By:  Amanda Lee and Jeffrey Bewley                Printable Version  

Proper nutrition is crucial to the development of calves, heifers, and cows. Researchers from around the world are exploring novel options to promote healthy growth and development in heifers, reduce transition cow diseases, and provide proper nutrition for pasture animals. With an increased emphasis on cow longevity and overall health, exploring new options for nutrition can help producers to better understand how to effectively feed their animals.

Researchers from South Dakota State University reported that high forage, low concentrate diets might have low feed efficiency because of poorly digestible fiber. Thus, alternative nutritional sources or feeding protocols, such as limit feeding, are needed to provide heifers with quality, highly digestible sources of fiber. In limit feeding, producers feed a set amount of nutrient dense diet and ad libitum hay to improve feed efficiency and decrease the cost of growing feed. The objective of the study was to compare the effects of limit feeding with distiller grain versus ground corn and soybean product mix when fed with ad libitum grass hay. A 16-week feed trial exposed 24 cows to one of two treatments: distillers grain concentrate mix or corn and soybean product concentrate mix. Because distiller’s dried grains had a greater fat concentration, the diet intake composition had a significantly higher NDF and ether extract in heifers fed distillers dried grain. However, there was no difference in average daily gain, DMI, BW, or frame growth between the two groups of cows. Looking at rumen fermentation, cows fed distillers dried grains had greater propionate and butyrate than cows fed ground corn and soybeans. However, when considering total tract digestibility, there were no differences in dry matter, organic matter, crude protein, or NDF between the diets. Overall, the study suggests that limit feeding with distillers dried grain as the primary concentrate in addition to ad libitum grass hay maintains the same level of growth performance, energy status, dry matter intake, and nutrient digestibility. 

Take home message: When considering how and what to feed heifers, all aspects of the diet must be analyzed. Although no perfect feed exists, a ration must be balanced to provide adequate NDF, CP, and energy.

 

Okara is the residue extracted from soybeans used to make soy and tofu products. Frequently, okara is considered a waste product and it can be highly susceptible to bacterial growth if not properly dried. The crude protein content ranges from 25.5 to 37.5 % and 45.5 to 58.6 % total carbohydrates. In a previous study, up to 12 % okara as dry matter did not affect dairy cows milk production or digestibility. The objective of the current study conducted at the University of New Hampshire was to determine how replacing soybean meal with okara meal changes milk production, milk composition, and nutrient digestibility in dairy cows. Twenty cows were exposed to a soybean based or okara based diet for 21 days. Researchers found no difference in feed intake, feed efficiency, energy corrected milk, 4% fat corrected milk, and milk yield between the groups. However, cows fed okara meal had significantly lower true protein percent. In considering change in digestibility, no difference was seen between okara and soybean meal in dry matter intake and digestibility, organic matter intake and digestibility, or NDF intake or digestibility, although CP intake was significantly lower in cows fed soybean meal.

Take home message: Overall, okara meal can potentially replace up to 8% of soybean meal when fed on a dry matter basis without affecting milk yield or dry matter intake.

 

Transition cows require additional management to prevent ketosis and hypocalcemia, and researchers in Canada are trying to determine when and how a producer might intervene to prevent disease incidence. Flax oil may serve to aid in the energy balance during early lactation of high producing dairy cows. Flax oil is approximately 41% fat and 20% protein and has been shown to reduce fatty liver disease and increase fertility. However, researchers are unsure which component contributes these benefits. Thus, researchers tested two groups of cows by infusing 0.6 lbs of flax oil into the abomasum daily. One group was also supplemented with an additional 15% flax meal in the dry matter. Blood, urine, liver, and mammary gland biopsies were collected from day 7 to 49 in milk. No difference was seen between the two groups in oxidative liver damage, but greater DNA damage was seen in the group supplemented with flax oil in both mammary gland and liver. Overall, flax meal did not reduce the risk of disease in fresh cows.

Take home message: Flax meal must be analyzed further to determine if there is potential benefit in feeding to the fresh cows.

Because Irish dairies typically keep cows on pasture 220 days per year, seasonal calving must occur to prevent grass shortages. With the abolishment of the quota system in 2015, producers are no longer limited by production, but continue to face challenges in land and feed availability. Because there is a high cost associated with cereal growth, there has been increased emphasis on replacing cereals with other byproducts such as palm kernel, soya hulls and distillers grain. The objective of the study was to determine the effects of byproduct inclusion on body weight, BCS, and DMI. Cows were separated into four groups: cows fed 6.6lbs concentrate by-product at 35% inclusion level, 13.2 lbs by-product fed at 35% inclusion level, 6.6 lbs concentration by-product at 95% inclusion level, and 13.2 lbs by-product fed at 95% inclusion level. By feeding 13.2 lbs rather than 6.6 lbs of concentrate, cows tended to produce 4.3 lbs more of milk (or 1.3 lbs more per lb of concentrate above 6.6 lbs). No differences were seen in milk solids or protein produced or pasture DMI intake. Kilograms of milk fat per cow per day were significantly greater in cows fed 13.2 lbs of concentrate than 6.6 lbs of concentrate. Although rumen pH was significantly lower in cows consuming the higher concentrate, the cows still had normal rumen pH and were not at a higher risk for SARA.

Take home message: Cows can be fed up to 95% concentrate with byproducts without changes in DMI, milk production and composition, BCS and BW. Although feeding 13.2 lbs of concentrates resulted in higher milk production and fat concentration, it is currently not economical to feed such high concentrate levels at current milk prices.

This research was presented at the American Dairy Science Association and American Society of Animal Science Joint Annual Meeting in Salt Lake City, Utah on 20 July 2016.