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1.
旨在探讨20~35kg杜湖杂交F1代母羔羊常量元素(Ca、P、Na、K和Mg)的净维持和生长需要量。选择35只母羔羊(初体重为(19.2±0.36)kg)用于本试验。随机选取7只羊(起始组BL),在大约20kg时进行屠宰以测定常量元素体成分的初始值。另外7只羊随机选择(中间屠宰组IM),且饲喂全混合颗粒饲粮,自由采食,体重在大约28kg时进行屠宰。剩余的21只羔羊随机分为3个组,分别为自由采食组(AL)、70%AL组和40%AL组,每组7只羊。当自由采食组体重大约为35kg时,将这3组羔羊屠宰。屠宰后,测定空腹体常量元素含量(头+足、皮、内脏+血液和胴体)。本研究结果显示,在20~35kg体重阶段,杜湖杂交羊F1代母羔的常量元素净维持需要量分别为每天每千克空腹体重(EBW):22.21 mg钙(Ca)、11.65 mg磷(P)、3.41 mg钠(Na)、6.92 mg钾(K)和1.23mg镁(Mg)。母羔的净生长需要量分别为每千克空腹体增重(EBWG):11.93~11.68g Ca、6.12~5.71g P、1.34~1.24g Na、1.58~1.63g K和0.41~0.36g Mg。20~35kg杜湖F1代母羔羊常量元素净需要量的确定将有助于此生长阶段合理饲粮的配制和羔羊生产性能的提高。 相似文献
2.
《畜牧兽医学报》2016,(12)
旨在研究35~50kg杜泊×晋中绵羊F1代公羔铜(Cu)、铁(Fe)、锰(Mn)、锌(Zn)在体内分布特点及其净需要量。试验选取杜泊×晋中绵羊F1代公羔30只,采用比较屠宰试验,在试验羊平均体重达到35kg时,随机抽取6只进行屠宰,作为初始屠宰组(BL),用于估测试验羊初始体组成;另随机选取6只羊,自由采食并在平均体重达到43kg时屠宰,作为中期屠宰组(M);剩余18只羊分为3个饲喂水平组:自由采食组(AL)、65%限饲组(65%)和40%限饲组(40%),当自由采食组的平均体重达到50kg时,剩余18只羊全部屠宰。屠宰后,分别测定肌肉、脂肪、骨骼、血+内脏、羊皮、羊毛中铜、铁、锰、锌含量,建立数学模型分析微量元素在体组织中的分布规律,并预测其净维持及净生长需要量。结果表明,随着体重的增加,公羔骨骼、肌肉生长速度逐渐降低,脂肪生长速度逐渐增加。铜、铁、锰主要分布于内脏(血液)中,分别占体内总含量的86.34%、49.12%、68.65%,锌主要分布于肌肉和骨骼中,分别占体内总含量的42.17%、24.19%。35~50kg杜泊×晋中绵羊F1代公羔铜、铁、锰、锌净维持需要量以空腹体重(EBW)表示分别为0.016、0.281、0.007和0.085mg·kg-1 EBW·d-1,以体重(BW)表示分别为0.013、0.228、0.006和0.069mg·kg-1BW·d-1;净生长需要量以空腹体重(EBW)表示分别为12.61~15.62、77.82~82.55、2.74~3.45和25.36~23.98 mg·kg-1 EBW,以体重(BW)表示分别为10.17~12.75、62.76~67.39、2.21~2.82和20.45~19.57mg·kg-1 BW。本研究中公羔微量元素维持需要量除锌略低外,其他都高于NRC(2007)推荐量;铁、锌净生长需要量与NRC(2007)推荐量接近,而铜、锰需要量较推荐量高。 相似文献
3.
本试验旨在研究35~50 kg道赛特×小尾寒羊杂交公羔钙、磷、钾、钠、镁的维持需要量和净生长需要量。选取(34.54±0.40)kg、6月龄道赛特×小尾寒羊杂交公羔25只分为5组,初期组,中期组,末期100%组、末期60%组、末期40%组(饲喂水平分别为100%、60%、40%),初期组、中期组、末期组分别在羔羊体重为35、43和50 kg时屠宰。测定动物体组织中的钙、磷、钾、钠、镁含量,建立数学模型对矿物质的维持需要量和净生长需要量进行预测。结果显示:道寒杂交公羔在35~50 kg体重阶段,钙、磷、钾、钠、镁的维持需要量分别为0.73、0.72、0.32、0.32、0.13 g/d,基于空腹体重(EBW)的净生长需要量分别为13.47~14.00 g/kg EBW、7.18~7.41 g/kg EBW、0.13~0.17 g/kg EBW、1.20~1.73 g/kg EBW、0.45~0.58 g/kg EBW。本研究得出了35~50 kg道赛特×小尾寒羊杂交公羔矿物质维持需要量和净生长需要量的模型。 相似文献
4.
本试验旨在探讨杜泊羊×湖羊(杜湖)杂交F1代母羔羊在4~6月龄生长阶段的蛋白质代谢规律的同时确定其净蛋白质需要量。选取4月龄左右湖羊杂交F1代母羔[(35.68±1.68)kg]42只,结合比较屠宰试验(30只)和消化代谢试验(12只),利用析因法探讨预测维持和生长净蛋白质需要量的方法。比较屠宰试验:正试期第1天随机挑选6只母羔进行屠宰(A屠宰批次,n=6),其余24只羊随机分为自由采食(AL)组(n=12)、低限饲(LR)组(n=6)和高限饲(HR)组(n=6)3组,当AL组羊均重达42 kg时,选取6只进行屠宰(B屠宰批次,n=6),待其余自由采食组羊均重达50 kg时,将AL组、LR组和HR组羊屠宰,分别作为C、D和E屠宰批次(n=6)。消化代谢试验:将12只羊按照比较屠宰试验的设计,分3组(n=4)进行饲喂。预试期7 d,正试期5 d。结果表明:4~6月龄杜湖杂交F1代母羔的内源性氮损失量为261 mg/kg SBW0.75(SBW为宰前活重),换算为维持净蛋白质需要量为1.63 g/kg SBW0.75。该品种肉羊在35~50 kg体重阶段,平均日增重为100~300 g/d的生长净蛋白质需要量为9.83~25.08 g/d。本试验建立了利用氮沉积量与氮摄入量估测4~6月龄杜湖杂交F1代母羔维持净蛋白质需要量的模型以及体蛋白质含量与排空体重估测生长蛋白质需要量的模型。 相似文献
5.
本试验旨在探讨20～35 kg杜泊×小尾寒羊F1代杂交公羔羊钙、钠、钾、镁生长需要量。采用比较屠宰试验,分别在羔羊体重20、28和35 kg时屠宰,测定动物体组织器官的钙、钠、钾、镁含量,建立数学模型对体内矿物质含量变化规律及需要量进行预测。结果显示,羔羊在20～35 kg体重阶段,肌肉生长速度较稳定,骨骼生长速度逐渐减慢,而体内脂肪组织在迅速增加;羔羊体内矿物质含量与空腹体重(EBW)具有高度相关性(R2=0.84～0.98),钙、钠、钾、镁净生长需要量(NRG)预测公式分别为NRGCa=15.26EBW-0.171,NRGNa=1.67EBW-0.085,NRGK=1.94EBW0.023和NRGM g=0.34EBW0.051。由此可计算得出,杜泊×小尾寒羊F1代羔羊在20～35 kg阶段,以空腹体增重(EBG)表示,机体钙、钠、钾、镁的NRG分别为8.56～9.36 g/kg EBG、1.15～1.20 g/kg EBG、2.07～2.09 g/kg EBG和0.39～0.40 g/kg EBG;以体增重(BWG)表示,分别为7.18～8.18 g/kg BWG、0.96～1.05 g/kg BWG、1.76～1.81 g/kgBWG和0.34 g/kg BWG。 相似文献
6.
本试验旨在探讨20 ～ 35 kg杜泊×小尾寒羊F1代杂交公羔羊钙、钠、钾、镁生长需要量.采用比较屠宰试验,分别在羔羊体重20、28和35kg时屠宰,测定动物体组织器官的钙、钠、钾、镁含量,建立数学模型对体内矿物质含量变化规律及需要量进行预测.结果显示,羔羊在20 ～ 35kg体重阶段,肌肉生长速度较稳定,骨骼生长速度逐渐减慢,而体内脂肪组织在迅速增加;羔羊体内矿物质含量与空腹体重(EBW)具有高度相关性(R2=0.84 ～0.98),钙、钠、钾、镁净生长需要量(NRG)预测公式分别为NRGca=15.26EBW-0.171,NRGNa=1.67EBW-0.085,NRGK=1.94EBW0.023和NRGMg=0.34EBW0.051.由此可计算得出,杜泊×小尾寒羊F1代羔羊在20～35kg阶段,以空腹体增重(EBG)表示,机体钙、钠、钾、镁的NRG分别为8.56 ～9.36 g/kg EBG、1.15 ～ 1.20 g/kg EBG、2.07～2.09 g/kg EBG和0.39 ～ 0.40 g/kg EBG;以体增重(BWG)表示,分别为7.18～8.18 g/kg BWG、0.96 ～ 1.05 g/kg BWG、1.76～1.81 g/kgBWG和0.34 g/kg BWG. 相似文献
7.
本试验旨在研究40～90 kg牦牛犊牛硒的维持需要量及净生长需要量,为牦牛犊牛的饲养标准提供基础依据。选取(60±3)d日龄、身体健康、出生体重相近的35头公牦牛犊作为试验动物,分为起始屠宰组(BL组)、中期屠宰组(M组)、末期自由采食组(AL高饲喂水平组)、70%自由采食组(IR70中饲喂水平组)和40%自由采食组(IR40低饲喂水平组)。在试验开始时对BL组进行屠宰,平均体重为48 kg;在平均体重达到约64 kg时对M组进行屠宰;在AL组体重达到约88 kg时,从AL组、IR70组和IR40组各组随机选取5头犊牛进行屠宰。对样品进行处理并测定各组织中的硒含量,计算出试验期间硒的沉积量,根据硒沉积量与EBW和干物质采食量DMI的关系,分别建立牦牛犊牛硒元素生长需要量模型和维持需要量模型。结果表明,硒主要分布于牦牛犊牛的肌肉和内脏,分别占体内总硒量的47.43%和23.85%;硒的维持需要量=-0.162 7+0.832 2 DMI,硒的净生长需要量=0.096 6×EBW0.348 3。综上所述,40～90 kg牦牛犊牛硒的维持需要量为0.16 mg·d 相似文献
8.
《饲料工业》2016,(7)
试验旨在研究20~35 kg道寒杂交母羔铜、铁、锰、锌的生长需要量。选取18只初始体重为19 kg的道寒杂交母羔作为试验对象,分为3组,第一组在体重达到20 kg时屠宰,另外两组在体重分别达到28、35 kg时屠宰。测定动物体组织器官的铜、铁、锰、锌含量,建立数学模型对矿物质需要量进行预测。通过对数异速生长方程计算羔羊体内矿物质含量与空腹体重(EBW)之间的相关关系,结果显示,它们具有较高的相关性(0.705~0.909);铜、铁、锰、锌净生长需要量(NRG)预测公式分别为NRG_(Cu)=0.329×EBW~(0.998)、NRG_(Fe)=106.659×EBW~(0.049)、NRG_(Mn)=0.807×EBW~(-0.092)、NRG_(Zn)=12.768×EBW~(0.197)。由此可得,道寒杂交母羔在20~35 kg阶段,以空腹体增重(EBW)表示,铜、铁、锰、锌的NRG分别为5.51~10.63 mg/kg EBW、55.40~62.70 mg/kg EBW、0.91~1.12 mg/kg EBW、22.29~25.38 mg/kg EBW;以体增重(BWG)表示,分别为4.63~9.84 mg/kg BWG、51.29~52.50 mg/kg BWG、0.84~0.94 mg/kg BWG、18.73~23.50 mg/kg BWG。 相似文献
9.
《中国饲料》2020,(15)
本试验针对35～50 kg杜寒杂交育肥羊进行试验,建立钙、磷、钠、钾、镁净生长需要模型,旨在研究出符合白城地区肉用羊特点的矿物质需要量。结果显示:育肥羊体内矿物质含量与空腹体重(EBW)具有高度相关性,钙、钠、钾、镁净生长需要量(NRG)预测公式分别为:NRG_(Ca)=14.2485×EBW~(-0.457),NRG_p=1.4658×EBW~(-0.0257),NRG_(Na)=1.8547×EBW~(-0.0459),NRG_K=1.789×EBW~(-0.0235)和NRG_(Mg)=0.4579×EBW~(-0.1248)。35～50 kg杜寒杂交公羊矿物质元素钙、磷、钠、钾、镁净生长需要量以空腹体增重(EBG)表示,分别为:10.52～12.35 g/kg EBW、7.75～8.22 g/kg EBW、1.63～1.76 g/kg EBW、1.07～1.31 g/kg EBW、0.34～0.35 g/kg EBW。以体增重(BWG)表示,分别为:8.81～10.24 g/kg SBW、6.49～6.81g/kg SBW、0.90～1.09 g/kg SBW、1.35～1.47 g/kg SBW、0.28～0.29 g/kg SBW。 相似文献
10.
采用比较屠宰试验和消化代谢试验测定了35～50 kg体重德国美利奴杂交育肥母羊的净能(NE)和代谢能(ME)需要量.选用49只5月龄、平均体重34 kg的德国美利奴羊×内蒙古细毛羊育肥母羊,其中34只用于比较屠宰试验,15只用于消化代谢试验.比较屠宰正试期开始时,从比较屠宰羊中随机选取6只屠宰进行初始屠宰测定,剩余28只羊随机分为4组、每组7只,其中3组分别按自由采食量的100％、75％和55％饲喂同种全混颗粒饲料(TMR,精粗比55:45),自由采食组羊体重达到50 kg时,3组羊同时屠宰.剩余的一组羊自由采食同种TMR,当体重达43 kg时屠宰.用于消化代谢试验的15只羊饲养于代谢笼内,随机分为3组,分别按自由采食量的100％、75％和55％饲喂TMR,正试期内同时进行消化代谢试验和甲烷排放测定,以评定TMR在不同饲喂水平的ME值.结果表明:TMR按自由采食的100％、75％和55％饲喂时,能量表观消化率分别为62.2％、64.9％和68.5％,CH4排放分别为52.1、44.3和39.9 L/d,ME分别为9.35、9.64和9.85 MJ/kg干物质.每日的维持净能(NEm)为239.2kJ/kg BW0.75,维持代谢能(MEm)为331.6 kJ/kgBW0.75,MEm的利用效率km(NEm/MEm)0.72.日增重100～300g BW/d时,每千克增重的生长净能(NEg)需要量12.5～15.5 MJ,每千克增重的生长代谢能(MEg)需要量30.2～34.5 MJ,MEg的利用效率kg(NEg/MEg)0.45. 相似文献
11.
Energy requirements of Texel crossbred lambs 总被引：8，自引：0，他引：8
Two trials were conducted to determine the energy requirements of feedlot Texel crossbred lambs. In a comparative slaughter trial, thirty 11/16 Texel x 5/16 Ile de France crossbred noncastrated male lambs, weaned at 42 d of age (16.2 +/- 2.1 kg of shrunk BW; SBW), were used. Five lambs were randomly chosen and slaughtered after 10 d of experimental management and diet adaptation (baseline group). Fifteen lambs then were fed for ad libitum intake and slaughtered at 25, 30, or 35 kg of SBW. The remaining 10 lambs were randomly assigned to 2 levels of DMI, either 70 or 55% of the ad libitum intake, and were slaughtered concomitantly with lambs of the 35 kg of SBW group. Total body N, fat, and energy contents were determined. In a digestibility trial, 6 Texel x Ile de France crossbred lambs (30.4 +/- 2.6 kg of SBW) were housed in metabolic cages and used in a replicated 3 x 3 Latin square experiment to evaluate the energetic value of the diet at different feed intake levels. Net and ME requirements for maintenance were 58.6 and 91 kcal/kg(0.75) of SBW, respectively. Consequently, partial efficiency of energy use for maintenance was 0.64. Body fat content varied from 72.7 to 125.9 g/kg of empty BW, respectively, for 13.1 and 28.2 kg of empty BW. Net energy requirements for growth of lambs at 15 and 35 kg of SBW at an ADG of 250 g were 424 and 553 kcal/d, respectively. Partial efficiency of energy use for growth was 0.47. Texel x Ile de France crossbred growing lambs used in this study showed decreased nutritional requirements than those reported by most nutritional systems. 相似文献
12.
Fernandes MH Resende KT Tedeschi LO Fernandes JS Silva HM Carstens GE Berchielli TT Teixeira IA Akinaga L 《Journal of animal science》2007,85(4):1014-1023
Meat production by goats has become an important livestock enterprise in several parts of the world. Nonetheless, energy and protein requirements of meat goats have not been defined thoroughly. The objective of this study was to determine the energy and protein requirements for maintenance and growth of 34 (3/4) Boer x (1/4) Saanen crossbred, intact male kids (20.5 +/- 0.24 kg of initial BW). The baseline group was 7 randomly selected kids, averaging 21.2 +/- 0.36 kg of BW. An intermediate group consisted of 6 randomly selected kids, fed for ad libitum intake, that were slaughtered when they reached an average BW of 28.2 +/- 0.39 kg. The remaining kids (n = 21) were allocated randomly on d 0 to 3 levels of DMI (treatments were ad libitum or restricted to 70 or 40% of the ad libitum intake) within 7 slaughter groups. A slaughter group contained 1 kid from each treatment, and kids were slaughtered when the ad libitum treatment kid reached 35 kg of BW. Individual body components (head plus feet, hide, internal organs plus blood, and carcass) were weighed, ground, mixed, and subsampled for chemical analyses. Initial body composition was determined using equations developed from the composition of the baseline kids. The calculated daily maintenance requirement for NE was 77.3 +/- 1.05 kcal/kg(0.75) of empty BW (EBW) or 67.4 +/- 1.04 kcal/kg(0.75) of shrunk BW. The daily ME requirement for maintenance (118.1 kcal/kg(0.75) of EBW or 103.0 kcal/kg(0.75) of shrunk BW) was calculated by iteration, assuming that the heat produced was equal to the ME intake at maintenance. The partial efficiency of use of ME for NE below maintenance was 0.65. A value of 2.44 +/- 0.4 g of net protein/kg(0.75) of EBW for daily maintenance was determined. Net energy requirements for growth ranged from 2.55 to 3.0 Mcal/kg of EBW gain at 20 and 35 kg of BW, and net protein requirements for growth ranged from 178.8 to 185.2 g/kg of EBW gain. These results suggest that NE and net protein requirements for growing meat goats exceed the requirements previously published for dairy goats. Moreover, results from this study suggest that the N requirement for maintenance for growing goats is greater than the established recommendations. 相似文献
13.
From data reported by authors who had serially determined the chemical composition of the empty body of growing lambs of a wide range of genotypes, the energy density of empty body gains (E/G) at intervals from 20 to 50 kg empty body weight (EBW) were estimated. Energy density of empty body gain was related to the EBW of these lambs and to an approximation of the mature weight for the genotype (MW) obtained from a separate data set. The addition of MW to the function relating E/G to EBW increased the r2 from .793 to .940 and reduced the residual standard deviation from .550 to .300 Mcal/kg. Combining EBW and MW as predictors of E/G provided the following function: E/G = 5.718 + .093 (EBW) - .036 (MW). Energy density of empty body gain was approximately constant across all genotypes when comparisons were made at a constant EBW/MW. Thus, both EBW and mature weight of the genotype are closely related to E/G and should be considered important for accurately predicting net energy of gain requirements for growing lambs. 相似文献
14.
T. Ma G.‐S. Xu K.‐D. Deng S.‐K. Ji Y. Tu N.‐F. Zhang Q.‐Y. Diao 《Journal of animal physiology and animal nutrition》2016,100(6):1081-1089
The net and metabolizable energy (NE and ME) requirements of Dorper cross‐bred female lambs with BWs of 20–35 kg were assessed in a comparative slaughter trial. Thirty‐five Dorper × thin‐tailed Han cross‐bred female lambs weaned at ~50 days of age (20.3 ± 2.15 kg BW) were used. Seven randomly selected lambs were slaughtered at the start of the trial (baseline group). An intermediate group consisting of seven randomly selected lambs fed ad libitum was slaughtered when the lambs reached an average BW of 28.5 kg. The remaining 21 lambs were allotted randomly to three levels of dry matter intake: ad libitum or restricted to 70% or 40% of the ad libitum intake. All the lambs were slaughtered when the sheep fed ad libitum reached a BW of 35 kg. Total body energy, nitrogen, fat, ash and moisture content were determined. In a digestibility trial, an additional 15 Dorper × thin‐tailed Han cross‐bred female lambs (28.7 ± 1.75 kg BW) were housed in metabolism cages and used in a completely randomized design experiment to evaluate the ME value of the diet at the three feed intake levels. The maintenance requirements for NE and ME were 245.5 and 380.3 kJ/kg metabolic shrunk body weight (SBW0.75) respectively. The partial efficiency of energy use for maintenance was 0.645. The NE requirements for growth ranged from 1.18 to 5.18 MJ/d for the lambs gaining 100–350 g/d from 20 to 35 kg BW. Partial efficiency of ME for growth was 0.44. In conclusion, the current study suggests that the NE requirement for maintenance and growth of Dorper early‐weaned cross‐bred female lambs is lower than the current AFRC and NRC recommendations. 相似文献
15.
Net requirements of calcium, magnesium, sodium, phosphorus, and potassium for growth of Nellore × Red Angus bulls, steers, and heifers 总被引：1，自引：0，他引：1
Mario Luiz Chizzotti Sebastio de Campos Valadares Filho Luis Orlindo Tedeschi Pedro Veiga Rodrigues Paulino Mrio Fonseca Paulino Rilene Ferreira Diniz Valadares Paloma Amaral Pedro Del Bianco Benedeti Tainnah Ikegami Rodrigues Mozart Alves Fonseca 《Livestock Science》2009,124(1-3):242-247
A comparative slaughter trial was conducted to assess the net requirements for gain of Ca, P, Na, K and Mg of bulls, steers and heifers of Nellore and Red Angus crossbreds. Twenty seven F1 Nellore and Red Angus crossbred calves (9 steers, 9 bulls, and 9 heifers), averaging 274 kg BW, were used. At the beginning of the trial, three animals from each gender were slaughtered to determine the initial body composition. The remaining 18 animals (3 animals of each gender) were randomly assigned to two treatments: fed 0.75 or 1.5% of BW of concentrate. The diets were based on corn silage and were isonitrogenous (2% N, DM). After three growing periods of 28 d, all animals were slaughtered. The cleaned gastrointestinal tract, organs, carcass, head, hide, tail, feet, and tissues were weighed to determine the empty BW (EBW). These parts were ground separately and subsampled for chemical analyses. The log of the contents of each mineral in the empty body was regressed on the log of the EBW to estimate the net requirement for each mineral per kg of empty body gain (EBG). There were no differences (P > 0.05) in the net requirements for growth of all macrominerals among genders. The equations of the pooled data of the net requirements for growth (g/kg EBG) were: 332.6 × EBW − 0.6367 for Ca, 112.1 × EBW − 0.5615 for P, 10.85 × EBW − 0.3992 for Na, 4.01 × EBW − 0.153 for K, and 3.589 × EBW − 0.462 for Mg. Our findings indicated that retained Ca and retained P were poorly related to the retained protein. 相似文献
16.
旨在研究不同饲喂水平对绵羊睾丸发育、睾酮（T）合成相关基因与雄激素受体（androgen receptor, AR）表达的影响。本研究采用单因素完全随机试验设计,将18只健康、体重相近（（35±0.5） kg）的杜泊羊（♂）×晋中绵羊（♀）杂F1代4月龄公羔随机分为3组,每组6只,分别按照自由采食（AL组）、自由采食量的65%（AL65组）和自由采食量的40%（AL40组）3个水平进行饲喂。当AL组任意1只羔羊体重达到50 kg时全部屠宰,测定睾丸的周径与长度后采集睾丸组织,通过苏木精-伊红（hematoxylin-eosin,H-E）染色观察曲精细管生精上皮结构;酶联免疫（enzyme linked immunosorbent assay,ELISA）法测定睾酮（testosterone,T）的水平;用定量PCR（quantitative real-time PCR,qRT-PCR）检测T合成相关基因和AR mRNA的表达情况;通过免疫组化和Western blotting的方法对绵羊睾丸组织中的AR进行定位与定量分析。结果表明,AL40组羔羊睾丸周径和长度显著低于AL组（P<0.05）,但与AL65组差异不显著（P>0.05）;AL40组曲精细管生精上皮厚度与AL65组差异不显著（P>0.05）,但均显著低于AL组（P<0.05）。随着饲喂水平的提高,生精细胞和间质细胞密度显著增加（P<0.05）,T水平和STAR、3β-HSD基因以及AR mRNA和蛋白表达量均显著提高（P<0.05）;睾丸间质细胞、初级精母细胞、精子细胞、管壁肌样细胞层和间质血管平滑肌细胞中均观察到AR阳性产物。综上所述,绵羊的睾丸发育、T含量、T合成相关基因和AR的表达均受到日粮营养水平的调控。日粮营养水平可能通过改变T水平和生精细胞对T的敏感性来调控精子发生过程,从而影响其性成熟和繁殖性能。 相似文献
17.
Tedeschi LO Boin C Fox DG Leme PR Alleoni GF Lanna DP 《Journal of animal science》2002,80(6):1671-1682
Data from three comparative slaughter experiments with individually fed Nellore bulls (n = 31) and steers (n = 66) were utilized to determine their NEm and NEg requirements when fed high-forage diets. The experimental design provided ranges in ME intake, BW, and ADG for the development of regression equations to predict NEm and NEg requirements. The Nellore bulls (Trial 1) were divided into two intake levels (ad libitum and 65% of the ad libitum). The steers (Trials 2 and 3) were allocated to three intake levels (ad libitum and 55 and 70% of the ad libitum). In both trials, there were three slaughter groups within each intake level. The three end points for the bulls were different days on treatment (100, 150, and 190 d and 130, 180, and 200 d, respectively, for older and younger animal subgroups). The steers were slaughtered when animals of the ad libitum treatment reached 400, 440, and 480 kg shrunk BW (SBW) on average for the first, second, and third group, respectively. For all body composition determinations, whole empty body components were weighed, ground, and subsampled for chemical analysis. In each of the trials, initial body composition was determined with equations developed from a baseline slaughter group, using SBW and empty BW (EBW), fat (EBF), and protein (EBP) as variables. The NEm was similar for bulls and steers; NEm averaged 77.2 kcal/ kg0.75 EBW. However, the efficiency of conversion of ME to net energy for maintenance was greater for steers than for bulls (68.8 and 65.6%, respectively), indicating that bulls had a greater ME requirement for maintenance than steers (5.4%; P < 0.05). Our analyses do not support the NRC (2000) conclusion that Nellore, a Bos indicus breed, has a lower net energy requirement for maintenance than Bos taurus breeds. An equation developed with the pooled data to predict retained energy (RE) was similar to the NRC (2000) equation. A second equation was developed to predict RE adjusted for degree of maturity (u): RE = (6.45 - 2.58/u) x EWG x e(0.469) x u), where u = current EBW/final EBW in which final EBW was 365 kg for steers and younger bulls and 456 kg for older bulls at 22% EBF, respectively. 相似文献
18.
Our objectives were to evaluate maternal body changes in response to dietary restriction or the increased nutrient requirement of fetal growth. In Exp. 1, 28 mature crossbred ewes (61.6 +/- 1.8 kg initial BW) were fed a pelleted forage-based diet to evaluate effects of pregnancy and nutrient restriction on visceral organ mass. Treatments were arranged in 2 x 3 factorially, with dietary restriction (60% restriction vs. 100% maintenance) and reproductive status (nonpregnant [NP], d 90 or d 130 of gestation) as main effects. Dietary treatments were begun at d 50 of gestation, and restricted ewes remained at 60% of maintenance throughout the experiment. Nonpregnant and d-90 ewes were fed dietary treatments for 40 d and slaughtered. The d-130 ewes were fed dietary treatments for 80 d and then slaughtered. In Exp. 2, four Romanov ewes were naturally mated (Romanov fetus and Romanov dam; R/ R), and two Romanov embryos were transferred to each of four Columbia recipients (Romanov embryos and Columbia recipient; R/C). Three Columbia ewes were naturally mated (Columbia fetus and Columbia recipient; C/C). In both experiments, maternal organ weights were reported as fresh weight (grams), scaled to empty body weight (EBW; grams per kilogram) and maternal body weight (MBW; grams per kilogram). In Exp. 1, ewe EBW and fetal mass were decreased (P < 0.02) with restriction compared with maintenance. Dietary restriction decreased liver mass (16.7 vs. 14.5 g/kg EBW or 18.8 vs. 16.4 g/kg MBW; P < 0.01), but dietary restriction did not affect total digestive tract mass. In Exp. 2, ewe BW was less for the R/R compared with R/C and C/C (44.8 vs. 110.4 and 98.1 +/- 7.9 kg, respectively; P < 0.01). Fetal weight at d 130 was less for the R/R than for R/C and C/C (2.2 vs. 3.3 and 4.7 +/- 0.3 kg, respectively; P < 0.01) when measured as individual fetuses; however, when measured as total fetal mass carried in each ewe, there was no effect of ewe type. These data suggest that the gastrointestinal tract, along with other maternal organs, responds to both level of dietary intake and nutrient requirements for gestation, and that fetal weight is decreased as a result of a 40% decrease in nutrients offered. 相似文献
19.
This study investigated effects of birth weight and postnatal nutrition on growth and development of skeletal muscles in neonatal lambs. Low (L; mean +/- SD 2.289 +/- .341 kg, n = 28) and high (H; 4.840 +/- .446 kg, n = 20) birth weight male Suffolk x (Finnsheep x Dorset) lambs were individually reared on a liquid diet to grow rapidly (ad libitum fed, ADG 337 g, n = 20) or slowly (ADG 150 g, n = 20) from birth to live weights (LW) up to approximately 20 kg. At birth, weight of semitendinosus (ST) muscle in L lambs was 43% that in H lambs; aggregate weights of ST and seven other dissected muscles were similarly reduced. In ST muscle of L lambs, mass of DNA, RNA, and protein were also significantly reduced to levels 67, 60, and 34%, respectively, of those in H lambs. However, myofiber numbers of ST, tibialis caudalis, or soleus muscles did not differ between the L and H birth weight lambs and did not change during postnatal growth. During postnatal rearing, daily accretion rate of dissected muscle was lower in L than in H lambs. Accretion of muscle per kilogram of gain in empty body weight (EBW) was reduced in the slowly grown L lambs compared with their H counterparts, although the difference was less pronounced between the rapidly grown L and H lambs. Throughout the postnatal growth period, ST muscle of L lambs contained less DNA with a higher protein:DNA ratio at any given muscle weight than that of H lambs. Slowly grown lambs had heavier muscles at any given EBW than rapidly grown lambs. Content of DNA and protein:DNA ratio in ST muscle were unaffected by postnatal nutrition, but RNA content and RNA:DNA were greater and protein:RNA was lower at any given muscle weight in rapidly grown lambs. Results suggest that myofiber number in fetal sheep muscles is established before the presumed, negative effects of inadequate fetal nutrient supply on skeletal muscle growth and development become apparent. However, proliferation of myonuclei may be influenced by fetal nutrition in late pregnancy. Reduced myonuclei number in severely growth-retarded newborn lambs may limit the capacity for postnatal growth of skeletal muscles. 相似文献