Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 26, 2013
Publication Date: August 29, 2013
Citation: Abdelfattah, E.M., Schutz, M.M., Lay, Jr., D.C., Marchant-Forde, J.N., Eicher, S.D. 2013. Effect of group size on behavior, health, production and welfare of veal calves. Journal of Animal Science. 91:5455-5465. Interpretive Summary: Veal production systems are just beginning to group calves and have many unanswered questions. To determine the impact on production, health, and behavior of housing calves in groups with the same space allocation, calves were housed in groups of 2, 4, or 8 calves with the same area per calf for 5 months. Calves housed in larger groups (4 or 8 calves per pen) showed more contact with other calves,more walking, more standing, and more disturbance and displacement from the feed trough and less manipulation of objects, less self-licking, and less lying when compared to calves housed in small groups (2 calves per pen). During feeding, group size had no effect on any behavioral pattern except for duration of contact with other calves.Calves in different group sizes were similar for hip height change and heart girth change over the duration of the experiment. Coughing was greater for calves in groups of 8 during the first 2 months, but they had fewer incidence of nasal discharge during the last month. Overall, production, health, and behavior differences were transient and not negatively affected by the changes in group sizes. Veal calves can be grouped at least up to groups of 8 without prolonged negative impacts on production or well-being of the calves when given excellent housing and management attention.
Technical Abstract: The objective of the present study was to determine the effect of group size on behavior, health, growth, and welfare of veal calves. Holstein-Friesian bull calves (n = 168), 44 ± 3 days of age, were used to investigate the effect of group size. Calves were randomly assigned into 1 of 3 treatments of group housing with 2, 4, or 8 calves per pen. The pens used for housing were 3 × 1.20 meters (2 calves/pen), 3 × 2.40 meters (4 calves/pen), and 3 × 4.80 meters (8 calves/pen). The total pen area per calf was kept constant on 1.82 square meters per calf for all group sizes. Behavior was recorded from video data throughout the day from 0700 to 1700, using scan sampling every 5 minutes within 30 minute observation sessions every month for 5 months and around feeding time by continuous focal sampling (30 minutes before-feeding and 30 minutes feeding and 30 minutes after-feeding on d 0, 1, 5, 14, 42, and 70 after grouping). Calves housed in large groups (4 or 8 calves per pen) showed more conspecific contact (biting, licking, sniffing, or sucking another calf), walking, standing, and more disturbance and displacement from the feed trough and less manipulation of objects, self-licking, and lying when compared to calves housed in small groups (2 calves per pen). Group size had no effect on play behavior (P = 0.05) throughout the experiment. During feeding times, group size had no effect on any behavioral pattern except for duration of conspecific contact. Group size treatments were similar for hip height change (P = 0.41) and heart girth change (P = 0.18) over the duration of the experiment. Both hip height and heart girth increased with calves’ age (P = 0.001). An interaction of treatment and month was detected for both cough (P = 0.03) and nasal discharge (P = 0.02) scores. During month 1, calves in groups of 8 or 4 coughed more compared to calves in groups of 2; while in month 2, calves in groups of 8 coughed more than calves in groups of 4 or 2. In month 4, calves in groups of 2 and 4 had more nasal discharge than calves in groups of 8. Ocular discharge, ears, and fecal scores did not differ (P = 0.05) among treatments. Plasma cortisol concentration was not affected by group size (P = 0.37). Blood hemoglobin concentration was similar among treatments (P = 0.14). The number of veal calves in a group, when given the same space, did not affect production, physiological, and hematological indicators of welfare during the 5-month finishing period. Veal calves can be grouped at least up to groups of 8 without prolonged negative impacts on production or well-being of the calves when given excellent housing and management attention.