Location: Dairy Forage Research
2018 Annual Report
Objectives
Objective 1: Develop and evaluate strategies that optimize growth and development; maximize feed nutrient use efficiency; increase milk production potential; and increase the lifetime productivity, health, and well-being of dairy heifers.
Objective 2: Develop and evaluate dietary feed formulation strategies that increase the utilization of conventional feeds/forages and alternative feeds/forages that reduce competition with human food consumption, enhance nutrient use efficiency, and increase milk production.
• Sub-objective 2.A. Evaluate effects of forage type, amount, and quality on animal performance, nutrient digestibility, and feed conversion efficiency.
• Sub-objective 2.B. Evaluate effects of alternative/byproduct feeds that replace or reduce grain in the diet on animal performance, nutrient digestibility, and feed conversion efficiency.
Objective 3: Develop and evaluate dairy diets that enhance milk production and quality, reduce manure nutrient excretions, and reduce environmental impacts of dairy farms.
Approach
Objective 1. Dry matter intake, body weight, and growth measurements at prepubertal (6 months of age) and postpubertal (12 months of age) stages of dairy heifers growth will be determined as part of a study that will help us determine whether efficiency of growth changes during the lifetime of the dairy animal. Growth measurements for prepubertal and postpubertal dairy heifers will be combined with calfhood and mature cow measurements to evaluate if growth efficiency is correlated through the lifespan of a dairy animal.
Objective 2. A series of lactating dairy cow studies will be conducted to evaluate the effect of forage type, forage amount, and forage quality on animal performance, nutrient digestibility, and feed conversion efficiency. In addition, alternative forages and byproduct feedstuffs will be evaluated as replacements for traditional feedstuffs used in dairy cow diets. We will collect production measurements, gaseous emissions, digesta, and feces to determine the effects of altering fiber digestibility on ruminal fermentation, lactation performance, and environmental output.
Objective 3. Several studies will be conducted to evaluate dairy diets that enhance milk production, reduce nutrient excretion, and reduce the environmental impacts of dairy production systems. Cows will be fed diets with differing ratios of alfalfa silage and corn silage at high and low forage inclusions and at different dietary crude protein concentrations to evaluate the effect of diet formulation on production measures, gas emissions, and nutrient excretion. Manure collected from these experiments will further studied in laboratory emission chambers to determine effect of manure chemistry on gaseous emission during storage. Stored manure will then be applied to a field to determine plant nutrient uptake during a growing season. Gas measurements will be taken to evaluate the impact of manure application on carbon dioxide, ammonia, and nitrous oxide emissions.
Progress Report
The impact of dosing newborn and pre-weaned calves with rumen fluid from cows with different milk production efficiency status on intake, structural growth, and feed efficiency at different stages of growth is being evaluated in a long term, collaborative study (Objective 1). Calves were inoculated with one of three types of rumen fluid: 1) from a cow with high milk production efficiency, 2) from a cow with low milk production efficiency, and 3) a control treatment containing a sterilized mixture of the two rumen fluids. This portion of the study will evaluate how the dosing of different rumen inoculums may impact feed intake, body weight, and structural growth of the calves from weaning until calving at approximately two years of age.
A study was conducted to evaluate the inclusion of brown-mid rib (BMR) sudangrass silage as an alternative to traditional forages such as corn silage in lactating dairy cow diets (Objective 2.A). Forages that use less water, but are high in digestibility, are sought as alternatives to traditional forages in geographical areas where rainfall is limited or where emergency forages are needed. In this study, corn silage and alfalfa silage were replaced with increasing concentrations of BMR sudangrass silage. Forty-eight Holstein cows in mid-lactation to late lactation received diets with increasing concentration of BMR sudangrass silage to evaluate its effect on intake, milk production, milk composition, and feed efficiency.
A study was conducted to evaluate the replacement of concentrate feeds with alternative/byproducts feeds in lactating dairy cow diets (Objective 2.B). The nutritive value of corn stover can be improved by an application of alkaline treatment and combining it with a protein source and then pelleted into a feedstuff available for ruminant diets. In this study, 45 lactating dairy cows in mid-lactation were fed diets with either no pellet, a treated corn stover-soybean meal pelleted diet, or a treated corn stover-distillers grain pelleted diet. Pellets were included in the diet at 17% (on a dry matter basis) replacing a combination of soybean hulls, soybean meal and limestone. Lactation performance, nutrient digestibility, and feed efficiency were evaluated with the inclusion of the treated corn stover pelleted with 2 different protein sources into lactating dairy cow diets.
Accomplishments
1. Canola meal can replace soybean meal in the diets of lactation dairy cows. Canola meal is a high protein, high fiber byproduct produced from the canola oil industry. While it has been evaluated previously in the diets of mid to late lactation dairy cows, it has not been extensively evaluated in early lactation when the demand for nutrients is the greatest. Recent research by ARS researchers at Madison, Wisconsin demonstrated the inclusion of canola meal as a replacement for soybean meal results in 9.8 pounds/day more milk over the first four months of lactation. A follow-up study was conducted to evaluate whether protein source (canola meal and soybean meal) affects dairy cow performance when fed at a limited rate of intake compared to ad libitum intake. This study evaluated protein source effect and amino acid supply on production performance for cows fed under the requirement for amino acids (specifically Met and Lys), metabolizable protein, and metabolizable energy. Limit feeding to the animal’s nutrient requirement can be a successful method to reduce feed waste without loss of milk production. In this experiment, limit feeding was effective at equalizing dry matter intake in soybean meal and canola meal-fed animals, however, milk yield decreased and feed efficiency did not commensurately compensate. These findings demonstrate to dairy producers that canola meal is an effective protein supplement in dairy cow diets.
Review Publications
Aarons, S.R., Gourley, C.J., Powell, J.M., Hannah, M.C. 2017. Estimating nitrogen excretion and deposition by lactating cows in grazed dairy systems. Soil Research. 55:489-499.
De Klein, C., Monaghan, R.M., Alfaro, M., Gourley, C., Oenema, O., Powell, J.M. 2017. Nitrogen performance indicators for dairy production systems. Soil Research. 55:579-488.
Drewery, J.L., Choi, C.T., Powell, J.M., Luck, B.D. 2018. Computational model of methane and ammonia emissions from dairy barns: development and validation. Computers and Electronics in Agriculture. 149:80-89.
Drewry, J.L., Powell, J.M., Choi, C.Y. 2017. Design and calibration of chambers for the measurement of housed dairy cow gaseous emissions. Transactions of the ASABE. 60:1291-1300.
Hristov, A.N., Kebreab, E., Niu, M., Oh, J., Bannink, A., Bayat, A.R., Boland, T.M., Brito, A.F., Casper, D., Crompton, L.A., Dijkstra, J., Eugene, M., Garnsworthy, P.C., Haque, N., Hellwing, A.F., Huhtanen, P., Kreuzer, M., Kuhla, B., Lund, P., Madsen, J., Martin, C., Moate, P.J., Muetzel, S., Munoz, C., Peiren, N., Powell, J.M., Reynolds, C.K., Schwarm, A., Shingfield, K.J., Storlien, T.M., Weisbjerg, M.R., Yanez-Ruiz, D.R., Yu, Z. 2018. Symposium review: Uncertainties in enteric methane inventories, measurement techniques, and prediction models. Journal of Dairy Science. 101:6655-6674.
Martin, N.P., Russelle, M.P., Powell, J.M., Sniffen, C.J., Smith, S.I., Tricarico, J.M., Grant, R.J. 2017. Invited review: Sustainable forage and grain crop production for the U.S. dairy industry. Journal of Dairy Science. 100(12):9479-9494.
Su, H., Akins, M.S., Esser, N.M., Ogden, R.K., Coblentz, W.K., Kalscheur, K., Hatfield, R.D. 2017. Effects of feeding alfalfa stemlage or wheat straw for dietary energy dilution on nutrient intake and digestibility, growth performance and feeding behavior of holstein dairy heifers. Journal of Dairy Science. 100:7106-7115.
