Diarrhea in Pre-Weaned Calves: Relative Risk Rates for Morbidity and Mortality in 13 Commercial Farms of Hot Arid Zone

摘要

Problem statement: In many hot arid countries, pregnant Holstein Friesian heifers are imported for herd replacement. The calves obtained from exotic cows are exposed to adverse cjimate in feedlot system resulting in very high morbidity and mortality rates. Diarrhea, dehydration anckdeaths are causing a major loss to the producers. This study examines the Risk Rates (RR) for morbidity and mortality in pre-weaned calves. Approach: Thirteen commercial dairy farms of small, medium and large sizes were surveyed using 1,280 newborn calves. A survey was conducted for calves from their birth to weaning at 90 day. Parameters of the study were birth weights, colostrum feeding, growth rate, incidences of diseases, clinical symptoms, post-mortem findings and results of laboratory investigations of samples obtained from sick and dead calves. Calf housing and feeding management of 13 farms were investigated. Results: RR for morbidity and mortality ranged from 0.3-1.00 and being highest during the first week. Most common disease was diarrhea representing 90.6% of the total calves affected. Common pathogens causing diarrhea were E. coli, Salmonella sp. Klebsiella, Pasturella and rotavirus. Relationship between calf management and morbidity RR for diarrhea was significant (r2^ 627, p = 0.01) and the growth rate was positively correlated (r2 = 0.761, p = 0.1). Diarrhea caused a significant negative impact on gross margins of the calf enterprises. Conclusion: Colostrum feeding and housing management were the key factors for causing a high RR for morbidity and mortality. Gross margin loss was significantly influenced by morbidity and mortality RR of calves.