不同中性洗涤纤维来源开食料对湖羊羔羊生长性能和养分消化代谢的影响

本试验旨在分析湖羊羔羊采食两种不同中性洗涤纤维(neutral detergent fiber, NDF)来源开食料时生长性能和养分消化代谢的差异。采用对照试验设计,选择28只初生重相似(3.5±0.7 kg)的湖羊公羔,0～2日龄吮食母乳,3日龄羔羊与母羊分离,并开始饲喂代乳粉至28日龄断奶,7日龄(补饲前)按同质性原则将试验羔羊分为两个处理组,每个处理组14只,分别饲喂以苜蓿干草(alfalfa hay, AH)和甜菜粕(beet pulp, BP)为主要NDF来源的全混合饲粮。羔羊54日龄至60日龄进行消化代谢试验,70日龄时结束试验。结果表明,7～28日龄时AH组羔羊平均日增重以及养分和代谢能采食量均显著高于BP组(P 0.05),而29～70日龄时无显著差异(P 0.05)。AH组羔羊对开食料干物质(dry matter, DM)、NDF和酸性洗涤纤维(acid detergent fiber, ADF)的表观消化率显著低于BP组(P 0.05)。表明本试验条件下,以苜蓿干草为NDF来源开食料能显著提高湖羊羔羊断奶前的生产性能及采食量,而以甜菜粕为NDF来源开食料能显著提高湖羊羔羊断奶后DM、NDF和ADF表观消化率。     

不同NDF水平饲粮对羔羊生长性能、营养物质消化、消化道重量及瘤胃乳头发育的影响

本试验旨在研究不同中性洗涤纤维(NDF)水平饲粮对羔羊生长性能、营养物质表观消化率、消化道重量及瘤胃乳头发育的影响。选用60只体况良好,体重为(3.23±0.20) kg的初生母羔羊,随机分为4组,每组5个重复,每个重复3只羊。试验羔羊于10日龄补饲开食料,开食料NDF水平分别为12%(12NDF组)、16%(16NDF组)、20%(20NDF组)和24%(24NDF组)的饲粮。试验期60 d,饲养试验所有羔羊均随母哺乳,消化试验所有羔羊不随母哺乳。结果显示:1)随着日龄的增加,羔羊的体重极显著增加(P0.01);各日龄阶段日增重均差异不显著(P0.05);随日龄的增加,羔羊干物质采食量(DMI)极显著增加(P0.01),饲喂不同NDF水平饲粮,各组羔羊DMI差异不显著(P0.05)。2)24NDF组羔羊干物质(DM)、有机物(OM)采食量和总能(GE)摄入量显著高于16NDF、20NDF组(P0.05)。24NDF组羔羊粗蛋白(CP)采食量显著高于20NDF组(P0.05);24NDF组羔羊中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)采食量极显著高于20NDF组(P0.01),20NDF组极显著高于16NDF、12NDF组(P0.01);24NDF组羔羊DM、OM表观消化率显著低于12NDF、16NDF组(P0.05),24NDF组GE表观消化率显著低于16NDF组(P0.05),但20NDF、24NDF组NDF、ADF表观消化率显著或极显著高于12NDF组(P0.05或P0.01);24NDF组羔羊粪能显著高于12NDF、16NDF和24NDF组(P0.05)。各试验组CP表观消化率和消化能差异不显著(P0.05)。3)12NDF组羔羊全胃重显著高于16NDF、20NDF组(P0.05)。12NDF组羔羊瘤胃重显著高于20NDF组(P0.05)。12NDF组羔羊瘤胃占宰前活重的比例显著高于16NDF、20NDF和24NDF组(P0.05)。12NDF组羔羊十二指肠重及十二指肠占宰前活重的比例显著高于16NDF组(P0.05)。其余各指标均差异不显著(P0.05)。综上所述,母羔羊在0～60日龄最适的NDF水平为16%～20%。     

果寡糖对哺乳羔羊营养物质表观消化率及粪便微生物菌群的影响

本试验旨在研究果寡糖对哺乳羔羊营养物质表观消化率及粪便微生物菌群的影响。选择15日龄、体重相近的湖羊羔羊44只,随机分为4组：对照组开食料中不添加果寡糖,Ⅰ、Ⅱ和Ⅲ组开食料中分别添加0.5%、1.0%和1.5%果寡糖。所有羔羊60日龄断奶,记为第0天。羔羊第-7、7天进行消化代谢试验。试验期间记录羔羊腹泻情况并采集直肠粪样。断奶后继续饲喂至74日龄,试验期共59 d。结果表明：1)处理显著影响哺乳羔羊腹泻率以及腹泻频率(P<0.05),对照组哺乳羔羊腹泻率和腹泻频率显著高于各试验组(P<0.05)。时间、处理×时间对羔羊腹泻率和腹泻频率无显著影响(P>0.05)。2)处理对羔羊干物质采食量(DMI)及粗蛋白质(CP)、中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)的表观消化率影响显著(P<0.05),对干物质(DM)和粗脂肪(EE)的表观消化率无显著影响(P>0.05)。Ⅱ组DMI显著高于对照组(P<0.05),与Ⅰ、Ⅲ组无显著差异(P>0.05)。对照组羔羊CP表观消化率显著低于各试验组(P<0.05)。时间显著影响了DMI、CP、EE...     

日粮脂肪水平对湖羊双胞胎公羔生长性能及血清指标的影响

旨在研究日粮不同脂肪水平对早期断奶双胞胎湖羊公羔生长发育、体尺指标、断奶前腹泻率及血清指标的影响。选择7日龄体重相近、健康的湖羊双胞胎公羔30对,采用配对试验设计,分为正常脂肪组(NF)和高脂肪组(HF),一对双胞胎随机分到两个组中。7日龄断母乳,NF组开始饲喂脂肪含量为15%的代乳品和2.8%的开食料,HF组开始饲喂脂肪含量27%的代乳品及5.0%的开食料,饲喂至60日龄断液体饲料(代乳品)。60~120日龄统一饲喂开食料(US)。所有羔羊定期晨饲前称重,记录每日采食量及腹泻情况;在60、90及120日龄晨饲前颈静脉采血,用于测定血清学常规指标。结果表明:1)在30、50、90及120日龄时,HF组羔羊体重显著高于NF组(P0.05),而断代乳品时,HF组羔羊体重有显著高于NF组的趋势(0.05P0.10)。在7~60日龄阶段,HF组代乳品平均采食量显著高于NF组(P0.05),但开食料采食量、平均日增重及饲料转化率在两组间差异不显著(P0.05);在60~90日龄阶段,HF组平均日增重及开食料采食量显著高于NF组(P0.05),而饲料转化率HF组显著低于NF组(P0.05);在90~120日龄期间,HF组羔羊采食量显著高于NF组(P0.05),而饲料转化率有显著高于NF组的趋势(0.05P0.10)。在整个试验期,HF组总平均采食量显著高于NF组(P0.05),平均日增重及饲料转化率在两组间差异不显著(P0.05)。2)试验期内HF组羔羊断奶前腹泻率有显著低于NF组的趋势(0.05P0.10)。试验期间两组羔羊体尺指标基本上无显著差异(P0.05)。断奶前饲喂高脂肪日粮可以在一定程度上提高湖羊双胞胎公羔断奶前后的生长性能;高脂肪日粮可以降低断代乳品前腹泻率;且本试验条件下高脂肪日粮对羔羊血液指标的影响在其自身调节的范围内。     

不同NDF水平饲粮对羔羊生长性能、营养物质消化、消化道重量及瘤胃乳头发育的影响

本试验旨在研究不同中性洗涤纤维（NDF）水平饲粮对羔羊生长性能、营养物质表观消化率、消化道重量及瘤胃乳头发育的影响。选用60只体况良好,体重为（3.23±0.20）kg的初生母羔羊,随机分为4组,每组5个重复,每个重复3只羊。试验羔羊于10日龄补饲开食料,开食料NDF水平分别为12%（12NDF组）、16%（16NDF组）、20%（20NDF组）和24%（24NDF组）的饲粮。试验期60 d,饲养试验所有羔羊均随母哺乳,消化试验所有羔羊不随母哺乳。结果显示：1）随着日龄的增加,羔羊的体重极显著增加（P<0.01）;各日龄阶段日增重均差异不显著（P>0.05）;随日龄的增加,羔羊干物质采食量（DMI）极显著增加（P<0.01）,饲喂不同NDF水平饲粮,各组羔羊DMI差异不显著（P>0.05）。2）24NDF组羔羊干物质（DM）、有机物（OM）采食量和总能（GE）摄入量显著高于16NDF、20NDF组（P<0.05）。24NDF组羔羊粗蛋白（CP）采食量显著高于20NDF组（P<0.05）;24NDF组羔羊中性洗涤纤维（NDF）、酸性洗涤纤维（ADF）采食量极显著高于20NDF组（P<0.01）,20NDF组极显著高于16NDF、12NDF组（P<0.01）;24NDF组羔羊DM、OM表观消化率显著低于12NDF、16NDF组（P<0.05）,24NDF组GE表观消化率显著低于16NDF组（P<0.05）,但20NDF、24NDF组NDF、ADF表观消化率显著或极显著高于12NDF组（P<0.05或P<0.01）;24NDF组羔羊粪能显著高于12NDF、16NDF和24NDF组（P<0.05）。各试验组CP表观消化率和消化能差异不显著（P>0.05）。3）12NDF组羔羊全胃重显著高于16NDF、20NDF组（P<0.05）。12NDF组羔羊瘤胃重显著高于20NDF组（P<0.05）。12NDF组羔羊瘤胃占宰前活重的比例显著高于16NDF、20NDF和24NDF组（P<0.05）。12NDF组羔羊十二指肠重及十二指肠占宰前活重的比例显著高于16NDF组（P<0.05）。其余各指标均差异不显著（P>0.05）。综上所述,母羔羊在0~60日龄最适的NDF水平为16%~20%。     

口感化及颗粒化开食料对早期断奶羔羊生长和胃肠道发育的影响

分析探讨口感化及颗粒化开食料对早期断奶羔羊生长和胃肠道发育的影响。选取新生健康的双羔湖羊公羔42只,随机分为两组,分别饲喂颗粒化和口感化开食料,试验期42 d。两组羔羊21日龄之前的采食量、体重和绝对生长的变化趋势相似。21日龄以后,口感化开食料组羔羊的采食量、体重、绝对生长和相对生长均明显高于颗粒化开食料组,42日龄体重、后两周的采食量及15～21日龄的相对生长率在两组间有显著差异(P < 0.05)。口感化开食料还显著提高(P < 0.05)了羔羊42日龄时的育肥指数、体长指数、胸围指数、管围指数和断奶前的瘤胃质量和瘤胃/胴体。以上结果表明,与颗粒化开食料相比,口感化开食料更有利于羔羊早期断奶前后的瘤胃发育、采食量提高、体重和体尺的发育,但对其他胃室及肠道发育没有影响。     

口感化及颗粒化开食料对早期断奶羔羊生长和胃肠道发育的影响

分析探讨口感化及颗粒化开食料对早期断奶羔羊生长和胃肠道发育的影响.选取新生健康的双羔湖羊公羔42只,随机分为两组,分别饲喂颗粒化和口感化开食料,试验期42 d.两组羔羊21日龄之前的采食量、体重和绝对生长的变化趋势相似.21日龄以后,口感化开食料组羔羊的采食量、体重、绝对生长和相对生长均明显高于颗粒化开食料组,42日龄体重、后两周的采食量及15～21日龄的相对生长率在两组间有显著差异(P<0.05).口感化开食料还显著提高(P<0.05)了羔羊42日龄时的育肥指数、体长指数、胸围指数、管围指数和断奶前的瘤胃质量和瘤胃/胴体.以上结果表明,与颗粒化开食料相比,口感化开食料更有利于羔羊早期断奶前后的瘤胃发育、采食量提高、体重和体尺的发育,但对其他胃室及肠道发育没有影响.     

强制补饲日龄对兰州地区小尾寒羊羔羊生产性能的影响

试验旨在研究强制补饲日龄对兰州地区小尾寒羊羔羊生产性能的影响。选择出生健康的小尾寒羊公羔(一胎双羔)共40只,初生重3.62 kg±0.72 kg,随机分为2组,一组7日龄开始强制补饲开食料,另一组35日龄开始强制饲喂开食料。两组均在56日龄断奶,并逐渐开始替换为生长羔羊料,饲喂至70日龄,统计整个哺乳期羔羊体重及采食量。结果表明:7日龄和35日龄补饲组羔羊体重均随着日龄增加逐渐上升,42、49、56和63日龄时,7日龄补饲组体重显著高于35日龄补饲组(P0.05)。42~49日龄时,7日龄补饲组平均日增重显著小于35日龄补饲组(P0.05)。随日龄增加,两组羔羊采食量均逐渐增加,56日龄断奶后,采食量迅速增加,且7日龄补饲组采食量高于35日龄补饲组。在该试验条件下,饲喂开食料可提高羔羊生产性能,相对于35日龄饲喂开食料,7日龄饲喂更利于促进其快速生长。     

饲粮蛋氨酸水平对湖羊公羔营养物质消化、胃肠道pH及血清指标的影响

本试验旨在研究饲粮蛋氨酸水平对湖羊公羔营养物质消化、胃肠道pH及血清指标的影响。选取12对7日龄断奶的湖羊双胞胎公羔,采用配对试验设计,分为对照(CON)组和低蛋氨酸(LM)组,1对双胞胎羔羊分别分到2个组中。试验分2个阶段进行,第1阶段(8~56日龄),CON组羔羊饲喂基础代乳粉和基础开食料;LM组羔羊饲喂的代乳粉和开食料在CON组基础上分别全部扣除(0.70%和0.40%)额外添加的蛋氨酸,其余营养水平保持一致。第2阶段(57~84日龄),2组羔羊停止饲喂代乳粉且饲粮均为基础开食料。分别在第1阶段结束前(46~55日龄)和第2阶段结束前(74~83日龄)随机选取4对双胞胎羔羊进行消化代谢试验。结果表明:1)56日龄,LM组羔羊对饲粮粗蛋白质、粗脂肪、中性洗涤纤维的表观消化率均显著低于CON组(P0.05);84日龄,2组羔羊在营养物质表观消化率上均差异不显著(P0.05)。2)56日龄,LM组羔羊胃肠道中除十二指肠pH显著低于CON组(P0.05)外,其他胃肠道pH均差异不显著(P0.05);84日龄,2组羔羊在胃肠道pH上均差异不显著(P0.05)。3)除了56日龄LM组羔羊的生长激素和胰岛素浓度显著低于CON组(P0.05)外,2组羔羊其他血清指标56和84日龄均无显著性差异(P0.05)。由此可见,8~56日龄,饲粮低蛋氨酸水平可降低湖羊公羔营养物质表观消化率,以及抑制十二指肠pH和血清中生长激素、胰岛素浓度的增加;57~84日龄,提高饲粮蛋氨酸水平后,湖羊公羔的营养物质表观消化率、胃肠道pH及血清激素指标随之得到补偿。     

断奶日龄和日粮营养水平对4～6月龄陕北白绒山羊消化代谢的影响

旨在研究断奶日龄和日粮营养水平对4～6月龄陕北白绒山羊主要营养物质消化代谢的影响。本研究选取54日龄左右的陕北白绒山羊羔羊54只(平均体重(10.73±1.03)kg),随机分为6组,每组3个重复,每个重复3只羊。试验Ⅰ、Ⅱ、Ⅲ组山羊饲喂标准日粮,断奶日龄分别为90、75、60d。试验Ⅳ、Ⅴ、Ⅵ组山羊的断奶日龄均为60d,分别饲喂消化能和粗蛋白水平为标准日粮85%、115%、130%的试验日粮。试验期180d,饲养试验测定羔羊体重和采食量。分别于114～120、144～150、174～180日龄从每个重复中随机挑选1只羊(共18只羊),进行3期消化代谢试验,采集饲料和粪尿样品,测定主要营养物质表观消化率、能量和氮的利用率。结果表明:1)Ⅰ、Ⅱ、Ⅲ组断奶羔羊平均日增重分别为95.97、104.58、108.75g·d-1,Ⅲ组显著高于Ⅰ组(P0.05),Ⅱ和Ⅲ组的干物质采食量显著高于Ⅰ组(P0.01)。2)Ⅴ组4～6月龄断奶羔羊的食入能、消化能、代谢能、消化氮、沉积氮和氮表观沉积率显著提高(P0.05)。3)4～6月龄断奶羔羊的日增重和干物质采食量随日粮营养水平的增加呈先上升后下降的趋势(P0.05)。4)日粮营养水平显著影响DM、EE、NDF、ADF、Ca、P、N、能量的消化代谢率(P0.05)。5)除干物质外,EE、NDF、ADF、Ca、P、N、能量的消化代谢率随着月龄的增加呈上升趋势。本试验条件下,就陕北白绒山羊断奶羔羊生长性能而言,60日龄断奶最佳;就4～6月龄断奶羔羊整体营养平衡和消化代谢而言,日粮能蛋水平按现行饲养标准的1.15倍设置为宜。     

Effect of exogenous fibrolytic enzyme on ruminal fermentation and digestibility of alfalfa and rye-grass hay fed to lambs

This experiment was carried out to study the effect of a directly fed exogenous fibrolytic enzyme on intake and digestion of DM, OM, protein, NDF, ADF, and hemicellulose of alfalfa and ryegrass hay by sheep. Four diets were randomly assigned to four ruminally cannulated lambs using a 4 x 4 Latin square design, repeated in time, with a factorial arrangement (2 x 2) of diets: 1) alfalfa hay; 2) alfalfa hay + exogenous fibrolytic enzymes (enzyme); 3) ryegrass hay; and 4) ryegrass hay + enzyme. Lambs consumed more DM and OM from alfalfa than from ryegrass hay (P < 0.001). The ADF intake was not different between the hays, but NDF intake was lower for alfalfa (P < 0.001). For both hays, the enzyme increased intake of DM (P < 0.01), as well as OM and CP (P < 0.05); however, NDF and ADF intake were not changed. Alfalfa hay had higher apparent digestibility of DM, OM, and CP (P < 0.001), but lower digestibility for NDF, ADF, and hemicellulose. The enzyme increased apparent digestibility of CP, hemicellulose (P < 0.05), and NDF (P < 0.10) for alfalfa. Also, for both hays, the enzyme improved N balance because lambs retained more N (P < 0.05). The enzyme increased (P < 0.05) total VFA concentration (3 and 6 h) for both hays. Results from this trial indicate that directly fed exogenous fibrolytic enzymes may change ruminal fermentation, intake, and digestibility of forages with different nutritive value.     

过瘤胃保护甜菜碱和过瘤胃保护胆碱对1～3月龄湖羊生长性能、消化性能、屠宰性能和脂肪沉积的影响

本试验旨在研究过瘤胃保护甜菜碱(RPB)和过瘤胃保护胆碱(RPC)对1~3月龄湖羊生长性能、消化性能、屠宰性能和脂肪沉积的影响。试验选用30只体重相近的1月龄左右的湖羊公羔,随机分成3组,分别为对照组、RPB组和RPC组,每组10只。对照组饲喂基础饲粮,RPB组和RPC组则饲喂在基础饲粮干物质(DM)基础上分别添加2.9 g/kg RPB和2.5 g/kg RPC的试验饲粮。预试期21 d,正试期54 d。结果表明:1)饲粮中添加RPB和RPC对1~3月龄湖羊的平均日增重、平均日采食量和料重比均无显著影响(P0.05),但RPB组、RPC组的平均日增重较对照组分别增加了19.97%和27.75%。2)饲粮中添加RPB和RPC对1~3月龄湖羊的粗蛋白质(CP)、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)、DM和有机物(OM)的表观消化率均无显著影响(P0.05)。3)饲粮中添加RPB和RPC均可以显著降低1~3月龄湖羊的背膘厚(P0.05),对宰前活重、屠宰率、胴体重、GR值、眼肌面积、腹脂重、肾周脂肪重和肌内脂肪(IMF)含量无显著影响(P0.05),但RPB组和RPC组眼肌面积较对照组分别增加了10.86%和3.16%,IMF含量较对照组分别增加了17.27%和36.36%,肾周脂肪重较对照组分别降低了20.60%和22.67%。综合以上试验结果得出,饲粮中添加2.9 g/kg RPB或2.5 g/kg RPC均可以改善1~3月龄湖羊的脂肪沉积部位和胴体品质,并且从消化性能、生长性能和屠宰性能来看,在满足维持需要的饲粮营养水平下,2种添加剂的作用相当     

竹叶和茶叶渣对断奶犊牛生长性能、消化代谢及血清抗氧化和免疫指标的影响

本试验旨在研究全混合日粮(TMR)中相同中性洗涤纤维(NDF)水平下,以竹叶或茶叶渣替代苜蓿对断奶犊牛生长性能、消化代谢及血清抗氧化和免疫指标的影响。按照随机区组设计将45头105日龄的荷斯坦公犊牛分成3组,每组15头犊牛,分别饲喂苜蓿(AH组)、竹叶(BL组)或茶叶渣(TR组)为主要NDF来源的TMR。预试期15 d,正试期60 d。结果表明:1)180日龄时,TR组的体重显著低于AH组(P<0.05);试验期间,BL组与AH组之间的平均日增重、干物质采食量和料重比无显著差异(P>0.05)。2)与AH组相比,BL组的干物质(DM)和酸性洗涤纤维(ADF)表观消化率显著降低(P<0.05),而有机物(OM)和NDF表观消化率差异不显著(P>0.05);TR组的NDF表观消化率显著提高(P<0.05),而DM、OM和ADF表观消化率差异不显著(P>0.05)。3)与AH组相比,BL组的尿能、总能消化率、总能代谢率和消化能代谢率显著降低(P<0.05)。4)与AH组相比,BL组的尿氮显著提高(P<0.05),氮沉积率显著降低(P<0.05);TR组的粪氮显著提高(P<0.05),氮表观消化率显著降低(P<0.05)。5)与AH组相比,BL和TR组的血清谷胱甘肽过氧化物酶(GSH⁃Px)和过氧化氢酶(CAT)活性显著降低(P<0.05),血清免疫球蛋白A(IgA)、丙二醛(MDA)含量显著升高(P<0.05);BL组的血清总抗氧化能力(T⁃AOC)显著降低(P<0.05)。由此可见,与饲喂苜蓿饲粮相比,饲喂竹叶饲粮的断奶犊牛生长性能及OM、NDF表观消化率相近,但能量和氮的利用率降低;饲喂茶叶渣饲粮的断奶犊牛能量利用率相近,而NDF表观消化率显著提高,生长性能和氮的利用率降低;饲喂竹叶饲粮和茶叶渣饲粮的断奶犊牛血清IgA含量显著提高,抗氧化能力降低。综上所述,断奶犊牛阶段可以用竹叶(24.38%)替代苜蓿作为饲粮的粗饲料。     

Buffel grass (Cenchrus ciliaria L.) substitution for orange pulp on intake, digestibility, and performance of hairsheep lambs

Twenty Dorper x Pelibuey male lambs were used to evaluate the effect of substitution of forage with fresh orange pulp (FOP) in diets for fattening lambs on productive behavior, nutrient intake, apparent digestibility coefficient, and feeding costs. Lambs were divided into five groups (n?=?4) and then housed in individual pens during 70 d. Treatments consisted of five levels of FOP (0, 25, 50, 75 and 100%) which substituted buffel grass hay on the base diet (40:60%, forage:concentrate). Additionally, changes in chemical composition of FOP stored in stack during 8 d were evaluated (from the day 1 until day 8). Daily feed intake expressed as kg/day and % live weight, lamb growth rate, feeding cost of each lamb per day and per fattening period, hemicellulose intake, and DM, OM, CP, NDF and hemicellulose digestibility showed a quadratic effect (P?<?0.05), while DM, OM and CP intake presented a cubic effect (P?<?0.05) with the increasing level of FOP. The maximum estimated value for those variables was observed at 75% of hay replacement with FOP. With respect to changes in chemical composition of pulp stored, DM content increased (P?=?0.0011) from 210 to 310 g/kg FOP and OM, fiber fraction, and ash content were constant (P?>?0.05) among storage days. Therefore, replacing around 75% of buffel grass hay with FOP in diets for fattening lambs resulted in the best growth rate and more efficient diet utilization. Fresh orange pulp stored in a stack did not change its chemical composition, and did not affect its utilization as a sheep feedstuff.     

Digestibility and dry matter intake of diets containing alfalfa and kenaf

Two experiments were conducted to determine the dietary value of pellets containing kenaf (Hibiscus cannabinus cv. 'Everglade 41') hay. Averaged across both experiments, kenaf pellets contained 82.6% kenaf hay, 16.6% liquid molasses, and 0.8% mineral oil. The chemical composition of the kenaf pellet was 12.6% crude protein (CP), 41.2% neutral detergent fiber (NDF), and 14.4% acid detergent fiber (ADF). In Exp. 1 (digestion and N balance trial), 18 lambs (body weight [BW] = 36.4 kg) were blocked by BW. Lambs were randomly assigned within a block to Diet 1 (59.5% corn and 40.5% alfalfa pellet), Diet 2 (59.7% corn, 28.4% alfalfa pellets, and 11.9% kenaf pellets), or Diet 3 (59.6% corn, 16.5% alfalfa pellets, and 23.9% kenaf pellets). Diets were formulated so that CP was the first-limiting nutrient. Each diet was limit-fed at 2.4% of BW. Replacing alfalfa pellets with kenaf pellets tended to decrease (P = 0.10) CP and ADF intakes, but increased (P = 0.01) DM digestibility. Diet had no effect (P = 0.33) on N balance. In Exp. 2 (dry matter [DM] intake trial), 32 lambs (BW = 30.4 kg) were blocked by gender and BW. Within a block, lambs were randomly assigned to one of four diets in a 2 x 2 factorial arrangement. Main effects were hay (bermudagrass or fescue) and supplemental protein source (kenaf or alfalfa pellets). Lambs were housed in individual pens with ad libitum access to the assigned hay. Supplemental protein was fed (185 g of DM) once daily. Hay intake was measured weekly for 8 wk. Lambs consumed more (P = 0.002) fescue than bermudagrass hay (743 vs 621 g/ d). Lambs fed fescue hay gained weight more rapidly (P = 0.001) than lambs fed bermudagrass hay (120 vs 72 g/d). Hay intake and ADG were similar (P = 0.90) for lambs fed alfalfa or kenaf pellets. Kenaf hay mixed with molasses and mineral oil can be formed into a pellet. In the diets used in this experiments, kenaf pellets can replace alfalfa pellets in diets fed to lambs without altering forage intake, gain, or N retention.     

Effects of early experience with low‐quality roughage on feed intake,digestibility and metabolism in lambs

The objective of this study was to compare the feed intake, digestibility and metabolism in lambs fed low‐quality roughage with those of lambs fed normal roughage from an early stage of their life. The study consisted of two treatments [low‐quality roughage group (LR) and control group (C)] over three time periods (P1, P2 and P3; 2 months each). Four lambs (4 months old) were allocated to each treatment. In P1 and P2, LR was fed sudangrass hay (CP: 5.1% DM; NDF: 70.4% DM), whereas C was fed timothy hay (CP: 8.4% DM; NDF: 60.3% DM). In P3, all lambs were fed sudangrass hay. Although the feed intake was significantly greater (p < 0.05) in C in P1, there were no differences between the groups in P2. The digestibility, serum glucose (GLU), urea nitrogen (SUN) and insulin‐like growth factor 1 (IGF‐1) did not differ between the groups in P1 and P2. The average nitrogen retention, triiodothyronine (T3) and thyroxine (T4) were significantly higher in C (p < 0.05) during P1 and P2. No interaction was observed between the treatment and periods. In P3, the feed intake was greater in C (p < 0.05), whereas digestibility and nitrogen retention tended to be greater in LR. The body weight did not differ between the treatments. T4 and T3 were numerically lower in LR, while the SUN was greater in LR (p < 0.05). These results suggest that the early experience with low‐quality roughage may have improved feed digestibility and nitrogen metabolism in lambs after 4 months of rearing. Furthermore, the experienced lambs became more efficient at utilizing the low‐quality roughage. The lower thyroid hormone concentrations observed in LR suggest an adaptive change occurred in experienced lambs that to a lower basal metabolic rate.     

Growth of sheep fed tannin-rich Albizia gummifera with or without polyethylene glycol

Twenty-four intact male Bonga lambs were studied in a 100-day experiment to evaluate the effect of feeding tannin rich leaves of Albizia gummifera (AG) on nutrient utilization, growth performance, and carcass composition. The dietary treatments consisted of hay alone (T₁, control), AG at 30 % of control diet + T₁ (T₂), and T₂ + polyethylene glycol 6000 (PEG) (T₃, 40 mg PEG, 1 kg AG/head on a dry mass (DM) basis. The lambs were individually fed at 50 g DM/kg live weight. In the last 10 days of the experiment, all animals from each treatment were harnessed with feces collection bags. At the end of the experiment, lambs were slaughtered after overnight fasting for measurements of carcass characteristics. Crude protein, neutral detergent fiber, and condensed tannin contents of AG were 300, 586, and 108 g/kg DM, respectively. Lambs fed AG with PEG had higher (P?2 were able to utilize AG, the efficiency of its utilization was lower (P?相似文献   

Effects of corn processing and dietary fiber source on feedlot performance, visceral organ weight, diet digestibility, and nitrogen metabolism in lambs

In Exp. 1, early-weaned Targhee and Polypay crossbred lambs (60 ewes and 66 rams; initial BW 24 +/- 1.0 kg) were used in a 2 x 3 factorial experiment to determine the effects of corn processing (whole shelled corn [WSC] or ground and pelleted corn [GC]) in combination with supplemental fiber (none [control]; soybean hulls, SBH [highly digestible]; or peanut hulls, PH [highly indigestible]) on DMI, ADG, feed efficiency, and visceral organ weight. For the total trial, WSC resulted in a 4% increase (P < .01) in ADG vs GC, and supplemental fiber resulted in increased (P < .01) DMI and ADG vs the control diet. Experiment 2 was conducted using 12 Targhee and Polypay crossbred wether lambs (initial BW 25 +/- 7 kg) to determine the effects of corn processing and fiber source in high-concentrate diets on diet digestibility and N retention using the same diets as in Exp. 1. Lambs fed WSC had greater (P < .001) apparent N digestion, true N digestion, and N retention (P < .01) than those fed GC. The apparent digestibilities of DM, OM, and NDF were greater (P < .001) for WSC than for GC diets. Peanut hulls resulted in decreased (P < .01) DM, OM, and NDF apparent digestibilities compared with the control and SBH diets. Starch digestion was not affected (P > .10) by diet. Whole corn resulted in improved DM, OM, NDF, and N digestibility compared with GC. Overall, both the SBH and PH diets resulted in greater DMI and ADG than the control diet, which lacked supplemental fiber.     

Effect of supplementing Rhodes grass hay (Chloris gayana) with Berchemia discolor or Zizyphus mucronata on the performance of growing goats in Kenya

Twenty growing Small East African goats were used to determine the effects of feeding sun-dried leaves of the browse forages Berchemia discolor and Zizyphus mucronata as supplements to low-quality basal diet, Rhodes grass (Chloris gayana) hay, on voluntary feed intake (VFI), digestibility and growth performance. The grass hay and maize bran were used as a control. The dried leaves were then included at the rates of 15% and 30% of the dry matter intake (DMI). Berchemia discolor had the highest crude protein (CP) content of 195.5 g/kg DM, while Z. mucronata had CP content of 169.5 g/kg DM. The grass hay had the lowest CP content of 50.9 g/kg DM. The browse forages had low fibre content [Neutral detergent fibre (NDF); 257.9-369.5 g/kg DM], while the grass hay had high fibre content (NDF; 713.1 g/kg DM). Goats in the groups supplemented with either of the browse forages had higher total DMI, nitrogen (N) intake and retention and live-weight gains than those in the control diet group. The digestibility of DM and organic matter (OM) was not affected by supplementation, but the CP digestibility increased with supplementation. The use of the browse forages as supplements for goats fed on poor-quality basal diets would enhance the performance of the animals.