In order to control emissions of nitrogen and phosphorus in feces and urine of dairy cows without effects on performance, this study investigate the effects of reduction of dietary nitrogen and phosphorus or u-sing compound additives on production performance, blood biochemical parameters, and nitrogen and phos-phorus emissions of lactating Holstein cows. Thirty-six lactating Holstein cows were randomly selected and di-vided into 3 groups with 12 cows per group. Cows in control ( CR) group were fed the original diet in farm, those in low protein and phosphorus group ( LPP) group were fed an experimental diet which had 0.70％ and 0. 03％ lower protein and phosphorus than the original diet in farm, and those in compound additive group ( CA) group were fed the original diet in farm and compound additives ( composed of active yeast, enzyme preparation and organic zinc ) . The pre-test lasted for 7 d, and the formal test lasted for 30 d. The results showed as follows: there were no significant differences of milk yield, dry matter intake and milk composition (P>0.05); compared with CR group, apparent digestibility of acid detergent fiber and phosphorus were in-creased by 73.12％ and 42.94％(P<0.05), respectively; compared with CR group, emissions of total nitro-gen and total phosphorus in LPP group were decreased by 9.11％ and 26.34％ (P<0.05), respectively, and those in CA group were decreased by 16.35％ and 16.10％ (P<0.05), respectively; blood aspartate amin-otransferase ( ALT) activity and phosphorus content in CA group were significantly higher than those in CR group ( P<0.05) , while blood biochemical parameters in CR group and LPP group were not significantly dif-ferent ( P>0.05) . Under the condition of normal nutritional requirements are satisfied, appropriately controlling nitrogen and phosphorus intakes of cows, or using the compound additives can reduce the emission of nitrogen and phosphorus.%本试验研究了减少饲粮氮磷水平或使用复合添加剂对泌乳荷斯坦奶牛的产奶性能、血液生化指标及氮磷排放量的影响,旨在不影响生产性能的前提下减少奶牛粪尿中氮磷的排放量.采用配对试验设计,将36头泌乳荷斯坦奶牛分为3组,每组12头,分别为对照(CR)(原奶牛场配方饲粮)、低氮磷(LPP)组[原奶牛场配方饲粮减少0.70％的氮(粗蛋白质)、0.03％的磷]、复合添加剂(CA)组[原奶牛场配方饲粮+复合添加剂(由活性酵母、酶制剂和有机锌混合组成)].预试期7 d,正试期30 d.测定产奶量、乳成分、血液生化指标及氮磷排放量.结果表明:各组产奶量、干物质采食量、乳成分无显著差异(P>0.05);LPP组与CR组相比,酸性洗涤纤维、磷的表观消化率分别提高了73.12％、42.94％(P<0.05);与CR组相比,LPP组总氮、总磷排放量分别降低了9.11％和26.34％(P<0.05),CA组分别降低了16.35％和16.10％(P<0.05);LPP组与CR组之间血液生化指标差异不显著(P>0.05),CA组的血液谷丙转氨酶(ALT)活性和磷含量显著高于CR组(P<0.05).结果提示,在满足正常营养需求的情况下,适当控制奶牛氮磷摄入量和使用复合添加剂均能降低氮磷的排放量.
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