Oosting S J, Van Bruchem J, Chen X B
Department of Animal Husbandry, Agricultural University, The Netherlands.
Br J Nutr. 1995 Sep;74(3):347-68. doi: 10.1079/bjn19950140.
The effects of ammoniation of wheat straw with or without supplementation of protein sources of either high (casein) or relatively low (potato protein) rumen degradability on intake and digestion were studied with four sheep in a 4 x 4 Latin square design. Rations offered were: (1) untreated wheat straw (UWS), (2) ammoniated wheat straw (AWS), (3) AWS supplemented with 3.2 g casein/kg live weight (W)0.75 per d (AWSC) and (4) AWS supplemented with 3.9 g potato protein/kg W0.75 per d (AWSP). Straw was offered ad lib. and all rations were supplemented with sugarbeet pulp and a mineral mixture. NH3 treatment increased intake and digestion. Supplementation of AWS with potato protein increased total digestible organic matter intake (DOMI) compared with AWS whereas supplementation with casein did not affect total DOMI. Protein supplementation of AWS significantly reduced rumen digestion of cellulose, and when the supplementation was with casein it reduced rumen digestion of neutral-detergent fibre and hemicellulose also. This lower rumen digestion was compensated by a higher proportion of digestion occurring in the hindgut for hemicellulose (P < 0.05 for AWSC, P > 0.05 for AWSP), but not for cellulose. Across all rations, rumen fluid volume increased with increasing cell-wall intake. The efficiencies of microbial protein synthesis were (average of three different methods of estimation) 23.3, 26.2, 34.8 and 31.7 g N/kg apparently-rumen-degraded organic matter for UWS, AWS, AWSC and AWSP respectively. The difference between UWS and AWS was not significant, but values for AWSC and AWSP were significantly higher than that for AWS. The rumen digestion of feed amino acid-N (AA-N) was significantly higher for AWSC than for the other rations. The apparent small-intestinal digestion of AA-N and N was significantly higher for AWSP than for the other rations. The true small-intestinal digestion values were 0.86, 0.84 and 0.68 for AA-N, N and non-protein-N respectively. Ileal endogenous losses of AA-N were approximately 6 mg/g duodenal non-protein dry-matter flow. Linear relationships were observed between DOMI and N balance and truly absorbed AA-N, indicating that DOMI could have been limited by small-intestinal amino acid availability. Regression of N balance v. truly absorbed AA-N resulted in an estimate of net efficiency of utilization of truly absorbed AA-N or 0.54.
采用4×4拉丁方设计，用4只绵羊研究了添加或不添加瘤胃降解性高（酪蛋白）或相对低（马铃薯蛋白）的蛋白质来源对氨化麦秸采食量和消化率的影响。提供的日粮有：（1）未处理麦秸（UWS），（2）氨化麦秸（AWS），（3）AWS每天每千克体重（W）0.75补充3.2克酪蛋白（AWSC），（4）AWS每天每千克W0.75补充3.9克马铃薯蛋白（AWSP）。麦秸自由采食，所有日粮均补充甜菜粕和矿物质混合物。氨处理增加了采食量和消化率。与AWS相比，AWS添加马铃薯蛋白提高了总可消化有机物采食量（DOMI），而添加酪蛋白对总DOMI没有影响。AWS补充蛋白质显著降低了纤维素的瘤胃消化率，当补充酪蛋白时，也降低了中性洗涤纤维和半纤维素的瘤胃消化率。半纤维素在瘤胃中较低的消化率通过在后肠中较高比例的消化得到补偿（AWSC的P<0.05，AWSP的P>0.05），但纤维素没有。在所有日粮中，瘤胃液体积随着细胞壁采食量的增加而增加。微生物蛋白合成效率（三种不同估计方法的平均值）分别为UWS、AWS、AWSC和AWSP的23.3、26.2、34.8和31.7克氮/千克明显瘤胃降解有机物。UWS和AWS之间的差异不显著，但AWSC和AWSP的值显著高于AWS。AWSC的饲料氨基酸氮（AA-N）瘤胃消化率显著高于其他日粮。AWSP的AA-N和氮的表观小肠消化率显著高于其他日粮。AA-N、氮和非蛋白氮的真小肠消化率分别为0.86、0.84和0.68。AA-N的回肠内源损失约为6毫克/克十二指肠非蛋白干物质流量。在DOMI与氮平衡和真吸收AA-N之间观察到线性关系，表明DOMI可能受小肠氨基酸可利用性的限制。氮平衡对真吸收AA-N的回归得出真吸收AA-N利用净效率的估计值为0.54。
