Nuñez-Hernandez G, Wallace J D, Holechek J L, Galyean M L, Cardenas M
Dept. of Anim. and Range Sci., New Mexico State University, Las Cruces 88003-0003.
J Anim Sci. 1991 Mar;69(3):1167-77. doi: 10.2527/1991.6931167x.
In the first of two experiments, four wether lambs (BW = 26.8 kg) and four wether Angora goats (BW = 31.7 kg) were used in two simultaneous 4 x 4 Latin squares to study the influence of condensed tannins (CT) on nutrient usage and concentrations of serum urea N, somatotropin (GH), and insulin (INS) when the animals were fed low-quality diets containing mountain mahogany (MM; Cercocarpus montanus) leaves. Diets were 8% CP and contained 25% or 50% MM (with hay or straw, respectively), either untreated or treated with polyethylene glycol (PEG; molecular weight 3,350) to reduce total reactive CT. Diets treated with PEG and 25% MM diets had less (P less than .05) CT than diets without PEG or those with 50% MM. Diets containing 50% MM resulted in greater N balance and lower serum urea N (P less than .01) than 25% MM diets. Concentrations of GH and INS were similar in animals fed the 25% and 50% MM diets. Reducing CT by adding PEG did not affect N balance or improve nutrient digestion by lambs or goats fed low-quality diets. In Exp. 2, four wether lambs (BW = 28.4 kg) were used in a 4 x 4 Latin square and fed the same diets as animals in Exp. 1 to study the influence of CT on ruminal fermentation and digesta kinetics. Dietary PEG treatment did not affect digesta kinetics except for a 30% increase in ruminal volume; 50% MM diets had faster particulate passage rates (P less than .05) than 25% MM diets. Ruminal ammonia N was greater (P less than .01) in lambs fed PEG-containing or 25% MM diets; however, rate of in situ NDF disappearance was not reduced by the lower ammonia N in the latter diets.
在两项实验的第一项中，四只去势羔羊（体重=26.8千克）和四只去势安哥拉山羊（体重=31.7千克）被用于两个同步的4×4拉丁方实验，以研究当动物采食含有山地桃花心木（MM；Cercocarpus montanus）叶的低质量日粮时，缩合单宁（CT）对养分利用以及血清尿素氮、生长激素（GH）和胰岛素（INS）浓度的影响。日粮粗蛋白含量为8%，含有25%或50%的MM（分别搭配干草或稻草），要么未处理，要么用聚乙二醇（PEG；分子量3350）处理以降低总活性CT。用PEG处理的日粮和含25%MM的日粮比不含PEG的日粮或含50%MM的日粮CT含量更低（P<0.05）。含50%MM的日粮比含25%MM的日粮能带来更高的氮平衡和更低的血清尿素氮（P<0.01）。采食含25%和50%MM日粮的动物体内GH和INS浓度相似。添加PEG降低CT对采食低质量日粮的羔羊或山羊的氮平衡或养分消化率没有影响。在实验2中，四只去势羔羊（体重=28.4千克）被用于一个4×4拉丁方实验，并采食与实验1中的动物相同的日粮，以研究CT对瘤胃发酵和食糜动力学的影响。日粮PEG处理除了使瘤胃容积增加30%外，对食糜动力学没有影响；含50%MM的日粮比含25%MM的日粮颗粒通过速率更快（P<0.05）。采食含PEG或含25%MM日粮的羔羊瘤胃氨氮含量更高（P<0.01）；然而，后一种日粮中较低的氨氮并未降低中性洗涤纤维原位消失率。
