Nearly 200 participants attended the 9th International Dairy Nutrition Symposium organized by the Centre for Animal Nutrition, this year in collaboration with Balchem Corporation, Diamond V, Cargill Animal Nutrition and Wageningen Institute of Animal Sciences. Seven speakers discussed the various aspects of the relationship between nutrition and the health of dairy cattle. Conclusion: there is more behind a healthy diet than just ration formulation.
The first speaker Dr. Ariëtte van Knegsel (Wageningen UR) discussed the latest results of her research projects on the optimization of dry period length. Ration composition is an important factor here; in early lactation glucogenic nutrients can support metabolism, and if milk production declines further in lactation overfeeding should be avoided. The individual differences between cows in their response to management and diet composition are large and provide new tools for individual management. Prof. Claire Wathes (Royal Veterinary College, University of London) continued with new insights from her research on the relationship between nutrition, IGF1, growth and fertility. A high IGF1 level in calves may predict a lower age at first calving; in adult cattle, a deep negative energy balance should be prevented for a good IGF1 level and good fertility results. Dr. Barry Bradford (Kansas State University) spoke on the importance of balanced nutrition for the immune function of the cow. Rumen and gut health, energy metabolism and the immune system are closely intertwined. In case of a health problem 'chicken and egg' are hard to identify; if one is out of balance, the others will be disturbed as well.
After lunch Dr. Georg Eller (HCS Herdenmanagement Consulting & Service) discussed rumen disorders in practice. Rumen acidosis is not just a matter of fibre vs. starch; ration management and herd management are just as important. Be sure to look at the cow and the whole picture, instead of staring at your ration formulation! Kasper Dieho (Wageningen UR) continued with his recent work on the effects of diet on the rumen flora, rumen papillae, and the absorption of volatile fatty acids in the first weeks of lactation. His experiments showed that the rumen and its microbes can adapt quickly to the changes after calving; if a fresh cow is able to eat sufficient dry matter at a constant pace, a high proportion of fermentable organic matter in the ration does not seem to cause trouble. Reuben Newsome (University of Nottingham) presented the latest insights on the relationship between nutrition and claw health. Claw horn lesions such as sole ulcers and white line disease are multifactorial, but appear to be closely related to the relaxation of connective tissue around calving and the loss in body condition (BCS): lean cows have a thinner 'digital (fat) cushion', which is needed for shock dissipation in the claw. Dr. Trevor DeVries (University of Guelph) concluded the day with his analysis of the relationship between cow behaviour and health. Close monitoring of rumination and lying behaviour using sensors can help in early detection of risk animals. Using these data for early interventions in housing and management can prevent problems like mastitis and ketosis!