Holstein-Friesian bull calves (n = 168; 44 ± 3 d of age), were used to investigate the effect of group size on performance, health, hematology, and welfare of veal calves. Groups of calves were assigned to 1 of 3 group housing treatments with 2, 4, or 8 calves per pen (initial BW 65.3 ± 3.7, 66.5 ± 3.7, and 67.6 ± 3.7 kg, respectively). The pens within 2 barns were 3 × 1.20 m (2 calves/pen), 3 × 2.40 m (4 calves/pen), and 3 × 4.80 m (8 calves/pen), and provided the same space (1.8 m2 per calf) during the 5-mo finishing period. All calves were fed milk replacer and solid feed twice daily at 12 h intervals. Body weights were measured at the beginning (Initial BW) and at the end of the experiment (Final BW). Hip height and heart girth were recorded monthly for 5 mo. Health was evaluated monthly using the University of Wisconsin calf health scoring chart. Data were analyzed as a RCB with repeated measures using PROC MIXED (SAS). No differences (P ≥ 0.5) among treatments were found regarding BW or ADG for the entire 5-mo period. Group size resulted in similar hip height change (P = 0.41) and heart girth change (P = 0.18) over 5 mo. The incidence of diarrhea was similar among treatments (P ≥ 0.15). An interaction of treatment and month was detected for both cough (P = 0.03) and nasal discharge (P = 0.02) scores. During mo 1, calves in groups of 8 or 4 coughed more compared with calves in groups of 2, whereas, in mo 2, calves in groups of 8 coughed more than calves in groups of 4 or 2. In mo 4, calves in groups of 8 had less nasal discharge than calves in groups of 2 or 4. Plasma cortisol (P = 0.37) and blood hemoglobin (P ≥ 0.13) concentration were not affected by group size. In conclusion, the number of veal calves in a group, given the same space, has no detrimental effect on performance, and has transient effects on health of veal calves. Housing veal calves in group size of 2, 4, or 8 can be equally effective in terms of production and has no clear negative effect on welfare. Key Words: group size, production, veal calf |
