Dr. Maurice Eastridge, Extension Dairy Specialist, The Ohio State University
The Ohio Dairy Research Fund was developed to support research by voluntary dairy producer contributions. Since 1982, about $731,000 in producer investments have funded research that has greatly benefited Ohio's dairy industry. From time to time, results of this research will be included in the Buckeye Dairy News. For this issue, the results from five recent projects are provided below.
Assessing Biotin Status of Lactating Cows
William P. Weiss and G. Ferreira, Department of Animal Sciences, The Ohio State University
The addition of supplemental biotin (a B-vitamin) to dairy diets is becoming more common. In research studies, the addition of biotin to dairy diets has consistently improved measures of hoof health. In many studies, but not all, biotin has also increased milk yield apparently independent of effects on hoof health. The objective of this study was to determine whether an index of biotin status could be identified that was related to the likelihood of obtaining a milk response. Based on previous studies, high producing cows are more likely to have a milk yield response to supplemental biotin than low producing cows. Therefore, we conducted an experiment with high producing (average yield = 95 lb/day) and low producing cows (51 lb/day). All cows were fed the same basal diet with and without supplemental biotin (approximate supplementation rate was 20 mg/day). Blood, milk, and urine were sampled and analyzed for biotin. In addition, cows were given an intraruminal infusion of valeric acid and urinary excretion of a metabolite was monitored. Valeric acid is a normal product of ruminal fermentation and its metabolism depends on biotin-containing enzymes. If biotin is limited, then providing additional valeric acid might overwhelm the normal biochemical pathways and an alternate metabolite (3-hydroxyisovaleric acid) will be produced and excreted in the urine.
Supplemental biotin increased milk yield by about 6 lb/day in high producing cows but had no effect on milk yield of low producing cows. The response by high producing cows occurred within 3 days of supplementation. Supplemental biotin increased concentrations of biotin in plasma, milk, and urine in both high and low producing cows, but responses were similar in both production groups. Urinary excretion of hydroxyisovaleric acid following the infusion of valeric acid was higher for high producing cows, but biotin supplementation had no effect. We were not successful in identifying a measure of biotin status in lactating cows that could be used to determine when cows were likely to respond to supplemental biotin.
Supplemental Rumen-Protected Choline and Methionine for Lactating Dairy Cows
Maurice Eastridge, Joanna Engel, and Claudio Ribeiro, Department of Animal Sciences, The Ohio State University
The primary purposes of the experiments were to establish the magnitude of protection of 3 commercially available, rumen protected choline (RPC) sources [Reashure® (REA), Balchem Encapsulates, New Hampton, NY; By Pass Choline (BPC), Robt Morgan, Inc., Paris, IL; and Pro-CholineTM 40, Probiotech, Inc., St-Eustache, QC, Canada] and to determine the effects of supplemental rumen-protected choline (REA) and rumen protected methionine (Smartamine MTM, Adisseo, Antony Cedex, France) on the metabolism and performance of lactating dairy cows. Using in situ procedures in Experiment I , Reashure was found to be more rumen stable than the other two choline sources. In Experiment II, 56 lactating dairy cows were fed one of 4 diets at parturition: 1) control [duodenal flow of lysine:methionine (lys:met) 3.8], 2) 0.26% rumen protected choline (RPC) (REA fed at 60 g/d to provide 15 g/d of choline; lys:met 3.8; REA-L), 3) 0.52% RPC (REA fed at 120 g/d to provide 30 g/d of choline; lys:met 3.8; REA-H), or 4) 0.096% rumen protected methionine (Smartamine MTM; lys:met 3.0; MET). The diets were fed as a total mixed ration for 13 weeks and were composed of 52% forage (76% corn silage and 24% alfalfa hay), 9% whole linted cottonseed, and 39% concentrates. The diets were 16.8% crude protein, 39.2% NDF, and 20% forage NDF. Thirty-one Holstein and 17 Jersey (48 total) cows completed the trial. Dry matter intake (45.3 lb/day), milk yield (80.3 lb/day), milk fat (4.35%), and milk protein (3.14%) were found to be the same among all 4 diets. The milk urea nitrogen was the highest for REA-H (19.1 mg/dl) and intermediate for MET (18.1 mg/dl). Milk choline concentration was highest for MET, but plasma choline and non-esterified fatty acids were not different for the diets. Plasma glucose was higher for both the control and MET diets than for either REA diet. Plasma methionine was significantly higher for the MET diet than for other diets. Conclusions from the study were: 1) Reashure was more rumen stable than the other two choline sources, 2) milk choline is a better indicator of choline status than plasma choline, and 3) feeding MET to the periparturient dairy cow may be beneficial for reducing risks of metabolic diseases and improving animal performance related to choline status.
A Survey of Bovine Practitioners to Determine the Prevalence of and Factors Associated with Acute Bloat Syndrome in Pre-Weaned Dairy Heifers
Dianne Shoemaker, Department of Extension; Päivi Rajala-Schultz, Department of Veterinary Preventive Medicine; and Lowell Midla, Department of Veterinary Preventive Medicine; The Ohio State University
Acute Bloat Syndrome (ABS) has been identified by 276 veterinarians across the country on a median of four farms per practitioner. Common symptoms included abdominal distension, fluid slosh in the abdomen, colic, and dehydration. Symptoms did not commonly include either diarrhea or an elevated temperature. The majority of cases were seen in calves 4 to 21 days old. Knowledge of these common clinical signs can help calf managers detect problems in calves as early as possible and to begin treatment of the syndrome.
In calves exhibiting clinical symptoms, respondents suggested effective treatments and therapies. Some combination of antibiotics, rumen tonics, anti-inflammatories, and bloat-relieving measures may be effective in some cases. The majority of possible preventive therapies focused around the diet and feeding program. However, no particular diet or feeding strategy in place on any of the case farms precluded a case of ABS from occurring.
Notwithstanding that management was rated as good to excellent on most farms where a case had been seen, various improvements in calf management practices (e.g. consistency in feeding time intervals) were cited as being effective at preventing future cases. This underscores the idea that attention to detail cannot be overstated regarding calf management practices.
While isolation of Clostridia spp. from clinical cases in no way proves that Clostridia spp. are the causative agents of ABS, the frequency with which these organisms were isolated deserves to be noted. Sarcinia spp. were the second most common bacterial isolate. Sarcinia spp. have been associated with an abomasal bloat type syndrome in goat kids. Further research to clarify the role of Clostridia spp. and Sarcinia spp. in the pathogenesis of ABS is needed.
Capturing and Recycling Dairy Nitrogen Manure Nutrients with Winter Cover Crops
James J. Hoorman, James N. Lopshire, Chris L. Bruynis, Glen J. Arnold, Alan P. Sundermeir, and Steve C. Prochaska, The Ohio State University
Nitrogen prices have doubled, motivating producers to conserve nutrients with winter cover crops (WCC). With increased regulations on the winter application of manure, planting WCC's to capture fall and early winter applied manure nutrients is an option for livestock farmers. Ohio State University Extension assisted nine livestock farmers in saving nitrogen from the fall application of manure by planting WCC plots. The WCC treatments included annual ryegrass (ARG), cereal rye (CR), and oilseed radish (OSR) compared to bare land. Each treatment had three rates (0, 6,000, and 12,000 gallons) of dairy liquid manure applied. Measurements were recorded for soil nitrogen, soil nutrient losses, plant nitrogen, and survivability. Our research has shown that WCC are great scavengers of excess nitrogen (up to 500 lb/acre) and phosphorous (60 lb/acre). Plant biomass analysis showed that OSR and ARG absorbed significantly more nitrogen than CR (P < 0.01) and significantly more soil nitrate nitrogen (P < 0.0001) and soil total nitrogen for the next crop. Carbon was significantly higher for CR (P < 0.0001) and for carbon-nitrogen ratio (P < 0.01).
Preliminary data show that grass WCC such as annual ryegrass (ARG) and cereal rye (CR) have the potential to be utilized by livestock farmers to absorb manure nutrients and prevent manure winter runoff. The nitrogen in dairy manure can be recycled to the next crop if the WCC are killed in early April and the cover crops have time to decay and release nutrients back into the soil. Annual grass WCC are preferred to other cover crops (oil seed radish) because they provide the additional benefit of protecting the soil during the winter months from soil erosion. Additional research is needed to quantify the effects of cover crops on recycling other manure nutrients (phosphorous and potassium), coliform survivability, water infiltration, and water retention in the soil profile.
Determining Annual Trend of H2S and Odor Levels at Dairy Manure Storage Ponds and Downwind Property Line for Effective and Economic Air Quality Management
Lingying Zhao, X. Wang, M. Darr, R. Manuzon, M. Brugger, E. Imernan, and G. Arnold, The Ohio State University
The study results indicated that there are large seasonal variations in ammonia (NH3), hydrogen sulfide (H2S), and odor levels at the dairy manure storage pond. Warmer months, such as May to August, were generally associated with high levels of NH3 and odor. The H2S levels varied without a trend. During the eight-month study period, the overall gas and odor levels at the manure storage pond were generally not high enough to cause air quality concerns. The mean NH3 levels varied from 1.2 to 7.4 ppm; H2S 2 to 72 ppb (parts per billion); and odor level 96 to 381 OU/m3.
Since odor is a subjective perception of an individual, it is difficult to say exactly what odor level is odor free and what level is very offensive. However, the study indicated that hot months generally had relative high odor levels. If odor is a concern to neighbors and limited mitigation can be afforded, then warmer months are the critical time for odor abatement practices.
The H2S levels on the dairy farm studied were generally low. The H2S dispersed well during noon sampling periods. The dairy facility did not significantly affect the ambient H2S level at the 1000 ft downwind neighboring areas during the study period.
The NH3 emission from the 650 to 700 cow operation was likely more than 100 lb/day in warmer months. However, H2S was not a concern at all in reference to the Comprehensive Environmental Response, Compensation, and Liability Act and the Emergency Planning and Community Right-To-Know Act reporting requirements.