延長光照處理對乳山羊之泌乳性能影響

Effect of Long Daily Photoperiod on Milk Production of Dairy Goat

任蔚平(Wei-Ping Jen)

指導教授 ： 徐濟泰

國立臺灣大學/生物資源暨農學院/動物科學技術學研究所/碩士(2006年)

https://doi.org/10.6342/NTU.2006.02190

摘要

延長光照提升泌乳牛產能，包括了生長及泌乳的效益已被證實，而促進泌乳牛產能主要是藉由類胰島素生長因子-I (insulin-like growth factor-1, IGF-I) 於血液中濃度的提升所造成。然而，延長光照對於季節性發情育種的乳山羊產能影響仍不清楚；因此，本研究即企圖探討延長光照對於泌乳羊可能之影響。試驗動物為10 頭 Alpine 經產羊及3頭初產羊，依產次、分娩日期及體型平均分配於長日照組 (long daily photoperiod, LP)，與自然日照組 (natural daily photoperiod, NP)。LP 組光照長度為16小時 (0400 - 2000)，照度設定於羊隻眼睛高度處大於 600 lux。實驗期為分娩後 22 週，於 2005年二月至八月進行。兩組皆採符合 NRC 建議泌乳山羊營養需要量所配製之相同日糧配方。每日擠乳2次，並於每次擠乳後餵飼當日日糧 1/2 量。每週末二日記錄乳量、餵飼量及剩料量，並採集乳樣及剩料進行乳組成及營養成分分析。結果顯示，延長光照處理對於乳糖、乳脂率及乳生菌數皆未有影響 (P > 0.05)。LP 組血漿中 IGF-I 濃度增加 (P < 0.05)，原始乳量則於第6及7週有提升之趨勢 (3.74 vs. 2.24 kg/d; 3.76 vs. 2.54 kg/d; P < 0.10)，4% 乳脂校正乳亦是相似結果。延長光照平均增加 IGF-I 達 25.5%，4% 乳脂校正乳乳量達 23.2%，及採食量 41.4%。綜合上述，延長光照可有效增進乳羊產能。

關鍵字

乳山羊 ； 延長光照 ； 乳產量

並列摘要

The long daily photoperiod (LP) has been proved to enhance dairy cattle production including growth and lactation through increasing the concentration of plasma IGF-I. However, its effect on dairy goat, a seasonal breeder, was unclear. In this study, we intended to elucidate the effect of long daily photoperiod on milk production of dairy goat. Ten multiparous and three primiparous Alpine dairy goats were evenly assigned to LP (16 h lighting per day, 0400 - 2000) or natural daily photoperiod (NP) according to parity, kidding date, and body condition. Light intensity was set more than 600 lux at goats’ eyes level. The experiment lasted for 22 weeks after kidding from Feb to Aug, 2005. Same diet, meeting nutrient recommendation for lactating dairy goat by NRC, was offered to both groups. Goats were milked twice daily, and offered half of daily ration after each milking. Milk, feed, and refusal were weighted and sampled on last two days each week. Results showed that LP had no effect on lactose and milk fat concentrations and raw milk total bacterial number (P > 0.05). The average concentration of plasma IGF-I was increased by LP treatment (P < 0.05). Milk yield on weeks 6 and 7 tended to be increased by LP (3.74 vs. 2.24 kg/d; 3.76 vs. 2.54 kg/d; P < 0.10). The 4% fat corrected milk (FCM) response was similar to milk yield. The LP treatment increased IGF-I, FCM and feed intake by 25.5%, 34.7% and 41.4% on average, respectively. In conclusion, photoperiod is an effective method to improve dairy goat production.

並列關鍵字

Dairy goat ； Long daily photoperiod ； Milk production

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