Animal Science Research Centre, Harper Adams University College, Newport, Shropshire, TF10 8NB, United Kingdom.
J Anim Sci. 2011 Nov;89(11):3663-76. doi: 10.2527/jas.2009-2617. Epub 2011 May 13.
Two experiments were conducted to investigate the effect of inclusion of whole-crop pea (WCP) silages, differing in condensed tannin content, as a substitute for grass silage (GS) and soybean meal on lamb metabolism, performance, plasma metabolites, digestibility, and carcass characteristics. In both experiments lambs were offered either solely GS or a 50:50 mix on a DM basis of GS with either low-tannin (LTPS) or high-tannin (HTPS) pea silage ad libitum. Each forage mix was fed with either 400 g/d of low-protein (LP) concentrate or 400 g/d of LP with an additional 200 g/d of pelletized soybean meal (HP), resulting in 6 dietary treatments. Experiment 1 examined the effects of the diets on metabolism, digestibility, and N balance using 6 lambs in 4 periods of 21 d in an incomplete crossover design. Experiment 2 used 48 lambs and examined the effects of the diets on ADG, plasma metabolites, and carcass characteristics over 56 d. Both experiments were analyzed using a 3 × 2 factorial arrangement of treatments. In Exp. 1, lambs offered the LTPS diets had a greater (P < 0.05) digestibility of DM and OM than those offered the GS diets. Lambs offered the WCP silages had an increased (P < 0.05) N intake, N output, and digestibility of GE compared with those offered GS. Mean N digestibility was greatest (P < 0.05) in lambs offered LTPS. Lambs offered HP diets had increased (P < 0.001) digestibility of DM, OM, GE and N, and N- intake, output, retention, and digestibility compared with those offered the LP diets. In Exp. 2, there was no effect (P > 0.05) of forage type on intake, slaughter BW, or feed conversion efficiency (FCE). However, lambs offered the LTPS had a greater (P < 0.05) ADG than those offered the GS diets. Feeding diets containing HP increased (P < 0.001) total DMI, slaughter BW, ADG, and FCE. Lambs offered the WCP had a greater (P < 0.05) plasma β-hydroxybutyrate and urea concentration compared with those offered the GS diets. Feeding lambs HP diets increased (P < 0.05) plasma urea and total protein. Forage mix had no effect (P > 0.05) on carcass composition except for fat depth, which was greater (P < 0.05) in lambs offered WCP silage. Diets containing the HP increased (P < 0.05) carcass weight, hind leg circumference, chop dimensions, and kidney weight. It was concluded that lambs offered LTPS performed better than those offered GS and that LTPS has a concentrate sparing effect. Additionally, the increased tannin concentration in HTPS did not increase performance over lambs offered either GS or LTPS.
进行了两项实验，以研究包含全株豌豆青贮（WCP）的日粮，其在浓缩单宁含量方面存在差异，作为替代草青贮（GS）和大豆粉对羔羊代谢、性能、血浆代谢物、消化率和胴体特征的影响。在两项实验中，羔羊单独或自由采食基于 DM 的 GS 与低单宁（LTPS）或高单宁（HTPS）豌豆青贮 50:50 混合物，要么单独提供 GS，要么提供 400 g/d 的低蛋白（LP）浓缩物，要么提供 400 g/d 的 LP 加 200 g/d 颗粒化大豆粉（HP），共 6 种日粮处理。实验 1 使用 6 只羔羊，在不完全交叉设计的 21 天 4 个时期内，检查日粮对代谢、消化率和 N 平衡的影响。实验 2 使用 48 只羔羊，在 56 天内检查日粮对 ADG、血浆代谢物和胴体特征的影响。两项实验均采用 3×2 因子处理安排。在实验 1 中，与提供 GS 日粮的羔羊相比，提供 LTPS 日粮的羔羊具有更高（P<0.05）的 DM 和 OM 消化率。与提供 GS 的羔羊相比，提供 WCP 青贮的羔羊的 GE 摄入、输出和消化率增加（P<0.05）。与提供 LTPS 的羔羊相比，平均 N 消化率最高（P<0.05）。与提供 LP 日粮的羔羊相比，提供 HP 日粮的羔羊的 DM、OM、GE 和 N 消化率以及 N 摄入量、输出、保留和消化率增加（P<0.001）。在实验 2 中，饲粮类型对采食量、屠宰 BW 或饲料转化率（FCE）没有影响（P>0.05）。然而，与提供 GS 日粮的羔羊相比，提供 LTPS 的羔羊具有更高（P<0.05）的 ADG。饲喂含有 HP 的日粮增加（P<0.001）总采食量、屠宰 BW、ADG 和 FCE。与提供 GS 日粮的羔羊相比，提供 WCP 的羔羊具有更高（P<0.05）的血浆β-羟丁酸和尿素浓度。饲喂 HP 日粮的羔羊的血浆尿素和总蛋白增加（P<0.05）。饲粮类型对胴体组成没有影响（P>0.05），除了脂肪深度，提供 WCP 青贮的羔羊脂肪深度更大（P<0.05）。含有 HP 的日粮增加（P<0.05）胴体重、后腿围、排骨尺寸和肾重。结果表明，与提供 GS 的羔羊相比，提供 LTPS 的羔羊表现更好，LTPS 具有节约精饲料的效果。此外，与提供 GS 或 LTPS 的羔羊相比，HTPS 中增加的单宁浓度并没有提高性能。
