|Kehrli Jr, Marcus|
Submitted to: Ruminant Physiology International Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 8/30/2004
Publication Date: N/A
Interpretive Summary: Dairy cattle die as a result of many diseases. This has been estimated to cost over $75 million annually in the United States. The majority of this loss can be categorized into deaths due to pneumonia and diarrhea. This article reviews reported effects of negative energy and protein status on the ability of the dairy cow's immune system to respond to pathogens and vaccines against important respiratory and diarrhea pathogens such as bovine viral diarrhea virus (BVDV), around the time of calving. The effects of stress combined with nutritional deficiencies during the critical transition period of the pregnant, non-lactating cow into a high producing dairy cow have a profound impact on the economic viability of dairy farms. It is recognized that anamnestic responses to vaccines given during the first week after calving are very poor. This article discusses nutritional metabolism research areas of importance in improving the ability of the transition dairy cow to respond to vaccines and pathogens. Methods to improve the energy and protein status of transition dairy cows will undoubtedly improve vaccine responses and the level of protection afforded by these same vaccines. This type of research may eventually reduce morbidity and mortality rates associated with BVDV as well as, reduce antibiotic usage on farms by farmers implementing more effective vaccination protocols for their livestock herds.
Technical Abstract: We will provide an overview of the effects of energy and protein status on the immune system, with a particular focus on the periparturient dairy cow. Recent studies have shown a significant component of the leukocyte proteome is committed to energy metabolism and cell signalling machinery. The various proteins involved in enabling and maintaining leukocyte function represent a demand on the host's protein metabolism. As part of this discussion we will focus on metabolic challenges facing the transition cow and how milk production influences metabolism and immune function. We also know there is considerable genetic control over the immune system capacity to function. There is as much genetic difference in immune function during the periparturient period between cows of average milk production capability as there is between cows of high milk production capacity. Therefore, very high milk production will not likely dictate that a cow will experience a greater magnitude or duration of immune suppression than a lower producing cow. It is more likely the inability of individual cows to adapt to the metabolic demands of milk production dictates the degree and duration of immune suppression experienced at calving.