Effect of Replacing Soybean Meal with Cottonseed Meal or Rapeseed Meal on Growth Performance, Meat Quality, and Metabolome of Raw and Cooked Meat in Finishing Lambs

Objectives: To evaluate the effects of replacing soybean meal (SBM) with rapeseed meal (RSM) or cottonseed meal (CSM) in finishing lamb diets on meat, untargeted metabolomics were used to explore underlying mechanisms of metabolites related to Volatile Organic Compounds (VOCs) between raw and cooked meat. Methods: Twenty-four lambs were fed isocaloric and isonitrogenous diets for 90 days and longissimus thoracic (LT) meat was sampled for quality evaluation. Results: Results showed that growth performance and most traits of meat were unaffected, including feed intake, average daily growth, pH, cooking loss, shear force, most color values, and fatty acids. However, the yellowness (b*) in RSM and CSM meat, as well as Met and Tyr in CSM meat, were increased. Muscle metabolomics identified five different metabolite-associated flavor precursors that varied, including galactose, L-pyrdosine, and 13-octadecenoic acid. In total, 223 VOCs detected in cooked meat showed no major differences among diets. Key flavor compounds, including 1-octen-3-ol and lipid-derived aldehydes, were consistent across treatments. Conclusions: In conclusion, RSM and CSM are viable SBM alternatives, changes in raw meat metabolites do not alter the volatile compounds of cooked meat.