This study examines poultry production stocking density (SD) effect on bird welfare and economic performance. It is based on a large dataset from commercial production including observations for 2.2 million male broilers and 2.3 million female broilers from 37 production sites, with SD ranging from 20.63 kg/m2 to 41.15 kg/m2. The data collection was originally motivated by a processor’s economic concerns that increasing SD could cause slower broiler growth, higher condemnations, and lower grade meat. The data was examined using several linear regressions to determine how production parameters impacted these performance indicators. Results regarding foot pad lesion, condemnations, and mortality rates are consistent with those found in the literature. However, we find that daily weight gain is positively associated with SD, contrasting with past experimental results. The difference between the scope of commercial and experimental productions is discussed as a possible reason for these conflicting results.

The goal of this study was to evaluate the impact of winter rearing environment on the growth performance and meat quality of heavy lambs. Half of sixty-four Dorset lambs (32 males and 32 females) were raised in each of two different environments: warm and cold with average temperature of 10.9 ± 0.7 °C and -2.0 ± 5.2 °C, respectively. The lambs were slaughtered at live weights of 41-45 kg for females and 46-50 kg for males. Cold environment had no adverse effect on either growth performance or carcass quality. The rate of longissimus dorsi muscle deposition (P = 0.049) and its depth at slaughter (P = 0.027) were rather greater in lambs reared in the cold environment and a higher proportion of oxido-glycolytic fibres (P = 0.047) was also observed in this muscle. Rearing environment had only a minor effect on the organoleptic qualities, with the cold environment promoting juiciness of the meat (P = 0.043). Therefore, cold environment rearing such as used in this study represents an economic advantage for lamb producers by reducing the costs associated with the construction of insulated barns, while maintaining growth performance, as well as carcass and meat quality. Key words: Lamb, rearing environment, temperature, growth, carcass, meat quality

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