Dairy Pipeline: February 2006
Robert E. James
Extension Dairy Scientist,
(540) 231-4770 email: firstname.lastname@example.org
There seems to be some confusion over the best strategy for feeding the close up dry cows and after calving. It's been standard practice for some time for cows to consume a lower energy, higher fiber diet during the first half of the dry period followed by a ration with more energy (more grain) for at least two weeks pre partum. After calving some producers have continued to feed a lower energy, lower fat diet to enable the cow to "ease" into lactation. Others recommend immediately transitioning fresh cows to a high energy diet. In a study conducted in Wisconsin, dairy cows were fed either high (.77 Mcal NE/lb.) or low (.71 Mcal NE/lb.) energy diets from 4 weeks pre partum until calving. After calving, half of each group was fed either a high or low energy diet. As expected the cows fed the high energy diet were in positive energy balance. However, there were no differences in blood concentrations of metabolites, insulin, or liver fat stores. Changes in liver stores of fat were more related to the change in diet after calving. There were significant interactions between the pre and post partum treatments indicating that delaying higher concentrate feeding until day 21 after calving could be offset by higher concentrate feeding pre partum.
Two significant findings have practical implications for feed management recommendations for this period of time. Cows fed low energy diets had a higher incidence of white line hemorrhage scores (sore feet) between calving and 10 weeks post partum than cows fed higher energy diets. Cows receiving the high energy diet in the dry period followed by the low energy diet post partum had the greatest increase in white line scores. The most favorable metabolic profile occurred when cows were fed the higher energy diets immediately after calving. It's also interesting to note that there was no difference in the incidence of udder edema between the different treatment regimes. What's it all mean? Consistency is important in any feeding management program. Dairy cattle respond best to consistent pre partum diets whether they are high or low energy. Negative effects of weather must be minimized by covering feed bunks and providing good cow comfort. Effective fiber must be present regardless of the energy level of the diet. The benefits of low energy post partum diets are minimal which means that diets immediately after calving should contain high levels of energy and feature forages of optimal palatability that encourage high intake post partum.