The nutritive value of fat in the diet of the milk-fed lamb

Abstract

1. Thirty-five male cross-bred lambs at 3 d of age were given artificial milks with a protein- calorie concentration of 25 % and containing either lard, coconut fat, cottonseed oil, rapeseed oil, groundnut oil, soya-bean oil, safflower oil, tallow, maize oil or olive oil, homogenized with reconstituted skimmed cow's milk to provide 50 yo of the total energy of the diet. Two lambs were given a low-fat diet of reconstituted dried skim milk. All lambs were bottle-fed for 28 d.2. The dietary fats and oils were highly digestible (97.2–99.5 %) with the exception of lard (89.1 %), rapeseed oil (61.9 %) and tallow (77.8 %). The indigestibility of these dietary fats was related to their content of stearic or erucic acids. The fatty acid patterns of the faecal fat were similar within each dietary group, but differed between diets.3. Metabolic faecal fat excretion was 4.1 k0.5 g/100 g faecal dry matter. There was no similarity between the fatty acid composition of the metabolic faecal fat and that of the faecal lipids excreted by lambs given fat in their diet. The metabolic faecal fat made only a minor contribution to the total faecal lipids, so that the apparent and ‘ corrected’ digestibility coeffi-cients were very similar.