| Abstract: | 本試驗旨在探討肉雞飼糧中添加卵磷脂對改善肉雞對脂肪消化率之效 果，是否受到脂肪種類及肉雞年齡之影響；並測定卵磷脂之代謝能值。試 驗一，120隻3日齡愛拔益加雛公雞逢機分配至2 (飼糧添加8%大豆油或牛 脂)×2 (飼糧添加0或2%卵磷脂)複因子設計中，每處理6重複，每重複5隻 。雞隻飼 養於電熱式金屬網底代謝籠中；於7日齡及21日齡起分別收集糞 便5日。結 果顯示，大豆油之消化率較牛油者高(P < 0.01)；21日齡肉雞 對脂肪消化 率亦較7日齡者高(P < 0.01)；脂肪種類及年齡間有交互作 用(P < 0.01)； 添加卵磷脂改善脂肪消化率(P < 0.06)；而卵磷脂與脂 肪種類及年齡間均 無交互作用(P > 0.05)，顯示卵磷脂促進脂肪消化率 之效果，並不受脂肪 種類及肉雞年齡之影響。大豆油中個別脂肪酸之消 化率較牛油中之個別脂 肪酸消化率高(C16:0, C18:0, C18:2及C18:3: P < 0.01; C18:1: P < 0.05)，21日齡時之個別脂肪酸消化率亦較7日齡時 高(C16:0, C18:0, C18:1, C18:2及C18:3: P < 0.01)，卵磷脂提高C16:0 及C18:0之消化率(P < 0.01)，而對C18:1, C18:2及C18:3消化率則無影 響(P < 0.05)。 試驗二，120隻8日齡愛拔益加(Arbor Acres)雛公雞 逢機分配至4處理組，分別飼予以下四種玉米-大豆粕為主飼糧：(1) 基礎 飼糧，含20%葡萄糖；(2) 含15%葡萄糖及5%卵磷脂；(3) 含10%葡萄糖 及10%卵磷脂；(4) 含20%卵磷脂；每處理6重複，每重複5隻，雞隻飼養於 電熱式金屬網底代謝籠中；於14日齡開始收集糞便，至21日齡結束。以指 示劑法計算飼糧中所含之代謝能；以迴歸法估算卵磷脂之代謝能值。結果 測得，卵磷脂之代謝能值為6,147仟卡/公斤。
The objects of the study were to investigate (1) whether fatsource and age of chicks affecting the efficacy of lecithin inimproving the digestibility of fat in broilers and (2) themetabolizable energy value of lecithin. Experiment 1, one hundred and twenty 3-d old Arbor Acres chickswere allotted to a 2?2 factorial design arrangement. Chicks werefed diets supplemented with 8% of soybean oil or tallow and 0 or2% of lecithin. Lecithin was supplemented by replacing starch ofthe diets. And 0.25% Cr2O3 was added in diet as an indicator.There were six replicates each treatment with five chicks eachreplicate. Chicks were fed in a heated wire-floored metabolismcage; excreta were collected for 5d each starting from age 7 and21 d. The results indicated that the digestibility of soybean oilwas higher than the digestibility of tallow (P< 0.01). Elderchicks had a higher fat digestibility than younger chicks had (P <0.01). Adding lecithin to diets improved fat digestibility (P <0.06). There were no interaction between fat source?lecithin andbetween lecithin?age (P > 0.05). The digestibility of fatty acidsin soybean oil was higher than the fatty acids in tallow (C16:0,C18:0, C18:2 and C18:3: P < 0.01; C18:1: P < 0.05). Elder chickshad a higher individual fatty acid digestibility than youngerchicks had (C16:0, C18:0, C18:1, C18:2 and C18:3: P < 0.01).Adding lecithin to diets could improve C16:0 and C18:0digestibility (P < 0.01). But not the digestibility of C18:1,C18:2 and C18:3 (P > 0.05). Experiment 2, one hundred and twenty 8-d old Arbor Acres chickswere allotted to four treatments and were fed one of four corn- SBMdiets: (1) Diet 1, containing 20% glucose; (2) Diet 2, containing15% glucose and 5% lecithin; (3) Diet 3, containing 10% glucoseand 10% lecithin; (4) Diet 4, containing 20% lecithin. And 0.25%Cr2O3 was added in diet as an indicator. There were six replicateseach treatment with five chicks each replicate. Chicks were fed ina heated wire-floored metabolism cage; excreta were collected from14 to 21-d old. The metabolizable value of lecithin was determinedby extrapolating lecithin to 100% of diet according to the linearregression between the metabolizable energy of diets and thelecithin contents. The determined metabolizable energy of lecithinwas 6147 kcal/kg. |
