CAJ | 학술논문

为了探索南方夏季缓解肉牛热应激的方法和措施，研究了安装接力送风机加喷淋降温和饲粮添加铬对封闭型房舍式小群饲养肉牛生产性能和牛舍热环境的影响。试验采用双因素设计，选取28头平均体质量379.3kg的西杂肉牛，随机分成4组，试验1组牛舍安装风机加喷淋，并在饲粮中添加烟酸铬；试验2组安装风机加喷淋，饲粮中不添加烟酸铬；试验3组不安装风机加喷淋，但饲粮中添加烟酸铬；试验4组（对照组）不安装风机加喷淋，不添加烟酸铬。铬的添加量为800μg/kg，进行为期30 d生长试验。分别测定了牛舍的环境指标、肉牛生理指标和肉牛增质量，并对经济效益进行了分析。结果如下：①安装接力送风机加喷淋系统牛舍14：00平均室温可降低1.84℃（P＜0.01），风速增加8.27倍（P＜0.01）；②安装风机加喷淋降温降低肉牛呼吸频率4.93次/min（P＜0.01），饲粮添加铬降低直肠温度0.23℃（P＜0.01），安装风机加喷淋降温和饲粮添加铬对肉牛呼吸频率和直肠温度无交互作用。③1组肉牛平均日增质量比2组、3组和对照组分别提高了12.37%（P＜0.05）、19.59%（P＜0.05）和34.02%（P＜0.05）。2组比对照组平均日增质量提高了24.71%（P＜0.05）。1组比对照组增加毛利4.44元/(头·d)。表明南方夏季肉牛舍安装风机加喷淋和饲粮中添加铬均缓解了肉牛热应激，提高了平均日增质量和经济效益，二者结合使用效果较好。
위료탐색남방하계완해육우열응격적방법화조시，연구료안장접력송풍궤가분림강온화사량첨가락대봉폐형방사식소군사양육우생산성능화우사열배경적영향。시험채용쌍인소설계，선취28두평균체질량379.3kg적서잡육우，수궤분성4조，시험1조우사안장풍궤가분림，병재사량중첨가연산락；시험2조안장풍궤가분림，사량중불첨가연산락；시험3조불안장풍궤가분림，단사량중첨가연산락；시험4조（대조조）불안장풍궤가분림，불첨가연산락。락적첨가량위800μg/kg，진행위기30 d생장시험。분별측정료우사적배경지표、육우생리지표화육우증질량，병대경제효익진행료분석。결과여하：①안장접력송풍궤가분림계통우사14：00평균실온가강저1.84℃（P＜0.01），풍속증가8.27배（P＜0.01）；②안장풍궤가분림강온강저육우호흡빈솔4.93차/min（P＜0.01），사량첨가락강저직장온도0.23℃（P＜0.01），안장풍궤가분림강온화사량첨가락대육우호흡빈솔화직장온도무교호작용。③1조육우평균일증질량비2조、3조화대조조분별제고료12.37%（P＜0.05）、19.59%（P＜0.05）화34.02%（P＜0.05）。2조비대조조평균일증질량제고료24.71%（P＜0.05）。1조비대조조증가모리4.44원/(두·d)。표명남방하계육우사안장풍궤가분림화사량중첨가락균완해료육우열응격，제고료평균일증질량화경제효익，이자결합사용효과교호。
Heat stress in summer can cause beef cattle to decrease feed intake and perform poorly, but such declines can be lessened if the beef cattle are cooled. Both the barn installed cooling fan and the chromium supplementation in diet are effective measures to relieve the degree of heat stress. The objective of this study was to investigate the effects of fanning and sprinkling and chromium added to diet on physiological indexes and growth performance of beef cattle in summer in the Southern China. Twenty-eight Simmental Crossbred beef cattle (average body weight 379.3 kg) were chosen and randomly divided into four groups, and were raised in enclosed feedlot barn for 30 days. In treatment I (T1), fans and spraying system were installed and chromium nicotinate was supplemented in the diet. Only fans and spraying system was assembled in treatment II (T2). In treatment III (T3), only chromium nicotinate was supplemented. Neither the fan and spraying system nor chromium nicotinate was used in the control (T4). The dosage of chromium was 800μg/kg. The indexes such as environmental factors, temperature-humidity index (THI), rectal temperature (Tr), respiration rate (RR), average daily gain (ADG) and economic benefits were collected. The results showed that compared with the barn without fans and spraying system, the average room temperature was lowered by 1.84℃ (P<0.01) and wind speed increased by 8.27 times (P<0.01) in 14:00 in barns installed with fans and spraying system. The RR was reduced by 4.93 times (P<0.01) by fans and spraying system, and Tr was reduced by 0.23℃ (P<0.01) by chromium supplementation compared to T4. No interaction effect on RR and Tr was obtained between chromium supplementation and fans and spraying system. The ADG in T1 was increased by 12.37%(P<0.05), 19.59% (P<0.05) and 34.02% (P<0.05) respectively to T2, T3, and T4. Compared with the control group, the ADG of T2 were increased by 24.71% (P<0.05), and gross profit of T1 was increased by 4.44 yuan per head per day. In conclusion, both the fans and spraying system and chromium supplementation relieved the heat stress of beef cattle, and the average daily weight gain was improved, and finally the economic benefits was increased. However, the combination use of the two measures could lead to better results.