Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
Agriculture and Agri-Food Canada, Winnipeg, Manitoba, Canada.
PLoS One. 2021 May 3;16(5):e0236231. doi: 10.1371/journal.pone.0236231. eCollection 2021.
Limited use of medication in poultry feed led to the investigation of exogenous enzymes as antibiotic alternatives for controlling enteric disease. The objective of this study was to evaluate the effects of diet β-glucanase (BGase) and medication on β-glucan depolymerization, digestive tract characteristics, and growth performance of broilers.
Broilers were fed hulless barley (HB) based diets with BGase (Econase GT 200P from AB Vista; 0 and 0.1%) and medication (Bacitracin and Salinomycin Na; with and without) arranged as a 2 × 2 factorial. In Experiment 1, 160 broilers were housed in cages from d 0 to 28. Each treatment was assigned to 10 cages. In Experiment 2, broilers (2376) were housed in floor pens and vaccinated for coccidiosis on d 5. Each treatment was assigned to one floor pen in each of nine rooms.
In Experiment 1, the soluble β-glucan weighted average molecular weight (Mw) in the ileal digesta was lower with medication in the 0% BGase treatments. Peak molecular weight (Mp) and Mw were lower with BGase regardless of medication. The maximum molecular weight for the smallest 10% β-glucan (MW-10%) was lower with BGase addition. In Experiment 2, Mp was lower with medication in 0% BGase treatments. Beta-glucanase resulted in lower Mp regardless of medication, and the degree of response was lower with medication. The MW-10% was lower with BGase despite antibiotic addition. Body weight gain and feed efficiency were higher with medication regardless of BGase use through-out the trial (except d 11-22 feed efficiency). Beta-glucanase resulted in higher body weight gain after d 11 and worsened and improved feed efficiency before and after d 11, respectively, in unmedicated treatments.
BGase and medication caused the depolymerization of soluble ileal β-glucan. Beta-glucanase acted as a partial replacement for diet medication by increasing growth performance in coccidiosis vaccinated broilers.
由于在禽类饲料中有限地使用药物，因此人们开始研究外源性酶作为替代抗生素控制肠道疾病的方法。本研究的目的是评估日粮 β-葡聚糖酶（BGase）和药物对 β-葡聚糖解聚、消化道特征和肉鸡生长性能的影响。
本试验以裸大麦（HB）为基础日粮，日粮中添加 BGase（AB Vista 的 Econase GT 200P；0 和 0.1%）和药物（杆菌肽和盐霉素 Na；有和无），采用 2×2 因子设计。试验 1，160 只肉鸡在笼中饲养，从 0 日龄到 28 日龄。每个处理组分配到 10 个笼中。试验 2，2376 只肉鸡在地板笼中饲养，在 5 日龄时接种球虫疫苗。每个处理组分配到 9 个房间中的一个地板笼中。
在试验 1 中，在 0%BGase 处理中，有药物组回肠食糜中可溶 β-葡聚糖的重均分子量（Mw）较低。添加 BGase 后，不论是否添加药物，最大分子量（Mp）和 Mw 均降低。最小的 10%β-葡聚糖（MW-10%）的最大分子量降低。在试验 2 中，在 0%BGase 处理中，有药物组 Mp 较低。不论是否添加药物，添加 BGase 后 Mp 降低，且响应程度较低。尽管添加了抗生素，但添加 BGase 后 MW-10%降低。整个试验过程中（除 11-22 日龄饲料效率外），添加药物可提高体重增重和饲料效率。无论是否使用 BGase，添加药物后 11 日龄后体重增重更高，在未添加药物的处理中，11 日龄前和 11 日龄后分别改善和降低了饲料效率。
BGase 和药物导致可溶的回肠 β-葡聚糖解聚。在接种球虫疫苗的肉鸡中，BGase 可部分替代日粮药物，提高生长性能。
