Jia W, Slominski B A, Bruce H L, Blank G, Crow G, Jones O
Department of Animal Science, University of Manitoba, Winnipeg, Canada R3T 2N2.
Poult Sci. 2009 Jan;88(1):132-40. doi: 10.3382/ps.2008-00204.
The effects of diet type (corn- vs. wheat-based) and multicarbohydrase addition on growth performance, digesta pH and viscosity, intestinal populations of Clostridium perfringens and lactic acid bacteria, and gut lesion score (from 0 to 4, where 0 = no gross lesions, 4 = severe extensive necrosis) of broiler chickens during oral challenge with C. perfringens (none or 10(8) cfu/bird on d 13) were studied in a 39-d experiment. A total of 1,216 male Ross-308 chickens was assigned to 8 dietary treatments in a randomized complete block design providing 8 replicate pens per treatment. Diets were formulated to meet the NRC protein requirement but were suboptimal in energy level. When compared with birds fed corn-based diets, chickens fed wheat-based diets had inferior (P < 0.01) final BW (2.49 vs. 2.59 kg) and feed conversion ratio (FCR; 1.83 vs. 1.78). Pathogen challenge significantly (P < 0.05) impaired growth performance and increased C. perfringens numbers and average lesion score. Increased (P < 0.01) C. perfringens counts (2.4 vs. 1.5 log(10) cfu/g of digesta) and intestinal lesion score (0.9 vs. 0.4) were observed for challenged birds fed wheat-based diets. No difference in digesta pH and lactic acid bacteria numbers were found among the treatments. Enzyme addition to both the corn- and wheat-based diets increased bird final BW (2.57 vs. 2.51 kg; P < 0.01), decreased overall FCR (1.78 vs. 1.83; P < 0.01), and, in those consuming wheat-based diets, reduced digesta viscosity (from 4.1 to 2.7 mPa.s; P < 0.01). Enzyme supplementation assisted the challenged birds in maintaining their optimal growth performance by improving (P < 0.05) average daily gain (59.5 vs. 56.9 g) in those consuming corn-based diets and FCR (1.83 vs. 1.90) in those consuming wheat-based diets to values similar to those observed in control birds (59.7 g/d and 1.84, respectively). In conclusion, enzyme addition improved growth performance and mitigated the negative effects of C. perfringens challenge.
在一项为期39天的试验中，研究了日粮类型（玉米型与小麦型）和添加多种碳水化合物酶对肉鸡在口服产气荚膜梭菌（第13天不接种或每只鸡接种10⁸ cfu）攻毒期间的生长性能、食糜pH值和粘度、产气荚膜梭菌和乳酸菌的肠道数量以及肠道损伤评分（0至4分，0分表示无明显损伤，4分表示严重广泛坏死）的影响。总共1216只罗斯308雄性肉鸡被随机完全区组设计分配到8种日粮处理中，每个处理设8个重复栏。日粮配方满足NRC蛋白质需求，但能量水平欠佳。与饲喂玉米型日粮的鸡相比，饲喂小麦型日粮的鸡最终体重较低（2.49 vs. 2.59 kg，P < 0.01）且饲料转化率较低（FCR；1.83 vs. 1.78，P < 0.01）。病原菌攻毒显著（P < 0.05）损害生长性能，增加产气荚膜梭菌数量和平均损伤评分。对于饲喂小麦型日粮的攻毒鸡，观察到产气荚膜梭菌计数增加（P < 0.01，2.4 vs. 1.5 log₁₀ cfu/g食糜）和肠道损伤评分增加（0.9 vs. 0.4）。各处理间食糜pH值和乳酸菌数量无差异。在玉米型和小麦型日粮中添加酶均增加了鸡的最终体重（2.57 vs. 2.51 kg；P < 0.01），降低了总体FCR（1.78 vs. 1.83；P < 0.01），并且在饲喂小麦型日粮的鸡中，降低了食糜粘度（从4.1降至2.7 mPa·s；P < 0.01）。酶添加通过提高（P < 0.05）饲喂玉米型日粮鸡的平均日增重（59.5 vs. 56.9 g）和饲喂小麦型日粮鸡的FCR（1.83 vs. 1.90），使其达到与对照鸡相似的值（分别为59.7 g/d和1.84），从而帮助攻毒鸡维持其最佳生长性能。总之，添加酶改善了生长性能并减轻了产气荚膜梭菌攻毒的负面影响。
