Van Oeckel M J, Casteels M, Warnants N, Boucqué C V
National Institute for Animal Nutrition, Government Agricultural Research Centre-Ghent, Melle-Gontrode, Belgium.
Arch Tierernahr. 1997;50(1):31-42. doi: 10.1080/17450399709386117.
The extent of incorporation of dietary alpha-linolenic acid -readily available in linseed- in pig diets, in view of repercussions on zootechnical performance, carcass and fat quality of pigs, is investigated. Ninety hybrid pigs (Piétrain x Seghers hybrid cross, 41 barrows and 49 gilts), divided in three comparable groups, were fed ad libitum three experimental diets, containing respectively 4 g, 7 g and 10 g alpha-linolenic acid per kg feed, originating from linseed. The increase of polyunsaturated fatty acid content in the feed (11.9 g, 15.2 g and 18.8 g per kg feed, resp.) could almost be completely attributed to the variation in alpha-linolenic acid. Despite several anti-nutritional factors, present in linseed, zootechnical performance was not affected by the diet. However, carcass quality, in terms of lean meat % and conformation, was less favourable for the highest linseed level compared to the intermediate level. Loin fat thickness was not influenced by the fat source in the diet. More pronounced was the effect of sex on zootechnical and carcass parameters: gilts showed a lower feed intake and weight gain, resulting in a more favourable feed conversion ratio, a thinner backfat layer, a higher meat content and a superior conformation, compared to the barrows. The linolenic acid content in the backfat increased from 3.1 g to 6.8 g per 100 g of total fatty acids for the barrows and from 3.4 g to 7.0 g per 100 g of total fatty acids for the gilts. A significant positive correlation was found between the live weight at slaughter and C16:0 and C18:0 content in the backfat; C18:2 and C20:4 content, on the contrary, were negatively correlated with the live weight at slaughter. A more unsaturated fatty acid pattern of the backfat, as a result of higher C18:3 levels in the feed, resulted in higher TBA-values (thiobarbituric acid), without occurrence, though, of off-odours during the fat thawing. Thus PUFA content in the backfat reached a maximum of respectively 18 g and 19 g per 100 g of total fatty acids for the barrows and the gilts, without implications for the consistency of the fat.
鉴于日粮中添加亚麻籽中易于获取的膳食α-亚麻酸对猪的饲养性能、胴体及脂肪品质的影响，对其在猪日粮中的添加量进行了研究。将90头杂交猪（皮特兰×西格尔斯杂交品种，41头公猪和49头母猪）分为三个可比组，自由采食三种试验日粮，每千克饲料分别含4克、7克和10克源自亚麻籽的α-亚麻酸。饲料中多不饱和脂肪酸含量的增加（分别为每千克饲料增加11.9克、15.2克和18.8克）几乎完全归因于α-亚麻酸含量的变化。尽管亚麻籽中存在多种抗营养因子，但日粮对饲养性能未产生影响。然而，就瘦肉率和胴体形态而言，与中等亚麻籽添加水平相比，最高亚麻籽添加水平组的胴体品质较差。日粮中的脂肪来源对猪腰荐部脂肪厚度没有影响。性别对饲养性能和胴体参数的影响更为显著：与公猪相比，母猪的采食量和体重增加较低，饲料转化率更优，背膘层更薄, 肉含量更高，胴体形态更佳。公猪背膘中亚麻酸含量从每100克总脂肪酸中的3.1克增加到6.8克，母猪则从每100克总脂肪酸中的3.4克增加到7.0克。屠宰时的活重与背膘中C16:0和C18:0的含量呈显著正相关；相反，C18:2和C20:4的含量与屠宰时的活重呈负相关。由于饲料中C18:3水平较高，背膘中脂肪酸模式的不饱和程度更高，导致硫代巴比妥酸（TBA）值升高，但脂肪解冻过程中未出现异味。因此，公猪和母猪背膘中多不饱和脂肪酸（PUFA）含量分别最高达到每100克总脂肪酸18克和19克，且对脂肪的稠度没有影响。
