飼糧粗蛋白及植酸酶添加量對白肉雞生長性能與屠體性狀之影響

本研究旨在探討飼糧不同粗蛋白及植酸酶添加量，對白肉雞生長性能及屠體性狀之影響，以及雞糞墊料堆肥化前後之成分變化。選取1日齡之愛拔益加（Arbor Acres）品系白肉雞480隻，公母各半，逢機分置於2種粗蛋白質含量×3種植酸酶含量的飼糧處理組。基礎飼糧以玉米－大豆粕為主要原料，含代謝能3,200 kcal/kg、並添加8 mg/kg的銅和40 mg/kg的鋅。粗蛋白質（CP）含量方面，高蛋白質處理組（HCP）在雞隻生長期（1－21日齡）及肥育期（22－35日齡）分別提供CP23%及CP20%的飼糧，低蛋白質處理組（LCP）則提供CP20%及CP17%並補充胺基酸，使離胺酸、甲硫胺酸及羥丁胺酸含量分別與CP23%和CP20%的飼糧相同。植酸酶（PHT）含量方面，區分為PHT250組、PHT500組及PHT750組，分別在雞隻生長期和肥育期飼糧中添加250U/kg、500U/kg及750U/kg的植酸酶。試驗期間飼糧及飲用水皆採取任飼，測定雞隻生長性能及屠體性狀，並收集試驗期間雞隻墊料進行堆肥化處理，分析堆肥化前、後成分變化及測定堆肥種籽相對發芽率。結果顯示，HCP組和LCP組雞隻在試驗期間的日增重、採食量、飼料效率及飼糧成本皆無顯著差異，對雞隻的屠體性狀亦無顯著的影響。PHT 750組雞隻的日增重和採食量，顯著地較PHT 250組為高，活體重（P＜0.01）和胸肉蛋白質含量（P＜0.001）皆極顯著地較PHT 250組為高。雞糞墊料經堆肥化後，其灰分、銅、鋅、磷和鉀的濃度皆明顯地較堆肥化前提高，而氮的濃度則降低，且銅和鋅的濃度皆符合現行法令之規範。綜合以上結果，降低飼糧粗蛋白質含量並以合成胺基酸補充飼糧胺基酸含量，對白肉雞的生長性能無顯著的影響，飼糧添加750 U/kg的植酸酶，有提高雞隻日增重和採食量的效果。

關鍵字

白肉雞；屠體性狀；合成胺基酸；生長性能；植酸酶

並列摘要

The purpose of this study was to investigate the dietary crude protein (CP) and phytase (PHT) supplementation on growth performance and carcass characteristics in broilers, and the compositions change before and after composting of broilers litter. A total of 480 1-d-old Arbor Acres commercial broilers, half male and half female, were alloted into a 2 × 3 factorial arrangement of treatments. Broilers were fed the basal corn-soybean meal diet which contained ME 3,200 kcal/kg and 8 mg Cu/kg and 40 mg Zn/kg. The experimental diet with two levels of CP were groups of high crude protein (HCP) and low crude protein (LCP) and three supplements of phytase levels were groups of PHT 250, PHT 500 and PHT 750. The birds in group HCP were fed diet containing CP 23% and CP 20% in grower period (1 to 21 d-old) and finisher period (22 to 35 d-old), respectively, and birds in group LCP were fed diet with CP 20% plus amino acid (CP 20 + AA) and CP 17% plus amino acid (CP 17 + AA) in grower period and finisher period, respectively. The amino acid content in group LCP diet was adjusted by adding lysine, methionine and threonine to the level of group HCP diet. The birds of groups PHT 250, PHT 500 and PHT 750 were fed diets containing phytase 250, 500 and 750 U/kg in grower-finisher period, respectively. Feed and tap water were provided ad libitum during the experimental period. The growth performance and carcass characteristics of birds were measured. The litters collected were used for compost processing subsequently at the end of feeding trial. Before and after composting, the Cu, Zn, nitrogen (N), phosphorus (P) and potassium (K) concentration of compost were analyzed. After composting, the relative seed germination of compost was measured. The results showed that the average daily gain (ADG), average daily feed intake (ADFI), feed efficiency (gain/feed, G/F) and diet cost were similar for groups HCP and LCP. The birds of group PHT 750 had higher (P ＜ 0.05) ADG and ADFI than the group PHT 250. The dietary CP levels did not affect the carcass characteristics. The group of PHT 750 had significantly larger body weight (P ＜ 0.01) and protein content of breast muscle (P ＜ 0.001) when compared to the group of PHT 250. In the final compost, the ash, Cu, Zn, P and K concentrations were increased and the N concentration decreased when compared to the broiler litter before composting. In conclusion, the dietary supplementation of crystalline amino acids and reduced the content of crude protein in diet did not affect the growth performance for broiler. The birds of group PHT 750 had larger (P ＜ 0.05) ADG and ADFI when compared to the group PHT 250.

並列關鍵字

Broiler ； Carcass characteristics ； Crystalline amino acid ； Growth performance ； Phytase

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