AN INVITRO ASSAY FOR PREDICTION OF BROILER INTESTINAL VISCOSITY AND GROWTH WHEN FED RYE-BASED DIETS IN THE PRESENCE OF EXOGENOUS ENZYMES
AN INVITRO ASSAY FOR PREDICTION OF BROILER INTESTINAL VISCOSITY AND GROWTH WHEN FED RYE-BASED DIETS IN THE PRESENCE OF EXOGENOUS ENZYMES
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DOI：
10.3382/ps.0720137
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发表时间：
1993-01-01
期刊：
影响因子：
4.4
通讯作者：
CLASSEN, HL
中科院分区：
文献类型：
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作者：
BEDFORD, MR;CLASSEN, HL
为预测肉鸡黑麦基饲粮中微生物酶源的功效，建立了两阶段体外测定程序。该方法使用全饲粮作为底物来预测饲喂这种饲粮的鸟类体内肠道粘度和最终体重。以黑麦为基础的日粮最大限度地提高其体外粘度的最佳条件是消化。6克饮食（通过1毫米的筛网碾碎）。9毫升。1 N HCI，含2,000 U胃蛋白酶/mL，在40℃下孵育45分钟。加入含有8 mg胰酶/mL（8倍USP）的1 M NaHCO3 3 mL，密封试管，间歇涡旋孵育2 h。然后将食糜离心（12,700 x g），收集上清液使用数字粘度计进行粘度分析。该试验用于以黑麦为基础的饮食，其中含有0、1,。2,。4,。8，或1.6%的木聚糖酶来源（实验长achiachiatum木霉产品）。将结果与饲喂这些饲粮的19日龄肉鸡梅克尔憩室近端和远端体重和肠道粘度进行比较。体外试验能准确预测鸡体内肠道黏度（近端r2 = 0.758, P < 0.0001，远端r2 = 0.667, P < 0.0001）和最终体重（r2 = 0.660, P < 0.0001）。上述数据表明，体外试验是评估酵素制剂在黑麦基饲粮中促进雏鸡生长能力的可靠方法。
A two-stage in vitro assay procedure was developed for predicting the efficacy of microbial enzyme sources in rye-based diets for broiler chicks. The procedure uses the complete diet as substrate to predict the in vivo intestinal viscosity and final weight of birds fed such diets. The optimum conditions for maximizing in vitro viscosity of a rye-based diet consisted of digesting .6 g of diet (ground through a 1-mm screen) in .9 mL of .1 N HCI containing 2,000 U pepsin/mL for 45 min at 40 C. At the end of this incubation phase, .3 mL 1 M NaHCO3 containing 8 mg pancreatin/mL (8 x USP) was added and the tube sealed and incubated for 2 h with intermittent vortexing. The digesta was then centrifuged (12,700 x g) and the supernatant collected for viscosity analysis using a digital viscometer. This assay was used for a rye-based diet containing either 0, .1, .2, .4, .8, or 1.6% of a xylanase source (experimental Trichoderma longibrachiatum product). The results were compared to weight and intestinal viscosity proximal and distal to Meckel's diverticulum of broilers (19 days of age) that had been fed these diets. The in vitro assay accurately predicted the in vivo intestinal viscosity (proximal r2 = .758, P < .0001, distal r2 = .667, P < .0001) and final weight of these birds (r2 = .660, P < .0001). The data suggest that the in vitro assay is a reliable assay for assessing the growth-promoting ability of an enzyme preparation in chicks fed rye-based diets.