Effects of Dietary γ-Oils on the Composition of Tissue and Plasma Lipids in Swine
This study report that the gamma linolenic acid content of pork is higher in finishing pigs fed diets containing hemp seed oil, evening primrose oil or borage oil as the sources of gamma linolenic acid. Thirty six three crossing swines (Landrace×Yorkshire×Duroc), 80 kg of body weight, were randomly separated into four treatment groups with three pens per treatment and three animals per pen. The finishing swines were fed the experimental diets for 35 days until they reached the market weight of 110 kg. The animals were assigned to the four experimental diets: control diet containing 5.00% tallow, T1 containing 5.00% hemp seed oil(hemp seed oil 40 : soybean oil 60), T2 containing 5.00% evening primrose oil(primrose oil 40 : soybean oil 60), T3 containing 5.00% borage oil(borage oil 40 : soybean oil 60). The plasma triacylglycerol and total cholesterol content of the swine in the gamma fatty acids-fed groups were significantly(p<0.05) lower than those in the control group. No gamma linolenic acid was detected in the plasma of the control group, while the level of gamma linolenic acid treatment groups was significantly(p<0.05) higher than the control in the order of T3, T2 and T1. Moreover, the level of gamma linolenic acid increased with increasing number of feeding days. There was a significant difference between the treatment groups (p<0.05). There was a difference in the amount of saturated fatty acid and polyunsaturated fatty acid accumulated in the pork according to the treatment groups or the parts of the pork meat. The level of n-3 fatty acid of pork was highest in T1, which had been fed the hemp seed oil, followed in order by T3 and T2(p<0.05). The content of gamma linolenic acid in pork was highest in T3, which had been fed the borage oil, followed in order by T2 and T1(p<0.05). In particular, the level of gamma linolenic acid in pork increased in the order of the back fat, pork belly, ham and loin.