改善轉換期飼養與管理對經產牛與初產牛生產、健康與行為之影響

Abstract

轉換期為分娩前三週至分娩後三週之階段，在這個階段乳牛歷經了一連串充滿壓力的事件，包含胎兒快速生長、分娩造成的緊迫、泌乳高峰前的準備、負能量平衡、代謝疾病好發期、以及子宮卵巢恢復等重要階段，此時期對初產牛來說可能更為嚴峻，因為牠們還須面對自身生長營養需求的提升與缺乏此時期的經驗，導致此時期的初產牛更容易罹患代謝性疾病，面臨產量降低、繁殖障礙甚至是淘汰的結局。本次研究之目的有二，其一為透過分群管理搭配飼糧調整之新型轉換期飼養管理模式，期望能讓乳牛順利度過轉換期。研究目的之二為藉由自動電子行為偵測系統判斷實驗牛健康，尋找轉換期不同疾病的特殊行為模式變化徵兆供做未來現場應用參考。實驗結果證實分群管理搭配飼糧調整之模式會延長初產牛在分娩前之採食時間與減少分娩後之站立時間，並減少經產牛分娩後後酮體之生成、提高反芻量與提高乳蛋白率，另外，對照組經產牛在轉換期反芻量顯著低於處理組經產牛，亦反映到其較高血液中酮體濃度與乳中體細胞數，證實了行為之變化可作為判斷其健康狀態之依據。此外，本次實驗篩選產後發生胎衣滯留之實驗牛，發現其產前反芻量顯著低於健康實驗牛，這表示或許分娩前行為之變化可作為提早偵測產後代謝性疾病之指標。總結來說，本次研究採用之新型轉換期飼養管理模式對初產牛與經產牛皆有正面之改善，而在初產牛方面，或許延長其分群管理時間，能使改善狀況更為明顯。乳牛行為之變化則具有應用於偵測乳牛健康狀態與分娩前疾病指標之潛力，以在未來提早發出警訊予管理者，使其能做出相對應之預處置，降低產後代謝性疾病之發生率，提升分娩前之飼養管理效率，減少乳牛在轉換期淘汰率，延長乳牛使用年限。

The transition period is defined as three weeks before and three weeks after calving. In this period dairy cattles face a series of difficult events, including fetal rapid growth, stress of parturition, preparation of lactation peak, negative energy balance, metabolic diseases prompt period, and uterine and ovary recovery. This period is more difficult for primiparous cows, because they must cope with an extra nutrition demand for growth, and lack of experience which leads them more likely to suffer from metabolic diseases, reduced milk yield, reproductive disorder and even being culled in this period. The purpose of this study is twofold. One was to utilize new transition period feeding management protocol to ensure them safely passing through the transition period. The second purpose of the study was to monitor the health of the experimental cows by the automatic electronic behavior detection system and find specific behavior pattern before metabolic diseases occurring for future application in the field. The results confirmed that the new feeding management protocol could prolong the feeding time of the primiparous cows before calving, also reduce ketone bodies, increase the rumination time and increase the milk protein ratio of multiparous cows after calving. We found that the rumination time of multiparous cows in the control group was significantly lower than that in the treatment group, and reflected in the higher blood BHBA concentration and milk somatic cell counts. Confirm that changes in behavior can be used as a basis for monitoring cows’ health status. In addition, this experiment screened out the experimental cows with retained placenta after calving, and found that their pre-partum rumination time was significantly lower than the healthy experimental cows, which indicated that the change of pre- partum behavior can be used as an early detection indicator of postpartum metabolic diseases. In conclusion, the new transition period feeding management protocol used in this study has a positive improvement for effect both primiparous and multiparous cows. In terms of primiparous cows, extending the separate grouping time may be able to make the improvement more obvious. Behavior change of dairy cows has the potential to be used to monitor the health status of dairy cows and as pre-partum disease indicator. In the future, early warnings can be sent to farm managers so that they can make precise prevention action to reduce the incidence of post-partum metabolic diseases, improve the efficiency of pre-partum feeding management, reduce the culling rate of dairy cows during the transition period, and extend the production life of dairy cows.