Location: Livestock Behavior Research
Project Number: 5020-32000-010-03
Start Date: Sep 28, 2012
End Date: Feb 15, 2014
Six-week-old calves in each group size will be blocked by weight and feed consumption (N = 300). Calves from Strauss Veal calf barns (adequate passive transfer is determined by close monitoring of a standardized SOP) will be weighed coming into the group housing and leaving the group housing. After moving to group facilities at 44 ± 3 d of age, calves will be randomly assigned to group pens of 2, 4, or 8 calves per pen. Ten replicates of these treatments will be completed. Initially all calves will be place in groups of 2, calves will be moved to keep slow consumers and quick consumers of the liquid feed together. After the first week of re-grouping calves will be placed in groups of 2, 4, or 8 and have blood collected for initial evaluation of cortisol, immune measures, and behavior data initiated. These measures will be collected at 1, 2, 3, and 4 months of group housing. Samples of blood will be collected in 5 mL EDTA tubes and 10 mL into ACD tubes the day the calves are moved into the groups, then monthly thereafter. The ACD tube will be collected only on one selected calf from each pen. The ACD blood will be used to extract RNA using the Leukolock system. The EDTA blood will be used for 5 part differential count, IDEXX analysis for iron and other blood components, and cortisol concentration determination and Quantitative RT-PCR will be used to determine expression of TAC1, CCR5, IL-1, and TNF-a. expression in blood leukocytes. Blood iron values and FAMACHA-like comparisons will be made for a subset of calves to validate a quick assessment method of anemia.