添喂多库酯和聚丙烯酰胺对乳牛消化和泌乳性能的影响

Effect of supplementation of docusate and polyacrylamide on digestion and milking performance of dairy cattle

本试验旨在研究添喂多库酯(DOC)和聚丙烯酰胺(PAM)对乳牛自由采食、消化和泌乳性能的影响,以期改善乳牛的生产性能。在两个独立的试验中,分别选用约2.3岁、产犊后200~300 d的二胎泌乳牛56头(试验1)和93头(试验2),饲喂相同日粮条件下在试验1和试验2的试验期分别添喂DOC 1.71 g/kg日粮和PAM 2.0 g/kg日粮(对照期均不添加)。记录每期牛群的饲喂量和剩料量,收集牛群的代表性粪样(每天n=4);记录每头牛的产奶量,收集牛群代表性奶样(每天n=4);并以木质素为标记物,测定牛群的表观消化率;测定乳成分和计算标准乳产量。每个试验包括对照和试验两期,每期包括适应期16 d,采样期8 d。结果表明:添喂DOC或PAM,乳牛干物质自由采食量分别增加17.0%或15.2%(P<0.01);日粮干物质、有机物、粗蛋白质、纤维素和能量的表观消化率在试验1分别提高8.1%、5.2%、5.9%、5.3%和4.8%(P<0.01);在试验2分别提高11.6%、9.0%、10.6%、11.9%和10.9%(P<0.01)。乳中非脂固形物、乳脂和乳蛋白含量在试验1分别提高6.1%、7.9%(P<0.01)和7.9%(P<0.05),在试验2分别提高6.0%、6.8%和6.8%(P<0.05),但添喂DOC或PAM对乳糖含量没有显著影响。生鲜乳产量在试验1和试验2分别增加8.3%和5.0%(P<0.01);折合标准乳产量分别增加12.8%和9.0%(P<0.01)。除增加产乳外,给乳牛自身的可消化粗蛋白质和可消化能量的供应量在添喂DOC时分别增加35.7%和40.5%,在添喂PAM时分别增加56.1%和73.6%。添喂DOC或PAM均可提高乳牛的自由采食量和日粮表观消化率,增加乳产量和给乳牛自身的营养供应,有利于提高乳牛的生产性能。

Effects of supplemental docusate(DOC)and polyacrylamide(PAM)on voluntary feed intake(VFI),digestion and lactation of dairy cattle were studied,aimed to improve the production performance of dairy cattle.In two independent trials,56(Trial 1)and 96(Trial 2)of dairy cattle of second parity,with about 2.3 year’s old and at 200 to 300 days after calving,were fed same diet.In experiment periods of Trial 1 and Trial 2,DOC(1.71 g/kg diet)and PAM(2.0 g/kg diet)were supplemented respectively,without any supplement in two control periods.The feeds,surplus,representative fecal samples(n=4 per day),representative milk samples(n=4 per day)of whole herd,and individual milk production,were recorded or collected,respectively.Dietary apparent digestibility was calculated by lignin marker method.Milk composition was analyzed and standard milk was calculated.Each trial consisted of control and experiment periods,with 16 days for adaptation and 8 days for sampling in each period.The results showed that supplementation of DOC and PAM increased voluntary feed intake(VFI)by 17.0%and 15.2%(P<0.01),respectively.Apparent digestibility of dry matter(DM),orgainc matter(OM),crude protein(CP),cellulose and energy increased by 8.1%,5.2%,5.9%,5.3%and 4.8%(P<0.01)in Trial 1;and by 11.6%,9.0%,10.6%,11.9%and 10.9%(P<0.01)in Trial 2,respectively.The non-fat solids,fat and protein in milk increased by 6.1%,7.9%(P<0.01)and 7.9%(P<0.05)in Trial 1;and by 6.0%,6.8%and 6.8%(P<0.05)in Trial 2,respectively,without significant affect on contents of the lactose,calcium and phosphorus of milk by supplementary DOC and PAM.Fresh and standard milk yields increased by 8.3%and 12.8%(P<0.01)in Trial 1,and 5.0%and 9.0%(both P<0.01)in Trial 2,respectively.Furthermore,the crude protein and energy supply for dairy cattle themself increased by 35.7%and 40.5%when DOC supplemented,respectively;and by 56.1%and 73.6%when PAM supplemented,respectively.Supplementation of DOC or PAM increases VFI,dietary digestibility,milk production and nutrient supply to dairy cattle themself,and was beneficial to production performance of dairy cattle.