摘要
ABSTRACT Two experiments were conducted to evaluate the inclusion of feed enzymes into beef cattle creep feeds. In the first one, the following treatments were tested in vitro: (1) 100% bermudagrass (GRASS); (2) a mixture of 75% bermudagrass and 25% creep feed (CREEP); (3) CREEP enhanced with endo-1,4-β-xylanase (XYLAN); (4) CREEP enhanced with endo-1,3(4)-β-glucanase (BGLUC). Degradation of fibre was greatest (P ≤ 0.03) for BGLUC, whereas in vitro dry matter digestibility was greatest (P = 0.01) for XYLAN. In the second experiment, cow-calf pairs from 2 farms were split into 3 groups: (1) Group with no supplementation of calves (NO FEED); (2) Group where calves were supplemented in a creep feeding system (PLAIN FEED); and (3) Same feed regimen as PLAIN FEED, but with the addition of endo-1,4-β-xylanase due to the positive results observed in experiment 1 (ENZYME FEED). There was a numerical increase in calf average daily gain in the 2 groups that were supplemented, however, only ENZYME FEED was significantly different (P ≤ 0.03) than NO FEED. At one farm, supplement gain:feed was improved (P = 0.01) in ENZYME FEED, compared to PLAIN FEED. Collectively, these results indicate that xylanase can be used to enhance beef cattle creep feeds.
摘要译文
摘要进行了两个实验，以评估饲料酶在肉牛creep饲料中的含量。在第一个实验中，对以下处理进行了体外测试：（1）100％百慕大草（GRASS）； （2）75％的百慕大草和25％的蠕虫饲料的混合物（CREEP）； （3）内-1,4-β-木聚糖酶（XYLAN）增强CREEP； （4）内-1,3（4）-β-葡聚糖酶（BGLUC）增强CREEP。 BGLUC的纤维降解最大（P≤0.03），而XYLAN的体外干物质消化率最大（P = 0.01）。在第二个实验中，将来自两个农场的母牛-犊牛对分为3组：（1）不补充犊牛的组（NO FEED）； （2）小牛在蠕动进给系统中补充的组（PLAIN FEED）； （3）与普通饲料相同的饲料方案，但由于在实验1（酶饲料）中观察到阳性结果，因此添加了内-1、4-β-木聚糖酶。补充的2组小腿平均日增重均有所增加，但只有酶饲料与无饲料有显着差异（P≤0.03）。在一个农场，与普通饲料相比，酶饲料的增重提高了（P = 0.01）。总而言之，这些结果表明木聚糖酶可用于增强肉牛的蠕动饲料。
J. M. Lourenco[1];F. J. Maia[2];J. H. J. Bittar[3];J. R. Segers[4];J. J. Tucker[4];B. T. Campbell[5];R. L. Stewart[6]. Utilization of exogenous enzymes in beef cattle creep feeds[J]. Journal of Applied Animal Research, 2020,48(1): 70-77