Caton J S, Erickson D O, Carey D A, Ulmer D L
Department of Animal and Range Sciences, North Dakota State University, Fargo 58105.
J Anim Sci. 1993 Mar;71(3):779-87. doi: 10.2527/1993.713779x.
Ten ruminally and duodenally cannulated (326 +/- 28 kg) and four esophageally fistulated (394 +/- 23 kg) steers grazing cool-season pasture throughout the growing season were used to evaluate the influence of Aspergillus oryzae fermentation extract (AO) supplementation on intake, forage nutrient utilization, and duodenal amino acid flow. Steers grazed a predominantly smooth brome (Bromus inermis L.) pasture, and measurements were taken in three periods (June, July, and August). Steers were dosed daily at 0700 via the ruminal cannula with AO (2 g of AO per steer daily; DM basis) or not supplemented with AO. Each period consisted of 18 d for adaption to AO and 7 d for collection. Forage N was greater, and ADF was lower (P < .10), in June than in July and August. Ruminal pH, ammonia, total VFA concentration, and VFA proportions were not affected (P > .10) by AO supplementation. In vitro DM digestibility (percentage) and forage OM intake (grams/kilogram of BW) were greater (P < .10) for steers supplemented with AO. Ruminal and total tract NDF and ADF digestibilities were lower in June and greater during July (P < .10) in steers supplemented with AO. Total tract percentage of N disappearance was lesser during June and greater (P < .10) during July for steers receiving AO. Total, essential, and nonessential amino acid flows were increased (P < .10) by both AO supplementation and advancing season. In situ rate of ruminal CP degradation was not affected (P < .10) by treatment during any period.(ABSTRACT TRUNCATED AT 250 WORDS)
在整个生长季节，选用10头安装了瘤胃和十二指肠瘘管（体重326±28千克）以及4头安装了食管瘘管（体重394±23千克）的阉牛，这些阉牛在冷季牧场放牧，以评估添加米曲霉发酵提取物（AO）对采食量、饲草养分利用率和十二指肠氨基酸流量的影响。阉牛主要在无芒雀麦（Bromus inermis L.）牧场上放牧，并在三个时期（6月、7月和8月）进行测量。阉牛每天早上7点通过瘤胃瘘管给予AO（每头阉牛每天2克AO；干物质基础）或不添加AO。每个时期包括18天的AO适应期和7天的采集期。6月的饲草氮含量更高，酸性洗涤纤维（ADF）含量更低（P<0.10），高于7月和8月。添加AO对瘤胃pH值、氨、总挥发性脂肪酸（VFA）浓度和VFA比例没有影响（P>0.10）。添加AO的阉牛体外干物质消化率（百分比）和饲草有机物质采食量（克/千克体重）更高（P<0.10）。添加AO的阉牛，6月瘤胃和全消化道中性洗涤纤维（NDF）及ADF消化率较低，7月较高（P<0.10）。接受AO的阉牛，6月全消化道氮消失百分比更低，但7月更高（P<0.10）。添加AO和季节推进均使总氨基酸、必需氨基酸和非必需氨基酸流量增加（P<0.10）。在任何时期，处理对瘤胃粗蛋白降解的原位速率均无影响（P<0.10）。（摘要截断于250字）
