Effects of administration of three different by-pass lipids on growth performance, rumen activity and feeding behaviour of beef cattle

A study was carried out on beef cattle to compare three different by-pass lipids administration in relation to their intake, performance, bunk behaviour and rumen fermentation characteristics. Ninety-six Charolaise males were subdivided into three groups. Each group was fed a specific diet including differentiated sources of rumen by-pass fats. The first group received 500 g/head/day of calcium salts (CaS), the second and the third received 420 g/head/day of hydrogenated fatty acids (HF) and triglycerides (AL), respectively. The three by-pass fats differ in fatty acids composition, chain length and mean particle size. AL group had average daily gain significantly greater (P=0.0005) than animals fed calcium soaps. No difference was observed between AL and HF groups (P=0.08) and between HF and CaS groups. Final body weights of AL animals were significantly higher (P=0.005) than CaS group. There were no differences between AL group and HF group and between HF group and CaS group. Average dry matter intake (DMI) was higher (P<0.05) in AL and HF groups compared with CaS group. Feed conversion rate was better for AL and CaS groups (P<0.05) compared with HF group. Evaluating their behaviours in approaching feed, the animals seemed to prefer hydrogenated fats flavour as regard to calcium soaps. No differences were highlighted in ruminal pH and ruminal volatile fatty acids composition among the three groups. When high dosage of fat is included into a beef cattle diet, the administration of hydrogenated triglycerides, characterized by a pleasant flavour and a small mean particle size, is likely to be more suitable than adding calcium soaps or hydrogenated free fatty acids, probably thanks to its higher DMI and feed conversion rate, respectively. With regard to the latter higher rate, it could be only supposed that it is related to the smaller mean particle size of hydrogenated triglycerides.