复合益生菌对泌乳中后期奶牛生产性能和瘤胃发酵参数的影响

选用48头产奶量、泌乳天数和胎次相近的泌乳中后期奶牛进行配对设计,分为4组,即对照组(复合益生菌0g/d)、试验1组(复合益生菌10g/d)、试验2组(复合益生菌20g/d)和试验3组(复合益生菌30g/d),试验期60d,其中预饲期7d。结果表明:与对照组相比,复合益生菌能够提高泌乳中后期奶牛的产奶量,同时能够显著提高乳蛋白率、乳糖率和总固形物(P<0.05);对血液生化指标无显著影响(P>0.05);复合益生菌能显著提高瘤胃中NH_3-N和微生物蛋白(MCP)含量(P<0.05);与对照组相比,试验2组的粗蛋白(CP)和粗脂肪(EE)表观消化率均显著提高(P<0.05);试验1,2,3组比对照组每头奶牛每天分别获益2.28,4.80和4.09元。以产奶性能、瘤胃发酵参数、营养物质表观消化率和经济效益为主要衡量指标,以每头奶牛日喂20g效果最佳。     

饲粮中添加过瘤胃赖氨酸对福清山羊生长性能、养分表观消化率和氮代谢的影响

本试验旨在研究饲粮中添加过瘤胃赖氨酸(RPLys)对福清山羊生长性能、养分表观消化率和氮代谢的影响。选择体况良好、体重[(12.06±1.65)kg]相近的4月龄福清山羊羯羊30只,采用单因素试验设计,随机分为5组,每组6只。对照组饲喂基础饲粮,试验Ⅰ、Ⅱ、Ⅲ和Ⅳ组在基础饲粮中每只羊添加2.5、5.0、7.5和10.0 g/d RPLys。预试期15 d,正试期60 d。结果表明:1)饲粮中添加RPLys对福清山羊干物质采食量(DMI)、总能采食量、初始体重、终末体重、总增重和平均日增重(ADG)均无显著影响(P>0.05),试验I组的DMI最高,试验Ⅱ组的总增重和ADG最高。2)饲粮中添加RPLys对福清山羊干物质、有机物、总能、中性洗涤纤维和酸性洗涤纤维的表观消化率均无显著影响(P>0.05)。3)对照组的进食氮显著低于各试验组(P<0.05),试验Ⅳ组的进食氮显著高于试验Ⅰ和Ⅱ组(P<0.05)。试验Ⅳ组的粪氮显著高于试验Ⅱ组(P<0.05)。试验Ⅰ、Ⅱ和Ⅲ组的沉积氮显著高于对照组(P<0.05)。各组之间的尿氮、排泄氮、氮沉积率和氮生物学价值无显著差异(P>0.05)。由此可见,在本试验条件下,饲粮中添加RPLys对福清山羊生长性能无显著影响,饲粮中添加2.5~7.5 g/d RPLys显著提高了福清山羊的沉积氮。     

牛至油和过瘤胃蛋氨酸组合添加对奶牛瘤胃微生物蛋白产量与养分消化率的影响

本试验旨在研究牛至油(Oo)与过瘤胃蛋氨酸(RPMet)的不同添加组合对奶牛瘤胃微生物蛋白(MCP)产量与养分消化率的影响。选取年龄、体重、胎次、产奶量、乳成分及泌乳期(90±15)d的荷斯坦奶牛40头,分为10个组,每组4头。对照(C)组饲喂基础日粮,试验组饲喂不同添加水平的Oo和RPMet,Oo设置3个梯度,添加量分别为11.5(L)、13(M)、14.5(H)g/(d·头);RPMet设置3个梯度,添加量分别为22.5(L)、25(M)、27.5(H)g/(d·头),共组成9个不同的添加量组合,分别为LL、ML、HL、LM、MM、HM、LH、MH、HH(第1个字母为Oo添加水平,第2个字母为RPMet添加水平)。预试期15 d,正试期60 d。结果表明:各试验组奶牛的微生物蛋白(MCP)产量均有提高,其中MH、ML、LH、LM、HM组的MCP产量显著提高;试验组奶牛的养分表观消化率有提高趋势,其中MH、HM组粗蛋白质消化率极显著提高;HH、MH组中性洗涤纤维消化率显著提高,酸性洗涤纤维消化率极显著提高;MH组干物质消化率显著提高。在本试验条件下,综合考虑瘤胃MCP产量以及各主要养分的表观消化率,以Oo 13 g/(d·头)、RPMet 27.5 g/(d·头)组合(MH组)效果最好。     

牛至油和肉桂醛添加组合对奶牛瘤胃微生物蛋白产量与养分消化率的影响

本试验旨在研究牛至油(Oo)与肉桂醛(CA)的不同添加组合对奶牛瘤胃微生物蛋白产量与养分消化率的影响。选取年龄、体重、胎次、产奶量、乳成分相近及泌乳期为(90±15)d的荷斯坦奶牛40头,随机分为10个组,每组4头。对照组(C)饲喂基础日粮,试验组饲喂不同添加水平的Oo和CA,Oo 3个梯度分别为11.5(L)、13(M)、14.5(H)g/(d·头);CA 3个梯度分别为15(L)、18(M)、21(H)g/(d·头),共组成9个不同的添加量组合,分别为LL、ML、HL、LM、MM、HM、LH、MH、HH(第1个字母为Oo添加水平,第2个字母为CA添加水平)。预试期15 d,正试期60 d。结果表明:试验组奶牛的瘤胃微生物蛋白(MCP)产量均有提高趋势,其中LH组效果最好,瘤胃MCP产量比C组提高了12.82%(P<0.05);试验组奶牛在养分表观消化率方面有提高趋势,其中以LH组最优,干物质与粗蛋白质的消化率高于C组(P<0.05),中性洗涤纤维与酸性洗涤纤维的消化率高于C组(P<0.01)。本试验条件下,综合考虑瘤胃MCP产量以及各主要养分的表观消化率,以添加Oo 11.5 g/(d·头)、CA 21 g/(d·头)为最佳。     

丙酸钙对西门塔尔牛玉米秸秆瘤胃降解率的影响

选用4头体重500 kg,年龄3.5岁装有永久性瘤胃瘘管的中国西门塔尔牛阉牛,采用4×4拉丁方设计,以混合精料和玉米秸秆为基础日粮,研究丙酸钙(0、100、200 g/d和300 g/d)对玉米秸秆瘤胃降解率的影响.结果表明:200 g/d组玉米秸秆干物质(DM)瘤胃有效降解率较对照组提高,但差异不显著(P>0.05),有机物(OM)、中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)瘤胃有效降解率较对照组显著提高(P<0.05).本试验结果表明,日粮中丙酸钙的适宜添加水平为200 g/d.     

半胱胺对小尾寒羊瘤胃原虫和养分消化率及血清生化指标的影响

为了研究半胱胺对小尾寒羊瘤胃原虫和养分消化率及血清生化指标的影响,试验选择体质量40 kg左右小尾寒羊40只,随机分为4组,每组10只,半胱胺每天每只的添加量分别为0.1(1组)、0.2(2组)、0.3(3组)、0(对照组),结果表明,(1)半胱胺能够激发瘤胃原虫的生长率和增长数量.(2)试验羊采食正常,各组间采食量无显著差异.试验3组的日增重达到0.234 kg,显著高于其他组(P<0.05),试验1组、试验2组和对照组间日增重无显著差异(P>0.05).试验3组的耗料/增重显著低于其他各组(P<0.01),试验1组和对照组间无显著差异(P>0.05).试验3组的粗蛋白消化率显著高于对照组(P<0.05),粗脂肪消化率则极显著高于对照组(P<0.01);中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)消化率组间差异不显著(P>0.05).(3)每天每只添加0.3 g半胱胺试验组的血糖(glucose)水平最高,显著高于其他各组(P<0.05);血清尿素氮(BUN)值最低,显著低于其他各组(P<0.05),生长抑素(SS)值为56.02 ng/L,极显著低于对照组的71.45 ng/L(P<0.01);血清3-碘甲状腺原氨酸(T3)和甲状腺素(T1)水平均高于对照组(P<0.05),而生长激素(GH)和胰岛素样生长因子(IGF-1)水平也显著高于对照组(P<0.01);试验组的血清胰岛素(INS)水平与对照组不显著(P>0.05).     

日粮能量水平对山羊个体和瘤胃上皮生长的影响

系统研究日粮能量水平对山羊瘤胃上皮生长的影响,并初步探讨了高能量日粮促进瘤胃上皮生长的细胞和分子生物学机理。选取18只青年波杂山羊(波尔山羊×淮南羊,120 d,体重(14.27±0.69)kg)随机分成高能量组(HL,n=9,ME:1.00 MJ/(kg0.75·d))和低能量组(LL,n=9,ME:0.60 MJ/(kg0.75·d)),饲喂持续42 d。结果:与LL组相比,HL组山羊日增重、瘤胃干重、瘤胃上皮乳头长度和表面积显著增大(P0.05),表明高能量日粮显著促进瘤胃上皮乳头生长。组织切片观察发现,HL组棘突层和颗粒层细胞层数增多(P0.05),体积减小(P0.05),提示高能量日粮促进瘤胃乳头生长主要通过加速细胞增殖,而非细胞肥大。     

日粮甜菜碱和过瘤胃脂肪对育肥湖羊生长性能和消化参数的影响

选取48只3月龄湖羊公羔,随机分为6个处理组、每个处理组8个重复,每个重复1只羊,试验过渡期10d、预试期7d、试验期50d。采用2×3双因素试验,即两个RPF添加浓度(0和2.4%),3个Bet水平(0、4和8g·d-1)。旨在研究添加甜菜碱(betaine,Bet)和过瘤胃脂肪(rumen protected fat,RPF)对育肥湖羊生长性能、血液参数和瘤胃发酵参数的影响。结果表明,1)添加2.4%的RPF能显著降低湖羊日增重、采食量和末体重(P0.05),显著提高血浆中胆固醇(TCH)和甘油三酯(TG)含量(P0.05),对血浆中的葡萄糖(Glu)含量无显著影响(P0.05);日粮添加Bet对育肥湖羊生长性能和血液指标无显著影响(P0.05)。二者交互对育肥湖羊生长性能和血液指标无显著作用(P0.05)。2)添加2.4%的RPF能显著降低饲料中中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)消化率(P0.05),对干物质(DM)、有机物(OM)和粗蛋白(CP)消化率无显著影响(P0.05),对瘤胃挥发性脂肪酸浓度及比例无显著影响(P0.05);日粮添加Bet对养分消化率和瘤胃挥发性脂肪酸浓度及比例无显著影响(P0.05)。二者互作对瘤胃发酵和养分消化率无显著影响(P0.05)。综上可知,在本研究条件下,甜菜碱对湖羊无调控作用,RPF主要通过降低湖羊采食量及纤维消化率影响生产性能。实际生产中,若以羊肉产量为目标不宜添加2.4%RPF。     

烷基多糖苷添加水平对山羊瘤胃发酵特性的影响

本试验通过研究日粮中添加不同水平的烷基多糖苷(alkyl polyglycoside,APG)对山羊瘤胃发酵特性的影响,考察APG在饲料添加剂领域的潜在用途.试验选用4头体重为(19.5±0.8)kg装有瘤胃瘘管的黑山羊,按4×4拉丁方设计,分别在山羊标准精料中添加0、5、10和20 mL/kg的APG,试验期48 d.试验结果表明,APG对山羊瘤胃pH没有显著影响(P>0.05);APG极显著地增高了山羊瘤胃氨氮浓度、总挥发性脂肪酸(TVFA)、乙酸含量以及乙酸与丙酸含量的比值(P<0.01),还使戊酸含量和乙酸摩尔百分比显著增高(P<0.05),但是对丙酸、丁酸、异丁酸、异戊酸含量以及除乙酸外其他各酸的摩尔百分比皆无显著影响(P>0.05).由此可知,添加APG不影响山羊瘤胃pH,极显著提高氨氮浓度,提高TVFA和乙酸含量,改善了山羊瘤胃发酵特性.     

不同亚油酸来源的日粮以绵羊瘤胃发酵和营养物质表观消化率的影响

研究探讨日粮添加花生油、玉米油和大豆油对绵羊瘤胃发酵和营养物质表观消化率的影响.选取4只雄性、健康且安装有永久性瘤胃瘘管的成年东北半细毛羊×陶赛特杂交绵羊,体重(40±1)kg,采用4×4拉丁方试验设计,预饲期10 d,正试期6 d,4个处理组分别为不添加油脂组(CK组)、添加4%花生油(PO组)、2.84%玉米油(CO组)和2.86%大豆油(SO组)的加油组,日粮精粗比均为40:60,经测得3个加油组亚油酸水平一致.结果表明:添加植物油后,对绵羊瘤胃液pH值、NH3-N浓度、VFA没有影响(P>0.05),花生油处理组原虫数量比对照组降低了42.18%(P<0.05),玉米油和大豆油处理组原虫数量分别比对照纽降低28.07%、29.81%(P>0.05);对DM、CP和NDF的瘤胃动态降解率没有影响(P>0.05);对日粮DM、CP、NDF和ADF的全消化道表观消化率没有影响,显著提高了EE的全消化道表观消化率(P<0.05).日粮添加植物油对瘤胃发酵没有负面影响,并显著提高了EE的全消化道表观消化率.     

陕北白绒山羊羯羊能量和蛋白质需要量

本试验旨在研究陕北白绒山羊羯羊能量和蛋白质的需要量,为制定其饲养标准提供数据。选取36只体重相近、健康状况良好的陕北白绒山羊周岁羯羊,按3×3(能量×蛋白质)完全随机设计分为9组,每组4个重复,每个重复1只。各组饲粮消化能和粗蛋白质水平分别参照NRC(1981)推荐量的100%、110%、120%和90%、110%、130%设定。预试期7 d,正试期46 d。结果表明:1)饲粮能量水平对周岁羯羊的干物质采食量和平均日增重都有极显著影响(P0.01),蛋白质水平对干物质采食量影响显著(P0.05);饲粮能量和蛋白质水平对干物质采食量有显著的互作效应(P0.05)。2)低能量水平组的可消化氮显著低于中能量水平组与高能量水平组(P0.05);低蛋白质水平组的进食氮、可消化氮、沉积氮、氮表观消化率均极显著低于中蛋白质水平组和高蛋白质水平组(P0.01)。3)总能消化率和总能代谢率均随着能量水平的提高而极显著地升高(P0.01);高蛋白质水平组的总能代谢率和消化能代谢率显著低于低蛋白质水平组(P0.05);能量和蛋白质水平对总能消化率、总能代谢率和消化能代谢率均产生显著或极显著的互作效应(P0.05或P0.01)。本试验得到了陕北白绒山羊周岁羯羊能量和蛋白质需要量的回归方程,饲粮的消化能和代谢能分别以8.80~10.61 MJ/kg和7.34~8.76 M J/kg较为适宜,粗蛋白质和可消化粗蛋白质分别以10.00%和7.34%为宜。     

Feed intake and weight gain of growing goats fed diets of various energy and protein levels

Growing goats, 45 Alpine and 45 Nubian, were used in a 3 x 3 factorial arrangement to quantify the influence of dietary energy and protein levels on daily DM intake and nutrient utilization for growth. Goats had ad libitum access to complete mixed diets containing either 2.46, 2.77 or 3.05 Mcal/kg ME plus 11.2, 12.7 or 15.1% CP for 16 wk. Dry matter intake decreased curvilinearly as dietary ME density increased (P less than .001). Dry matter intake increased linearly (P less than .05) as dietary CP level increased during all growth intervals except wk 25 to 28 of age. Average daily gain was 115, 113 and 99 g/d for goats fed diets containing 2.46, 2.77 and 3.05 Mcal/kg ME, respectively. Average daily gain was 104, 106 and 117 g/d for goats fed diets with 11.2, 12.7 and 15.1% CP, respectively. Dry matter intake was higher (P less than .01) for Alpine than for Nubian goats, whereas ADG was similar between breeds. Intake of ME was 248, 260 and 198 kcal/(kg.75.d) for goats fed the low- medium- and high-energy diets, respectively. Intake of CP was 9.1, 10.7 and 13.2 g/(kg.75.d) for goats fed low-, medium- and high-protein diets, respectively. Average requirements for growth derived from regression analysis of all data points were 4.6 kcal ME and .26 g CP/g ADG. The prediction equation for intake of growing goats of 4 to 8 mo of age was: DMI, g/d = 1,749 - 496 DE, kcal/g + 18 live weight, kg + 3 ADG, g/d; r2 = .73 (Sy.x = 127, P less than .0001, n = 90). The requirement of ME for growth was 33% lower than the value recommended in 1981 by the National Research Council.     

Effects of Pasting Anionic Salt and RPC on Production Performance and Blood Biochemical Indexes of Perinatal Dairy Cows

This experiment was conducted to study the effects of pasting anionic salt and RPC on production performance and blood biochemical indexes of perinatal dairy cows.Using randomized trial design, 20 healthy Holstein cows which according to the tire time (2 to 4), age, last time lactation quantity and parturition date were chosen.They were divided into four groups, 5 cows per group.The control group was fed TMR diet, Ⅰ, Ⅱ, Ⅲ groups were fed the basal diet +200 g pasting anion salt and supplemented with 10, 20, 30 g/(head·d) RPC, respectively.There were 7 days to pilot test, formal test was from antenatal 21 d to parturition.The results showed that:①DMI of all experimental groups were significantly higher than that of control group during most of antenatal 21 days (P< 0.05);The nutrients apparent digestibility of all experimental groups were generally higher than that of control group;Add 20, 30 g/(head·d) RPC was significantly increased the apparent digestibility of CP, NDF, ADF (P< 0.05);The apparent digestibility of Ca of all experimental groups were significantly higher than that of control group (P< 0.05);Add 30 g/(head·d) RPC was significantly increased the apparent digestibility of EE (P< 0.05).②Among postpartal 90 days, the total milk yield of all experimental groups were significantly or extremely significantly higher than that of control group (P< 0.05;P< 0.01);Add 20, 30 g/(head·d) RPC was significantly enhanced the feed conversion rate (P< 0.05);Add 30 g/(head·d) RPC was improved the percentage of milk dry matter, milk protein and milk fat of colostrum (P< 0.05).③Serum Ca²⁺ concentration of all experimental groups were significantly higher than that of control group (P< 0.05);Add 20, 30 g/(head·d) RPC was significantly increased the part time plasma TG levels (P< 0.05), significantly reduced the part time plasma contents of TCHO, BHBA and NEFA (P< 0.05).In conclusion, among the perinatal period added pasting anionic salt and RPC could improve early prenatal DMI and part nutrients apparent digestibility, improve perinatal blood calcium and blood lipid metabolism, and enhance the production performance and feed conversion rate, based on adding 200 g pasting anion salt among early perinatal, the best add amount of RPC was 30 g/(head·d).     

糊化阴离子盐和过瘤胃氯化胆碱对围产期奶牛生产性能和血液生化指标的影响

本试验旨在研究日粮中添加糊化阴离子盐和过瘤胃氯化胆碱(RPC)对围产期奶牛生产性能和血液生化指标的影响。采用随机分组试验设计,选取20头健康荷斯坦奶牛,按胎次(2~4)、年龄、上一胎次泌乳量和预产期相似原则分为4组,每组5头。对照组饲喂TMR日粮,试验Ⅰ、Ⅱ、Ⅲ组在饲喂TMR日粮＋200 g糊化阴离子盐基础上分别添加10、20、30 g/(头·d)RPC。预试期7 d,正试期从预产期前21 d饲喂至产犊结束。结果表明:①各试验组产前21 d大部分时间点的干物质采食量(DMI)均显著高于对照组(P< 0.05);各试验组营养物质表观消化率普遍高于对照组,其中添加20、30 g/(头·d)RPC能显著提高粗蛋白质(CP)、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)的表观消化率(P< 0.05),各试验组钙(Ca)表观消化率均显著高于对照组(P< 0.05),添加30 g/(头·d)RPC能显著提高粗脂肪(EE)表观消化率(P< 0.05)。②各试验组产后90 d内的总泌乳量显著或极显著高于对照组(P< 0.05;P< 0.01);添加20、30 g/(头·d)RPC能显著提高饲料转化率(P< 0.05);添加30 g/(头·d)RPC能显著提高初乳中乳干物质率、乳蛋白率和乳脂率(P< 0.05)。③各试验组血清Ca²⁺含量显著高于对照组(P< 0.05);添加20、30 g/(头·d)RPC能显著提高部分时间点血浆甘油三酯(TG)含量(P< 0.05),显著降低部分时间点血浆总胆固醇(TCHO)、β-羟丁酸(BHBA)和游离脂肪酸(NEFA)的含量(P< 0.05)。综上所述,围产前期添加阴离子盐和PRC能提高奶牛产前干物质采食量和部分营养物质表观消化率,改善围产期血钙和血脂代谢,提高生产性能和饲料转化率,围产期奶牛日粮在添加200 g糊化阴离子盐的基础上,PRC的最适添加量为30 g/(头·d)。     

不同能量水平对羊生产性能及激素水平的影响

选用山羊和绵羊各21只,研究能量水平对羊采食量(DMI)、日增重(ADG)、饲料转化率(FCR)、胰岛素、生长激素和孕酮浓度的影响。结果表明:绵羊的DMI显著大于山羊的(P<0．05),低能量水平下,绵羊的DMI显著大于山羊的(P<0．05)。绵羊的ADG显著高于山羊的(P<0．05),高能量水平下两种羊的ADG显著高于低能量水平的(P <0．05),FCR在绵羊与山羊之间、不同能量水平之间及互作之间都不显著(P>0．05)。试验前期山羊血清胰岛素水平显著大于绵羊的(P<0．05),在低能量水平下,山羊的血清胰岛素浓度显著高于绵羊的(P<0．05)。试验前期山羊的孕酮水平显著高于绵羊的(P<0．05),高能量水平下的孕酮极显著地高于中、低能量水平下的孕酮(P<0．01),中等能量水平下,山羊的孕酮浓度显著高于绵羊的(P<0．05)。     

饲粮能氮比对简州大耳羊生长性能及养分消化代谢的影响

【目的】本试验旨在研究全价颗粒饲粮代谢能/总氮（ME/N）和性别对全舍饲简州大耳羊生长性能及养分消化代谢的影响。【方法】采用2×4两因素试验设计,选择健康、体况良好的5月龄简州大耳羊64只,公羊（26.56 kg±2.96 kg）和母羊（25.75 kg±2.46 kg）各32只,公母各随机分成4组,每组8只羊,分别饲喂ME/N为0.59、0.51、0.43、0.35的全价颗粒饲粮,过渡期5 d,预饲期10 d后进行30 d饲养试验,再按照平均体重每组选择4只羊开展为期11 d的全收粪尿消化代谢试验（预饲7 d,正试期4 d）。【结果】①饲粮ME/N显著影响试验羊平均日增重（ADG）和干物质采食量（DMI）（P＜0.05）,在ME/N为0.43时ADG达到最佳（259±58 g/d）;试验公羊ADG和DMI显著高于试验母羊（P＜0.05）,饲粮ME/N和性别对DMI具有显著的交互作用（P＜0.05）。②随着ME/N降低,试验羊尿能（UE）显著增加（P＜0.05）,对总能摄入量（GEI）、粪能（FE）、消化能（DE）和总能（GE）表观消化率无显著影响（P＞0.05）;试验公羊GEI、FE、DE均显著高于试验母羊（P＜0.05）。③随着饲粮ME/N降低,试验羊摄入氮（NI）和氮表观消化率均显著增加（P＜0.05）,公羊NI、沉积氮（NR）、净蛋白利用率（NPU）和氮的生物学价值（BV）均显著高于母羊（P＜0.05）。④随着饲粮ME/N降低,试验羊粗脂肪（EE）和酸性洗涤纤维（ADF）的表观消化率先增加后降低（P＜0.05）,其他养分消化率无显著变化（P＞0.05）;公羊干物质（DM）、磷（P）、ADF、中性洗涤纤维（NDF）的表观消化率均显著高于母羊（P＜0.05）;性别和饲粮ME/N对养分表观消化率无显著交互作用（P＞0.05）。【结论】当全价颗粒饲粮能量一致,适当降低ME/N（增加N浓度）可以显著提高全舍饲生长育肥期简州大耳羊生长性能和养分表观消化率,但继续降低ME/N不能提高试验羊生长性能和养分消化代谢,在本试验条件下最适的饲粮ME/N为0.43;生长育肥期公羊对养分消化代谢及生长性能均优于同期母羊。     

Growth and slaughter traits of Boer x Spanish, Boer x Angora, and Spanish goats consuming a concentrate-based diet.

The number of Boer crossbred meat goats has been increasing rapidly, although how their growth and slaughter traits compare with those of Spanish goats and influences of maternal genotype have not been thoroughly evaluated. This information would be useful to achieve optimal meat goat production systems and yield of goat products desired by consumers. Therefore, postweaning growth (9 to 24 wk of age) and slaughter traits (212 +/- 5.0 d of age) of Boer x Spanish, Spanish, and Boer x Angora wethers (n = 16, 18, and 18 for growth measures, respectively, and n = 6 per genotype for slaughter traits) consuming a concentrate-based diet were compared. Over the 16-wk performance period, ADG, DMI, and ADG:DMI were greater (P < 0.05) for Boer crossbreds than for Spanish goats (ADG: 154, 117, and 161 g; DMI: 646, 522, and 683 g/d; ADG:DMI: 263, 235, and 261 g/kg for Boer x Spanish, Spanish, and Boer x Angora, respectively). Dressing percentage (46.3, 47.3, and 47.0% of BW; SE = 1.21) and quality grade score (11.17, 9.67, and 11.17 for Boer x Spanish, Spanish, and Boer x Angora, respectively; SE = 0.66 [12 = Choice+; 11 = Choice; 10 = Choice-; 9 = Good+]) were similar among genotypes. Weights of some noncarcass components were greater for Boer crossbreds than for Spanish goats, but relative to empty BW, noncarcass component weights were similar among genotypes. Concentrations of moisture, ash, fat, and protein in carcass and noncarcass components did not differ among genotypes. Contributions to the carcass of different primal cuts were similar among genotypes, and there were few differences in concentrations of separated lean, bone, and fat in primal cuts. In conclusion, when consuming a concentrate-based diet, early postweaning growth rate was similar between Boer x Spanish and Boer x Angora wethers and greater for Boer crossbreds than for Spanish wethers. Slaughter traits were primarily related to differences in final BW.     

育成期崂山奶山羊能量需要量

本试验旨在研究饲粮能量水平对育成期崂山奶山羊能量利用率的影响。选择体重为(18.43±0.76)kg的崂山奶山羊育成母羊30只,采用单因素随机分组设计分成3组,每组10个重复,每重复1只羊。分别饲喂粗蛋白质、钙及磷水平基本一致,消化能水平分别为10.40、11.47及12.51 MJ/kg的3种全混合日粮。预试期10 d,正试期90 d。结果表明:1)试验后期3组试羊随着饲粮能量水平的提高,总能消化率依次提高,12.51 MJ/kg组试羊的总能消化率、总能代谢率及消化能代谢率显著高于10.40 MJ/kg组(P0.05);3组试羊的总能、粪能及尿能间呈显著差异(P0.05),10.40 MJ/kg组11.47 MJ/kg组12.51 MJ/kg组;10.40 MJ/kg组试羊的甲烷能显著低于11.47及12.51 MJ/kg组(P0.05)。2)10.40 MJ/kg组试羊末重及平均日增重显著低于11.47及12.51 MJ/kg组(P0.05),但11.47 MJ/kg组与12.51 MJ/kg组间无显著差异(P0.05)。3)育成期崂山奶山羊消化能和代谢能需要量与代谢体重和平均日增重关系的回归公式:DE=0.675W~(0.75)+0.110ADG(P=0.006,R~2=0.982);ME=0.526W~(0.75)+0.076ADG(P=0.027,R~2=0.873)[式中DE为消化能(M J/d),ME为代谢能(M J/d),W~(0.75)为代谢体重(kg),ADG为平均日增重(g)]。综合得出,育成期崂山奶山羊母羊饲粮中消化能以11.47~12.51 MJ/kg(干物质基础)较为适宜。