What's new at the U? Dairy cattle nutrition research update
This article will highlight some of the University of Minnesota dairy research my laboratory group and I are conducting this fall. The overall objective of our work is to use "adaptive nutrition" to improve performance and health in both transition cows and nursery calves. We are currently running three research studies (two on the St. Paul Campus and one dairy farm field study). The following is an overview of the three studies:
Study #1. Effects of daily dry matter adjustment of ingredients in a total mixed ration using an IRM NIR (near-infrared reflectance) forage analyzer on pen dry matter intake, and individual milk production and milk components. This study is in cooperation with Dinamica Generale, an Italian company, and Gar-Lin Dairy, Eyota, MN, to evaluate a new precision feeding tool (Figure 1).
Figure 1. Bucket mounted NIR (near infrared reflectance) scanner, evaluates every bucket of forage fed at the Gar-Lin Dairy research trial.
- Background: Dairy producers are adapting new technology to improve the precision of managing their dairy herd. Examples of technology include advanced record keeping software, automated calf feeders, intelligent milking parlors, and robotic milking systems. Little has changed over the last ten years when it comes to feeding cows with greater precision. Dinamica Generale has made the first steps towards precision feeding with their new bucket mounted NIR feeding system.
- Experimental design: Switch-back design with two periods with two pens. Each pen contains approximately 250 cows and is balanced by milk production and days in milk.
- Control: All individual ingredients are sampled weekly, dried in a 100°C oven, and ingredient dry matter (and final diet dry matter) is adjusted weekly.
- Treated: The NIR system scans individual ingredients (corn silage, alfalfa silage, and high moisture corn) and adjusts ingredient dry matter at each feeding.
- Expected outcomes: Feeding with greater precision will result in greater and more efficient cow performance.
Study #2. Effects of moderate energy diets with negative DCAD (dietary cation-anion difference) fed for either 21 or 42 days during the dry period on milk fever prevention and postpartum performance. Transition cow health challenges remain one of the largest problems and sources of cow variability on most dairy farms. This study aims at using adaptive nutrition strategies to reduce these health challenges in transition cows.
- Background: Optimal dry cow feeding strategies to consistently reduce the incidence of hypocalcemia (low blood calcium or milk fever) in transition dairy cows remains elusive. Hypocalcemia can result in lower postpartum feed intake, increased risk for displaced abomasum, increased SCC, increased incidence of retained placenta and metritis, and may be associated with a slow immune response. Moderate energy diets fed during the dry period help maintain dry matter intake during the transition period, which may reduce hypocalcemia. Combining moderate energy diets with feeding negative DCAD diets during the entire dry period (vs. the traditional 21 days before calving) would reduce the need for a diet and potential pen switch during the dry period.
- Expected outcomes: Feeding a negative DCAD diet for 21 days will result in similar postpartum performance compared with a negative DCAD diet fed for 42 days.
Study #3. Effects of feeding supplemental colostrum during the nursery phase on dairy calf growth and health. We teamed up with Dr. Jeremy Schefers at the University of Minnesota Diagnostic Lab to conduct a nursery calf study aimed at interactions of nutrition and health. We want to determine if supplementing heat treated colostrum during the first 14 days of life will reduce fecal score (1 = normal; 4= diarrhea), improve ADG, and reduce morbidity and mortality.
- Background: Pre-weaning mortality rate in dairy calves in the United States is 8%. Over half of these mortalities are associated with diarrhea and subsequent dehydration. Field evidence suggests that supplementing small amounts of heat treated colostrum (120 grams per calf per day) to dairy calves during the first two weeks of life reduces mortality and morbidity. Colostrum may work by reducing pathogens' ability to colonize the small intestine in addition to adding other factors that may improve calf health and growth.
- Experimental design: In addition to their normal milk replacer, two groups of calves will be supplemented with either frozen colostrum ice cubes or nutritionally equivalent milk replacer ice cubes (Figure 2).
- Expected outcomes: Colostrum supplemented calves will have greater calf performance and health compared with control fed calves.
Figure 2. Future animal scientists demonstrate the colostrum cubes for our current nursery calf trial.
Our hope is that our research will yield practical results and recommendations that are useful on your dairy farm. We look forward to sharing results from these studies in the near future.
Published in Dairy Star October 15, 2010