减少奶牛热应激负效应的日粮调整措施.ppt

减少奶牛热应激负效应的日粮调整措施Reducing Negative Effects of Heat Stress Through Dietary Change 比尔 . 斯拉克2004年03月29日 杭州 现代奶牛如同 一座工厂， 消耗和加工大量 原材料（饲料） ， 在生产出大量高质量产品（牛奶） 的同时，生产出副产品（例如产热）。 The modern dairy cow like a factory consumes and processing large quantities of raw materials (feedstuffs) and producing a large volume of high quality product (milk) and by-products such as heat. 奶牛理想周围环境温度范围为 - 4~5℃至+18~21℃ The ideal ambient temperature for a dairy cow can range from minus 4 or 5 °C to plus 18 or 21 °C. 为减少热应激负面影响，实施有效的环境管理系统的收效最大；而针对热应激进行日粮营养调控的作用相对较小 If you have RMB to put towards reducing heat stress, the greatest return will come from developing an effective environmental management system. When efforts here are exhausted, the remaining RMB should go towards nutritional considerations. （1）背景回顾 Background and Review 热应激的原因和结果 Cause and Effect of Heat Stress 奶牛的生理反应 Physiological Responses To Heat Stress 奶牛如何减少体热 How Animals Reduce Body Heat （2）热应激和水 Heat Stress and Water （3）热应激和干物质采食 Heat Stress and DMI （4）饲料的热增耗 Heat Increment of Feedstuffs （5）热应激和粗料质量 Heat Stress and Forage Quality （6）热应激和添加脂肪 Heat Stress and Added Fat （7）热应激和粗蛋白 Heat Stress and Crude Protein （8）热应激和矿物质 Heat Stress and Minerals （9）热应激和阴阳离子差 Heat Stress and DCAD （10）维生素 Vitamins （11）添加剂 Additives - 缓冲剂 Buffers - 真菌和酵母培养物 Fungal and yeast cultures? - 烟酸 Niacin 热应激的原因和结果 Cause and Effect of Heat Stress 2个热源 Two sources of heat impact the cow： 温度 Temperature 环境 Environment 温度/湿度指数(THI) 湿度 Humidity 营养代谢 Nutrient Metabolism 热应激 = ￥$￡损失 Effects of heat stress are costly 产量下降15-40% Production drops (15 to 40%) 理化指标 - 乳脂下降 Component - fat drops 繁殖表现下降：受孕率低下、发情活动减少 、卵泡活动降低、早期胚胎死亡、难产率增加、、、 Reproductive performance is impaired - lower conception rate, reduced estrus activity, reduced follicular activity, early embryonic death, increased occurrence of difficult births. 热应激 = ￥$￡损失 Effects of heat stress a