Influence of early rearing conditions on the development of feather pecking and cannibalism in domestic fowl

Abstract

The influence of early rearing conditions on the development of feather pecking and cannibalism was investigated in 28 groups of 40 non beak-trimmed chicks (20 Lohmann Brown and 20 Lohmann Selected Leghorn). The chicks were reared on either sand and straw (10 sand groups), straw (10 straw groups), or wire (8 wire groups) between 0-4 weeks of age. From the fifth week of age, all groups were kept on sand and straw. At 18 weeks, all birds were moved to egg-laying facilities where they were kept on straw, 7 hens/m2 in the original rearing groups. The experiment finished when the birds were 45 weeks old. The plumage condition of all individuals was evaluated at 19, 33 and 45 weeks of age and observations were made of feather pecking activity when the birds were 5-6 and 40-41 weeks old. The plumage evaluations showed that birds reared on sand and straw during the first 4 weeks of life had significantly better plumage when they were 19 (P < 0.05), 33 (P < 0.001) and 45 weeks old (P < 0.001) than birds reared on straw or wire. Birds reared on straw had significantly better plumage than hens reared on wire when they were 19, 33 and 45 weeks old (P < 0.001). Birds reared on wire feather pecked more when they were 5-6 (P < 0.001) and 40-41 weeks old (P < 0.01) than sand and straw birds. Most feather pecking activity took place on the perches. At 5-6 and 40-41 weeks of age, dustbathing activity was lower in wire groups than in sand and straw groups (P < 0.05, P < 0.01). At 42 weeks of age, wire birds were more fearful in a TI (tonic immobility) test than sand and straw birds (P < 0.05). At the end of the experiment, the mean mortality rate was found to be significantly higher for groups of wire birds than for groups of sand and straw birds (P < 0.01). The higher mortality rate was mainly caused by cannibalism in the groups reared on wire and significantly more cannibalistic injuries were found during rearing in groups of wire birds (P < 0.01). Groups of wire birds laid significantly fewer eggs per hen-day both in trial 1 (P < 0.05) and trial 2 (P < 0.001) than sand and straw birds. The results demonstrate that the rearing conditions during the first 4 weeks of life have a major influence on the subsequent development of feather pecking in laying hens. If feather pecking develops early in life in groups of domestic chicks, feather pecking does not stop after the chicks are provided with sand and straw, and the behaviour results in bad plumage condition, increased mortality rates and decreased production.