白肉雞利用棕櫚油粉所含能量之探討

Abstract

隨著白肉雞產業的快速發展，對高效能量來源的需求日益增加。棕櫚油因其高能量密度及改善飼料嗜口性的特性，在家禽飼料中具有重要應用價值。而棕櫚油粉在保育豬飼糧中已展現優異表現，然其在家禽飼糧中的應用效果尚待評估。本研究旨在探討白肉雞對棕櫚油粉所含能量的利用能力。 研究分為三個試驗：試驗一以全糞收集法檢測能量之消化率，選用39週齡來亨蛋公雞，測定棕櫚油、含游離甘油棕櫚油粉與不含游離甘油棕櫚油粉的氮矯正真可代謝能（TMEn）濃度，結果分別為8683.77、7063.70與8489.60 cal/g，三者均呈現高達90% 的能量消化率。試驗二採用指示劑法，以0日齡Ross 308白肉雞為實驗動物，將生長階段分為育雛期、生長期與肥育期，評估不同油脂來源對能量消化率的影響。結果顯示，隨著白肉雞生長，各組飼糧之能量消化率均呈現上升趨勢。棕櫚油在育雛期、生長期和肥育期的AME分別為5492.4、6784.4與7683.2 kcal/kg；含游離甘油棕櫚油粉分別為2227.8、4994.4與6583.9 kcal/kg；不含游離甘油棕櫚油粉則為2012.2、3743.9與7853.2 kcal/kg。試驗三進行生長試驗，評估不同油脂來源對白肉雞生長性能的影響。結果顯示，棕櫚油組展現最佳生長表現，體重增加達2108克，飼料轉換率為1.29。 本實驗結果顯示，白肉雞對油脂的利用呈現明顯的階段性差異：早期生長階段因消化系統發育不完全，對長鏈飽和脂肪酸的消化吸收效率較低；隨著生長進入後期，不同油脂來源的能量利用效率則趨於一致。此發現說明成熟蛋公雞AMEn 濃度不宜直接作為白肉雞早期飼糧配方設計的唯一依據。儘管棕櫚油粉在保育豬飼糧中具有良好效果，但證實不適合做為白肉雞飼糧油脂來源。含游離甘油處理組雖未達顯著差異，但在最終上市體重方面呈現正面趨勢。建議實務應用上應採取更精確的分階段營養策略飼養白肉雞，特別是在油脂來源的選擇上，應依據白肉雞不同生長階段的生理特性進行調整。

With the rapid development of the broiler industry, the demand for high-efficiency energy sources is increasing. Palm oil holds significant application value in poultry feed due to its high energy density and ability to improve feed palatability. While palm oil powder (POP) has shown excellent performance in nursery pig diets, its effectiveness in poultry feed requires evaluation. This study aimed to investigate the ability of broiler chickens to utilize the energy contained in POP. The research comprised three experiments. Experiment 1 determined the nitrogen-corrected true metabolizable energy (TMEn) concentration of palm oil, POP containing free glycerol, and POP without free glycerol using the total excreta collection method with 39-week-old Leghorn roosters. The TMEn values were 8683.77, 7063.70, and 8489.60 cal/g, respectively, with all exhibiting high energy digestibility exceeding 90%. Experiment 2 employed the indicator method using day-old Ross 308 broiler chickens, divided into starter, grower, and finisher phases, to evaluate the effect of different fat sources on energy utilization. Results showed that the apparent metabolizable energy (AME) of diets in all groups increased as the broilers grew. The AME values (kcal/kg) for palm oil during the starter, grower, and finisher phases were 5492.4, 6784.4, and 7683.2, respectively; for POP containing free glycerol, they were 2227.8, 4994.4, and 6583.9, respectively; and for POP without free glycerol, they were 2012.2, 3743.9, and 7853.2, respectively. Experiment 3 conducted a growth trial to assess the impact of different fat sources on broiler growth performance. Results indicated that the palm oil group exhibited the best growth performance, with a body weight gain (BWG) of 2108 g and a feed conversion ratio (FCR) of 1.29.

The results demonstrate significant age-dependent differences in fat utilization by broilers: efficiency of digesting and absorbing long-chain saturated fatty acids is lower during the early growth stage due to the immature digestive system; however, energy utilization efficiency from different fat sources tends to converge in later growth stages. This finding suggests that TMEn values determined in adult roosters should not be the sole basis for formulating diets for early-stage broilers. Despite its effectiveness in nursery pig diets, POP proved unsuitable as a fat source for broiler feed. Although the treatment including free glycerol (POP containing free glycerol) did not show significant differences, it exhibited a positive trend regarding final market body weight. It is recommended that practical applications adopt more precise phase-feeding strategies, particularly in selecting fat sources adjusted according to the physiological characteristics of broilers at different growth stages.