Características de carcaça in vivo e in situ e proteômica do músculo Longissimus thoracis de ovinos Santa Inês e Somalis Brasileira terminados em sistema de Integração Lavoura Pecuária no semiárido do Nordeste do Brasil

• Ano de defesa: 2022
• Autor(a) principal: Batista, Nielyson Junio Marcos
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Palavras-chave em Português: Biomarcadores; Ovinos; Proteômica
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/65359

Sheep farming is an important livestock activity in Northeast Brazil, as it generates income and contributes to social development, particularly for small and medium-sized producers. In sheep farming, among the stages of the production system, the finishing of lambs, has been widely discussed and studied in recent years, due to the high demand for better quality products to meet the consumer market. In this sense, present study evaluates the meat quality of Santa Inês and Brazilian Somalis lambs finished in an Integrated Crop Livestock system through in vivo evaluation, in the carcass and by proteomic approach. For this, 28 lambs (14 Santa Inês and 14 Brazilian Somalis), not castrated, with initial average body weight (18 ± 3 kg) and approximately 120 days of age, were used in a completely randomized design.The animals were identified and kept in one hectare of an area defined as a Crop Livestock Integration system. This area contained corn (Zea mays) plants and two forage species, massai grass [Megathyrsus maximus cv. massai (Sin. Panicum maximum)] and “cunhã” (Clitorea ternatea). Animals were allowed free grazing in that area during the experiment and daily supplemented (2% of body weight) with concentrate (73% corn, 23% soybean meal, 1.2% mineral core, 1% sodium chloride, 1% urea and 0.8%). The duration of the experiment was determined by the time required for the average body weight of one of the experimental groups to reach 28 kg, at which time all animals were slaughtered. After slaughter, carcass analyzes were carried out. Also, shortly after slaughter, 20 samples of Longissimus thoracis muscle were collected and stored until the time of proteomic analysis, by means of two-dimensional electrophoresis and mass spectrometry. The highest carcass yields (P<0.05) were observed in Brazilian Somalis lambs (44.60%) compared to the Santa Inês breed (42.23%), which on the other hand showed higher (P<0.05) weight loss on cooling (1.24%). Regarding meat cuts, the highest (P<0.05) neck yield (7.47%) was observed in Santa Inês lambs, while the highest (P<0.05) hind loin yield (6.89%), ribs (7.96%) and flank steak (4.83%) in Brazilian Somalis. The analysis of tissue composition indicated a higher (P<0.05) proportion of muscle tissue (67.64%) and bone tissue (20.75%) in Santa Inês breed, but a higher (P<0.05) percentage of fat (22.97%) in Brazilian Somali. In Pearson's correlation analysis, a high correlation was observed between the loin eye area measured in the carcass and by ultrasonography (0.81) and between the subcutaneous fat thickness in the carcass and by ultrasonography, a moderate correlation between hot carcass weight and loin eye area in the carcass (0.56) and by ultrasonography (0.55), the hot carcass yield and the carcass compactness index (0.67) and subcutaneous fat thickness in the carcass (0.56). About proteomic analysis on average, 202 ± 15 and 212 ± 12 spots were detected in the 2-D gels with LT muscle proteins from Brazilian Somalis and Santa Inês lambs, respectively. The spots present in the master gel correspond to the spots detected in the reference gels and spots added from other match sets. A total of 126 spots in the Brazilian Somalis and 123 spots in the Santa Inês gel were identified by mass spectrometry, corresponding to 39 and 51 different proteins, respectively. Structural proteins present in two abundances in the protein map of the races. Proteins associated with energy metabolism, cellular organization and acting on oxidative stress were also identified in both races. Therefore, the analysis of the in vivo characteristics and the measurements on the carcass resulted in the identification of carcass yields, meat cuts, muscularity indices and subcutaneous fat coverage interesting for understanding the efficiency of the production system adopted in the finishing of lambs., in addition, the analysis of the hour sample of Longissimus thoracis by 2-D SDS-A PAGE/MS resulted in contracted chemical and biological properties from the identification of MS/MS with a chemical quality event. Results of the present open new perspectives for the future of research focused on the evaluation of meat from hairless lambs raised in tropical regions.