不同環境溫度和飼糧能量來源對白肉雞生長之影響

Effects of different environmental temperatures and dietary energy sources on the growth of broilers

羅蘭(Ndlandla Nonhlanhla Fortunate)

指導教授 ： 翁瑞奇 ； 李嘉偉

國立屏東科技大學/農學院/動物科學與畜產系所/碩士(2021年)

https://doi.org/10.6346/NPUST202100400

摘要

育肥肉雞於合適溫度（22°C至26°C）可達最佳生長性能。然而，在熱帶地區正常環境條件下飼養之肉雞暴露於高溫（30°C以上）下導致熱緊迫。因此，本研究為探討調整飼糧中澱粉與脂肪比例對熱緊迫肉雞之行為、生長性能、屠體性狀及血液的影響。針對15至36日齡肉雞進行兩項試驗，包括飼養試驗及實驗室分析。在32℃ ± 2℃的高溫（區域1）及23℃ ± 2℃的適溫（區域2）條件下，餵飼肉雞不同澱粉脂肪比之飼料（處理1：低脂＝14.69及處理2：高脂＝6.24）。生長試驗採2（溫度）×2（飼糧）複因子設計，隨機分組至每區域，每處理3重複。行為試驗採隨機分組，2飼糧處理組3重複，共計6個實驗組。結果顯示，與處理1的肉雞相比，處理2中肉雞飼料採食量、平均增重和飼料轉換率（FCR）有顯著差異（P＜0.05），但屠體性狀及血液異嗜性白血球與淋巴球比值（heterophils to lymphocytes ratio, H/L ratio）無顯著差異（P＞0.05）。肉雞在高環境溫度（0.45）下喘氣比例顯著（P＜0.05）高於適溫環境溫度（0.15），而在適溫環境溫度下肉雞採食量顯著高於高環境溫度。高脂試驗雞隻飼料採食時間顯著高於低脂試驗雞隻（P＜0.05）。偏好測試中結果顯示，在熱緊迫條件下的肉雞在兩種試驗飼糧中偏好高脂飼糧。因此，在熱緊迫條件下，減少飼糧中澱粉脂肪比例能改善肉雞生長性能並提高生產力。

關鍵字

行為 ； 肉雞 ； 熱緊迫 ； 生理學 ； 澱粉脂肪比

並列摘要

Finishing broilers grown under thermo-neutral temperatures (22℃ - 26℃) can perform to their optimum growth capacity. However, broilers raised under the normal environmental conditions in Tropical regions are exposed to very high temperatures (above 30℃) leading to heat stress. Therefore, the effects of different dietary starch to lipid ratios on the behaviour, performance, carcass characteristics and blood parameters of broilers under heat stress were evaluated in the present study. Two trials comprising of a feeding trial and laboratory analysis were carried out on broilers aged from 15 to 36 days. The birds were given grower-finisher diets with different starch to lipid ratio (Treatment 1: Low lipid diet = 14.69 and Treatment 2: High lipid diet = 6.24) under cyclic heat stress 32℃ ± 2℃ (block 1) and thermoneutral zone 23℃ ± 2℃ (block 2). A randomised complete block design laid down in a 2 x 2 factorial experiment with 3 replications per treatment diet within block was used for the growth experiment. The behaviour experiment was laid down in a randomised complete block design with two treatment diets, three replicates and a total of six experimental units. Results showed that, there were significant differences (p < 0.05) in the feed intake, average weight gain and FCR of broilers in treatment 2 compared to broilers in treatment 1. The carcass characteristics and heterophil to lymphocyte ratio (H:L ratio) were not significantly affected (p > 0.05) by the treatments. The proportion of birds panting was significantly higher (p < 0.05) under high ambient temperature (0.45) than under normal ambient temperature (0.15) whilst proportion of birds exhibiting feed behaviour was significantly higher under normal temperature than under high temperature A significantly higher proportion of birds were observed on feeders with the high lipid diet than those with the low lipid diet (p < 0.05). Results of preference test indicated that when broilers are offered a choice between the two diets under heat stress conditions they may be able to make their choice based on their preference for high lipid diet. A reduction in dietary starch to lipid ratio may improve broiler performance and increase productivity, under heat stress conditions.

並列關鍵字

behaviour ； broilers ； heat stress ； physiology ； starch to lipids ratio

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