Dairy Science Department
BS in Dairy Science
The objective of this project was to determine if increased stress levels could affect morbidity and mortality rates in calves. The source for this study was a group of 132 calves at the Cal Poly Dairy available for observation. For each test day, calves were scored on a scale of 1-3 based on how stressed the calf was. After all the data were collected, relationships between age, sex, breed, and observation day were determined in SAS using a Proc Probit method. The effects of breed and sex were not significant in the analysis. However, one of the observation days (January 17th, 2012) may have been significant, which led me to determine if weather affects the results. When observing the raw data, more calves scored a 2 or 3 on days when the weather changed. Although this method proved to not be very effective when determining stress levels in calves, I was able to pinpoint reasons as to why morbidity and mortality rates may increase on large dairies. Muddy, wet conditions have proven to be the source of increased morbidity because disease-causing bacteria can grow rapidly in these conditions. On days when the calf hutches were surrounded by mud, scores went up. Some practices that could be implemented to improve calf hutch conditions could be regular cleaning and keeping calves in a dry, draft-free area. Calf maintenance is crucial on any dairy to keep animals healthy and prevent economic loss.