本研究以兩個試驗分別探討飼糧中添加不同精油對肉雞每日飼料採食量、營養分消化率及腸道菌相之影響。試驗一，30羽17日齡愛拔益加肉雞，個別籠飼，逢機分配至5處理組，每處理組6重複，分別飼予不添加或添加200 ppm不同精油： (1) 百里香 (thyme；T)； (2) 肉桂 (cinnamon； C)； (3) 牛至 (oregano；O) 或 (4) 迷迭香 (rosemary；R) 之試驗飼糧，為期20天。試驗二，30羽27日齡羅斯肉雞，個別籠飼，逢機分配至5處理組，每處理組6重複，分別飼予與試驗一相同之試驗飼糧，為期18天。試驗一及二，測定雞隻每日飼料採食量、營養分消化率及腸道pH值與菌相。合併試驗一及二結果顯示，飼糧中添加R，在數字上提高每日飼料採食量，飼糧中添加不同精油皆提高總脂肪酸及飽和脂肪酸之全腸道及迴腸消化率 (P<0.01)。飼糧中添加T，C及R皆顯著提高蛋白質及不飽和脂肪酸之全腸道及迴腸消化率 (P<0.05)。T、O及R，顯著提高肉雞盲腸內容物中乳酸菌菌落數 (P<0.05)， C及R，提高肉雞盲腸內容物中乳酸菌/大腸桿菌菌落數 (P<0.05)。飼糧中添加精油，對腸道內容物pH值、大腸桿菌菌落數及乳酸菌及大腸桿菌總菌落數皆無顯著影響。綜合以上，飼糧中添加精油可有效地提高營養分消化率，改善盲腸菌相，其中以C及R之效果最佳。 Two trials were conducted to investigate the effect of dietary supplementation of different essential oil on daily feed intake, nutrient digestibility and intestinal microflora of broiler chickens. In trial 1, thirty 17-d-old Arbor Acres chicks were allotted to 5 treatments with 6 replicates per treatment. Chicks were reared in individual cages and fed diets without or with supplementing 200 ppm of different essential oil: (1) thyme (T); (2) cinnamon (C); (3) oregano (O) and (4) rosemary (R) for 20 days. In trial 2, thirty 27-d-old Ross chicks were allotted to 5 treatments with 6 replicates per treatment. Chicks were reared in individual cages and fed same diets as in trial 1 for 18 days. Daily feed intake, nutrient digestibility, pH and microbial counts of digestive tract contents were measured in trial 1 and 2. The combined results showed that dietary supplementation of R numerically improved daily feed intake. Supplementing different essential oil in diet improved fecal and ileal digestibility of total fatty acid and saturated fatty acid (P<0.01). Supplementing T, C and R in diet significantly improved fecal and ileal digestibility of protein and unsaturated fatty acid (P<0.05). Supplementing T, O and R in diet improved caecum lactobacillus counts (P<0.05). Supplementing C and R in diet increased caecum lactobacillus/coliforms (P<0.05). Supplementing different essential oil in diet did not affect pH of digestive tract contents, coliforms and lactobacillus+coliforms counts. In conclusion, supplementing EO, especially C and R, in diet effectively improved caecal microbial environment and nutrient digestibility of broiler chickens.
