University for Development studies, Faculty of Agriculture, Department of Animal Science, Tamale, Ghana.
J Anim Sci Technol. 2016 Jun 1;58:19. doi: 10.1186/s40781-016-0103-7. eCollection 2016.
Cowpea (Vigna unguiculata [L.]) is a legume cultivated throughout most tropical countries and is valued as food and feed for human and livestock respectively. The search for an improved cowpea variety has been on-going with the aim of improving traits such as grain yield, drought and pest resistance. But no information exist on the feeding value of these improved varieties. Phosphate (P) fertilizer application is recommended to augment grain yield in grain legumes but data on the effect of P fertilizer on haulm quality is limited.
Two separate experiments were conducted to determine the effect of P fertilizer dose on the nutritive value of haulms from different cowpea varieties (V). In experiment 1, effect of three P doses (30, 60 and 90 kg P2O5/ha) on in vitro gas production (IVGP) characteristics, concentrations of digestible organic matter (DOM), crude protein (CP), acid detergent fiber (ADF) and neutral detergent fiber (NDF) of haulms from five cowpea varieties (Zaayura-SARC 4-75, Songotra-IT97K-499-35, Hewale-IT93K-192-4, IT99K 573-1-1 and Asomdwe-IT94K-410-2) were investigated using the 3 (P) x 5 (V) factorial treatment arrangements in a completely randomized design. In experiment 2, the effects of two P doses (30 and 90 kg P2O5/ha) and two varieties (Zaayura-SARC 4-75 and Hewale-IT93K-192-4) on the voluntary feed intake, live weight, haematology and carcass characteristics of Djallonke lambs were also assessed using a 2(P) x 2(V) factorial treatment arrangement. The V x P interaction significantly affected CP, NDF and ADF with CP concentration increasing with increase in P doses in Zaayura-SARC 4-75 and Asomdwe-IT94K-410-2. Whilst an increase (P < 0.05) in NDF was observed in Songotra-IT97K-499-35and Asomdwe-IT94K-410-2 as P doses increased, the other V only increased from P dose 30 to 60 kg/ha and declined at P dose 90 kg/ha. The ADF decreased (P < 0.05) with increase in P dose for all V with the exception of Songotra-IT97K-499-35. There was a significant V effect on DOM with the highest reported in Zaayura-SARC 4-75 (43.44 %). Daily DM intake, carcass length and blood urea nitrogen of the lambs were significantly affected by the V x P interaction. There was a significant V effect on globulin and P effect on live weight at slaughter, dressed weight, chuck, leg, loin, rib and flank and liver and lungs.
It can be concluded that nutrient concentrations of cowpea haulms were positively influenced by different P dose and varieties with favorable effects on growth, haematology and carcass composition of lambs. Varieties Zaayura-SARC 4-75 and Hewale-IT93K-192-4 at P dose at 90 kg/ha are recommended to enhance growth performance and carcass yield of Djallonke lambs.
豇豆（Vigna unguiculata [L.]）是一种在大多数热带国家种植的豆科植物，分别被作为人和牲畜的食物和饲料。一直在寻找改良的豇豆品种，旨在提高谷物产量、抗旱和抗虫害等特性。但目前尚无关于这些改良品种饲料价值的信息。在豆科作物中，施用磷肥被推荐用于增加谷物产量，但关于磷肥对秸秆质量影响的数据有限。
进行了两项独立的实验，以确定不同豇豆品种（V）的磷肥施用量对秸秆营养价值的影响。在实验 1 中，采用 3（P）x 5（V）完全随机设计的因子处理安排，研究了 3 个磷剂量（30、60 和 90 kg P2O5/ha）对 5 个豇豆品种（Zaayura-SARC 4-75、Songotra-IT97K-499-35、Hewale-IT93K-192-4、IT99K 573-1-1 和 Asomdwe-IT94K-410-2）秸秆体外产气特性（IVGP）、可消化有机物质（DOM）、粗蛋白（CP）、酸性洗涤纤维（ADF）和中性洗涤纤维（NDF）浓度的影响。在实验 2 中，还评估了 2 个磷剂量（30 和 90 kg P2O5/ha）和 2 个品种（Zaayura-SARC 4-75 和 Hewale-IT93K-192-4）对 Djallonke 羔羊的采食量、活体重、血液学和胴体特性的影响，采用 2（P）x 2（V）因子处理安排。V x P 互作对 CP、NDF 和 ADF 有显著影响，Zaayura-SARC 4-75 和 Asomdwe-IT94K-410-2 的 CP 浓度随磷剂量的增加而增加。而 Songotra-IT97K-499-35 和 Asomdwe-IT94K-410-2 的 NDF 随着磷剂量的增加而增加（P < 0.05），而其他 V 仅从磷剂量 30 增加到 60 kg/ha，然后在磷剂量 90 kg/ha 时下降。所有 V 的 ADF 均随磷剂量的增加而降低（P < 0.05），但 Songotra-IT97K-499-35 除外。DOM 对 V 有显著影响，Zaayura-SARC 4-75 的报道值最高（43.44%）。羔羊的日 DM 摄入量、胴体长和血液尿素氮均受到 V x P 互作的显著影响。V 对球蛋白和 P 对活体重、屠宰体重、去骨体重、肩肉、腿肉、腰肉、肋骨和腹肉以及肝脏和肺脏有显著影响。
可以得出结论，不同磷剂量和品种对豇豆秸秆的养分浓度有积极影响，对羔羊的生长、血液学和胴体组成有良好影响。建议在 90 kg/ha 的磷剂量下使用 Zaayura-SARC 4-75 和 Hewale-IT93K-192-4 品种，以提高 Djallonke 羔羊的生长性能和胴体产量。
