Effects of level of inclusion of copra meal in balanced diets supplemented with synthetic amino acids on growth and fat deposition and composition in growing pigs fed ad libitum at a constant temperature of 25 °C

Abstract

Pigs, 32 male and 32 female housed at a constant temperature of 25 °C were fed, ad libitum over the liveweight range 25–55 kg, diets containing 0, 100, 200 and 300 g kg −1 of copra meal which were balanced for their essential amino acid compositions. Inclusion of 100 g kg −1 copra meal resulted in slightly poorer growth rates compared with the control diet, but no further deterioration was observed up to 300 g kg −1 ( P = 0.044). Increasing copra meal content of the diet was associated with a progressive reduction ( P = 0.017) in the voluntary feed intakes of the animals, although feed conversion ratio was unaffected by dietary treatment. With increasing inclusion of copra meal, backfat thickness decreased at points P 2 ( P = 0.018) and P 1 + P 3 ( P = 0.017). Increasing level of inclusion of copra meal was associated with increases ( P < 0.001) in levels of lauric acid (C12:0) and myristic acid (C14:0) and decreases ( P < 0.001) in stearic acid (C18:0) and linoleic acid (C18:2) in the bsckfat. Thsse changes reflected, to varying degrees, changes in the fatty acid composition of the dietary oil as the proportion of coconut oil in the diet was increased.