飼糧中添加酵素對於肉雞生長性能與腸道健康之影響

家禽飼糧中含有多量的非澱粉多醣（Non-starch polysaccharides, NSP），如阿拉伯木聚醣、β-葡聚醣等，單胃動物之內源性酵素難以消化利用，因此飼糧中可額外添加NSP酶，以提高NSP之利用率。本研究旨在探討飼糧中添加不同組合之酵素對肉雞生長性能及腸道健康之影響。試驗採用300隻1日齡ROSS 308白肉雞，隨機分配至五個處理組，分別為A：對照組（基礎飼糧）、B：基礎飼糧中添加250 g/ton Bestzyme EnerGen Supreme（木聚醣酶 ≥ 50,000 U/g、纖維素酶 ≥ 1,500 U/g、β-甘露聚醣酶 ≥ 5,000 U/g、β-葡聚醣酶 ≥ 6,000 U/g、澱粉酶 ≥ 500 U/g和蛋白酶 ≥ 30,000 U/g）、C：基礎飼糧中添加200 g/ton 禽用複合物、D：基礎飼糧中添加200 g/ton Rovabio® Advance（木聚醣酶 ≥ 25,000 黏度單位（visco unit, VU）/g、β-葡聚醣酶 ≥ 17,200 VU/g和阿拉伯呋喃醣苷酶 ≥ 9,250 VU/g）、E：基礎飼糧中添加100 g/ton Axtra® XAP（木聚醣酶20,000 U/g、澱粉酶2,000 U/g和蛋白酶40,000 U/g）。飼養過程中，飼糧及飲水皆採任食。每週雞隻個別秤重並記錄採食量，在試驗第21及42日齡時進行犧牲採樣並分析生長性能、血液生化值、腸道菌相、腸道性狀及營養消化率。試驗結果顯示，生長性能方面，飼糧中添加酵素可顯著改善飼料轉換率，且E組於整體期間顯著改善生長性能（P < 0.05）。由臟器重量結果顯示，E組顯著較A組增加21日齡雞隻之肝臟重量百分比；於42日齡時，C、D組之腸道重量及重量百分比、C組脾臟重量及重量百分比顯著低於A組（P < 0.05）。於血液生化值方面，E組顯著較A組增加21日齡肉雞血清中白蛋白及尿酸含量，並降低天門冬胺酸轉胺酶之含量；42日齡時，C組顯著較A組增加天門冬胺酸轉胺酶、尿素氮、尿酸、葡萄糖、三酸甘油脂及磷之含量，且E組與A組相比，顯著增加血漿中磷之含量，並降低總膽固醇及鈣之含量（P < 0.05）。於腸道菌相方面，無顯著性差異。由腸道性狀結果顯示，飼糧中添加酵素可顯著降低空腸及迴腸之腺窩深度，並提高絨毛高度與腺窩深度之比值（P < 0.05）。於營養消化率方面，於各處理組間皆無顯著差異。綜合上述，飼糧中添加酵素可改善肉雞之腸道性狀以提高生長性能，對於肉雞具有正面之影響。

關鍵字

肉雞；酵素；生長性能；腸道健康

並列摘要

Poultry diets contain a certain amount of non-starch polysaccharides (NSP), such as xylans, b-glucan etc. Endogenous enzymes in monogastric animals are difficult to digest and utilize, therefore, dietary supplementation of NSP enzymes can increase the utilization of NSP. The objective of this study was to evaluate the effect of dietary supplementation of enzymes on the growth performance and intestinal properties of broilers. Three hundred-day-old broilers were randomly divided into five treatments. The five treatment groups were= A: basal diet, B: 250 g/ton Bestzyme EnerGen Supreme (xylanase ≥ 50,000 U/g, cellulase ≥ 1,500 U/g, β- mannanase ≥ 5,000 U/g, β- glucanase ≥ 6,000 U/g, amylase ≥ 500 U/g and protease ≥ 30,000 U/g), C: 200 g/ton Bestzyme, D: 200 g/ton Rovabio® Advance (xylanase ≥ 25,000 VU/g, β- glucanase ≥ 17,200 VU/g and arabinofuranosidase ≥ 9,250 VU/g), E: 100 g/ton Axtra® XAP (20,000 U/g xylanase, 2,000 U/g amylase and 40,000 U/g protease). During the experiment, feed and water were provided ad libitum. Birds were weighed individually and recorded the feed intake. Birds were sacrificed on days 21 and 42 to analyze growth performance, blood biochemical, intestinal microflora, intestinal morphology, and nutrient digestibility. The results showed that adding enzymes to the feed can significantly improve the feed conversion rate and Group E showed significant improvement throughout the period (P < 0.05). According to the results of organ weight, Group E showed a significant increase in liver weight ratio of 21-day-old chickens compared to Group A; at 42 days of age, the intestinal weight, and intestinal weight ratio of Group C and D, spleen weight, and spleen weight ratio of Group C were significantly lower than Group A (P < 0.05). In terms of blood biochemistry, Group E showed a significant increase in albumin and uric acid content in 21-day-old broiler chickens compared to Group A, and a decrease in alanine aminotransferase content; at 42 days of age, Group C showed a significant increase in alanine aminotransferase, urea nitrogen, uric acid, glucose, triglycerides, and phosphorus content compared to Group A, and Group E showed a significant increase in plasma phosphorus content compared to Group A, and a decrease in total cholesterol and calcium content (P < 0.05). In terms of intestinal microflora, there was no significant difference. The results of intestinal morphology showed that adding enzymes to the feed can significantly reduce the depth of crypts in the jejunum and ileum, and increase the ratio of villus height to crypt depth (P < 0.05). In terms of nutrient digestibility, there was no significant difference among the treatment groups. In summary, adding enzymes to the feed can improve the intestinal morphology of broiler chickens and enhance growth performance, which has a positive impact on broiler chickens.