|Briggs, Robert - Bob|
Submitted to: Research Workers in Animal Diseases Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 11/8/1998
Publication Date: N/A
Technical Abstract: A group of 105 market stressed calves were gathered and held five days in an Eastern TN order buyer barn (OBB). Calves were processed while in the OBB and then shipped to the USDA-ARS research feedyard (FY) at Bushland, TX, where they were sorted randomly into three groups (dust-treated calves [D], n=35; control-non-dust-treated calves [CND], n=35; and control feedyard calves [CFY], n=35), with two pens per treatment group. Calves were monitored daily and scored for signs of acute bovine respiratory tract disease, if a sufficient score was maintained for 48 hrs, the calves were treated with antibiotics. On day two in FY, 300 g of organic dust containing 85.99 g of endotoxin (ET)/g of dust was aerosolized into 97.8 m**3, at a rate of 10 g/min over a 30 min period of time, calves were held in a closed tent for 1 hr. This process was repeated on FY day three, and twice on FY day four. Calves were grouped according to dust treatment, and dthe following variables - Pasteurella haemolytica A1 vaccination status, morbidity, mortality, treatment episodes, and rectal temperatures - were analyzed and no significant differences were found. The total antioxidant capacity (mean, 4,410 IU/ml of serum) of non-stressed calves (n=105) first entering the OBB was compared to the same calves after seven days of market stress (mean, 3,999 IU/ml serum) on FY day two, and this difference was significant (P <\= 0.002).