Muma E, Palander S, Näsi M, Pfeiffer A M, Keller T, Griinari J M
Department of Animal Science, University of Helsinki, Helsinki, Finland.
Poult Sci. 2006 Apr;85(4):712-20. doi: 10.1093/ps/85.4.712.
The main objective of the present study was to determine the minimum level of dietary plant oil supplementation that results in full recovery from loss of hatchability induced by conjugated linoleic acid (CLA). Another objective was to define the changes in egg yolk fatty acid composition associated with the loss and recovery of hatchability. Shaver hens were assigned to groups of 8 and were fed a diet containing either no CLA plus 0.5% soybean oil (control) or 0.5% CLA (1:1 mixture of cis-9, trans-11 and trans-10, cis-12 CLA) plus 0, 2, 4, 6, or 8% soybean oil for 15 d. Supplementation with CLA (CLA plus 0% soybean oil) resulted in complete loss of hatchability of fertile eggs. Hatchability was progressively improved by increasing doses of soybean oil, and full recovery of hatchability compared with the control levels was achieved at 6% soybean oil. There was no further improvement in hatchability when 8% soybean oil was added to the CLA-supplemented diet. Loss of hatchability was associated with a 2- to 3-fold decrease in desaturase ratios (cis-9 C16:1/C16:0 and cis-9 C18:1/C18:0) in the egg yolk total lipids, indicating marked inhibition of delta-9 desaturase in the chicken liver. In addition, the concentration of arachidonic acid was observed to decrease. Recovery of hatchability was associated with an increased proportion of linoleic acid and linolenic acid in the egg yolk. However, there was no change in desaturase ratios, suggesting that delta-9 desaturase inhibition persisted. Increased incorporation of dietary linoleic and linolenic acids might have compensated for the reduced levels of palmitoleic and oleic acid, thus allowing for the improvement in hatchability.
本研究的主要目的是确定膳食中补充植物油的最低水平，该水平能使因共轭亚油酸（CLA）导致的孵化率损失完全恢复。另一个目的是确定与孵化率损失和恢复相关的蛋黄脂肪酸组成的变化。将海兰母鸡分成每组8只，分别饲喂不含CLA加0.5%大豆油的日粮（对照组）或0.5%CLA（顺-9，反-11和顺-10，反-12 CLA的1:1混合物）加0、2、4、6或8%大豆油的日粮，持续15天。补充CLA（CLA加0%大豆油）导致可育蛋孵化率完全丧失。随着大豆油添加量的增加，孵化率逐渐提高，添加6%大豆油时孵化率与对照水平相比完全恢复。在添加CLA的日粮中添加8%大豆油时，孵化率没有进一步提高。孵化率丧失与蛋黄总脂质中去饱和酶比率（顺-9 C16:1/C16:0和顺-9 C18:1/C18:0）降低2至3倍有关，表明鸡肝脏中δ-9去饱和酶受到明显抑制。此外，还观察到花生四烯酸浓度降低。孵化率的恢复与蛋黄中亚油酸和亚麻酸比例增加有关。然而，去饱和酶比率没有变化，表明δ-9去饱和酶抑制持续存在。日粮中亚油酸和亚麻酸掺入量增加可能补偿了棕榈油酸和油酸水平的降低，从而使孵化率得到改善。
