作　　者： (蒲启建）; (王之盛）; (彭全辉）; (张灿）; (景小平）; (胡瑞）; (邹华围）;

机构地区： 四川农业大学动物营养研究所,牛低碳养殖与安全生产重点实验室,雅安625014

出　　处： 《动物营养学报》 2017年第9期3120-3131,共12页

摘　　要： 本试验旨在研究热应激对不同品种(系)青年肉牛生产性能、营养物质表观消化率及血液生化指标的影响,探究不同品种(系)肉牛的耐热性差异。选取体重[(185.89±14.02)kg]相近、健康的青年西杂牛(西门塔尔牛×宣汉黄牛)、地方黄牛(宣汉黄牛)和犏牛(娟姗牛×麦洼牦牛)各6头为研究对象,试验期间不同品种(系)的青年肉牛饲喂相同饲粮。试验时间为2015年4—9月,预试期7d,正试期180d。结果表明:1)试验牛舍5—8月温湿度指数(THI)高于72,属于热应激期,且显著高于4月(热应激发生前)和9月(热应激发生后)(P<0.05);热应激环境导致各试验牛呼吸频率和直肠温度显著升高(P<0.05)。试验期间犏牛呼吸频率和直肠温度显著高于西杂牛和地方黄牛(P<0.05)。2)热应激期内西杂牛、地方黄牛和犏牛单位体重干物质采食量均有不同程度降低,以6月为最低,均较4月显著降低(P<0.05),且降低幅度为犏牛>西杂牛>地方黄牛。西杂牛、地方黄牛和犏牛的平均日增重(ADG)均在6月最低,分别较4月降低了27.62%(P<0.05)、10.81%(P>0.05)和46.15%(P<0.05);西杂牛的ADG在4—7月显著高于犏牛(P<0.05)。西杂牛和犏牛的料重比(F/G)以6月为最高,分别较4月升高了63.01%(P<0.05)和89.03%(P<0.05);地方黄牛的F/G在9月最高,较4月升高了53.12%(P<0.05)。3)热应激期内西杂牛、地方黄牛和犏牛的粗蛋白质(CP)表观消化率均有不同程度降低,且7月均较4月显著降低(P<0.05);西杂牛7月的粗脂肪(EE)表观消化率较4月显著降低(P<0.05),而热应激对地方黄牛和犏牛的EE表观消化率无显著影响(P>0.05);热应激期内犏牛中性洗涤纤维(NDF)(6月)和酸性洗涤纤维(ADF)的表观消化率(5—8月)较热应激发生前显著降低(P<0.05);热应激期内西杂牛和犏牛钙(Ca)(西杂牛:6—8月;犏牛:5—8月)和磷(P)的表观消化率(西杂牛:6—7月;犏牛:5—8月)较热应激发生前显著降低(P<0.05)。试验期间,不同品� This experiment was conducted to investigate the effects of heat stress on performance, nutrient apparent digestibility and blood biochemical indices of different breeds of young beef cattle, in order to explore the heat resistance difference of different breeds of beef cattle. Six individuals of Simmental crossbred cattle （Simmental cattle×Xuanhan yellow cattle）, indigenous yellow cattle （Xuanhan yellow cattle） and cattle yak （Maiwa yak×Jersey cattle） were chosen based on similar body weight[（185.89±14.02） kg]. Animals were fed with the same diet and feeding experiment lasted 187 days, including 7-days adaption period and 180-days test period. The experiment from April 2015 to September 2015. The results showed as follows：1） the temperature humidity index （THI） of barn was above 72 from May to August and this stage belonged to heat stress （HS） period, and the THI of HS period was higher than April （pre HS） and September （after HS） （P〈0.05）. During the HS period, the respiratory frequency and rectal temperature were significantly increased （P〈0.05） for all experimental animals. The respiratory frequency and rectal temperature of cattle yak was significantly higher than those of Simmental crossbred cattle and indigenous yellow cattle in the period of experiment （P〈0.05）. 2） The dry matter intake per body weight of Simmental crossbred cattle, indigenous yellow cattle and cattle yak was decreased in HS period, and the lowest value in June and significantly lower than April （P〈0.05）, the degree of decreased was cattle yak〉Simmental crossbred cattle〉indigenous yellow cattle. The lowest values of average daily gains of Simmental crossbred cattle, indigenous yellow cattle and cattle yak were all in June, and decreased by 27.62% （P〈0.05）, 10.81% （P〉0.05） and 46.15% （P〈0.05） as contrasted April, respectively. The average daily gain of Simmental crossbred cattle was significantly higher than that of cattle yak from April to July （P〈0

关 键 词： 热应激 肉牛 生产性能 营养物质表观消化率 血液生化指标