Carcass quality is one of the main parameters to evaluate broiler welfare, and the presence of back scratches indicates that the birds were submitted to stress. The objective of this study was to identify the best management practices during rearing and catching, taking into consideration broiler genetic differences (genetic lines A and B) and sexes. The survey was carried out in 351 broiler houses belonging to an integrated company and located in the region of Dourados, MS, Brazil. Between January and October, 2010, 2% of broilers of all ages (one to 43 days old) in all flocks were sampled. The sampled flock was evaluated in 21 d intervals. Scratches were classified as present or absent. The results indicated that catching management has the strongest influence on back scratches (73%), followed by rearing management (17%) and equipment management (10%). In general, strain A females presented the lowest probability of presenting scratches after weighing, equipment management, and catching. It was concluded that, although rearing and equipment management practices affected the presence of scratches, catching caused the highest percentage of lesions in birds of both strains, and therefore, it is considered critical. Broilers from distinct that genetic strains reacted differently to management practices due to their temperament and growth rate. Therefore, broilers should be housed according to genetic strain due to their different temperaments.

This study aimed at evaluating the influence of genetic strain, sex, and season on the incidence of back scratches during the rearing period. Male and female broilers of two genetic strains reared during the hot or cold season were evaluated. This meta-analysis included 894 samplings in 351 broiler houses of contracted farms located in the state of Mato Grosso do Sul, Brazil, in 2010. Broilers of all ages (1 to 43 days) were sampled, capturing 2% of the birds in the house at each sampling. Each flock was evaluated twice, in 21-day intervals. Broilers were reared as single-sex flocks; there were no straight-run flocks. Scratch lesions were classified as present or absent. Strain A broilers presented lower scratch rates (p < 0.05) than strain B birds. During the starter period (1 a 21 days), males presented higher scratch rates (p < 0.05) than females, and the incidence of these lesions was lower during the hot season compared with the cold season. It was concluded that different management practices can be adopted to minimize back scratches in broilers of different sexes and strains during hot and cold seasons, such as reducing weight control frequency and the period of chick containment in brooder circles