The influence of live body weight on the behaviour and welfare of broilers

The broilers were initially weighed and the first heaviest 50 birds were accommodated in group A, next heaviest 50 birds in group C, other 50 birds higher in first 50 birds were kept in group B and remaining in group A, which were of lowest live body weight. Birds of group C and D spent relatively more time (3.92 and 3.41; 3.51 and 3.80 min/hr) during initial and final period for water consumption. The broilers in group A and B spent relatively less time for water consumption activity i.e. 2.42 and 2.39 min/hr during initial and 2.71 and 2.75 min/hr during final period, respectively. During initial period the broilers of group D spent significantly (P=0.050) greater time (7.51 min/hr) in feeding, while broilers in group C, B and A spent 7.31, 6.28 and 6.18 min/hr for feeding behaviour during the initial period and in group C (5.51 min/hr) and D (5.44 min/hr) as compared to the groups A (4.49 min/hr) and B (4.39 min/hr) during final period. Broilers of group A and B spent significantly (P=0.0313) more time (13.10 and 13.00 min/hr) in standing, while groups C and D spent 8.95 and 8.50 min/hr during initial period. During the final period birds in group A spent significantly (P=0.003) more time (6.10 min/hr) than group B (5.08 min/hr) and group C (4.15 min/hr), while broilers in group D spent minimum time (4.11 min/hr) in standing. Broilers in groups D and C spent significantly (P=0.001) more time (43.61 and 41.00 min/hr) in lying and sleeping state, while the broilers in groups B and A were relatively in less lying and sleeping behaviour with 37.40 and 36.35 min/hr, respectively, during initial period. During final period, the broilers spent more time in the stale of lying sand sleeping as compared to the initial period. Aggression initiated by the broilers in groups A, B, C and D was 1.61, 1.45, 0.70 and 0.71 incidences/24 hrs/bird, respectively. The behaviour of aggression received/target of broiler housed in groups A, B, C and D was 0.64, 0.84, 2.11 and 2.31 incidences/24 hrs/bird respectively. Aggression reduced with the progress in age of the broilers. The flying behaviour in broilers for groups A, B, C and D was 0.33, 0.31, 0.10 and 0.00 incidences per bird over 24 hours time, respectively. The frequency of walking, dust bathing and. scratching behaviour reduced with the increase in the live body weight of broilers. Aggression instigator and target behaviors were 3.92, 3.56, 1.34 and 1.55 incidences/bird/24 hours, total aggression behaviors (instigator + target + avoidance) 5.62, 5.66, 4.83 and 3.95 incidences/bird/24 hours and flying + playing behaviors 1.43, 1.41, 0.40 and 0.44 incidences/bird/24 hours in groups A; B, C and D, respectively. The overall behaviors were 10.97, 10.63, 6.57 and 5.94 incidences/bird/24 hours, respectively. It was observed that the broilers of higher live body weight group D were more affected with breast blisters (4.35%), hock burn (4.35%), pododermatitis (4.34%), foot ulceration (2.17%), scales and hocks (10.87%) as compared to group A. The broilers in group C consumed average feed of 3.95 kg/bird in group C took 3.25 kg/bird feed during 42 days of rearing period. The broilers in group A consumed least amount of feed (3.00 kg/bird). Similarly, maximum water (9.49 lit/bird) was consumed by the broilers of group D compared to those broilers in group C, B or A. Significantly greater weight gain (2.213 kg/bird) was recorded in group D. Statistically, the differences between the live body weight of different groups were significant (P=0.019). In case of carcass quantity, it was noted that the carcass weight in groups A, B, C and D was 0.792, 0.966, 1.153 and 1.316 kg/bird, respectively. The results showed that significantly higher carcass weight (1.316 kg/bird) was recorded in group D. Dressing percentage, it was observed that dressing percentage in groups A, B, C and D was 58.45, 58.36, 59.11 and 59.48 kg/bird, respectively. Relatively higher dressing percentage (59.48%) was recorded in group D while the dressing percentage was slightly reduced in the Toilers less in weight (groups A, B and C). Feed conversion ratio was better (1.96) in group B, while in groups D and C produced feed conversion ratio of 2.04 and 2.03 which were well acceptable when compared with the feed conversion ratio of 2.22 recorded in group A. It was observed that broiler death rate was higher in group D where 4 birds were found dead out of 50. The number of died birds was lower in groups C, B and A where 2, 3 and 2 birds were died out of 50, respectively.