ResumoO objetivo foi analisar modelos não lineares para descrever o crescimento de cordeiros criados em três Sistemas de produção. Os modelos utilizados forram: Brody, Von Bertalanffy, Richards e Gompertz. No Sistema de produção 1 utilizaram-se cordeiros alimentados em "creep-feeding", desmamados aos 60 dias de idade e mantidos em pastagem cultivada até atingirem media de 20 kg, quando foram confinados, e abatidos entre 28 e 30 kg. No Sistema de produção 2 utilizaram-se cordeiros desmamados aos 90 dias e mantidos em pastagem cultivada, sendo abatidos entre 28 e 30 kg. No Sistema de produção 3 utilizaram-se cordeiros desmamados com 90 dias de idade e mantidos em área de pastagem nativa suplementados com feno de capim elefante e de leucena no período crítico do ano e abatidos aos 28 e 30 kg. Foram utilizadas 17 pesagens de 30 animais, sendo 10 animais para cada Sistema, do nascimento aos 450 dias. Com base no estudo das curvas de crescimento, as que melhor se adaptaram para predição dos resultados de crescimento foram as de Richards e Brody, entretanto nenhum dos modelos de curva simulados apresentou resultados satisfatórios para o Sistema de produção 3. Palavras-chave: Desempenho, produção, "creep-feeding", pastagem cultivada, pastagem nativa, manejo AbstractThe objective was to analyze nonlinear models to describe growth of lambs in three production systems. The models used were: Brody, Von Bertalanffy, Gompertz and Richards. In a 1 production system was used lambs in "creep feeding", weaned at 60 days old and kept on pasture until they reach average 20 kg, when they were confined, slaughtered between 28 and 30 kg. In the 2 production system, lambs weaned at 90 days and kept on cultivated pasture and slaughtered between 28 and 30 kg, were used. In 3 Production System, lambs weaned at 90 days old and kept in an area of native pasture supplemented with elephant grass and leucena, in the critical period of the year and slaughtered at 28 to 30 kg were used. 17 weights of 30 animals, 10 animals for each system, from birth to 450 days, were used. Based on the study of the growth curves that are best adapted to predict the results of growth were those of Richards and Brody models, however none of the models simulated curve showed satisfactory results for the three production systems.

<p>This study was conducted to evaluate the <em>in vivo </em>and carcass characteristics of goats and sheep sold for slaughter, which originated from different regions of Ceará State, Brazil. Thirty-six (36) mixed-breed, uncastrated male animals (18 goats and 18 sheep), acquired from street markets, which were raised in an extensive production system from the regions of Quixadá, Sobral, and Tauá, were used in this experiment. Before slaughter, the animals were weighed, and body measurements were taken and the body condition score was assessed. Post-slaughter, the carcasses were weighed, morphometric measurements were obtained, and the commercial cuts were weighed and their yields were calculated. The mean <em>in vivo </em>body weight was 23.83 ± 3.76 kg for the goats and 25.22 ± 5.25 kg for the sheep; the body condition score was close to 2, and the mean age was 12 months, with no differences between the species. No differences were found between species and origin for the weights and yields of carcass or for chilling loss. The carcass conformation values were considered poor, and the fat cover was classified as too lean, with the goat carcasses considered superior to the sheep carcasses in these respects. The sheep had higher values for loin-eye area, subcutaneous fat thickness, and weight and proportion of leg than the goats. Mixed-breed goats and sheep reared in extensive systems in Ceará State and sold in street markets in the capital, irrespective of their origin, reach their slaughter weight at an advanced age and with a lean body condition, resulting in carcasses of a low quality, with a low muscle content and poor fat cover. In the extensive conditions of the state of Ceará, animals of the ovine species have a greater ability for meat production than caprine species.</p>

<p>This study was conducted to evaluate the <em>in vivo </em>and carcass characteristics of goats and sheep sold for slaughter, which originated from different regions of Ceará State, Brazil. Thirty-six (36) mixed-breed, uncastrated male animals (18 goats and 18 sheep), acquired from street markets, which were raised in an extensive production system from the regions of Quixadá, Sobral, and Tauá, were used in this experiment. Before slaughter, the animals were weighed, and body measurements were taken and the body condition score was assessed. Post-slaughter, the carcasses were weighed, morphometric measurements were obtained, and the commercial cuts were weighed and their yields were calculated. The mean <em>in vivo </em>body weight was 23.83 ± 3.76 kg for the goats and 25.22 ± 5.25 kg for the sheep; the body condition score was close to 2, and the mean age was 12 months, with no differences between the species. No differences were found between species and origin for the weights and yields of carcass or for chilling loss. The carcass conformation values were considered poor, and the fat cover was classified as too lean, with the goat carcasses considered superior to the sheep carcasses in these respects. The sheep had higher values for loin-eye area, subcutaneous fat thickness, and weight and proportion of leg than the goats. Mixed-breed goats and sheep reared in extensive systems in Ceará State and sold in street markets in the capital, irrespective of their origin, reach their slaughter weight at an advanced age and with a lean body condition, resulting in carcasses of a low quality, with a low muscle content and poor fat cover. In the extensive conditions of the state of Ceará, animals of the ovine species have a greater ability for meat production than caprine species.</p>