Lambert M G, Abrams S M, Harpster H W, Jung G A
U.S. Regional Pasture Research Laboratory, University Park 16802.
J Anim Sci. 1987 Dec;65(6):1639-46. doi: 10.2527/jas1987.6561639x.
Intake and digestibility trials were conducted with sheep to evaluate the effect of adding various levels of a typical fibrous grass forage (neutral detergent fiber, NDF = 68%) to a high quality, low fiber (NDF = 22%) brassica forage. Four forage rape:orchardgrass hay diets (0, 40, 70, 100% rape content on a dry matter basis) were fed to groups of six Polled-Dorset crossbred growing wether lambs (39.6 kg) individually housed in metabolism crates. After a 7-d ad libitum intake period, a 7-d digestibility trial was conducted at 90% of the observed ad libitum intake level. Digestible dry matter intake (DDMI) per unit metabolic body weight increased as rape in the diet was increased from 0 to 70%, with increases in both dry matter intake and dry matter digestibility (DMD). However, DDMI was similar for lambs fed the 70 and 100% rape diets, with DMI decreasing to the same relative extent as DMD increased. Digestibility of the cell wall fraction of the two intermediate diets (40% rape and 70% rape) was lower than predicted from component forage digestibilities. This observation suggests the existence of an associative effect similar to that often reported when forage and concentrates are fed in various ratios. Forage brassicas appear to be utilized in the ruminant in a manner more typically resembling a concentrate than a forage.
用绵羊进行了采食量和消化率试验，以评估向优质、低纤维（中性洗涤纤维，NDF = 22%）的芸苔属饲料中添加不同水平典型纤维性禾本科牧草（NDF = 68%）的效果。将四种饲用油菜与果园草干草日粮（干物质基础上油菜含量分别为0、40、70、100%）喂给六组圈养在代谢笼中的无角多塞特杂交生长羯羊（体重39.6千克）。在7天的随意采食期后，以观察到的随意采食量的90%进行为期7天的消化率试验。随着日粮中油菜比例从0增加到70%，单位代谢体重的可消化干物质摄入量（DDMI）增加，干物质摄入量和干物质消化率（DMD）均增加。然而，饲喂70%和100%油菜日粮的羔羊的DDMI相似，干物质摄入量下降的幅度与DMD增加的幅度相同。两种中等比例日粮（40%油菜和70%油菜）的细胞壁部分消化率低于根据各组分饲料消化率预测的值。这一观察结果表明存在一种关联效应，类似于当以不同比例饲喂牧草和精饲料时经常报道的情况。芸苔属饲料在反刍动物中的利用方式似乎更类似于精饲料而非牧草。
