畜舍軟墊種類及生理狀態對泌乳牛每日行為時間分配之影響

Abstract

由於氣候因素與廢水處理設施的限制，造成有機墊料與無機墊料的使用必須非常謹慎。軟墊因具備清洗方便又無墊料使用上的麻煩，而成為改善水泥地面不舒適的最佳選擇。目前尚無文獻探討台灣地區畜舍地面材質與泌乳牛行為之間的關係，故將台灣生產、專銷歐美的兩種軟墊（B，兆陽興業601S；G，鎔利興業MI-2522A）引入台灣大學乳牛試驗場，與原本使用於牧場的軟墊（MAT，購自永福畜牧）對不同生理狀態（包含：泌乳天數、分娩胎次與跛足程度）的泌乳牛，進行行為時間分配、自然行為表現（清潔行為）的比較試驗，並以五分鐘為間隔紀錄乳牛行為，以期能得知最能提升乳牛舒適度的軟墊特性。 跛足評分的結果顯示，台大牧場並無腳蹄完全健康或嚴重跛足的泌乳牛，平均分布在輕度至中等跛足的分級裡。跛足程度與分娩胎次在本試驗中皆不會影響每日行為時間分配，但隨著泌乳天數的上升，每日躺臥次數有下降的趨勢，每次躺臥時間顯著拉長，由此可見乳牛生理狀況確實會影響躺臥的行為。 乳牛在軟墊上進行的清潔行為次數高達水泥地面三倍之多（水泥地4次、軟墊總共12次）。以在各軟墊上的活動時間作為牛隻喜好判斷，牛隻於軟墊MAT的總躺臥與總站立時間最高，軟墊B的總活動時間排第二，幾乎沒有牛隻躺臥在水泥地面。水泥地的硬度為93.67 ± 2.34，而軟墊的柔軟程度排序，由最高至最低為：MAT、G、B（51.92 ± 1.69、58.50 ± 1.76與62.50 ± 2.17 Asker_C，數字越高硬度越高）。由此可見，軟墊硬度並非影響乳牛喜好的唯一因素，其它可能影響乳牛選擇的軟墊特性，諸如：摩擦力、排水性、表面刻紋等，則需要進一步的探討。 綜觀上述，確實能以五分鐘為間隔紀錄乳牛當下的行為狀態，來判斷乳牛對不同軟墊的喜好。若進行每日行為時間的乳牛行為研究時，也需考量牛隻生理狀態以避免取樣誤差。相較於堅硬的水泥地面，牛隻在軟墊上的活動時間顯著高於水泥地面，但還有除了柔軟程度外其他影響乳牛選擇的軟墊特性，必須進行進一步的研究。整體而言，若能在牧場原本的水泥地面鋪設軟墊，將能在不需要重建畜舍的前提下，有效的提升乳牛舒適度與福利。

Due to the unfavorable climate condition for the usage of organic bedding in Taiwan, soft lying mats are thought to be the optimal bedding material for dairy industry to improve cow comfort. To our knowledge, there are no research on the relationship of flooring material and cow behavior in Taiwan. With the aim of searching for best flooring material for dairy farm in Taiwan and determining the possible factors that would affect cow behaviors and cow comfort, we analyzed the influences of parity status, days in milk (DIM) and locomotion score (LMS) on time budget distribution in 16 lactating dairy cows. Then introduced two new kinds of soft mats: MI-2522A (G) and 601S (B), which were both produced in Taiwan, to compare with the original EVA soft mats and concrete floor at National Taiwan University Experimental Dairy Farm by preference study and grooming behavior display. We also analyzed the softness of these three soft mats by rubber hardness tester (GS-701N TECLOCK Co., Japan). There were no severe lame cow (LMS = 5) or healthy cow (LMS = 1) in the study. For the time budgets of the cows, parity status and the severity of lameness did not affect time distribution. But it showed with the increased DIM, number of lying bout decreased. Frequency for grooming behaviors showed 3 times greater on soft mats than concrete floor (4 times on concrete floor versus 12 times on soft mats). Cows also spent most of the time staying on soft mats rather than concrete floor. Ranking mean activity time that cows spent on each soft mats from high to low was: MAT, B, than G. The hardness of soft mats MAT, G, and B were 51.92 ± 1.69, 58.50 ± 1.76, and 62.50 ± 2.17 Asker_C (larger number represents greater hardness), respectively. Put all those results together, softness might not be the only factor to influence cows to choose flooring material. Other physical characteristics of soft mats with potential to influence cow choice (eg. surface friction force and drainage ability) needs further study. Overall, we successfully revealed cow preference among different types of soft mats and concrete floor by video recordings with five minutes intervals of 24 h behavior observations. And cows showed more natural behaviors and stayed on soft mats longer than concrete floor. With all the advantages on soft mats, choosing soft mats to cover on existing concrete floor will be the easiest way to elevate cow welfare status without changing housing structure.