Highlights of the Past and a Look into the Future of Dairy Nutrition

After working and interacting with dairy managers, extension educators, and dairy researchers for 41 years as an extension dairy specialist in Minnesota and Illinois, new approaches and changes in dairy nutrition have occurred while many principles remain the same (Hutjens, 2011). This paper will look back 30 years focusing on feeding changes, feeding challenges in 2012, and future feeding strategies and opportunities. 

Joining the University of Minnesota dairy extension staff in 1971 to 1979 allowed me to monitor changes in the dairy industry, benchmarking Midwest dairy feeding situations, and comparing possible changes to the dairy industry. Table 1 compares data obtained from the Hoard's Dairyman Magazine Market Surveys in 1976 and 2010. Each year, Hoard's Dairyman market researchers select 2000 random readers who subscribe to their magazine weighed for percent of readers in each state. Topics and dairy extension activities in the 1970's are listed below with comments on the impact on future directions and decisions. 

Table 1. Comparison of dairy data from 1976 and 2010 reflects changes in the dairy industry (Kerschensteiner, 1976; Vorpahl, 2010).

Extension programs were tied to DHI with one or two extension specialists responsible for the day-to-day management of the program and labs. The educational focus was county based meetings with specialists in Minnesota limiting the number to 80 Minnesota meetings annually with four dairy specialists (over 320 meetings) plus forage, farm management, dairy engineers, and milk quality specialists available in most states. Overhead projectors were delivery systems with slides becoming more common. Funding was excellent with opportunities to launch new programs and efforts. The Four State Dairy Extension group (WI, MN, IA, and IL) had been formed in the 1960's which became the model for other regional groups. 

 

Table 2. Benchmarking for 2010 feeding practices for future consideration (Vorpahl, 2010).

 

Table 2 lists feeding decisions and strategies for U.S. dairy managers in 2010. Dairy nutrition continues to have key economic impact for Midwest dairy managers with competitive advantages compared to Western states dairy managers. As forage and corn grain were produced on farm, forage quality was controlled and production costs of forages and grains were lower than current market prices. Illinois workers calculated the cost to raise alfalfa hay was $102 a ton while the market price is over $220 a ton in 2011. A similar financial competitive advantage pattern exists for corn silage, shelled corn, and soybeans. 

Herd feed efficiency ranges from 1.4 to 1.6 kg of 3.5% milk per kg of dry matter with each change of 0.1 FE point worth 38 cents per cow per day. Factors impacting feed efficiency include forage quality, fiber digestibility, ration formulation, dry matter intake, milk quality, somatic cell count status, rumen health, reproductive efficiency, and environmental impact. Milk protein efficiency will become another feed efficiency measure as dairy cows recover 25 to 30 percent of dietary protein as milk protein. This value will need to increase to 35 to 40 percent by genetic selection, feeding programs, and feed ingredients which will be a win-win-win-win for dairy cows, dairy managers, the environment, and consumers (Hutjens, 2007; Hutjens, 2010a; Linn et al., 2009).

Feed cost per kg of dry matter, currently about 26 cents per kg (12 cents per lb) of dry matter, reflects the cost of feed ingredients selected when building and balancing the ration. Feed ingredient selection, forage quality, and feed additives are key factors.

Feed cost per 45 kg (100 lb) of milk, usually about $8 to $9 per 45 kg, reflects the cost per pound of dry matter, amount of dry matter offered, weigh backs, shrink, and milk yield. Milk yield is the key factor.

Costs Income over feed costs ($9 to $11) per 45 kg (100 lb) of milk represents margin (dollars available) for fixed, variable and labor costs, and return to management. Milk price is a key factor in this value. Illinois dairy managers need $10 per 45 kg (100 lb) of milk to cover all costs. 

Corn hybrids offer flexibility with low lignin corn silage, corn silage specific hybrids, higher starch levels, and improved feed efficiency. Forages high in NDFD (neutral detergent fiber digestibility) provide sources of rumen fermentable carbohydrates reducing corn grain levels.

Use of computer modeling programs allows for fine-tuning rations. Lower levels of protein based on amino acid balancing and rumen microbial estimation can reduce feed costs while optimizing production. Milk protein yield continues to be important in the Midwest based on milk pricing systems.

With corn grain over six dollars a bushel, starch level and utilization must be optimal. Lower levels of starch (20 to 22 percent) can maintain milk production with high quality forage, rumen fermentable fiber, adding sugar, and/or feeding an ionophore. Plant or kernel processing of corn silage and processing corn grain can increase starch availability in the rumen and reduce fecal losses of starch. If fecal starch is over 5 to 6 percent, examine the cause of higher fecal starch values.

By-product feeds can be an economical nutrient source. Corn by-products continue to be economical sources of nutrients. Distillers grain and wet brewers grain can reduce protein costs while corn gluten feed, soy hulls, and wheat midds can maintain energy levels while reducing feed costs. Dairy managers and nutritionists must monitor corn by-products as ethanol producers continue to market corn nutrients in by-products (corn oil for bio-fuel, corn protein for monogastric animals, and corn bran for ruminants) to capture value-added feed markets.

Managing and monitoring weigh backs can increase profitability. One guideline is to target 1 to 2 percent weigh back per cow per day. Bunk management may allow feeding to an empty bunk and can reduce feed refusals, saving 0.5 to 1.3 kg (1 to 3 lb) of dry matter per cow per day or 12 to 36 cents per cow per day. Other areas to reduce feed shrink include mixing errors monitored by computer based software on weigh scales, mixing inside the building, minimizing weather and wind losses, and controlling waste.

Forage storage systems continue to shift to bunkers, baleage, bags and drive over piles. Herd size and local availability of forages impact these forage storage systems. Oxygen barrier covers reduce dry matter loss and shrink.

 

Precision feeding can be defined as delivery of the same ration and form every day to every cow (Hutjens, 2010b). Blending rations with consistent feed processing resulting in the same physical form and nutrient content ration in each batch of feed every day will be needed. Feed ingredients will be added with an exact mixing time (minutes of mixing time and revolutions of the TMR mixer) and feed order. NRC standard nutrient composition tables may not be used in ration formulation. Fuzzy cottonseed does not contain the same nutrient level due to new genetic selection of the crop and growing conditions. Measuring forage quality when harvesting forages using NIR sensors on the chopper will capture real time forage yield, dry matter changes, and nutrient level of the forage before it is stored. The field harvesting chopper will automatically adjust chopper theoretical length of chop (TLC) and roller clearance of kernel processor as dry matter content changes in the field to process uniform and desired corn silage forage for ensiling and feeding. Measuring and managing variation in forage quality will be available to nutritionists and dairy managers to correct nutrient content based on standard deviation of feed based on multiple test summarization. Ration balancing and protection of ration nutrient changes such as adequate protein (Chase et al., 2009) or a shortage of fiber can be programmed by the computer software program. Commercial forage testing labs provide summaries of specific forages from the dairy farm over several samples and time periods.

High forage-based rations (over 65 to 70 percent of the ration dry matter) will become economically attractive. As competition for corn and soybeans continues between human food uses and bio-fuel production, the dairy cow may not compete economically for these high quality food resources as feed. Dairy cattle have a rumen-based digestive tract that allows ruminants to consume feed ingredients that humans cannot utilize (such as grasses, pasture, distillers grains, wheat midds, urea, and other by-product feeds). Cornell researchers have measured herds producing over 80 pounds of milk fed rations containing 65 to 70 percent of the total ration dry matter as forage (Chase, 2010). Nutritionists and dairy managers will need to be skillful when managing these rations (inventory control, rumen models to predict results, and harvesting high quality forage). The future may dictate that dairy managers cannot afford corn or soybean-based feed ingredients for dairy feed as a hungry and growing human population continues to expand. 

Designer dairy products will become more than food that we consume providing high quality protein, calcium, potassium, B-vitamins, and other key nutrients. Cows will produce fatty acids (type of milk fat) in milk that will improve health and avoid diseases (an example is CLA or conjugated linoleic acids). Specific dairy proteins could also be a valuable food resource to reduce or slow memory loss and aging. Improved weight loss may be achieved with whey proteins. Calcium and vitamin D may have future human health benefits. 

Genomic and gene engineering (gene sequencing) has been identified for dairy cattle allowing researchers to find "the combination of genes" that could reduce mastitis, decrease transition cow health risks, and/or reduce milk fat synthesis. By selecting these genetic markers and turning on or off these genes, cows could produce milk containing two percent milk fat instead of four percent fat which may reflect consumer demand and lower energy needs of high producing cows. Illinois researchers have identified genes that are up regulated (turned on) or down regulated (turned off) based on the diet the dry cow consumes which may impact metabolic risks in transition cows. This biotechnology tool has tremendous potential in the dairy industry. 

New rumen-based feed additives that may enhance rumen function and efficiency continue to emerge from research labs and companies. Enzymes may increase feed digestibility providing more nutrients for the cow or rumen microbes and resulting in less manure; another win-win situation. Enzymes could be added to forage when ensiling, by treating feed prior to consumption, or fed to function in the rumen or lower digestive tract (protected from microbial destruction). Encapsulation technology is available to allow companies to "protect" key nutrients from rumen microbial destruction (such as rumen protected amino acids, fatty acids, niacin, and choline). Direct fed microbes will be identified through selection and DNA finger printing that can enhance rumen fermentation, reduce lactic acid build up, and improve cell and cow immunity. Essential oils are a class of feed additives that offer alternatives and opportunities depending on the future role of feeding antibiotics. 

Computer technology and software programs continue to improve rations with the ability to predict rumen microbial yields, amino acid flows, rumen pH, milk urea nitrogen (MUN) values, fatty acid levels, and the environmental impact of nitrogen and phosphorous excreted in dairy cow manure. Balancing long chain fatty acid levels and types to predict desired milk fatty acid composition is possible. In the future, we may not balance for NDF, but balance each fiber fraction (lignin, hemicelluloses, and cellulose) to predict performance. Computers will "see" and adjust for feed particle size, heat stress impact on the rumen environment and pH, impact of cow comfort on feed intake and digestion; they will refine dietary cation-anion difference (DCAD) calculations, adjust mineral levels based on bioavailability, and predict nutrient efficiencies (dry matter, protein, energy, and minerals) delivered by the ration feed ingredients monitored by feed models. 

Feeding cows over the last 40 years has been amazing in the changes in feed ingredients, ration balancing approaches and nutrients, and feeding systems. But, high producing cows always resulted in the best opportunity to make a profit while maintaining milk components and quality. The next 40 years will offer new challenges and opportunities for high producing cows. 

Chase, L. E. 2010. High forage rations for dairy cattle—how far can we go? WI Forage and Grassland Conference Proceedings.

Chase, L. E., R. J. Higgs, and M. E. Van Amburgh. 2009. Feeding low crude protein rations to dairy cows—opportunities and challenges. Proc. Cornell Nutr. Conf., Syracuse, NY. pp. 220-226.

Hutjens, M. F. 2011. Changes in feeding dairy cows during the last 40 years and what's ahead. Tri-State Nutr. Conf. pp. 1-7.

Hutjens, M. F. 2010a. Feeding economics in 2010. Four State Dairy Nutrition and Management Conference. pp. 27-29.

Hutjens, M. F. 2010b. Precision will fuel thee rumen and future feeding focus. Hoard's Dairyman Magazine. 155(11):446.

Hutjens, M. F. 2007. Practical approaches to feed efficiency and applications on the farm. Proc. Penn State Dairy Nutrition Workshop. Penn State University, University Park. http://spac.adsa.org

Kerschensteiner, M. H. 1976. Hoard's Dairyman continuing market survey. Fort Atkinson, WI.

Linn, J., T. M. Raeth-Knight, and N. Litherland. 2009. Role of feed (dairy) efficiency in dairy management. Proc. Pacific Northwest Nutr. Conf. http://spac.adsa.org

Vorpahl, G. L. 2010. Hoard's Dairyman 2010 Marketing Study. Fort Atkinson, WI.