瘤胃保护共轭亚油酸和亚油酸对奶牛产奶性能的影响

Effects of rumen-protected conjugated linoleic acid and linoleic acid on milk yield in lactating cows

选择健康、泌乳月份与产奶量相近的多胎荷斯坦泌乳牛20头,随机分成5组,每组4头,研究日粮中添加商业来源的瘤胃保护共轭亚油酸钙盐(Ca-CLA)同时添加自然来源亚油酸(葵花油)对奶牛生产性能的影响。试验期为52d。对照组基础日粮为60%粗饲料(苜蓿、羊草、青贮)和40%精料(以DM为基础),处理组在对照组日粮基础上分别添加Ca-CLA100g/d·头(CLA)、葵花油350g/d·头(Sunf);Ca-CLA100g/d·头+葵花油350g/d·头(CLA+Sunf),Ca-CLA50g/d·头+葵花油175g/d·头(1/2CLA+1/2Sunf)。结果表明:在奶牛日粮中,单独添加自然来源亚油酸产奶量较对照组差异不显著(P>0.05),而单独添加共轭亚油酸钙盐或与自然来源亚油酸高低不同剂量添加产奶量较对照组都分别显著提高2.20%、9.95%、11.16%,无论单独添加自然来源亚油酸或Ca-CLA或二者以高低不同剂量同时添加,牛奶的乳脂率较对照组都分别显著降低15.0%,6.24%,21.74%,14.35%。总之,奶牛日粮中同时添加Ca-CLA和自然来源亚油酸能显著提高产奶量,降低乳脂率,并且,减少Ca-CLA的添加量同时添加自然来源亚油酸可以达到高剂量添加Ca-CLA相同的效果。

The experiment was conducted to study the effect of rumen-protected conjugated linoleic acid （Ca-CLA） from commercially available ＋ linoleic acid （sunflower oil） in diet on milk performance in dairy cow.Twenty muhiparous healthy Holstein cows with similar milk period and similar milk yield were randomly assigned to five treatments （4 cows per treatment） in 52 d trial.The control diet consisted of 60 % forage （corn silage,Chinese wildrye and alfalfa hay） and 40 % concentrate on a dry matter （DM） basis,fed as a total mixed ration （TMR）.The treatment groups were partially added in the control diet with 100 g/d Ca-CLA （CLA）,350 g/d sunflower oil （Sunf）,100 g/d Ca-CLA and 350 g/d sunflower oil （CLA plus Sunf） ,50 g/d Ca-CLA and 175g/d sunflower oil （1/2 CLA plus 1/2 Sunf）.In conclusion,milk yield did not .lifter between linoleic acid and control, however, milk yield were increased 2.20 % ,9.95 %, 11.16 % （P 〈 0.05） among Ca-CLA, Ca-CLA plus linoleic acid, 1/2 CLA ＋ 1/2 linoleic acid than that of control ; Milk fat percentage decreased 15.0 %,6.24 %,21.74 %, 14.35 %（P 〈 0.05） among Ca-CLA,linoleic acid, Ca-CLA plus linoleic acid, 1/2 CLA plus 1/2 linoleic acid.The combination of tinoleic acid with Ca-CLA was particularly effective at increasing milk yield and decreasing milk fat percentage.The effect of decreaseing Ca-CLA with adding linoleic acid was similar with adding higher Ca-CLA.