Location: Livestock Behavior Research2013 Annual Report
1a. Objectives (from AD-416):
To determine: 1) the optimum group size of 2, 4, or 8 for veal calves grouped at 6 weeks of age; 2) behavioral changes in early and late production of veal calves in groups of 2, 4, or 8; and 3) determine health and production of veal calves grouped in groups of 2, 4, or 8.
1b. Approach (from AD-416):
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.
3. Progress Report:
This project investigated optimum group size for veal calves. The experiment has been conducted, data analyzed, and a manuscript has been submitted. Although each group size tested (2, 4, or 8) had its advantages and disadvantages in that the calves in groups of 8 had more positive social interactions while calves in groups of 2 showed less fighting; it appears that groups of 4 were best considering both behavior and health. Data were presented at the National American Society of Animal Science and American Association of Dairy Science joint meeting in Indianapolis July, 2013.