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The use of lambs from crossing of local with specialized sheep breeds for meat production may lead to higher meat deposition and a smaller fat amount in the carcass, with a more adequate nutritional profile for human consumption. This study investigated the performance, carcass and meat characteristics of lambs from the Morada Nova and Santa Inês locally adapted hair breeds and crosses between Dorper × Morada Nova and Dorper × Santa Inês slaughtered at approximately 35 kg. Morada Nova lambs showed lower (p < 0.05) performance compared to the other genetic groups resulting in a higher age at slaughter (p < 0.05). Crossbred Dorper × Santa Inês and Dorper × Morada Nova lambs showed better characteristics for meat production with better (p < 0.05) conformation as well as leg and carcass compacteness index. Dorper × Santa Inês have a fatty acid profile that is more suitable for human consumption than Dorper × Morada Nova lambs do (p < 0.05); however, both had lower (p < 0.05) intramuscular lipid content (as measured by ether extract levels from Longíssimus lumborum) compared with purebred lambs. Therefore, when the objective is to obtain lean meat, with improved nutritional profile to reduce risks of cardiovascular disease, the use of breeds and crosses that reduce animal slaughter age, such as the ½ Dorper × ½ Santa Inês crossbred, is an interesting alternative.

The replacement of diet soybean meal protein with crambe cake protein (0%, 22%, 44% and 66%) was investigated to evaluate the effect on lamb performance and meat quality, as well as the extent to which erucic acid was incorporated into the meat. The inclusion of increasing levels of crambe cake resulted in poorer lamb performance, as demonstrated by a linear decrease in final liveweight and carcass weight. There was also an increase in plasma blood concentrations of aspartate transaminase and alanine transaminase, indicating hepatic injury. Reduced ether extract concentration of meat was observed, leading to higher shear-force values and a linear decrease in meat luminosity. The fatty acid profile of meat was drastically modified, presenting a reduction in total saturated and polyunsaturated fatty acid concentrations, particularly in the concentration of α-linoleic acid. Additionally, the total monounsaturated fatty acid concentration in meat decreased, while the concentration of erucic acid increased from 0.11% of total fatty acids in Longissimus lumborum samples from lambs fed diets with no inclusion of crambe cake, to 3.70%, 5.82% and 8.04% of total fatty acids in those from lambs fed diets where 22%, 44% and 66%, respectively, of the soybean meal protein was replaced with crambe cake protein. Therefore, the concentration of erucic acid in fatty acid profile of meat was higher than concentration deemed safe for human consumption.