浓缩分离器副产物（脱糖蜜）对采食青草干草的育肥牛采食量、瘤胃发酵、消化及微生物效率的影响。

Effects of concentrated separator by-product (desugared molasses) on intake, ruminal fermentation, digestion, and microbial efficiency in beef steers fed grass hay.

作者信息

Shellito S M, Ward M A, Lardy G P, Bauer M L, Caton J S

机构信息

Department of Animal and Range Sciences, North Dakota State University, Fargo, 58105, USA.

出版信息

J Anim Sci. 2006 Jun;84(6):1535-43. doi: 10.2527/2006.8461535x.

DOI:10.2527/2006.8461535x

PMID:16699111

Abstract

Concentrated separator by-product (CSB) is produced when beet molasses goes through an industrial desugaring process. To investigate the nutritional value of CSB as a supplement for grass hay diets (12.5% CP; DM basis), 4 ruminally and duodenally cannulated beef steers (332 +/- 2.3 kg) were used in a 4 x 4 Latin square with a 2 x 2 factorial arrangement of treatments. Factors were intake level: ad libitum (AL) vs. restricted (RE; 1.25% of BW, DM basis) and dietary CSB addition (0 vs. 10%; DM basis). Experimental periods were 21 d in length, with the last 7 d used for collections. By design, intakes of both DM and OM (g/kg of BW) were greater (P < 0.01; 18.8 vs. 13.1 +/- 0.69 and 16.8 vs. 11.7 +/- 0.62, respectively) for animals consuming AL compared with RE diets. Main effect means for intake were not affected by CSB (P = 0.59). However, within AL-fed steers, CSB tended (P = 0.12) to improve DMI (6,018 vs. 6,585 +/- 185 g for 0 and 10% CSB, respectively). Feeding CSB resulted in similar total tract DM and OM digestion compared with controls (P = 0.50 and 0.87, respectively). There were no effects of CSB on apparent total tract NDF (P = 0.27) or ADF (P = 0.35) digestion; however, apparent N absorption increased (P = 0.10) with CSB addition. Total tract NDF, ADF, or N digestion coefficients were not different between AL- and RE-fed steers. Nitrogen intake (P = 0.02), total duodenal N flow (P = 0.02), and feed N escaping to the small intestine (P = 0.02) were increased with CSB addition. Microbial efficiency was unaffected by treatment (P = 0.17). Supplementation with CSB increased the rate of DM disappearance (P = 0.001; 4.9 vs. 6.9 +/- 0.33 %/h). Restricted intake increased the rate of in situ DM disappearance (P = 0.03; 6.4 vs. 5.3 +/- 0.33 %/h) compared with AL-fed steers. Ruminal DM fill was greater (P = 0.01) in AL compared with RE. Total VFA concentrations were greater (P = 0.04) for CSB compared with controls; however, ammonia concentrations were reduced (P = 0.03) with CSB addition. At different levels of dietary intake, supplementing medium-quality forage with 10% CSB increased N intake, small intestinal protein supply, and total ruminal VFA.

摘要

当甜菜糖蜜经过工业脱糖过程时会产生浓缩分离器副产品（CSB）。为了研究CSB作为禾本科干草日粮（12.5%粗蛋白；干物质基础）补充料的营养价值，选用4头安装了瘤胃和十二指肠瘘管的肉用公牛（332±2.3千克），采用4×4拉丁方设计，处理采用2×2析因排列。因素包括采食量水平：自由采食（AL）与限饲（RE；体重的1.25%，干物质基础）以及日粮中CSB添加量（0与10%；干物质基础）。试验期为21天，最后7天用于收集数据。按照设计，与限饲日粮相比，自由采食的动物干物质和有机物质摄入量（克/千克体重）更高（P<0.01；分别为18.8对13.1±0.69和16.8对11.7±0.62）。采食量的主效应均值不受CSB影响（P = 0.59）。然而，在自由采食的公牛中，CSB有提高干物质采食量的趋势（P = 0.12）（分别为0和10%CSB时，干物质采食量为6018对6585±185克）。与对照组相比，饲喂CSB导致全消化道干物质和有机物质消化率相似（分别为P = 0.50和0.87）。CSB对表观全消化道中性洗涤纤维（P = 0.27）或酸性洗涤纤维（P = 0.35）消化率没有影响；然而，添加CSB后表观氮吸收增加（P = 0.10）。自由采食和限饲的公牛之间全消化道中性洗涤纤维、酸性洗涤纤维或氮消化系数没有差异。添加CSB后氮摄入量（P = 0.02）、十二指肠总氮流量（P = 0.02）和进入小肠的饲料氮量（P = 0.02）增加。微生物效率不受处理影响（P = 0.17）。添加CSB提高了干物质消失率（P = 0.001；4.9对6.9±0.33%/小时）。与自由采食的公牛相比，限饲提高了原位干物质消失率（P = 0.03；6.4对5.3±0.33%/小时）。自由采食时瘤胃干物质充盈度比限饲时更高（P = 0.01）。与对照组相比，CSB组总挥发性脂肪酸浓度更高（P = 0.04）；然而，添加CSB后氨浓度降低（P = 0.03）。在不同采食量水平下，用10%CSB补充中等质量饲草可增加氮摄入量、小肠蛋白质供应和瘤胃总挥发性脂肪酸。