crimping/cracking of the stem (roller conditioners) or abrasion to the stems (impeller conditioners). Adjust roller conditioners so at least 90% of the stems are either cracked or crimped (roller conditioners) or show some mechanical abrasion (impeller conditioners).

    Some excellent guidelines for adjusting these mower conditioners can be found in an article by Dr. Ronald Schuler of the University of Wisconsin, available online at https://fyi.extension.wisc.edu/forage/adjusting-the-conditioning-system-....

    Consider Desiccants

    Desiccants are chemicals applied when mowing the crop that increase the drying rate. The most effective desiccants contain potassium carbonate or sodium carbonate. They are more effective on legumes than grasses and most useful for making hay rather than silage or baleage. Desiccants work best under good drying conditions. They do not help increase drying rate when conditions are humid, damp, and cloudy, such as we have often experienced this summer. Consider the weather conditions before applying them.  

    Maximize Exposure to Sunlight

    I once heard someone say "You can’t dry your laundry in a pile, so why do you expect to dry hay that way?"

    Exposure to the sun is the single most important weather factor to speed drying. The trick is to expose to sunshine as much of the cut forage as possible.

    The swath width should be about 70% of the actual cut area. The mowers on the market vary in how wide a windrow they can make, but even those that make narrow windrows have been modified to spread the windrow wider. Details can be found in articles at the University of Wisconsin website mentioned above (see especially “Getting the Most from the Mower Conditioner” by Kevin Shinners, https://fyi.extension.wisc.edu/forage/getting-the-most-from-the-mower-conditioner/).

    Another way to spread out and aerate the crop for faster drying is with a tedder. Tedders are especially effective with grass crops. They can cause excessive leaf loss in legumes if used when the leaves are dry. Tedders can be a good option when the ground is damp because the crop can be mowed into narrow windrows to allow more ground exposure to sunlight for a short time, and then once the soil has dried a bit, the crop can be spread out with the tedder. Tedding twice may decrease drying time. Tedding shortly after mowing allows 100% ground coverage, then tedding the next day helps keep the crop off the ground. Be cautious to set tedder properly so that dirt is not incorporated into the hay but that all hay is lifted off the ground.

    Take precautions to follow manufacturer recommendations on ground speed and RPM’s when tedding. Many of the modern in-line “fluffer” type tedders are ground driven and operators often exceed recommended speeds, which can result in bunching and wrapping of the hay, which will increase drying time and make raking more difficult.

    When making haylage, if drying conditions are good, rake multiple wide swaths into a windrow just before chopping. For hay, if drying conditions are good, merge or rake multiple wide swaths into a windrow the next morning when the forage is 40 to 60% moisture to avoid excessive leaf loss.

    Research studies and experience have proven that drying forage in wide swaths can significantly speed up drying. Faster drying in wide swaths results in less chance of rain damage and studies by the University of Wisconsin showed that wide swaths (72% of the cut width) result in lower neutral detergent fiber (NDF) and higher energy in the stored forage.

    Consider Preservatives

    Sometimes the rain just comes quicker than we have time for making dry hay. As mentioned above, making haylage helps us preserve good quality forage in those short rain-free windows. A second option is to use a preservative. The most effective preservatives are based on propionic acid, which is caustic to equipment, but many buffered propionic preservatives are available that minimize that problem.

    Preservatives inhibit mold growth and allow safe baling at moisture contents a little higher than the normal range for dry hay. Carefully follow the preservative manufacturer’s directions and application rates for the hay moisture content at baling. Be sure the application is uniform to avoid spots that spoil. Most products are effective when hay moisture is less than 25% but become iffy between 25 to 30% and do not work if moisture is over 30%. When utilizing preservatives, safe baling moisture can go up to 26% on small squares and round bales, but only 23% on large squares, according to label guidelines on most propionic acid-based products.  Baling at these moistures requires properly calibrated equipment to apply the correct amounts of preservative, and it does not guarantee that bales will not generate internal heat. 

    While the acid works to limit the production of mold and fungal spores that can lead to additional heating, any type of bale made over 20% moisture always has the potential to heat.  Although mold production may be limited, discoloration and caramelization of the higher moisture stems can still occur.  This heating can also degrade proteins in the hay, reducing overall feed quality, despite still helping to preserve the hay from spoilage and hopefully make it safe to store indoors. Keep in mind that preservative-treated hay should be fed within a year or less, as the preservative effect will wear off over time.

    If baling on the wet side, watch those bales carefully! If hay is baled at higher moisture contents that are pushing the safe limits, keep a close watch on them for two to three weeks. Use a hay temperature probe and monitor the internal temperature of the hay during the first three weeks after baling. See the following article for more information on monitoring wet hay: https://agcrops.osu.edu/newsletter/corn-newsletter/15-2021/hay-barn-fires-are-real-hazard

     

  9. Harvest Management of Sorghum Forages

    Dr. Mark Sulc, Professor and Extension Forage Specialist, Department of Horticulture and Crop Science; Dr. Bill Weiss, Professor Emeritus, Department of Animal Sciences; and Jason Hartschuh, Extension Educator, Agriculture and Natural Resources, Crawford County, The Ohio State University

    Summer annual grasses, such as sudangrass, sorghum-sudangrass, forage sorghum, pearl millet, and teff grass, are being used as additional sources of forage on dairy farms. This article discusses harvest and grazing management of these grasses.

    The general guidelines for harvesting or grazing these summer annual grasses as listed in the Ohio Agronomy Guide are shown in Table 7-12.

    Table 7-12: Harvest Information for Summer-Annual Grasses.

    We planted a trial on July 19, 2013 near South Charleston, OH to evaluate the yield and fiber quality of a conventional sudangrass variety (hereafter designated “Normal”) and a sorghum-sudangrass hybrid carrying the BMR-6 gene for reduced lignin (hereafter designated “BMR”). Forage yield, neutral detergent fiber (NDF) concentration and NDF digestibility (NDFD) were measured on four dates after planting, with the forage being cut to a 4-inch stubble height at each harvest. The NDF digestibility (NDFD) was measured after 30-hours of in vitro fermentation in rumen fluid plus buffer, followed by removal of microbial contaminants with neutral detergent solution.

    The results were not surprising in that yield and NDF increased while NDFD decreased sharply as the plants grew and matured (see Figures 1 and 2). The varieties were similar in yield and NDF, but there was a distinct NDFD advantage for the BMR hybrid over the non-BMR sudangrass variety (“Normal”).  

    In general, diets can be formulated for different classes of livestock based on the fiber quality of the forage. For lactating cows using these forages, the amount of forage that can be fed will be limited by the NDF level. For example, if harvest was delayed for higher forage yield, the NDF level was near 70%. At 70% NDF, the forage would probably have to be limited to 10% of the total diet of lactating dairy cows, on a dry matter basis.

    For lactating cows, forage with NDFD levels of 50% are usually acceptable, and levels as low as 40% NDFD could probably work if necessary. However, higher producing herds or groups within herds are more sensitive to NDFD and require NDFD values greater than 50%. Based on these parameters, the “Normal” sorghum-sudangrass provided acceptable forage for lactating cow diets when harvested between 40 to 60 days after planting (30 to 50 inches tall). Heifer cow diets could utilize this forage harvested at about 60 days (50 inches tall).

    The BMR hybrid provided a longer window of acceptable forage for dairy cows. In this study, the forage could have been harvested almost 80 days after planting (67 inches tall) and still be acceptable in lactating or heifer cow diets. This provides opportunity for significantly greater forage yields.

    Figures 1 and 2. Dry matter yield, total fiber (NDF,) and 30-hour fiber digestibility (NDFD) of two varieties of summer annual grasses planted on July 19, 2013 near South Charleston, OH.

    Forage having NDFD levels as low as 35 to 40% with high NDF levels are acceptable for dry cows or beef cattle provided they are part of a balanced diet and their mineral concentrations are not excessive relative to requirements. Based on the results shown above, the forage harvested from 60 to 80 days after planting (50 to 67 inches tall) would have been acceptable for dry cows or beef cattle.

    The results from the experiment shown here agree with a study conducted by researchers at Cornell University (Kilcer et al., 2005), who concluded that BMR sorghum-sudangrass has a larger harvest window for producing forage for lactating cow diets. However, they recommended that BMR sorghum-sudangrass be harvested for lactating cows when stand heights are about 50 inches (2-cuts possible with early June planting) because this will occur before the shift from vegetative to reproductive growth that lowers quality, and earlier harvest reduces the amount of water that must be evaporated for ensiling as yields increase. The Cornell researchers stated that if plantings were to be delayed into July, a second harvest may not be feasible, and delaying harvest to heights greater than 50 inches might be advantageous if extra forage is needed on the farm and good drying conditions exist to get rid of the extra moisture.

    In our study, we also investigated whether a 2-harvest system could provide similar forage yields with higher forage nutritive value compared with a single harvest after a mid-July planting date. The only combination of harvest dates that provided reasonable forage yields occurred when the first harvest was made at 35-days after planting with an 8-inch stubble height (to encourage faster regrowth) and the second harvest was made at a 4-inch stubble 48 days later (83 days after planting). Harvesting with an 8-inch stubble height may create some logistical challenges. Holding the machine up with the hydraulics causes the rolls to be higher than the cutter bar on many machines, which can cause issues with the crop feeding through the mower conditioner. However, many companies offer skids that can be used on mower conditioners to hold the head at this height and allow the rolls to run at the proper height. That 2-harvest combination produced a total dry matter yield of 3813 lb/acre for the BMR and 4870 lb/acre for the normal variety, with an average of 65% NDF for both varieties and 48% NDFD for the BMR and 45% NDFD for the normal variety. Therefore, we concluded the 2-harvest system showed no significant advantage over harvesting once at 60 days when plantings are made in mid-July.

    In summary, non-BMR sudangrass and sorghum-sudangrass planted in mid-July should be harvested between 40 to 60 days (30 to 50 inches tall) for lactating dairy cows. Harvesting should occur about 60 days after planting (50 inches tall) for feeding to heifers and 60 to 80 days after planting (50 to 67 inches tall) for beef cattle or dry cows. The BMR hybrid provided a wider harvest window for lactating cows, with acceptable forage harvested nearly 80 days after planting.

    Summer annual forage harvesting can be more challenging than other forages, especially if you are set up for a dry hay system. These summer annual grasses are best harvested as silage or baleage. Chopped silage stored in a bag, bunker, or silo is the best option. Harvesting at the proper moisture is critical because leaves and stems dry at different speeds. Over the last few years, we have had multiple silo fires due to these forages being put in the silo too dry. Similar to corn silage, 60 to 65% moisture is the ideal harvest moisture for silage made from summer annual grasses. Baleage should be slightly drier, between 50 to 60% moisture.

    We have also had at least one barn fire in Ohio caused by sorghum bales that seemed dry but were indeed too wet. The thick stems of these grasses often retain moisture, making it very challenging to dry hay to 15% or less moisture in the fall.  The dry leaves often cause baler moisture sensors to read drier than the forage really is. Forage from summer annual grasses should be bench tested for dry matter before attempting to make dry hay. This can be done by cutting plants up with scissors into 2-inch pieces and using a Koster tester, vortex drier, or microwave drying. Another challenge with baleage is getting the bales tight enough to exclude the oxygen. Having a rotary cutter on your baler can help with this issue. The rotary cutter also helps with feed out in a bale feeder, as the 6-foot long plants are sized better for less waste. Another challenge is that the stems of these grasses are tough and often break through the couple layers of plastic wrap. We highly recommend at least 6 layers of plastic over the last stem that breaks through, which means baleage will require 8 to 10 wraps to exclude oxygen and allow for proper fermentation.

    Keep in mind that the sorghum grasses should be harvested or grazed prior to a frost because toxic levels of prussic acid can be produced in the forage after a frost. Details of this risk are available at https://forages.osu.edu/news/be-alert-late-season-potential-forage-toxicities.  

    Reference:

    Kilcer, T.F., Q.M. Ketterings, J.H. Cherney, P. Cerosaletti, and P. Barney. 2005. Optimum stand height for forage brown midrib sorghum x sudangrass in North-eastern USA. J. Agronomy & Crop Science 191:45-40.

     

  10. Seeding Perennial Forages in Late Summer

    Dr. Mark Sulc, Professor and Extension Forage Specialist, Department of Horticulture and Crop Science, The Ohio State University

    The month of August provides a window of opportunity for establishing perennial forage stands or filling in seedings made this spring that have gaps. The primary risk with late summer forage seedings is having sufficient moisture for seed germination and plant establishment. The decision to plant or not will have to be made for each individual field, considering soil moisture status and the rainfall forecast. Rainfall and adequate soil moisture in the few weeks immediately after seeding is the primary factor affecting successful establishment.

    No-till seeding in August is an excellent choice to conserve soil moisture for seed germination. Make sure that the field surface is relatively level and smooth if you plan to no-till, because you will have to live with any field roughness for several years of harvesting operations.

    Sclerotinia crown and stem rot is a concern with no-till seedings of alfalfa in late summer where clover has been present in the past. This pathogen causes white mold on alfalfa seedlings and infects plants later during the cool rainy spells in late October and November. Early versus late August plantings dramatically improve the alfalfa's ability to resist the infection. Late August seedings are very susceptible to this disease, with mid-August plantings being intermediate.

    In a no-till situation, minimize competition from existing weeds by applying glyphosate burndown before planting. If herbicide-resistant weeds are present, such as marestail, this creates a very difficult situation with no effective control options in no-till management, so conventional tillage for seedbed preparation is probably a better choice in those situations.  

    For conventional tillage seeding, prepare a firm seedbed to ensure good seed-to-soil contact. Be aware that too much tillage depletes soil moisture and increases the risk of soil crusting. Follow the "footprint guide" that soil should be firm enough for a footprint to sink no deeper than one-half inch.  Tilled seedbeds do not need a pre-plant herbicide. 

    Patching in new 2021 spring seedings with gaps is possible this late summer, even for alfalfa. Autotoxicity will not be a limiting factor yet in alfalfa seedings made this spring. Alfalfa plants that are less than a year old will not release enough of those compounds into the surrounding soil that are toxic to new seedlings of alfalfa. So, this summer is the last opportunity to try to “patch-in” alfalfa in thin areas of alfalfa stands seeded this spring.

    Grassy weeds are probably present in the thin areas of those new spring seedings, so consider applying a grass herbicide as soon as possible. If broadleaf weeds are present, effective herbicide options are much more limited because most broadleaf herbicides labeled for use in alfalfa are only effective when the weeds are quite small. Before applying a herbicide, check its label for pre-plant time intervals that may be required. Use only herbicides with little or no time interval between application and seeding forages. Do take a cutting in early August and then immediately drill seed into the thin areas. Try to time drilling the seed when you see some rain in the forecast, especially if the soil is dry.

    The following steps improve the chances for stand establishment success, regardless of what type of seeding you are making:

    • Soil fertility and pH: The recommended soil pH for alfalfa is 6.5 to 6.8. Forage grasses and clovers should have a pH of 6.0 or above. The optimal soil phosphorus level for forage legumes is 30 to 50 ppm Mehlich-3 and for grasses 20 to 30 ppm Mehlich-3. The optimal soil potassium level is 120 to 170 ppm for most of our soils.
       
    • Check herbicide history of field. A summary table of herbicide rotation intervals for alfalfa and clovers is available at  http://go.osu.edu/herbrotationintervals.  Forage grasses are not included in that table, so check the labels of any herbicides applied to the field in the last 2 years for any restrictions that might exist.
       
    • Seed selection: Be sure to use high quality seed of adapted varieties and use fresh inoculum of the proper Rhizobium bacteria for legume seeds. “Common” seed (variety not stated) is usually lower yielding and not as persistent, and from our trials, the savings in seed cost is lost within the first year or two through lower forage yields.
       
    • Planting date: Planting of alfalfa and other legumes should be completed between late July and mid-August in Northern Ohio and between early and late August in Southern Ohio. Most cool-season perennial grasses can be planted a little later. Check the Ohio Agronomy Guide for specific guidelines (see http://go.osu.edu/forage-seeding-dates).
       
    • Planter calibration: If coated seed is used, be aware that coatings can account for up to one-third of the weight of the seed. This affects the number of seeds planted in planters set to plant seed on a weight basis. Seed coatings can also dramatically alter how the seed flows through the drill, so calibrate the drill or planter with the seed to be planted.
       
    • Seed placement: The recommended seeding depth for forages is one-quarter to one-half inch deep. It is better to err on the side of planting shallow rather than too deep.

    Do not harvest a new perennial forage stand this fall. The ONLY exception to this rule is perennial and Italian ryegrass plantings.  Mow or harvest those grasses to a two and a half to three-inch stubble in late November to improve winter survival.  Do NOT cut any other species in the fall, especially legumes.

    Scout your new forage seeding this fall on a regular basis. Post-emergence herbicide options exist for alfalfa that control late summer and fall emerging winter annual broadleaf weeds. A mid- to late fall application of Butyrac (2,4-DB), bromoxynil, Pursuit or Raptor are the primary herbicide options for winter annual broadleaf weeds. Fall application is much more effective than a spring application for control of these weeds, especially if wild radish/wild turnip are in the weed mix.  Pursuit and Raptor can control winter annual grasses in the fall in pure legume stands but not in a mixed alfalfa/grass planting.  Consult the 2021 Ohio, Indiana, Illinois Weed Control Guide and always read the specific product label for guidelines on timing and rates before applying any product (https://extensionpubs.osu.edu/2020-weed-control-guide-for-ohio-indiana-and-illinois-pdf/).