To evaluate reproductive efficiency, veterinarians and producers have relied on production benchmarks from various parts of the United States. These benchmarks are impacted heavily by reproductive performance and calf survival and growth. The evaluation of individual herd performance involves collecting data at critical points in time, calculating herd indices (primarily ratios), and comparing the herd’s performance to accepted benchmarks. Four veterinarians in each of the six extension districts (24 total) will be used to recruit four of their herds (16 per district; 96 total herds) t participate in this project. These veterinarians and producers will agree to collect needed reproductive performance data to construct benchmarks. These same herds will also track calf performance data to include calving dates, calf death loss and timing, causes of morbidity by body system, and weaning weights. This data will be used to construct benchmarks for calf performance. Participating producers will be surveyed at the beginning of this project to determine current production practices in the areas of reproductive management, calf health, herd health programming, and nutritional management (commodities fed, amounts, and cost). This information will be used to compare producer production practices to their production.
Bovine Research and Disease Topics
This involves multiple projects designed to evaluate the effect of an acidifying agent on the pH and bacterial pathogen load in bedded pack manure. We hypothesize that the strategic treatment of the bedding pack and pen floor with a commercially available drying agent will decrease the moisture content and pH of the manure, reduce ammonia production, and reduce the bacterial load in the bedding pack in the pen. The result will be fewer and less severe DD lesions in treated pens. Other projects within this protocol have documented significant decreases in bedding pH and bacterial counts as long as 8 hours post-treatment.
In this proposal, we will develop and test a multispecies bacterin to digital dermatitis in an experimental model. First, we will initially apply additional data modeling analysis to existing digital dermatitis lesion bacterial sequence data to identify most probable bacteria contributing to lesion development and perpetuation. Using this analysis, we can then perform targeted culture methods to isolate these bacteria from fresh or freezer samples. Once bacteria are isolated, bacteria will be inactivated and combined into a multispecies bacterin with adjuvants to enhance immune protection. This multispecies bacterin will be used to immunize sheep, which will then be experimentally infected with digital dermatitis lesion material.