饲喂不同消化能和粗蛋白质水平的饲粮对泌乳前期伊犁母马泌乳性能及马驹生长发育的影响

Effects of Feeding Different Levels of Digestible Energy and Crude Protein Diets on Milk Performance of Yili Mares during Early Lactation Period and Growth Development of Foals

本试验旨在研究饲喂不同消化能(DE)、粗蛋白质(CP)水平的饲粮对泌乳前期伊犁母马泌乳性能、乳成分及马驹生长发育和血浆生化指标的影响,为进一步探讨泌乳期伊犁母马能量和蛋白质的需要量提供参考依据。选取无亲缘关系,年龄、体重、胎次相近且处于泌乳前期的伊犁母马25匹,根据母马体重分成5组,每组5匹。试验期为60 d,分为2个泌乳月,每30 d为1个泌乳月。母马第1泌乳月DE、CP饲喂水平分别为101.41 M J/d、1.38 kg/d(Ⅰ组),112.05 M J/d、1.50 kg/d(Ⅱ组),122.40 M J/d、1.63 kg/d(Ⅲ组),133.27 M J/d、1.75 kg/d(Ⅳ组),143.84 MJ/d、1.87 kg/d(Ⅴ组);第2泌乳月DE、CP饲喂水平分别为129.73 MJ/d、1.82 kg/d(Ⅰ组),140.37 M J/d、1.94 kg/d(Ⅱ组),150.72 M J/d、2.07 kg/d(Ⅲ组),161.60 M J/d、2.19 kg/d(Ⅳ组),172.17 M J/d、2.31 kg/d(Ⅴ组)。每个泌乳月的第1~14天为预试期,最后10 d为采样期。结果显示:饲喂不同DE和CP水平的饲粮对泌乳前期伊犁母马的产奶量、常规乳成分和乳体细胞数无显著影响(P>0.05)。乳脂中饱和脂肪酸含量各组间均无显著差异(P>0.05),Ⅱ、Ⅳ组不饱和脂肪酸含量显著高于Ⅰ组(P<0.05),单不饱和脂肪酸含量各组间差异均不显著(P>0.05),多不饱和脂肪酸含量Ⅰ组显著低于饲粮Ⅱ、Ⅳ、Ⅴ组(P<0.05)。增加饲粮DE和CP水平后,乳脂中棕榈酸(C16∶0)、棕榈油酸(C16∶1)和亚油酸(C18∶2n6c)含量发生显著变化(P<0.05),其中棕榈酸和棕榈油酸的含量Ⅰ组显著高于其他组(P<0.05),亚油酸的含量Ⅰ组显著低于Ⅱ、Ⅳ和Ⅴ组(P<0.05)。伊犁母马泌乳前期饲喂不同DE、CP水平的饲粮对马驹体重、体长、胸围、管围均无显著影响(P>0.05),但马驹的体高表现为Ⅰ组显著高于Ⅱ、Ⅲ组(P<0.05)。马驹的血浆生理生化指标显示,各组间血浆甘油三酯、总蛋白、白蛋白、尿素氮含量差异均不显著(P>0.05)。由此可见,在第1和第2泌乳月,DE饲喂水平分别为101.41和129.73 M J/d、CP饲喂水平分别为1.38和1.82 kg/d时已能满足伊犁马泌乳的营养需要,增加饲粮DE和CP水平可降低马乳中棕榈酸和棕榈油酸的含量,提高亚油酸的含量。

The objective of this study was to evaluate the effects of feeding different levels of digestible energy(DE)and crude protein(CP)diets on milk performance and fatty acid composition in milk fat of Yili mares during early lactation period,and growth development and plasma physiological-biochemical indexes of foals,in order to provide references for further understand the requirements of energy and protein for Yili mares during lactation period.Twenty-five Yili mares in early lactation with similar age,body weight and parity and without genetic relationship were selected,and divided into five groups according to body weight of mares with five mares per group.The trial lasted for 60 days which divided into two lactation months,and every 30 days for a lactation month.In the 1st month of lactation,the DE and CP feeding levels of mares of the five groups were 101.41 MJ/d and 1.38 kg/d(groupⅠ),112.05 MJ/d and 1.50 kg/d(groupⅡ),122.40 MJ/d and 1.63 kg/d(groupⅢ),133.27 MJ/d and 1.75 kg/d(groupⅣ),143.84 MJ/d and 1.87 kg/d(groupⅤ),respectively.In the 2nd month of lactation,the DE and CP feeding levels of mares in the five groups were 129.73 MJ/d and 1.82 kg/d(groupⅠ),140.37 MJ/d and 1.94 kg/d(groupⅡ),150.72 MJ/d and 2.07 kg/d(groupⅢ),161.60 MJ/d and 2.19 kg/d(groupⅣ),172.17 MJ/d and 2.31 kg/d(groupⅤ),respectively.The 1st to 14th day of each lactation month was pre-trail period,and the last 10 days was sampling period.The results showed as follows:the milk yield,conventional milk composition and milk somatic cell count were not affected by feeding different levels of DE and CP diets(P>0.05).Subsequently,the content of saturated fatty acid in milk fat was not significant difference among groups(P>0.05).The content of unsaturated fatty acid in milk fat of groupsⅡandⅣwhich compared with groupⅠwas significantly increased(P<0.05).Meanwhile,There was no significant difference in monounsaturated fatty acid content in milk fat among groups(P>0.05).Compared with groupsⅡ,ⅣandⅤ,the content of polyunsaturated fatty acid in milk fat of groupⅠwas significantly decreased(P<0.05).Along with the increase of dietary DE and CP levels,the contents of palmitic acid(C16∶0),palmitoleic acid(C16∶1)and linoleic acid(C18∶2n6 c)in milk fat had significant changes(P<0.05).Among them,the contents of palmitic acid and palmitoleic acid in milk fat of groupⅠwere significantly higher than those of other groups(P<0.05),the linoleic acid content in milk fat of groupⅠwas significantly lower than that of groupsⅡ,ⅣandⅤ(P<0.05).Feeding different levels of DE and CP diets to Yili mares during early lactation period had no significant effects on body weight,body length,heart girth and cannon circumference of foals,but the body height of foals of the groupⅠwas significantly higher than that of groupsⅡandⅢ(P<0.05).From the plasma physiological-biochemical indexes of foals,such as plasma triglyceride,total protein,albumin and urea nitrogen contents,there were no significant differences among all groups(P>0.05).In conclusion,in the 1st and 2nd month of lactation,DE feeding level of 101.41 and 129.73 MJ/d,and CP feeding level of 1.38 and 1.82 kg/d,have been able to meet the nutritional needs for lactating Yili mares,and increase dietary DE and CP levels will reduce palmitic acid and palmitoleic acid contents and improve linoleic acid content in milk.