The influence of compound feed enrichment with rapeseed and linseed cake on the meat characteristics and fatty acids composition of beef bulls

Abstract

The trial was conducted with Lithuanian Black-and-White bulls of 10 to 16 months age. The bulls were divided into analogous groups according to their origin, age and weight. During the trial the bulls in both groups were offered the same amount of maize silage, clover-oat-pea mixture silage and compound feed, the only difference being the composition of compound feeds. The aim of the study was to investigate the effects of compound feeds containing rapeseed and linseed cake and different amounts of n-6 and n-3 fatty acids on the fatty acid pattern in the longest muscle of the back (Musculus longissimus dorsi) meat of Lithuanian Black-and-White fattening bulls. Fatty acids n-6:n-3 ratio in rapeseed cake was 2.75, and that in linseed cake 0.25. More favourable ratio in linseed cake was determined by higher content of linolenic acid (C18:3n-3). Different feeding of bulls as regards rapeseed and linseed cake, fatty acid content and n-6:n-3 ratio had no significant influence on the weight of bulls prior to slaughter, carcass weight and yield, lean meat content and fatness grades. According to the SEUROP carcass classification system, the carcasses in both groups of bulls met the requirements for lean meat content O and fatness 2 grades. The study indicated that ground beef contained 49.93% higher (P < 0.05) content of linolenic acid (C18:3n-3) when the animals were fed compound feed with linseed cake and, therefore, higher n-6:n-3 ratio was influenced by a higher content of this acid in the feed. The study also indicated that total n-3 fatty acid content was 1.3 times greater and n-6 to n-3 fatty acid ratio was found 1.5 times lower (P < 0.05) in M. longissimus dorsi when feeding bulls linseed cake.