Does how we feed and manage transition cows affect: (a) colostrum; and (b)the calves they produce? To find out, University of Illinois researcher Jim Drackley set out to answer the following, specific questions:
- Does dry-period nutrition affect colostrum quality or yield?
- Does dry-period nutrition affect the size and viability of the calf?
- Does maternal nutrition influence subsequent metabolic or production responses in the offspring?
By analyzing data from existing studies, Drackley determined that:
- Dry-period nutrition does not affect colostrum quality or yield in cows. Neither colostral IgG nor production levels varied significantly in two studies that compared cows fed various dry-period rations. Supplementation of dry-period rations with vitamins A and E, does, however, increase the content of those important vitamins in colostrum.
- Under reasonable nutritional management of dry cows, maternal nutrition will have little impact on calf size. However, recent research shows that a close-up diet enhanced with either additional energy or fat resulted in larger calves than in cows fed a single-group, controlled-energy diet.
- Under reasonable nutritional management of dry cows, maternal nutrition will have little impact on calf viability in-utero. However, over-fat cows are more susceptible to dystocia, which has been proven to suppress calves’ absorption of colostral IgG, and leave them susceptible to a host of other health and performance impairments.
- To date, results are inconclusive regarding the long-term performance of offspring whose dams were fed a higher plane of late-lactation nutrition. Drackley does believe, though, that results from other species indicate that enhanced in-utero nutrition could permanently impact future performance in offspring through DNA programming. He intends to pursue this question with further research.