第三章 以水簾牛舍紓解荷蘭泌乳牛熱緊迫之可行性評估 II. 採食行為、瘤胃
3.4.2 飼糧組成與採食
試驗正式期間的TMR 配方、個別飼糧組成與 TMR 組成的分析結果列於表 3.2 (乾基)。實際調配的 TMR 組成與計算值相近，兩種牛舍 TMR 採樣的分析結果也
顯示組成相近。兩組牛隻一日內每 10 分鐘的採食活動繪於圖 3.1，牛隻在兩次新
鮮TMR 餵飼後的採食活動明顯增加，尤其是清晨的餵飼，有高達 75% 的牛群一 齊採食，採食活動高峰持續約1.5 小時，下午餵飼後的採食活動高峰也可以近 75%
(傳統牛舍組) 或近 50% (水簾牛舍組)，但持續時間較久，一日內其餘時間的採食 活動則多在20%以下。將一日分成數個時間區段 (表 3.3)，水簾牛舍環境顯著降低 兩個時段的牛隻採食活動 (P < 0.05)，即上午約 7:30 – 11:00 (10.9% vs. 19.2%) 及 下午約3:30 新鮮 TMR 餵飼後的兩小時 (35.7% vs. 62.1%)，水簾牛舍牛隻在兩時段
的採食活動都只有傳統牛舍牛隻的 57%，水簾牛舍牛隻全日平均採食活動也較傳
統牛舍的降低了 19%，試驗結果顯示本次試驗水簾牛舍所提供的環境確實會減低
牛隻的採食行為。兩種牛舍環境對牛隻養分採食量的影響尚未達顯著差異水準 (表 3.4)，但數字上都以水簾牛舍牛隻的攝取量較低。水簾牛舍與傳統牛舍牛隻的每日 每頭乾物質採食量分別為17.0 kg 與 18.4 kg，水簾牛舍使乾物質採食量降低 8%，
即每日每頭達1.4 kg，因此使其他營養分的攝取量也隨之減少，尤其是非纖維性碳
水化合物 (non-fibrous carbohydrate, NFC) 的採食量 (P < 0.08)，營養分採食量的降 低應緣自於水簾牛舍環境減少牛隻的採食活動所致。
表 3.2 水簾牛舍紓解荷蘭泌乳牛熱緊迫試驗之完全混合日糧配方及組成 (%，乾 基)1
Table 3.2 TMR formulation and compositions fed to Holstein lactating cows in water-padding barn evaluation experiment (%, DM basis)1
Ingredients2 DM%
in TMR
Chemical compositions and in vitro digestibility, %3 (no. pooled for
1 Same TMR was offered to both groups ad libitum Individual feed ingredient was sampled two times a period and pooled for analyses. TMR was sampled at the last 15 days each period and pooled for analyses.
2 PG hay: pangolagrass hay, Dehy AP: Dehydrated alfalfa pellet, WP: water-padding barn, C: conventional barn, TMR: totally mixed ration.
3 DM: dry matter, CP: crude protein, ADF: acid-detergent fiber, ADL: acid-detergent lignin, NDF: neutral-detergent fiber, EE: ether extract, IVDMD: in vitro dry matter digestibility.
4 Each metric ton of concentrate was constituted by 575 kg of ground corn, 305 kg of soybean meal, 20 kg of fish meal, 50 kg of molasses, 4 kg of limestone, 8 kg of dicalcium phosphate, 25 kg of sodium bicarbonate, 5 kg of magnesium oxide, 3 kg of salt and 5 kg of vitamin and mineral premix (as fed basis).
圖3.1 水簾牛舍環境對熱季荷蘭泌乳牛每日採食活動之影響。
Figure 3.1 Effect of water-padding barn environment on the intake activities of Holstein lactating cows during hot summer. A total of 42 cows were assigned in a cross-over design with 30 days a period. Three 24-hintake activities each period were recorded by video and counted every 10 min.
Number of cows eating was calculated as the percentage of each group.
Asterisks indicated the higher intake activities of cows in conventional barn at those two time segments (P < 0.05).
表3.3 水簾牛舍環境對熱季荷蘭泌乳牛採食活動之影響1
Table 3.3 Effect of water-padded barn environment on the intake activities of Holstein lactating cows during hot summer1
Time segments
Conventional barn
Water-padded
barn SEM2 Sig.3
No. of observations 2 2
Daily average, % 22.6 18.3 1.6 NS
2 hrs after 5:30 feeding, %
(after a.m. milking) 56.9 58.4 9.0 NS
Around 7:30 – 11:00, % 19.2 10.9 0.4 * Around 11:00 – 14:00 , % 8.0 5.4 2.4 NS 2 hrs after 15:30 feeding, %
(after p.m. milking) 62.1 35.7 0.5 *
Around 17:30 – 22:00, % 16.2 16.4 2.7 NS Around 22:00 – 5:00 next day, % 8.1 11.7 1.0 NS
1 A total of 42 cows were randomly assigned into two barn treatments in a cross-over design with 30 days a period. Cows were group-fed in both free stall barns. Three 24-hintake activities each period were recorded by video and counted every 10 min.
Number of cows eating was calculated as the percentage of each group.
2 SEM: standard error of the mean.
3 Significant level: NS: non-significant, P > 0.05; * P < 0.05.
表3.4 水簾牛舍環境對熱季荷蘭泌乳牛養分採食量之影響1
Table 3.4 Effect of water-padded barn environment on the daily nutrient intakes of Holstein lactating cows during hot summer1
Items2
Conventional barn
Water-padded
barn SEM3 Sig.4
No. of observations 2 2
DM intake,kg 18.4 17.0 0.29 NS
CP intake, kg 3.27 2.97 0.09 NS
ADF intake, kg 4.41 4.20 0.10 NS
NDF intake,kg 6.78 6.58 0.14 NS
EE intake, kg 0.50 0.47 0.01 NS
NFC intake, kg 6.45 5.68 0.06 (P = 0.08)
1 A total of 42 cows were randomly assigned into two barn treatments in a cross-over design with 30 days a period. Cows were group-fed. TMR and refusal were weighted, sampled and dried daily for dry matter analyses from the last 15 days each period and pooled for the other nutrients analyses.
2 DM: dry matter, CP: crude protein, ADF: acid-detergent fiber, NDF: neutral-detergent fiber, EE: ether extract, NFC: non-fibrous carbohydrate.
3 SEM: standard error of the mean.
4 Significant level: NS: non-significant, P > 0.05; All nutrients intake were not affected by barn environment.
3.4.3 瘤胃消化
圖3.2 水簾牛舍環境對熱季荷蘭泌乳牛瘤胃內容物 pH (A)、氨態氮濃度 (B) 與 揮發性脂肪酸濃度 (C) 之影響。
Figure 3.2 Effect of water-padded barn environment on the diurnal rumen pH (A), NH3-N (B) and volatile fatty acid (VFA) (C) levels of Holstein lactating cows during hot summer.
表 3.5 水簾牛舍環境對熱季荷蘭泌乳牛瘤胃內容物 pH、氨態氮與揮發性脂肪酸 濃度之影響1
Table 3.5 Effect of water-padded barn environment on the rumen pH, NH3-N and volatile fatty acid (VFA) of Holstein lactating cows during hot summer1 Items Conventional barn Water-padded barn SEM2
No. of cows observed 4 4
1 Two consecutive 24-hrumen content samplings were conducted each period with two rumen cannulated lactating cows in each barn. Samples were immediately filtrated for pH measurement and acidified and frozen for later NH3-N and VFA analyses.
2 SEM: standard error of the mean; All rumen measurements were not affected by barn environment, P > 0.05.
泌乳牛對熱緊迫非常敏感，尤其是高產牛。當牛隻無法有效排熱，將導致體 溫升高、呼吸次數增加、採食量降低、乳量下降與繁殖性能低落等。本次試驗水 簾牛舍環境降低了牛隻的採食活動、採食量與乳量，同時進行的牛舍環境參數與 牛隻生理反應研究 (蕭等，2009)，得知兩種牛舍環境仍然使泌乳牛群 74% 的時間
處於中度熱緊迫 (78 < THI ≤ 84) 狀況下，水簾牛舍牛隻 4 a.m. 的呼吸數高於傳統
Figure 3.3 Effect of water-padded barn environment on the daily milk yield of Holstein lactating cows during hot summer in a cross-over design. Initial milk average of all cows attended the experiment was 26.2 kg a day. Cows in the conventional (Conv.) barn in period one (□) had average milk yield around 27 kg a day. When they transferred to the water-padded (WP) barn in period 2, milk yield dropped to about 22 kg, 5 kg milk decrease was noted. On the other hand, cows in the WP barn at period one (♦) had milk yield drop to around 25 kg per day. When they changed to the conventional barn, milk yield could be held around 24 kg a day. Only 1 kg decrease was found. Barn effect on milk yield was clearly illustrated from the cross-over design.
表3.6 水簾牛舍環境對熱季荷蘭乳牛泌乳性能之影響1
Table 3.6 Effect of water-padded barn environment on the lactation performance of Holstein cows during hot summer1
Items2
1 A total of 42 cows were randomly assigned into two barn treatments in a cross-over design with 30 days each period. Cows were group-fed. Milk yields were recorded daily and three individual a.m.-p.m. milk were sampled for composition analyses each period. Thirty three out of 42 head cows successfully finished the experiment.
2 BW: body weight, FCM: fat corrected milk, SCC: somatic cell count.
3 SEM: standard error of the mean.
4 Significant level: NS: non-significant, P > 0.05; * P < 0.05, ** P < 0.01, *** P <
0.001.
與屬於美國濕熱地區的試驗比較，國內氣候環境的相對濕度應更高，本次試
相對濕度較高時則降低到22℃氣溫，牛隻即開始感受到熱緊迫 (Armstrong, 1994;
West, 2003)。濕度高可使高溫的嚴重性更惡化，當氣溫與相對濕度增加時，牛隻採 法改善牛隻的採食及泌乳 (Bucklin et al., 1989)，噴霧降溫所配合的風速不夠時，
微細水霧反而會在牛隻體表毛髮上形成一層絕緣，負面影響熱的蒸發排散 (Hahn, 1985)，Missouri 研究報告指出，比較單獨遮蔭與遮蔭+噴霧+吹風的降溫效果，在 04:00 與 16:00 時的相對濕度分別為 77.7% 與 43.3% 及乾球溫度分別為 22℃與 30.9℃環境下，噴霧加上吹風可顯著增加 8.6% 乳量 (23.3 kg vs. 25.3 kg, P <
0.05)。當風速自每秒 0.2 m 增加至每秒 0.9 m 時，流汗速率可自每平方公尺體表面 積每小時的75 g 水分增加到 350 g (Hillman et al., 2001; Hillman, 2009)。
處於熱緊迫中，動物會增加夜間少量多餐的採食活動 (Hahn, 1999)，因此重 視熱季夜間降溫與餵飼是被推薦的管理策略 (Fuquay, 1981; Keister et al., 2004)，研 究顯示夜間乾球溫度若能低於21℃達 3 到 6 h，則可以將由熱引致的乳量下降程度 最小化 (Igono et al., 1992)，將以色列強度管理泌乳牛群 (乳量 42 kg，擠乳四次，
餵飼四次) 的白天餵飼量減少，也得到加強夜間餵飼可以提高飼糧能量利用效率的 結果 (Aharoni et al., 2005)。
3.5 結論與建議
臺灣高溫高濕環境造成畜禽嚴重的熱緊迫問題。水簾牛舍原本設計用於乾燥 地區的降溫，在臺灣是否可以用來紓解泌乳牛夏季熱緊迫，是本試驗希望探討與
評估的嘗試。民國94 年第一年的評估顯示，日間最高換氣速度每分鐘兩次的水簾
牛舍環境，雖然可以較有效的降低白日舍溫與THI，但對牛隻性能表現確實有負面
影響，牛隻採食活動、採食量、乳量及乳成分產量都明顯降低，水簾牛舍全日持 續高的相對濕度 (≥ 93.5%) 與偏低的換氣速度，很可能使牛隻無法順利自體表排 熱，熱負荷高造成採食下降與泌乳性能低落，水簾牛舍整體設計仍亟待修改，改
善方向將朝增加換氣速度或白日水簾+夜間運動場的搭配方式等進行。
第四章 以水簾牛舍紓解荷蘭泌乳牛熱緊迫之可行性評估 (comfort zone) 溫度，就會造成熱緊迫 (Bianca, 1962)。牛隻為紓解熱緊迫，以尋求 遮蔭、增加飲水、排汗、排尿與喘氣等來散熱 (Bucklin et al., 1991; Smith et al.,