Utilization of fat and fatty acids and energetic feed value (AME(N), TMEN)of several fat types for laying hens

The aim of the present study was to evaluate the fat and fatty acid utiliza tion as well as the energetic feed value of palm oil, coconut oil, peanut o il, olive oil, beef tallow, soybean oil, safflower oil and beef tallow-soyb ean oil blend (50:50) for laying hens. Balance experiments were performed with Lohmann Brown laying hybrids (26.-3 6. week of age) according to a multi-level assay which consisted of testing a low-fat diet (0.32% crude fat) alone and of the low-fat diet successivel y substituted by the fat type under test (50, 100 and 150 g.kg(-1)). Results of the balance studies were regressively evaluated to yield both ap parent and true utilization values of the different fat types. AMEN-content s (MJ.kg(-1)), apparent utilization (%) of crude fat and total fatty acids of palm oil, coconut oil, peanut oil, olive oil, beef tallow, soybean oil, safflower oil and beef tallow-soybean oil blend (50:50) were: 20.0, 55.4, 6 7.0; 32.1, 87.5, 89.3; 38.1, 92.7, 96.0; 36.3, 94.2, 96.7; 28.4, 70.7, 75.7 ; 35.6, 93.8, 95.6, 38.0, 95.7, 97.5 and 32.2, 84.8, 87.8; respectively. True utilization of fat and fatty acids as well as TME-values were only sli ghtly higher than the corresponding apparent figures. Endogenous fat losses were estimated to be in a range between 2.1 g.kg(-1) and 5.5 g.kg(-1) diet corresponding to 136 mg.d(-)1.W-0.75 and 356 mg.d(-1) .W-0.75.