FEED INTAKE, WEIGHT GAIN AND NUTRIENT DIGESTIBILITY OF PREGNANT WEST AFRICAN DWARF GOATS FED GUINEA GRASS BASAL DIET AND CASSAVA PEEL AND LEAF MEAL BASED CONCENTRATE

This study evaluated the performance of pregnant WAD goats fed Guinea grass basal diet and cassava peel and leaf meal based concentrate supplement. Twelve (12) West African dwarf goats (does) after their second parity with average weight (19.378 ± 2.30 kg) (mean ± SD) were used. Goats with undesired features such as supernumerary teats, mange, desired characteristics were separated. Three pregnant does were randomly allocated in a completely randomized design (CRD), to the one of the four (4) experimental treatments of Guinea grass basal diets and concentrate supplements at 50 %. The hypothesis was that dietary inclusion of cassava leaves and peels at different levels would or would not affect the performance of pregnant goats.The control (T1) was compounded from conventional feed ingredients (wheat offal, palm kernel cake and other feed ingredients) which are expensive and not easily assessable to the local goat farmers who are in control of a larger population of West African dwarf goats. The other treatments (2, 3 and 4) were compounded by replacing the wheat offal and palm kernel cake with cassava peel meal and cassava leaf meal respectively at graded levels. Cassava peel and leaf meal are high energy and crude protein respectively and values are comparable to those of wheat offal and PKC. The diets were T1 (control), T2 (25 % replacement of wheat offal (WO) and Palm kernel cake (PKC), with cassava peel meal (CPM) and cassava leaf meal (CLM) respectively, T3 (50 % replacement of WO and PKC, with CLM and CPM respectively) and T4 (75 % replacement of WO and PKC, with CLM and CPM respectively). Feed was offered at 50 g DM /Kg BW and water was given ad lib. Feed intake, weight changes, feed conversion ratio, digestibility were monitored for pregnant goats. Dry matter intake from grass likewise concentrate was non – significant across the four treatments. Although, the observed variation was not significant, the total DM intakes of pregnant does fed diets of replacement of WO and PKC with CPM and CLM were higher than that of the control, apart from T2, and the values ranged from 588.60, 555.12, 610.36 and 617.63 g/d for TI, T2, T3 and T4 respectively. The highest weight gain was recorded in pregnant goats fed 50 % replacement of wheat offal and PKC with CPM and CLM (T3), while the lowest was in T4 (75 % replacement with CPM and CLM). Furthermore, the replacement levels in the respective treatments did not affect apparent digestibility of DM (which was above 80 % for the four treatments), CP (which increased non – significantly with increase in CLM content of the diet), EE, NDF, ADF and HMC of the pregnant WAD goats significantly. However, apparent digestibility of ash was significantly lowest in the control and highest in the diets replaced with CPM and CLM. This investigation has shown wheat offal and PKC can be replaced at 25 %, 50 % and 75 %, without negative effect on foetal development and successful gestation.本研究评估了饲喂几内亚草（Guinea grass）基础日粮，以及以木薯皮粉、木薯叶粉为核心的浓缩补充剂的怀孕西非矮山羊（West African Dwarf, WAD）的生产性能。试验选用12头经产二胎的西非矮山羊母羊，平均体重为(19.378±2.30) kg（平均值±标准差）。试验淘汰具有副乳头、疥癣等不良性状的山羊，保留符合要求的个体。采用完全随机试验设计（Completely Randomized Design, CRD），将12头试验羊分为4组，每组3头，分别饲喂4种以几内亚草为基础日粮、浓缩补充剂占比50%的试验饲粮。本试验假设：不同添加水平的木薯叶与木薯皮日粮，会或不会对怀孕山羊的生产性能产生影响。 对照组（T1）采用常规饲料原料配制，包括小麦麸（Wheat Offal, WO）、棕榈仁饼（Palm Kernel Cake, PKC）及其他常规饲料原料，这类原料价格昂贵，且对于饲养大量西非矮山羊的当地养羊户而言不易获取。其余3个处理组（T2、T3、T4）则通过梯度替换的方式，分别以木薯皮粉（Cassava Peel Meal, CPM）、木薯叶粉（Cassava Leaf Meal, CLM）替代小麦麸与棕榈仁饼配制而成。木薯皮粉与木薯叶粉分别具有较高的能量与粗蛋白含量，其营养指标与小麦麸、棕榈仁饼相当。 试验饲粮具体分组如下：T1为对照组；T2分别以木薯皮粉、木薯叶粉替代25%的小麦麸与棕榈仁饼；T3分别以木薯叶粉、木薯皮粉替代50%的小麦麸与棕榈仁饼；T4分别以木薯叶粉、木薯皮粉替代75%的小麦麸与棕榈仁饼。试验羊按50g干物质（Dry Matter, DM）/kg体重（Body Weight, BW）的比例饲喂饲粮，饮水自由采食。监测怀孕山羊的采食量、体重变化、饲料转化率及养分消化率。 4个处理组的干草干物质采食量与浓缩饲料干物质采食量均无显著差异。尽管各组间的总变异无统计学显著性，但除T2组外，其余采用木薯皮粉与木薯叶粉替代小麦麸和棕榈仁饼的处理组，其怀孕母羊的总干物质采食量均高于对照组；各组总干物质采食量分别为：T1组588.60 g/d、T2组555.12 g/d、T3组610.36 g/d、T4组617.63 g/d。饲喂以木薯皮粉与木薯叶粉替代50%小麦麸和棕榈仁饼饲粮的T3组怀孕山羊，体重增长最高；而T4组（替代75%比例）的体重增长最低。 此外，各处理组的替换比例未对怀孕西非矮山羊的干物质表观消化率（4组均高于80%）、粗蛋白（Crude Protein, CP）表观消化率（随饲粮木薯叶粉含量提升呈不显著上升趋势）、粗脂肪（Ether Extract, EE）、中性洗涤纤维（Neutral Detergent Fiber, NDF）、酸性洗涤纤维（Acid Detergent Fiber, ADF）及半纤维素（Hemicellulose, HMC）的表观消化率产生显著影响。但对照组的灰分表观消化率显著最低，而采用木薯皮粉与木薯叶粉替代配制的饲粮组灰分表观消化率显著最高。 本研究表明，以木薯皮粉与木薯叶粉分别替代25%、50%及75%的小麦麸与棕榈仁饼，不会对胎儿发育及顺利妊娠产生负面影响。