Comparative evaluation of rumen-protected fat, coconut oil and various oilseeds supplemented to fattening bulls. 1. Effects on growth, carcass and meat quality.

Growth performance, carcass and meat quality were determined in 36 fattening Brown Swiss bulls fed with maize silage-hay-concentrate based rations supplemented with fats and various oilseeds. The concentrate diet in the control group contained only barley and soybean meal, while the treated groups included, as partial replacement of the concentrate, rumen-protected crystalline fat, coconut oil, whole crushed rapeseed, sunflower seed or linseed, providing additional 3% fat of total ration dry matter. Animals were housed in groups of six with one representative of each treatment in a monofactorial design and feed was offered using transponder controlled equipment. Daily gains were similar for control, protected fat, rapeseed and linseed treatments (1240 g/d on average), but were lower (P < 0.05) with sunflower seed (1135 g/d) and coconut oil (1038 g/d). Corresponding differences (P < 0.05) in carcass weights were observed. All fat supplemented groups had reduced rumen fluid protozoa counts (P < 0.05). Carcasses tended to be leaner with the fat supplements. Mostly no significant effects on other carcass quality (dressing percentage, conformation score) and meat quality traits (final pH, cooking loss, shear forces) as well as composition (dry matter, fat, collagen) occurred. Consequently, rumen protected fat and some oilseeds can be recommended to be fed to growing cattle as energy sources.