Effects of Dietary γ-Fatty Acids on the Fatty Acid Composition of Pork and Plasma Lipids in Swine

We 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 ($Landrace{\times}Yorkshire{\times}Duroc$), 80 kg in 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) and 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 tile 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.

감마지방산의 급여가 돼지의 혈액지질 및 고기부위별 지방산조성에 미치는 영향

본 연구는 우지를 대조구로 하는 사료와 대두유와 함께 삼씨유, 달맞이꽃 종자유 및 서양자초유를 혼합한 시험사료를 섭취한 비육말기 돼지에서 혈액지질 및 돈육의 부위별 감마지방산 함량을 조사하였다. 생체 중 80 kg의 3원 교잡종($Landrace{\times}Yorkshire{\times}Duroc$) 비육말기 돼지 36마리를 이용해서 시판체중인 110 kg 도달 시까지 35일 동안 시험사료를 급여하였다. 실험설계는 4처리$\times$3반복(반복당 3두)으로 완전임의 배치하였고, 4개의 실험처리구는 대조구(우지), T1(삼씨유 40:대두유 60), T2(달맞이꽃 종자유40:대두유 60) 그리고 T3(서양자초유 40:대두유 60)로 구분하였다. 돼지의 혈액 중성지방과 총콜레스테롤 함량은 실험사료 급여 일수가 지남에 따라서 우지를 섭취한 대조구가 증가한 반면에 감마지방산 급원을 섭취한 처리구는 유의적인 감소경향을 나타내었다(p<0.05). 혈액 내 감마리놀렌산 함량은 대조구의 경우 검출되지 않았으나 감마지방산 처리구의 경우 실험사료 급여일수가 지남에 따라서 T3, T2, T1순으로 증가경향을 나타냈으며 각 일자별로 측정된 각 처리구별 값은 처리구간 통계적인 유의차가 있었다(p<0.05). 돈육의 포화지방산과 고도불포화지방산 함량은 각 처리구별 그리고 부위별 차이가 있었으며, 돈육의 부위별 n-3지방산 함량은 삼씨유를 섭취한 T1이 가장 높았고 T3, T2 순으로 유의적인 증가경향을 나타냈다(p<0.05). 감마리놀렌산의 함량은 모든 부위에서 서양자초유를 섭취한 T3가 가장 높았으며 T2, T1 순으로 유의적인 증가경향을 나타내었다(p<0.05). 특히, 돈육의 부위별로 축적된 감마리놀렌산의 함량은 등지방, 삼겹살, 햄, 등심 순서로 높은 경향을 보여주었다.