The effects of cereal or by-product based finishing pig diets on growth performance and fatty acid profile of carcass fat

Three experimental diets were formulated to contain 210 g of crude protein, 11 g of lysine and 13.7 MJ of digestible energy per kilogram fresh weight, Diet 1 contained 700 g of cereals per kilogram fresh weight, which include d maize, and the main protein sources were fish meal and soya bean meal, Di et 2 also contained 700 g of cereals per kilogram fresh weight but maize an d fish meal were removed from the formulation, Diet 3 contained 300 g of ce reals per kilogram fresh weight and the remainder of the formulation contai ned soya bean meal and a range of by-products. Two-hundred and forty It-wee k-old crossbred pigs were randomly allocated, in groups of 8, to the three experimental treatments, balanced for gender and weight, Growth performance over the finishing period was recorded and at slaughter, fat samples were obtained and fatty acid profiles were determined. Production performance of pigs offered Diets 1 and 2 was not significantly different indicating that maize and fish meal may be removed from diets for finishing pigs, Pigs off ered the cereal-based diets (Diets 1 and 2) had a higher kill-out proportio n (P < 0.01) and a better feed:carcass gain (P < 0.05) than pigs on Diet 3, Offering the by-product diet had no significant effect on the composition of the lean tissue in a sample joint but did increase the degree of unsatur ation (P < 0.001) of both subcutaneous and intramuscular fat.