乳牛轉換期蹄部健康、產後代謝疾病與繁殖效能改善之策略

Abstract

轉換期乳牛經歷許多生理變化，包含胎兒生長和開始泌乳的相關代謝和營養需求增加，這將對蹄部健康、繁殖表現和產乳表現有不利影響。儘管在降低跛行和代謝疾病風險的飼養技術有很大的進步，但轉換期仍然是維持動物健康最具挑戰的管理階段之一。此外，酪農不能再忽視大眾對牧場經營中動物福祉和友善環境的議題。因此，在這項研究中，我們目標是發展友善環境的蹄部管理策略並藉由減少轉換期乳牛代謝紊亂的發生，以提高繁殖和產乳表現。 第一部分，研究蹄部損傷對轉換期乳牛各種健康參數、產後行為和修蹄的影響。該研究將 24 頭乳牛依據產犢後第 50-60 天進行的蹄部檢查，分為有蹄部損傷與無損傷兩組。結果顯示，產犢前特定的健康相關參數，如；BCS < 3.0、白蛋白 < 3.25 g/dl、低血糖，可以作為產犢後蹄部損傷的早期預防信號。患有蹄部損傷的乳牛表現出躺臥時間增加1.6-2.2 小時/天、步數減少37.1-51.8 步/小時和躁動比減少0.9-1.1。修蹄後大約 90 天，有蹄部損傷的乳牛和無損傷乳牛的行為狀況有所改善。另外為了避免誤判或低估跛足情況，建議同時監測行為和健康參數，以更準確發現蹄部損傷乳牛的健康狀況。 第二部分，我們比較了 1% 四級銨鹽類消毒水 (QASD) 與 2.5% 螯合銅鋅溶液 (CZS) 使用在蹄浴控制泌乳牛趾間皮膚炎的效果。目的是解決目前大多數酪農蹄浴使用的大量化學品，其所引起的危害人類健康風險和處理使用後蹄浴液的環境議題。將 51 頭泌乳牛隨機分配到兩個處理組，每週進行一次蹄浴，連續 15 週。結果顯示，與CZS組相比，QASD組的趾間皮膚炎臨床改善率較高。在 15 週期間，QASD組的趾間皮膚炎活動性病變發生率較低。 第三部分，目的是評估轉換期補充維生素 E 加螯合態硒 (Se) 或螯合態銅鋅錳複合物 (CZM) 是否有助乳牛降低代謝疾病風險，以表現更好的繁殖與產乳表現。24 頭轉換期乳牛分為三組，檢查免疫功能、能量平衡狀態、繁殖表現和產乳量。結果表示，補充維生素 E 和 Se 可以改善免疫功能、繁殖性能和產乳量，但對能量調控沒有顯著幫助；補充CZM通過改善免疫功能，而提高產乳量和改善能量調節，但對繁殖性能沒有顯著影響。 綜上結果表明，透過轉換期的管理對乳牛蹄部健康和繁殖產乳表現具有正面的影響。可以結合牛隻產前健康參數和產後行為資料，實現預防蹄部損傷的目標；另外，QASD蹄浴具有作為控制趾間皮膚炎之例行管理操作；轉換期補充維生素E加螯合態硒或CZM可降低乳牛代謝疾病的風險，對乳牛的繁殖和生產表現具有不同的益處。這項研究最終目的是提供轉換期蹄部與維生素/微量礦物質的管理策略，減少蹄病與代謝疾病風險，同時友善環境和提高酪農場營運效率。

During transition period, cows experience many physiological changes included the increased metabolic and nutritional demands associated with the fetus growth and onset of lactation leading to adverse effects on hoof health, fertility and production performance. In spite of the advancement have been made in feeding practices to minimize the risks of lameness and metabolic diseases, the transition period remains one of the most difficult phases in maintaining dairy cow health. Moreover, farmers cannot ignore the concerns raised by consumers regarding the issues of animal welfare and environmental friendliness in farming operations. Thus, in this study, we aim to develop environmentally friendly strategies for managing hoof health and improving fertility and reproduction performance by minimizing the occurrence of hoof diseases and metabolic disorders for Holstein dairy cows in transition period. Part I: to investigate the effects of hoof lesions on various health parameters, behavior, and hoof trimming in transition dairy cows. The study divided 24 transition cows into two groups based on hoof examination conducted 50-60 days after calving. The results revealed that specific health-related parameters, such as lower BCS (< 3.0), albumin (< 3.25 g/dl), and low glucose concentrate happened on hoof lesion cows before calving, which could serve as early warning signs of hoof lesions after calving. Cows with hoof lesions exhibited increased lying time (1.6-2.2 h/day), reduced step count (37.1-51.8 steps/h), and decreased restlessness 0.9-1.1. Approximately 90 days following hoof trimming, both cows with or without hoof lesions experienced improved behavior pattern. To avoid misinterpretation, it is recommended to monitor both behavior and health parameters to provide a more accurate picture of cows with hoof lesions. Part II: we examined the effectiveness of a 1% quaternary ammonium salt-based disinfectant (QASD) footbath compared to a 2.5% chelated copper-zinc (CZS) solution in controlling digital dermatitis (DD) in lactating cows. Because the use of large quantities of chemicals in footbaths on farms raises concerns regarding human health risk and the disposal of the used footbath solution in environment pollution. Fifty-one cows were randomly assigned to the two treatment groups and footbathing was performed once per week for 15 weeks. The results showed that the QASD group had a higher DD clinical improvement rate compared to the CZS solution group. The prevalence of active DD lesions was lower in the QASD disinfectant group over the 15-week period. Part III: our objective was to evaluate the effects of supplementing vitamin E plus amino acid chelated selenium (Se) or copper, zinc, and manganese complex (CZM) on transition dairy cows' reproduction performance and lactation. Twenty-four transition cows were divided into three groups, and we analyzed immune function, energy balance, reproductive performance, and milk yield. The results showed that the supplementation of vitamin E plus Se led to improvements in immune function, reproductive performance, and milk yield. On the other hand, CZM supplementation improved milk yield and energy regulation through immune function but did not significantly influence reproductive performance. Overall, the results indicated that management practices during the transition period had a significant impact on hoof health and reproductive performance in dairy cattle. By combining prepartum health parameters and postpartum behavior, early prevention of hoof lesions could be achieved. For the control of DD, the use of a QASD showed potential as an alternative footbath solution. The supplementation of vitamin E plus Se, or CZM during the transition period provided different benefits for reproductive and production performance in dairy cows. The final aim of this study is to provide management strategies for hoof health care and meeting the requirement of vitamin and trace mineral in transition period, thereby improving the efficiency of the herd and farm operations.