Buckeye Dairy News: Volume 12 Issue 3
Corn Silage Harvest is Imminent
Corn development has been progressing at a rapid pace with the recent warm temperatures. Early planted corn is already being harvested for silage in some parts of Ohio. So it is time to check the whole plant moisture content now, if you haven’t done so already.
Ensiling corn at the proper dry matter (DM) content provides high quality preservation, resulting in good animal performance and lower feed costs. Harvesting corn too wet (low DM content) results in souring and seepage of the silage and reduction in animal intake. Harvesting too dry (high DM content) promotes mold development because the silage cannot be adequately packed to exclude oxygen. Harvesting too dry also results in lower energy concentrations and reduced protein digestibility.
Harvest Moisture Guidelines
Corn silage preserved between 30 and 38% DM (62 to 70% moisture) generally provides good silage fermentation and animal performance. The optimal DM content varies with type of storage structure (Table 1).
Table 1. Optimal dry matter contents for different storage structures.
Type of Structure
Optimal % DM Horizontal bunkers
30 to 35
30 to 38
Upright, top unloading
33 to 38
Upright, bottom unloading35 to 40*
*The higher DM concentration for bottom unloading silos is a compromise
between forage quality and unloader requirements.
Kernel Stage Not a Reliable Guide for Timing Silage Harvest
Dry matter content of whole plant corn varies with maturity. Research has demonstrated that the position of the kernel milk-line is not a reliable indicator for determining harvest timing. Geographic location, planting date, hybrid selection, and weather conditions affect the relationship between kernel milk-line position and whole plant DM content. In a Wisconsin study, 82% of the hybrids tested exhibited a poor relationship between kernel milk-line stage and whole-plant DM. In Ohio, we have seen considerable variation in plant DM content within a given kernel milk-line stage.
Determining Silage Moisture
The only reliable method of determining the optimal time to harvest corn silage is to sample the crop and directly measure the percent DM of whole plants. This information combined with average whole plant dry-down rates can be used to roughly predict the proper time to harvest corn silage.
How to Sample Fields
Collect about 5 representative plants from the entire field. The plants should be representative from an area with representative plant population and not from edge rows. Collect separate samples from areas that may have different dry down rates, such as swales and knolls. The moisture concentrations of plants can vary within a field (plants will be wetter in low lying area and drier on knolls) and this should be considered when collecting your sample plants.
Put plants in a plastic bag, keep them cool, and chop as quickly as possible. The plants should be uniformly chopped (using a cleaver, machete, chipper shredder, or silage chopper) and then mixed thoroughly to obtain a sample with representative grain to stover ratios for DM determination. Some farmers prefer sampling only 2 or 3 plants without any additional sub-sampling to reduce the chances of a non-representative grain to stover ratio that can affect the results. In this case, choosing representative plants is even more critical.
Determine the DM content by drying the plant material using a Koster oven tester, microwave, convection oven, taking to a lab or using a vortex dryer. For more details on these and other methods, see the following links:
Make sure the sample does not dry down and keep it cool until the DM determination is performed. The accuracy of the percent DM value will be largely determined by the care taken in sampling, drying, and weighing the samples. Whole kernels and cob pieces can be difficult to dry completely without burning the leaf tissue.
When to Begin Field Sampling
We know that kernel milk stage is not reliable for determining the actual harvest date, but it is a useful indicator of when to sample fields to measure plant DM. Corn in Ohio should be first sampled to measure DM at full dent stage (100% milk, no kernel milkline) for conventional tower or bunker silos, and at 1/4 milkline (milkline one-fourth down the kernel, 75% milk remaining) for sealed (oxygen-limited) tower silos. It is important to begin sampling early as a precaution against variation in dry down.
Predicting the Harvest Date
Once whole-plant percent DM is determined, an average dry down rate of 0.5% unit per day can be used to estimate the number of days until the optimal harvest moisture. For example, if a given field measures 30% DM at the early sampling date, and the target harvest DM is 35%, then the field must gain an additional 5% units of DM, thus requiring an estimated 10 days (5% units divided by 0.5 unit change per day).
This procedure provides only a rough estimate for the harvest date. Many factors affect dry down rate, including hybrid, planting date, general health of the crop, landscape position, soil type, and weather conditions. Early planted fields and hot and dry conditions like we’ve been experiencing can accelerate dry down rates to 0.8 to 1.0 % unit per day. Fields should be monitored closely and more frequently under these conditions. In general, corn silage that is slightly too dry is worse than corn silage that is slightly too wet. Therefore, starting harvest a little early is usually better than waiting too long.
Harvesting and Storing Corn Silage
Dr. Bill Weiss, Dairy Nutrition Specialist, The Ohio State University (top of page) pdf file
Several important decisions regarding corn silage harvest must be made in the next few weeks and these decisions will affect the dairy herd for the next 12 months. Corn silage that is made and stored correctly is an excellent feed and one of the cheapest sources of nutrients in the Midwest. On the other hand, silage that is not made correctly can adversely reduce milk production when fed to cows and will have lower nutritional value resulting in higher supplementation costs.
The decisions that must be made (in order of importance) are:
1. When to chop the corn
2. Everything else
The “Everything else” category includes cutting height, chop length, kernel processing, use of inoculant, and how long the silage should be left before feeding. Although these are important, if the silage is not harvested at the correct stage, these other factors will not overcome the problems associated with either immature or mature corn silage.
When should the corn be harvested?
Corn silage that is chopped too early (i.e., too wet) often undergoes a poor fermentation that results in higher fermentation losses and can reduce intake when the silage is fed. Seepage also can occur which reduces the nutritional value and can cause environmental problems. On the other hand, wet silage usually does not heat or mold during feed out and digestibility can be high. Corn chopped too late (i.e., too dry) undergoes a limited fermentation, resulting in a substantially less stable silage. It often heats and molds at the silo face, during feedout, and in the feed bunk, and fiber and starch digestibility can be low. The ideal dry matter (DM) for corn silage is between 30 and 38% depending on the storage structure (closer to 30% for bunkers and closer to 38% for uprights). Slightly wet silage is usually better than slightly dry silage so err on the side of chopping early if necessary. Dry-down rates vary substantially because of hybrid and weather but ON AVERAGE corn plants gain about 0.5% units of DM each day after dent stage (can range between about 0.3 and 1% unit). Dry matter should be measured; do not rely on kernel milk line to make harvesting decisions.
How high should the plants be cut?
The least digestible part of the corn plant is the stalk. It has high concentrations of neutral detergent fiber (NDF) and lignin. When cutting height is increased, more stalk is left in the field which reduces the proportion of corn silage that is stalk and increases the proportion that is leaves and ears. Typical stubble height for corn is 4 to 6 inches and most of the research on high cut corn had stubble heights of 15 to 18 inches. The absolute certain response will be a 4 to 6% reduction in DM yield (this means a 4 to 6% increase in production costs). Usually NDF concentrations are reduced and starch and DM concentrations are increased by 2 to 4 percentage units when corn plants are cut high. However, milk production studies have failed to show consistent benefit. Because of the certainty of lost yield and the uncertainty of any positive response, I do not recommend this practice.
What is the correct chop length?
Fine chopping promotes good packing and increases the rate of fermentation in the silo, but fine chopping may result in silage that does not promote adequate chewing when fed to the cow. Coarse chopping may cause fermentation problems and can increase sorting when fed to cows. Chop length has been described as the theoretical length of cut (TLC) at which the chopper was set, but TLC is a poor descriptor of actual particle size of the silage. A better approach is to actually measure particle size at the time of chopping with a device such as the Penn State Particle Separator. Corn silage that had not been kernel processed with 3 to 6% of the silage on the top screen and 60 to 65% on the second screen (8 mm hole diameter) of the Penn State Separator usually ferments well and has good nutritional value. For processed corn silage, a very wide range in particle sizes (equivalent to approximately 2 to 21% on the top screen) had no effect on cows. If the processing rolls are set properly (i.e., most kernels are physically damaged), silage with 5 to 10% on the top screen is adequate. Particle size evaluation should be done during harvest so that adjustments can be made.
Should kernel processing be used?
Proper kernel processing is when most of the kernels are physically damaged which results in improved starch digestibility for kernel processed silage than conventional silage. However, the response is a function of the maturity of the corn plant and hybrid. Processing almost always increases the nutritional value of drier corn silage (but it is still not as good as silage made at the correct DM) and is a recommended practice. Processing silage made at the correct DM usually has a positive effect but the effect is much less than what is observed for dry silage. Processing immature corn can substantially decrease its energy value and is not a recommended practice. Chopped material should be visually examined during the harvest and if many undamaged kernels are observed, the processing rolls and/or chop length needs to be adjusted.
Should I use an inoculant?
The two types of inoculants for corn silage are lactic acid bacteria (LAB) and bacteria that produce acetic and propionic acid (bacterial species is Lactobacillus buchneri). Treating corn with LAB usually reduces fermentation losses because it ferments faster and has more lactic acid (and less acetic acid). On the other hand, L. buchneri increases acetic acid which increases fermentation losses but because acetic acid is inhibitory to yeasts and molds silage treated with L. buchneri is extremely stable during feed out which reduces storage losses. Conversely, silage treated with LAB often has reduced stability during feed out. The return on investment of LAB is usually slightly positive if feed out losses are not a problem. If spoilage and heating during feedout has been a problem or if silage feed out rate will be slow (less than about 6 inches/day) and/or the silage will be fed in the summer, L. buchneri could be quite useful.
How long should the silage be left undisturbed after filling?
Most studies with corn silage show that pH and acid concentrations become stable by 7 to 14 days post-ensiling if the silage is left undisturbed. Yeast and mold counts may require up to 60 days before stabilizing and opening a silo will increase that time. The digestibility of corn silage can continue to improve even after months of storage. Letting silage ferment undisturbed for several months has many benefits; however, maintaining silage inventory is not free. The best compromise is to let silage ferment undisturbed for 1 to 2 months before opening. This means that the first year you will need to harvest 13 or 14 months of silage and you need a place to store the silage that will not interfere with silo filling.
Pricing Standing Corn for Silage Harvest
How to price corn for silage as a crop standing in the field is a perennially challenging question. The optimal answer will vary depending on your point of view. Are you buying or are you selling?
This corn silage pricing discussion is based on a corn crop standing in the field. The owner’s goal is to recover the cost of producing and harvesting the crop plus a profit margin. Their base price would be the price they could receive for the crop from the grain market less harvest/drying/storage costs. Hopefully, this would meet the goal of covering production costs and generating a profit.
To the grain farmer, the corn crop may have more value than just the income from the sale of grain. If the crop is sold as silage, the corn fodder is no longer available as ground cover and/or as a source of some nutrients and organic matter. This creates a potential opportunity for the dairy to provide some nutrients and organic matter back to the corn fields from subsequent manure nutrient applications.
To look at the value of the corn as silage, we can estimate that a ton of corn silage, on average, contains ~7 bushels of corn. If corn is worth $3.70 per bushel, then the standing corn for silage would be worth about $26/ton before the cost of harvesting for grain, or between $23.50 and $24.50/ton depending on yield, assuming a grain harvest cost of ~$40 per acre. This is a value for corn silage at 35% dry matter (DM). Prices also have to be adjusted for different DM concentrations. If actual DM was 30%, then the value is about $20/ton (i.e., 30/35 = 0.85 x $23.50/ton). Corn chopped at more than about 38 % DM or less than about 30% DM may not ferment properly and can be a problem. The price for this corn silage should be discounted.
At the 2009 Tri-State Dairy Nutrition Conference, Normand St-Pierre reviewed the difference between valuing corn silage using the 7 bushels of corn per ton method plus harvest and storage costs and an adjustment for 10% fermentation loss, versus pricing based on prevailing feed nutrient value (Sesame) pricing method. This method values the silage at what its nutrients are worth based on a wider selection of feed prices plus the harvest and storage adjustments. The ratio of the two methods for 2005 to 2008 was 1.27. In other words, the nutrient value of silage to the cow was potentially worth up to 27% more than value based on the market price for corn.
The SESAME value for Ohio corn silage is available in the most current edition of the Buckeye Dairy News available online at https://dairy.osu.edu. Remember that this is the nutrient value for corn silage delivered to the cow, so harvest, storage, moisture, shrink and risk costs must be deducted from the SESAME value.
So, what does this mean in the real world? The 7-bushel method is a good starting point. There could be additional feed value to the buyer which has to be balanced against the harvest and fermentation risks that the buyer is assuming.
The last factor affecting the value of standing corn is risk. A farmer purchasing standing corn is assuming risk (Will it ferment properly? Can it be harvested at exactly the right time? What will the final nutrient content be?, etc.).
The price for the standing crop should be discounted to recognize these risks. What is the right amount to discount? This is not an easy question and is one of the factors to consider when buyer and seller are negotiating a final price. Setting the final, fair price for corn silage rests on an understanding of the needs of both the buyer and the seller and negotiating a price that ensures a reasonable profit for both.
Finally, it is critical that both parties agree on price, payment method and timing, crop measurement, restrictions, and similar details before the crop is harvested! Ideally, the agreement should be in writing and signed by both parties. These agreements are especially important when large quantities of crops (and money!) are involved. While this type of contracting may be uncomfortable for some producers, mainly because they aren’t used to conducting business on more than a handshake, it forces the parties to discuss issues up front and can minimize troubling misunderstandings after harvest.
This article was adapted from “Pricing Standing Corn for Silage”, 2005. Shoemaker, Weiss, St-Pierre and “Economical Value of Corn Silage, St-Pierre, Tri-State Dairy Nutrition Conference, 2009.
What is Your Corn Silage Worth?
Dr. Joanne Knapp, Principal Technical Consultant, Fox Hollow Consulting, LLC, Columbus, OH
Corn silage is a valuable feed ingredient in dairy rations, and its nutritional value is based on its starch and digestible neutral detergent fiber (NDF) content and lack of anti-nutritive compounds such as molds and mycotoxins. The starch and digestible NDF contribute to both NEl (Net Energy of lactation) and MP (Metabolizable Protein). The amount of starch and digestible NDF in corn silage is a function of maturity at harvest, how well the ears are filled, the cutting height, and how well the silage is preserved. Better corn silage will have more starch and less NDF (Table 1). Because starch in corn silage generally is more than 90% digestible in the total tract while the NDF is only 40 to 50% digestible, every point of starch is worth approximately twice as much as a point of NDF on a NEl basis. The starch contribution to MP depends on whether the starch is fermented in the rumen, providing energy for the rumen microbes to grow and produce the microbial protein portion of MP, or whether the starch is digested in the small intestine or fermented in the large intestine, neither of which contribute to MP.
Table 1. Nutritional value of corn silage in dairy rations. Comparisons were done at equal dry matter (DM) percentages (35%). At higher NDF contents, starch content is reduced and is reflected in lower NFC (non-fiber carbohydrate) contents and lower predicted nutritional values.
Corn Silage Quality
NDF (% of DM)
NFC (% of DM)
August 2010 Nutritional Value*
*Predicted using wholesale feed prices and SesameIII software.
Obviously, how well the ears fill will affect the grain and starch content of silage. However, cutting height also affects it, because the lower the stalk is chopped, the more NDF there will be in the silage. Typically, this NDF is also of lower digestibility than the NDF in the upper portion of the corn plant. When I was in California, it was rare to see corn silage with NDF less than 40% since most farmers chopped at 4” above the ground. They were able to do this because fields were laser-leveled for irrigation purposes. However, few considered that the bottom of the plant was pretty poor in terms of nutrient digestibility and availability; they were trying to maximize dry matter (DM) yield per acre.
Note that the SesameIII predicted value of corn silage is higher than the $35 to $40/ton that most producers consider to be their costs of production (seed, fertilizer, fuel, bunker covers, inoculants, etc.). This is a reflection of the nutritional value of corn silage in comparison to other feedstuffs available in the Ohio market area. Corn silage delivers nutrients at a lower price than most other feedstuffs. This is important to keep in mind as you go into the harvest season.
Minimizing DM losses in the harvesting and ensiling process means that more inexpensive nutrients are retained, and less purchased feeds will be needed in the coming year. At 10% DM losses in average (medium quality) corn silage, nutrient losses will be $6.80/ton. At 15% and 20% DM losses, this drain grows to $10.20 and $13.60/ton. I don’t know many producers who would pay those price differences on purchased commodities or concentrate mixes!
Compared to May 2010, the average price of feedstuffs and most nutrients are slightly up for August. The exception is non-effective NDF (neNDF), which was down 5.4¢/lb to –14.4¢/lb. It is common for neNDF to be negative, as feeds that have high levels of this nutrient, such as by-products like distillers’ grains, corn gluten feed, etc., are discounted in the market relative to other feeds. The NEl is estimated at 9.3¢/Mcal, MP is at 46.7¢/lb, and effective NDF (eNDF) is 5.1¢/lb. Good- to high-quality, home-grown forages continue to be an excellent and inexpensive source of eNDF, NEl, and MP. The cost of the key nutrients was estimated using SesameIII software and break-even prices of commodities and forages used in dairy rations were predicted (Table 2).
Based on early August wholesale prices for central Ohio, feed commodities fall into three groups:
Alfalfa hay, 44% NDF, 20% CP
Corn grain, ground
Distillers’ grains w/sol
Brewers’ grains, wet
Cottonseed meal, 41% CP
Meat and bone meal
Soybean meal, 48% CP
Soybean meal, 44% CP
The usual caveats with SesameIII™ results apply. nbsp; You cannot formulate a balanced diet using only the feeds in the Bargains column. These feeds represent savings opportunities and can be utilized in rations to reduce feed costs within limitations for providing a balanced nutrient supply to the dairy cow. Prices for commodities can vary 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. Feeds may also bring value to a ration in addition to their nutrient value, e.g. tallow as a “carrier” and dust suppressant in vitamin/mineral pre-mixes and molasses as a source of sugars.
The detailed results of the SesameIII™ analysis are given in Table 2. The lower and upper limits give the 75% confidence range for the predicted Break-Even prices. Feeds in the “Appraisal Set” are either those that were completely out of price range (outliers) or had unknown prices, such as the alfalfa hays of different nutritional quality.
Table 2. Prices of dairy nutrients and actual wholesale, breakeven (predicted), and 75% confidence limits for feed commodities used on Ohio dairy farms.
MarketView...U.S. Dairy Outlook Brief May through July 2010
Dr. Cameron Thraen, Extension Specialist, The Ohio State University
In this installment of The MarketView, I will take stock of the current milk production situation in Ohio and contrast this with the U.S. dairy situation. At the end of this piece, I will explore how this translates into the outlook for market price.
Milk Cows and Cow Productivity: Ohio
In the first two charts, Chart 1 and Chart 2, you will see the number of milk cows in Ohio (Chart 1) and the yield per cow (Chart 2). Yields and production data are each adjusted to reflect a 30 day month.
Cows in milk peaked in Ohio back in May through July 2008 at 282 thousand head. Looking at Chart 1, you can see two adjustment periods. The first period, beginning with August 2008 and ending December 2008, milk cows moved down 6000 head. The second period occurred in late 2009. In fact, milk cows increased marginally from May to September 2009 before starting down in earnest. This was due no doubt to the influence of the Milk Income Loss Contrast (MILC) payments and a short lived resurgence in milk price during this period. This promoted an atmosphere of optimism that holding on just a bit longer might pay off. Dairy cow herd expansion began in May 2010. The latest July numbers from the USDA put the Ohio dairy herd at 270,000 head.
Chart 2 shows the productivity on Ohio dairy farms. During the 2008 through April 2010 period, milk per cow per day increased by 6 lb (13%). During the financial calamity that was 2009, productivity on Ohio dairy farms actually increased from a low of 48 to 53 lb/cow/day. The latest run shows productivity increasing sharply over the January through April 2010 period. Milk output has increased from 50 to 56 lb/cow/day. This is a result of Ohio dairy producers culling low producing cows from the State herd. Removing these low producers while shrinking the whole herd raises the average milk cow output. Difficult weather, heat, and humidity is evident in the decline for June and July 2010.
Milk Cows and Cow Productivity: United States
In the second two charts, Chart 3 and Chart 4, you will find the number of milk cows, United States, (Chart 3) and the U.S. yield per cow (Chart 4).
The national dairy herd peaked during the April 2008 through January 2009 period at just over 9.3 million head. With the collapse of the milk price in February 2009, dairy producers began a more aggressive culling of low producing cows. The Cooperatives Working Together (CWT) program also began an aggressive campaign to use its farmer paid funds to remove dairy cows. This culminated in the dramatic slide in cow numbers nationally (see MarketView, BDN March edition for a detailed look at this culling activity). From a peak of 9.334 million head, December 2008 to a low of 9.082 million head in December 2009, the national dairy herd declined 2.7%. With better milk prices and lower input prices, this slide ended in January 2010, and over the first four months of this year, the dairy producers have added back 14,000 dairy cows. This trend continues into July 2010.
The productivity pattern for the national dairy herd is very similar to that experienced in Ohio. The latest numbers show milk productivity as increasing rather sharply from 55 to 60 lb/cow/day and then declining as the heat and humidity impacted productivity.
Annual Milk Production, Ohio and the United States
Charts 5 and 6 show the annual production levels for Ohio and the United States. Each monthly production level shows the 12 month rolling average, or the total production for the past 12 months. Looking at Chart 5, we can see that milk production in Ohio showed only a slight deviation from its trend during 2009. Milk production capacity is now slightly above 5.2 billion annually. Looking at the 12 month rolling average for the United States, Chart 6, we can see that the very significant trend in U.S. productive capacity for 2008 came to a halt in 2009, dropping back for most of the year, and then declining over the last four months of 2009. With stronger milk prices in the early months of 2010, increasing cow numbers and milk productivity, milk production capacity is on the upswing, but still below the 2008 peak.
Ohio Share of U.S. Milk Production
The final chart in the overview of Ohio and U.S. milk productive capacity is Chart 7. This chart shows the Ohio share of total milk production over the past two plus years. The message is clear. Ohio is increasing its share of milk production relative to the rest of the United States. This share has increased from a low of 2.67% in early 2008 to 2.74% as of July 2010.
Milk Production Capacity and the Class 3 Price
Chart 8 shows the relationship between the rate of change in the U.S. capacity to produce and market milk and the Class 3 milk price. I have used this chart in past Marketview articles to reinforce the point that rates of growth in our milk production capacity, which exceeds 2% per year, is accompanied by Class 3 milk price below $15/cwt. The only exception to this occurred at the peak of the world speculative housing bubble, 2007 and early 2008. This was an anomalous time period, when all commodity markets, including dairy commodity markets, were off the chart on the demand side. Looking at Chart 8, and setting aside this anomalous 2007-2008 period, high milk prices are created by negative annualized growth rates, as with 2004, or with annualized grow rates sustained below 2% per year, as with July 2006 through June 2007. We are currently increasing U.S. milk production in excess of what commercial demand will take and still yield Class 3 price above $15/cwt.
Current Market Price Outlook
The current Chicago Mercantile Exchange (CME) Class 3 milk futures price is shown in Chart 9, along with the median Class 3 price and the upper and lower quartile bounds. As of August 18, 2010, the August 2010 futures price is $15.10/cwt. The median price for August 2000-2009 is $13.70/cwt. The CME Class 3 price pattern shows prices above the long-term median price through October 2010 and then increasing significantly above the long-term median for the months of November 2010 through July 2011. Why the dramatic increase in the latter part of the coming 12 months? The answer is one of two views. Either there will be a renewed culling beginning in earnest at the end of the summer due to continued financial pressure on the nation’s dairy farms, including the impact of the latest CWT cow purchase program, or the market is anticipating a resurgence in domestic and more importantly international demand toward the end of 2010 and into 2011. Or possibly a combination of these two events. What will take place? I do not know. What I think you can take from this edition of the MarketNews, is that the growing milk production capacity in the United States suggests that milk prices will remain below the $15.00/cwt mark over the summer. If a resurgence of international demand does come about toward the end of 2010, the Class 3 price may be in the upper $14/cwt range. As a planning price, for those shipping milk in Ohio and the Mideast Federal Milk Marketing Order, I would suggest using a Class 3 price of $14.80/cwt and add another $1.00 to get a blend price of $15.80/cwt.
This would be a good time to learn more about the use of futures and options to protect your milk price should a pricing opportunity arise in the coming weeks or months. Also consider learning more about the Livestock Gross Margin (LGM) Insurance product available to dairy producers. A number of important changes to the LGM-Dairy program will go into effect in September or October. These changes will make the insurance product less expensive and easier to purchase. Each of these provide a management tool to which can assist in you in protecting your milk price in 2010 and 2011. You can find out more about this by visiting my website: http://aede.osu.edu/programs/ohiodairy. Look for the links to Livestock Gross Margin Insurance or Price Risk Management.
Effect of AI Technique and Semen Handling on Dairy Cattle Fertility
Dr.Gustavo Schuenemann, Extension Dairy Veterinarian, The Ohio State University
Artificial insemination (AI) is a widely accepted technique in the dairy industry. Accurate animal identification, semen handling, hygiene of the AI procedure, and site of semen deposition are paramount to achieve acceptable reproductive outcomes. Professional inseminators must review the procedure on a regular basis (e.g., monthly) to obtain consistent field results. In large dairy operations, where numerous cows are inseminated on a daily basis, AI technicians routinely thaw multiple straws of semen at the same time in order to timely inseminate cows. Simultaneous thawing of straws of semen could potentially compromise the semen quality, thus lowering reproductive performance. The recommended semen handling protocol includes: 1) thawing the straws in a water bath at 35°C for a minimum of 45 seconds, 2) drying the straws, 3) assembling the AI gun, and 4) depositing the semen into the uterine body. Inseminators should perform AI under appropriate hygiene procedures.
Semen handling: Dalton et al. (2004) evaluated the effects of simultaneous thawing of 4 straws of semen at once and the subsequent sequence of inseminations (1st, 2nd, 3rd, or 4th) on conception rate. The time elapsed between the initiation of the thawing process and the final seminal deposition on dairy cattle fertility was evaluated under field conditions. This study showed that the sequence of AI (from 1st to 4th AI) and the time elapsed from the initial thawing process to the 4th AI (~7 to 10 minutes) did not affect conception rate.
Cleanliness of the AI procedure: An appropriate and clean AI technique is recommended to optimize reproductive outcomes in dairy cows. However, the AI procedure (i.e., hygiene, site of semen deposition, semen handling, etc.) is often overlooked. Bas et al. (2009) evaluated the effectiveness of using protective AI cover sheaths (PS) to minimize vaginal contamination of the AI gun at the time of AI on pregnancies per AI (PAI) in dairy cows. In this study, nearly 1,000 services performed by the same AI technician in one commercial dairy farm were assessed. For first services postpartum, PAI did not differ between cows inseminated with or without the use of PS at the time of AI. However, PAI was increased for second or greater services in cows inseminated with the use of PS (43.8 ± 2.9%) compared to cows inseminated without the use of PS at the time of AI (32.3 ± 2.6%).
Implications: Results from these studies suggested that: 1) the use of PS at the time of AI improved reproductive outcomes in lactating dairy cows and 2) simultaneous thawing of 4 straws may not compromise fertility when semen is deposited into the uterine body within 10 minutes after thawing. Cleanliness of the whole AI procedure must become a top priority for professional AI technicians. To achieve consistent reproductive results over time, the AI procedure should not be compromised for convenience.
Bas, S., Hoet, A., Rajala-Schultz, P., Sanders, D., and Schuenemann, G.M. (2009). Effects of using protective AI cover sheaths on fertility of lactating dairy cows. Reprod. Fertil. Dev. 22:163-163.
Dalton, J.C., Ahmadzadeh, A., Shafii, B., Price, W.J., and DeJarnette, J.M. (2004). Effect of simultaneous thawing of multiple 0.5-mL straws of semen and sequence of insemination on conception rate in dairy cattle.
J. Dairy Sci. 87:972–975.
Applying Manure to Tiled Fields
Ms. Amanda Meddles, Extension Program Coordinator for Environmental Management, The Ohio State University
Most producers are aware of the rich nutrient found in manure and the value that manure provides to growing crops. Fewer are aware of the potential for the nutrients to exit fields through tile lines, contaminating surface waters. Manure also moves through cracks, worm holes, dead root channels, etc. This can be avoided by matching the water holding capacity of the soil and the manure application rate to avoid saturating the soil. However, dry cracked soil can be as much of a problem as saturation. The goal of this article is to express the importance of keeping manure nutrients in the root zone where crops can use them. The following article is an excerpt from the OSU Extension Fact Sheet Guidelines for Applying Liquid Animal Manure to Cropland with Subsurface and Surface Drains by James J. Hoorman, Jonathan N. Rausch and Larry C. Brown. It provides excellent tips to avoid nutrient loss through subsurface drainage. The entire fact sheet can be found at http://oema.osu.edu/OEMAPublications.htm under OSU Extension Fact Sheets.
The fact that liquid animal manure nutrients can be safely land recycled in some instances, but are discharged in subsurface drainage water under different circumstances, suggests a complex system that needs to be managed. Soil texture, available water holding capacity, tillage history, as well as the type and quantity of manure applied, application method, and timeliness of rainfall after application may all play a role in determining the fate of the manure. Suggested guidelines to minimize the downward movement of liquid manure are:
a. Identify subsurface drain outlets, and control or regulate discharge prior to application, or have on-site means of stopping the discharge from subsurface drains. Subsurface drainage outlets should be monitored before,
during, and after application for potential liquid manure discharge.
b. Liquid manure should not to be applied on soils that are prone to flooding, as defined by the National Cooperative Soil Survey (or in the Flooding Frequency Soil List posted in Section II eFOTG), during the period when flooding is expected. Manure can be applied if incorporated immediately or injected below the soil surface during periods when flooding is not expected.
c. Avoid applying manure when rainfall is predicted, eminent, or directly after a rainfall event. After a significant rainfall event, the site should be allowed to drain to below field capacity, so that the soil has the capacity to absorb additional water or liquid animal manure.
d. Repair broken drains and blowholes prior to application, and follow recommended/required minimum setback requirements (setback distances vary from state to state) for surface inlets. See fact sheet on Liquid Manure Application Rates for Subsurface and Surface Drained Cropland.
e. Liquid manure should not be applied to subsurface drained cropland if the drains are flowing. Generally, flowing subsurface drains indicate soil moisture levels that are near or exceeding the soil water holding capacity.
f. Application rates should be closely tied to nutrient requirements and available holding capacity of the soil. The method of application can influence application rates.
g. Liquid manure should be applied in a manner that will not result in ponding, or runoff to adjacent property, drainage ditches, or surface water regardless of crop nutrient need and should be uniformly applied at a known rate.
h. Fields with a history of downward movement of manure and/or bare/crusted soils may require some tillage to improve infiltration and absorption of the applied liquid. Prior to manure application, use shallow tillage to disrupt the continuity of worm holes, macropores and root channels (preferential pathways) to reduce the risk of manure reaching drain lines, or till the surface of the soil 3 to 5 inches deep to a condition that will enhance absorption of the volume of liquid manure being applied.
i. Clay soils with a high shrink swell capacity tend to have larger deeper cracks during dry conditions. These soils may require tillage to disrupt the cracks and macropores, and a lower initial application rate applied to the soil to help close the cracks.
j. Shallow injection is recommended for liquid manure. Till the soil at least 3 inches below the depth of injection prior to application, and/or control outflow from all drain outlets prior, during, and after manure application.
k. For perennial crops (hay or pasture) or continuous no-till fields where tillage is not recommended, all subsurface drain outlets from the application area should be monitored, and if manure laden flow should occur, all effluent should be captured. Crops with deep tap root systems (alfalfa) tend to have more problems than hay crops with fibrous roots (grass) because liquid animal manures may flow along the tap roots to subsurface drains and outlet to surface water.
These criteria may be waived if the producer can verify there is no prior history of manure discharge via subsurface drains, or if a system is in place to capture the discharge. However, if there is a discharge, the producer is liable for damages and is subject to being classified as a Concentrated Animal Feeding Operation (CAFO).
Where are Your Records for Manure Application
Ms. Amanda Meddles, Extension Program Coordinator for Environmental Management, The Ohio State University
Knock. Knock. “We’ve received a manure complaint. Can we see your records?”
Will you be prepared if this happens to you? Keeping accurate and detailed application records could mean the difference between avoiding a complaint and being fined for misapplying. Good records should include details about everything from the field it was applied on to the wind speed at the time of application.
Dairy Youth Events at the 2010 Ohio State Fair
Mrs. Bonnie Ayars, Extension Dairy Program Specialist, The Ohio State University
No other singular event in Ohio does more to promote positive youth development than the Ohio State Fair. With livestock, we have an even more unique opportunity to “tell our story” to consumers.
2010 is recorded, but it was certainly one to remember for dairy youth. Whether it was the skillathons, judging clinics, or the OSU judging teams managing the parlor, it was more than an annual event; it was a learning experience!
The dairy business has been challenging, but we continue to bring out youth to become involved in the Extension programs designed to educate the next generation. Have hope, something positive is happening with these kids.
In the past three years, we have only offered one dairy skillathon! However, this year, we returned to one offered during the first portion of the fair and another during the second week. This method was used to accommodate each of the breed rotations that exhibit at the fair
Emerging as one of the largest skillathons at the fair, there were 128 kids that completed all of the challenging stations associated with topics such as cattle selection and reproduction, equipment and calf management, nutrition, animal welfare issues, and health. It takes an “army” of loyal volunteers to manage such an event.
At the conclusion of the second one, results were tabulated and awards presented. One individual earned a perfect score. Mark Gordon (Wayne County) was the recipient of the overall dairy skillathon winner after being named tops in the 14 year old age division. It was an amazing accomplishment!
If you are interested in any of our content that tests dairy aptitude, do not hesitate to contact me. All results of the dairy skillathon can be reviewed by clicking on this link http://4hansci.osu.edu/skillathon/dairy.php.
Dairy Judging Clinics
Our State 4-H dairy judging contest is held during Spring Dairy Expo, so we conduct clinics at the Ohio State Fair. Again, we hold two of these because of the rotation of breeds for dairy cattle. They are more than clinics, but also competitions in which top winners can earn premium money. Some can attend both, and yet others can only make the trip once. We announce winners for each week and post the results for two age divisions.junior and senior. Nearly 100 individual prospective judges stood on the tanbark to test their skills. Seniors are required to give reasons, while I provide some basic guidance to junior participants on how to compose reasons. These clinics also provide the premise for the selection of 4-H teams at the fall contests.
Again, another loyal army of volunteers is on hand to assist with registration, serve as officials, evaluate reasons, and also to tabulate scores. It is not a simple process, but one that uses valuable time to teach about dairy cattle evaluation.
I also must extend a big thank you to all the exhibitors who so willingly allow us to use their cattle for the classes. It is good to have them as contributors, leaders, and observers. This makes it a multi-generational event!
Results for the contest are attached here for juniors and here for seniors. There are junior and senior scores for each of the two clinics, plus the overall winners. If you know any of these youth, give them a vote of confidence by commending them for their efforts.
The Milking Parlor
It is a unique opportunity for college students to learn as they manage the parlor during the Ohio State Fair. Some days, the parlor must be open nearly 12 to 15 hours to accommodate the needs of the many shows. The facility at the Ohio State Fair is nearly 40 years old and the equipment had a tendency to alert us to that this year. There were two major mechanical issues, but Prengers was on hand each time to make sure that the parlor was up and running at the hours posted. Problematic as it was, the venture was successful and the judging teams earned money to assist with their travels.
Many thanks to the dairy staff at the fair for their assistance and support as well as John Spreng and Stacey French associated with the Ohio State Fair. I would also like to mention that our direct communication with the consumer whether near the parlor, in the aisle of the dairy barn, or at the “I Milked a Cow”, was a priceless opportunity to display our pride in what we do with cows.