PDF(Pubmed)
Abstract：
This study evaluated the impacts of α-amylase (AM) and coated α-amylase (CAM) on bull performance, nutrient digestibility, and ruminal fermentation. This study randomized 60 Holstein bulls of 365 ± 11.5 days of age and 457.5 ± 9.35 kg body weight into three groups: without AM addition, adding AM 0.6 g/kg dry matter (DM), and adding CAM 0.6 g AM/kg DM, separately. This whole experimental period was 80 days, including a 20-day adaptation period and a 60-day data and sample acquisition period. In comparison with the unsupplemented control, dry matter intake (DMI) was unaltered; however, average daily gain (ADG) and feed efficiency (FE) were greater for AM or CAM addition. Bulls receiving AM or CAM supply had greater total-tract nutrient digestibility, ruminal total volatile fatty acids (VFA) content, propionate molar proportion, cellulolytic enzyme and AM activities, and the number of microorganisms. In addition, the activities of AM and trypsin in the jejunum and ileum and glucose, albumin, and total protein concentrations in serum were greater for AM or CAM addition compared to the control. When comparing the supplementation mode of AM, bulls receiving CAM addition had greater ADG and FE. The crude protein and starch digestibility and intestinal AM and trypsin activity were higher, while acid detergent fiber (ADF) digestibility was lower for CAM addition than for AM addition. The lower propionate molar proportion and cellobiase and carboxymethyl cellulase activities, together with Ruminococcus albus, Ruminococcus flavefaciens, and Fibrobacter succinogenes populations were observed for CAM addition compared with AM addition. However, there were greater glucose, albumin, and total protein concentrations in serum after adding CAM. According to the data, the supply of AM improved ADG, nutrient digestion, and rumen fermentation. Notably, the optimum supplementation mode was in the form of CAM in bulls.
摘要：
本研究评估了α-淀粉酶（AM）和包衣α-淀粉酶（CAM）对公牛性能的影响，营养素消化率，和瘤胃发酵。这项研究将60头365±11.5日龄和457.5±9.35kg体重的荷斯坦公牛随机分为三组：不添加AM，添加AM0.6g/kg干物质（DM），并添加CAM0.6gAM/kgDM，分开。整个实验期是80天,包括20天的适应期和60天的数据和样本采集期。与未补充的对照相比，干物质摄入量(drymatteradvance,drymatteradvantage,drymatteradvance,dometimes,dowever,添加AM或CAM时，平均日增重（ADG）和饲料效率（FE）更大。接受AM或CAM供应的公牛具有更大的总道养分消化率，瘤胃总挥发性脂肪酸（VFA）含量，丙酸盐摩尔比例，纤维素分解酶和AM活性，以及微生物的数量。此外,空肠和回肠中的AM和胰蛋白酶以及葡萄糖的活性，白蛋白,与对照组相比，添加AM或CAM时血清中的总蛋白浓度更高。当比较AM的补充模式时，接受CAM添加的多头有更高的ADG和FE。粗蛋白和淀粉的消化率和肠道AM和胰蛋白酶活性均较高,而添加CAM的酸性洗涤剂纤维（ADF）消化率低于添加AM。较低的丙酸摩尔比例和纤维二糖酶和羧甲基纤维素酶的活性，连同白斑Ruminococcus,黄反肠球菌，与AM添加相比，观察到CAM添加和琥珀酸纤维杆菌种群。然而,有更多的葡萄糖，白蛋白,添加CAM后血清中的总蛋白浓度。根据数据,AM的供应改进了ADG，营养消化，和瘤胃发酵。值得注意的是,最佳补充方式是公牛的CAM形式。
