营养限制及补偿对羔羊肉品质的影响

试验旨在研究营养限制期不同能氮水平和补偿期对羔羊肉品质的影响。选用80只蒙古羔羊,随机分为4组,分别为对照组(CG)、中等限制Ⅰ组(RG1)、中等限制Ⅱ组(RG2)和严重限制组(RG3)。营养限制期(60 d)4组羔羊日粮能量(ME)和蛋白质(CP)水平分别为10.88、10.88、9.41、8.62 MJ/kg和15.0%、10.0%、10.0%、5.7%。营养补偿期(90 d)4组羔羊日粮能量水平一致(ME 9.75 MJ/kg、CP 12%)。营养限制期结束和补偿期结束时,每组分别屠宰4只羔羊,测定背最长肌pH、失水率和剪切力值及胴体营养水平。结果表明,限制期结束时,RG3组羔羊背最长肌pH₁和胴体粗蛋白质、粗灰分含量显著高于CG组(P<0.05),背最长肌剪切力值显著低于CG组(P<0.05),胴体干物质含量极显著低于CG组(P<0.01);补偿期结束时,RG2组羔羊背最长肌pH₁显著高于CG组(P<0.05);RG1和RG2组羔羊背最长肌剪切力值和胴体粗蛋白质含量显著高于CG组(P<0.05);RG3组羔羊胴体粗灰分含量显著高于CG组(P<0.05)。因此,背最长肌pH、嫩度及胴体化学组成均受到营养限制的影响,经补偿后除嫩度外均能恢复到对照组水平,且随着受限程度的加剧,恢复速度越慢。     

营养限制与补偿对蒙古羔羊体重和血液中生长相关激素的影响

试验研究不同能氮水平的营养限制与补偿对蒙古羔羊体重和血液生长相关的激素影响。选用内蒙古草原上健康的、平均体重15 kg左右的蒙古羔羊64只,随机分为对照组(CG)、限制1组(RG1)和限制2组(RG2)三个组,营养限制期(60 d)分别饲喂ME 10.88 MJ/kg、CP 13.0%(CG),ME10.88 MJ/kg、CP 8.9%(RG1),ME 8.62 MJ/kg、CP 5.7%(RG2)三个营养水平的日粮;营养补偿期(90 d)各组饲喂同一能氮水平饲粮(ME 9.75 MJ/kg,CP 12%)。结果表明:①随着营养水平的逐步降低,在限制末期,RG1组和RG2组羔羊的平均体重显著低于CG组(P<0.05),在补偿期,RG2组平均日增重显著高于CG组(P<0.05)。②在限制末期RG2组血液中GHRH及RG1、RG2组血液中GH浓度显著高于CG组(P<0.05),而RG2组血液中SS、IGF-I浓度显著低于CG组(P<0.05)。在补偿期,RG1、RG2组血液中IGF-I浓度有升高的趋势(P>0.05)。结果提示,营养限制所导致的羔羊血液中GHRH浓度升高和SS浓度降低可能是其在限制期血液中GH浓度升高及其在补偿期快速生长的原因之一。     

营养限制及补偿对羔羊体重及外周血液CD4+和CD8+T淋巴细胞的影响

本试验旨在研究羔羊营养限制期(第1～60天)和营养补偿期(第61～150天)体重和外周血液中CD4+和CD8+T淋巴细胞的变化规律.选用80只体况中等、平均体重为(14.72±1.10)kg的3月龄乌珠穆沁羔羊,随机分为对照组(CG)、限制组Ⅰ(RG Ⅰ)、限制组Ⅱ(RGⅡ)和限制组Ⅲ(RG Ⅲ)4个组.营养限制期4组饲粮能氮水平分别为代谢能(ME):10.88、10.88、9.41和8.62 MJ/kg;粗蛋白质(CP):15%、10%、10%和5.7%.营养补偿期各组饲喂同一能氮水平饲粮(ME:9.75 MJ/kg;CP:12%).在试验期每周称重并在第1天、第30天、第60天、第90天和第150天饲喂前从各组羊颈静脉采血,采用流式细胞仪检测羔羊血液中的CD4+和CD8+T淋巴细胞比例.结果表明:1)营养限制结束,RG Ⅰ组、RG Ⅱ组和RG Ⅲ组平均体重均显著低于CG组(P＜0.05).补偿期RGⅢ组平均日增重显著高于CG组(P＜0.05).2)营养限制前期(第1～30天)各组CD4+和CD8+T淋巴细胞浓度均呈上升趋势.补偿期结束时CD4+T淋巴细胞浓度RG Ⅰ组最低RGⅡ组最高,CD8+T淋巴浓度RGⅡ组最低RG Ⅰ组最高,差异均不显著(P＞0.05).结果提示,乌珠穆沁羔羊受不同能氮营养水平限制后体重和免疫机能有补偿效应,而且低能高氮比高能低氮限饲后得到的补偿效果较好,表明限饲蛋白质比限饲能量对补偿生长的负影响更大.蛋白质和能量同时限饲补偿生长最差.     

营养限制和补偿对羔羊体质量和内脏质量的影响

选用内蒙古锡林郭勒草原上自然断奶的3月龄健康的80只蒙古羯羊,体质量约14.55 kg,试验羊按体质量相近原则分为对照组(代谢能(ME)10.88 MJ/kg,CP 15%)、限制组Ⅰ(ME 10.88 MJ/kg,CP 10%)、限制组Ⅱ(ME 9.41 MJ/kg,CP 10%)和限制组Ⅲ(ME 8.62 MJ/kg,CP 5.7%)。预饲期为4周,进入试验期,试验前8周(为限饲期)的日粮水平是限饲期的水平;后13周是补偿期,各组日粮能氮水平相同(ME 9.75 MJ/kg,CP 12%)。限饲期结束,限制组Ⅰ和限制组Ⅱ的平均体质量和相对生长速率均显著低于对照组,试验组Ⅲ的平均体质量和相对生长速率极显著低于对照组。限制组Ⅱ的肝和脾质量显著低于对照组。限制组Ⅲ的心脏、肺、肾和脾的质量均显著低于对照组;其肝质量差异极显著低于对照组。补偿期结束,限制组Ⅲ的平均体质量显著低于对照组。限制组Ⅰ和限制组Ⅲ的相对生长速率显著高于对照组。结果表明:羔羊受不同日粮水平限制后,体质量和内脏质量均具有补偿生长效应;限制组Ⅱ日粮水平比限制组Ⅰ日粮水平限饲后体质量能得到更好的补偿生长效果;限制组Ⅲ日粮水平限饲后体质量表现为不完全补...     

日粮营养限制及补偿对蒙古羔羊瘤胃内环境的影响

试验选用80只自然断奶的3月龄健康蒙古羔羊,平均体质量(14.72±1.10)kg,试验羊按各组体质量差异不显著的原则随机分为4个试验组。试验分为限饲期和补偿期,限饲期8周,各组日粮分别为:对照组(ME 10.88 MJ/kg,CP 15%)、低蛋白组(ME 10.88 MJ/kg,CP 10%)、低能量组(ME 9.41 MJ/kg,CP 15%)和双低组(ME 8.62 MJ/kg,CP 5.7%);限饲结束后进入补偿期,为期13周,各组日粮能氮水平相同(ME 9.75 MJ/kg,CP 12%)。试验结果表明:限制期及补偿期结束时,低能量组和对照组各内环境指标无显著差异。低蛋白组限制期氨态氮(NH3-N)质量浓度显著低于对照组;乙酸、丙酸及总挥发性脂肪酸(TVFA)质量浓度显著高于对照组;补偿期结束时,乙酸及TVFA质量浓度显著低于对照组。双低组限制期乙酸、丙酸、TVFA质量浓度和NH3-N质量浓度显著高于对照组,瘤胃菌体蛋白质量浓度显著低于对照组;补偿期乙酸、丙酸、TVFA质量浓度和NH3-N质量浓度显著低于对照组。说明在试验日粮限制条件下,蛋白营养限制和能量蛋白同时限制显著影响了瘤胃内环境,而能量限制对瘤胃内环境影响不显著。     

固原地区秦川牛及其利杂群体屠宰性能的研究

为了分析利木赞牛对固原地区秦川牛的改良效果,本实验对固原地区秦川牛及其利杂群体的屠宰性能进行了测定。结果表明:24月龄组利杂牛的屠宰率、净肉率、胴体产肉率和肉骨比高于固原地区秦川牛(P<0.05或P<0.01),分别提高了4%、4%、3%和0.72;而12月龄组利杂牛和固原地区秦川牛的屠宰率、净肉率、胴体产肉率和肉骨比均差异不显著(P>0.05)。利杂牛在眼肌面积、大理石花纹评分、脂肪色泽评分、肌肉附着和pH2 4指标上优于固原地区秦川牛(P<0.05)。利杂牛和固原地区秦川牛肉品中常规成分含量和脂肪酸分布差异不显著(P>0.05)。     

玉米秸秆替代苜蓿干草对育肥羔羊生长性能和屠宰性能的影响

为探究用玉米秸秆替代苜蓿干草对育肥羔羊生长性能及屠宰性能的影响,本试验选择体重相近、年龄均衡的健康小尾寒羊40只,随机分为4组,每组10只,1个对照组,3个试验组,每只育肥羔羊为一个重复。对照组日粮是以苜蓿为主要纤维来源的混合型饲粮,试验组分别是以玉米秸秆替代40%、60%和80%的苜蓿干草。预饲期7 d,正式期70 d。试验期间育肥羔羊自由采食和饮水。试验结果表明,在生长性能方面,与对照组相比,将日粮中40%的苜蓿甘草替换为玉米秸秆育肥羔羊的日均采食量、日增重均有增加趋势,饲料转化率降低,但组间差异不显著(P0.05)。屠宰性能方面,宰前活重、胴体重、净肉质量、肉骨比、胴体脂肪含量及眼肌面积均随饲粮中玉米秸秆替代量的增加呈先增加再降低的趋势;骨质量先降低后略有增加,40%玉米秸秆替代组显著低于对照组(P0.05),而屠宰率组间差异均不显著(P0.05),40%和60%玉米秸秆替代组的净肉率、胴体净肉率均显著高于对照组和80%玉米秸秆替代组(P0.05)。综上得知,用玉米秸秆替代育肥羔羊日粮中的苜蓿干草对其生长性能及屠宰性能有一定影响,最适宜的替代比例为40%。     

不同精粗比日粮对黑山羊屠宰性能和肉质品质的影响

为了研究不同精粗比日粮对黑山羊屠宰性能、肉质品质的影响,将36只体重为(15±1.61)kg的生长育成期的莱芜黑山羔羊平均分3组,每组2个重复(公、母各为一重复,分开饲养),每个重复6只,进行60 d饲养屠宰试验。日粮参考肉羊日增重为120 g/d的饲养标准(NY/T 816-2004),A、B、C组日粮精粗比依次为55∶45、45∶55、35∶65。结果表明:公羊屠宰率随日粮精料含量增加而增加(P0.05),B组净肉率、胴体净肉率、肉骨比、系水力均高于A、C组(P0.05),嫩度亦高于A、C组(P0.05);母羊的屠宰率B组显著高于A、C组(P0.05),而净肉率、胴体净肉率、肉骨比C组显著高于A、B组(P0.05),C组嫩度、熟肉率、系水力亦高于A、B组(P0.05);公、母羊肉中营养成分含量除了粗脂肪、粗蛋白随粗饲料含量增加而增加外,其他营养成分差异不显著(P0.05);公羊日粮适宜的精粗比为45:55,母羊精粗比为35:65。     

德西黄三元杂交幼牛产肉性能研究

本文对甘肃省武威市凉州区新华乡的6头德西黄三元杂交牛11-12月龄育肥牛的产肉性能进行测定。其结果：育肥期末体重、日增重、屠宰率、净肉率、胴体产肉率、肉骨比、眼肌面积分别是322.67kg、1101.85g、55.33%、45.09％、81.47％、5.09、75.9cm^2。表明该三元杂交组合的肉用性能良好，比二元杂交的西黄有明显提高。     

早胜牛肉用性能测定报告

选择18月龄早胜牛公牛6头,24月龄母牛4头屠宰,测定产肉性能,观察其产肉性能提高状况和了解不同性别的产肉特点。结果表明,18月龄公牛除屠宰率和净肉率与1982年测定结果差异不显著(P<0.05)外,胴体重、净肉重、胴体产肉率、肉骨比、肉脂比和眼肌面积测定结果均极显著(P>0.01)高于1982年测定结果。另外虽然公牛月龄小于母牛6个月,但净肉率、肉脂比和眼肌面积测定结果均显著地高于母牛,同时肉中脂肪含量显著低于母牛。     

不同营养水平对羔羊肌肉组织学性状的影响

本试验旨在研究羔羊在营养限制期和补偿期背最长肌、半腱肌和股二头肌的肌纤维直径、面积和密度的变化规律.选用蒙古羔羊(羯羊)80只,随机分为4个组,即:对照组(C组)、中等受限1组(R1组)、中等受限2组(R2组)、严重受限组(R3组),进行营养限制期60 d和补偿期90 d的羔羊生长试验.限制期4个组饲粮能氮水平分别为代...     

广西地方三黄鸡母雏(0～5周龄)最佳生长的饲粮ME、CP需要量的饲养试验研究

试验选用800只0日龄广西地方三黄鸡(母雏),试验各组饲粮ME及CP水平分别为：A组参照NRC(1994)肉仔鸡0～3周龄ME13．39MJ／kg,CP23％;B组参照中国地方品种黄肉鸡(1986)0～5周龄ME11．72MJ／kg,CP20％：C组为自拟中档营养水平MEl2．13MJ／kg,CP21％;D组为自拟高档营养水平ME12．55MJ／kg,CP21．5％。其中Ca、AP、Na、Cl均为同一水平(即Ca1％、AP0．45％、Na0．2％、C10．2％),B组的氨基酸水平是模拟中国肉仔鸡(1986)0～4周龄的标准推算而得。经2002～2003两年来多次对0～5周龄广西地方三黄鸡母雏最佳生长性能的饲粮ME及CP的需要量作饲养试验,结果表明,在华南地区(广东、广西、海南三省)育雏期0～5周龄广西地方三黄鸡母雏生长性能表现最佳的是自拟中档营养水平的C组(ME12．13MJ／k,CP21％)。     

不同代谢能和粗蛋白质水平对合浦鹅日粮养分消化率及生长性能的影响

本文旨在研究日粮不同代谢能和粗蛋白质水平对合浦鹅日粮干物质、粗蛋白质、粗脂肪、粗纤维、钙和磷等养分的消化率及生长性能的影响.将120只28日龄的合浦鹅随机分成6个组,进行2个饲养和消化试验:试验1组饲喂粗蛋白质水平为15.10%,代谢能水平分别为10.03、11.00和11.85 MJ/kg的3种日粮;试验2组饲喂代谢能水平为11.50 MJ/kg,粗蛋白质水平分别为12.50%、14.85%和17.83%的3种日粮.用4 mol/L HCI ALA方法测定日粮的养分消化率.结果表明:粗蛋白质水平为15.10%和代谢能水平为10.03 MJ/kg的日粮,具有较高的养分消化率,但不同代谢能水平对试鹅的生长性能影响差异不显著(P>0.05);代谢能水平为11.50 MJ/kg和粗蛋白质水平为12.50%的日粮也具有较高的养分消化率,但不同粗蛋白质水平对试鹅的生长性能影响差异也不显著(P>0.05).因此,28日龄以后的合浦鹅的日粮粗蛋白质和代谢能水平分别为15.10%和10.03 MJ/kg,或分别为12.50%和11.50 MJ/kg时,均具有较高的养分消化率,但对合浦鹅的生长性能无显著影响.     

Basal and hormone-stimulated metabolism in lambs varies with breed and diet quality

The present study investigated the effects of breed and diet quality on basal and hormone-stimulated energy metabolism in lambs. Twenty-four 7-mo-old merino (MM; n = 12) and second-cross (2X; n = 12) lambs were maintained indoors and fed ad libitum either a low-quality (7.8% crude protein [CP] and 8.1 MJ metabolizable energy [ME]/kg dry matter [DM]) or a moderate-quality (17.6% CP and 9.1 MJ ME/kg DM) diet in a crossover design. After 3 wk of feeding, lambs were injected intravenously with insulin (10 μg/kg body weight [BW]) and epinephrine (0.8 μg/kg BW) on consecutive days and blood samples were collected at -30, -15, -1, 3, 6, 10, 15, 20, 30, 45, 60, 90, and 120 min relative to time of injection. Lambs fed the low-quality diet had lower DM (P < 0.001), CP (P < 0.01), and ME (P < 0.001) intakes than lambs fed the moderate-quality diet. Baseline nonesterified fatty acid (NEFA) concentrations were higher (P < 0.001) in lambs fed a low-quality diet than in those fed a moderate-quality diet but there were no breed differences. Second-cross lambs had higher basal plasma concentrations of glucose (P < 0.001), lactate (P < 0.001), and cortisol (P < 0.02) than the MM lambs, although there was no effect of diet on any of these plasma variables. Insulin injection caused a rapid hypoglycemic response in all lambs but the response was more pronounced (P < 0.01) in MM lambs compared with 2X lambs. The cortisol response to insulin was twice as great (P < 0.05) in MM lambs compared with 2X lambs. There was a rebound in plasma NEFA concentrations after approximately 30 min postinjection that was most pronounced (P < 0.01) in MM lambs. Epinephrine injection caused a rapid increase in plasma NEFA, which tended to be lower in lambs fed the moderate-quality diet (P = 0.07) than in those fed the low-quality diet, but did not differ between breeds. Epinephrine injection caused rapid hyperglycemia, with the response being lower (P < 0.006) in lambs fed the moderate-quality diet compared with those fed the low-quality diet and greater (P < 0.050) in 2X than in MM lambs. Epinephrine injection caused a rapid increase in plasma lactate that tended to be greater (P = 0.07) in 2X lambs compared with MM lambs. The present study demonstrated clear breed differences in basal and hormone-stimulated metabolism, such that the 2X lambs appeared to be less sensitive to insulin and more sensitive to epinephrine than the MM lambs. These metabolic differences may be related to the fundamental differences in physiology that are associated with meat and wool production from 2X and MM breeds, respectively. They may also be related to adaptation of the MM breed to harsh environments through the ability of the body to metabolize fat resources, which are an efficient source of energy for survival.     

Protein and energy self-selection by turkey hens: reproductive performance

1. The influence of protein and energy self-selection on the reproductive performance of turkey hens was investigated. Large White turkey hens were fed on either a complete diet (185 g CP/kg, 11.30 MJ ME/kg) or were provided with a choice between a high protein-low energy diet (348 g CP/kg, 7.74 MJ ME/kg) and a high energy-low protein diet (81 g CP/kg, 13.39 MJ ME/kg). 2. Egg production, egg weight, and the fertility and hatchability of eggs produced were not significantly affected by the dietary treatments (P greater than 0.05). 3. While energy intake was not significantly different between groups, protein consumption decreased by approximately 40% (P less than or equal to 0.001) among self-selecting hens compared to hens fed on the complete diet. This resulted in a 10% (P less than or equal to 0.05) reduction in the food intake in the self-selecting birds.     

Effects of sex and protein and energy levels in the diet on the blood parameters of the chukar partridge (Alectoris chukar)

1. The effects of sex and dietary composition were investigated in 48 male and 48 female 16-week old chukar partridges. 2. Sixteen starter and 16 grower diets were arranged in a 4 x 4 factorial design with 4 concentration of crude protein (CP) and 4 concentration of metabolizable energy (ME). 3. Blood samples were collected at 16 weeks of age and analysed for total protein, triglycerides, uric acid, total cholesterol, glucose, calcium, phosphorus, sodium, potassium and chlorine. 4. There were no significant effects of sex on the measured parameters. 5. Serum total protein was highest in partridges fed on a diet containing 200/175 g CP/kg (starter grower). Serum cholesterol concentrations of partridge fed the diet with 240/200 or 280/225 g CP/kg were significantly higher than that for partridge fed diets containing a lower gCP/kg. 6. Serum total protein and glucose levels significantly decreased as dietary energy level was increased. Serum triglycerides and calcium were highest in partridge fed on the diets containing 13.39/13.81 and 11.71/12.55 ME MJ/kg, respectively. Serum phosphorus and chloride levels were highest in partridges given the diet containing 10.88/11.92 ME MJ/kg. 7. There were significant interactions between the effects of CP and ME on serum triglycerides, sodium and potassium levels. 8 The results of this study suggested that dietary CP, and especially ME concentration, significantly affect blood parameters in chukar partridge.     

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。     

日粮能量和蛋白质水平对5～10周龄仔鹅生产性能的影响

选用4周龄扬州鹅180只,以能量和蛋白质为试验因子,采用2因素3水平设计,研究日粮能量和蛋白质水平对生长期扬州鹅生产性能的影响。研究结果表明:①10周龄体重和日增重各组间差异不显著(P>0.05),屠宰指标间无明显规律。②对体重、日增重、屠宰率和腿肌率的影响,均是互作>能量>蛋白质,其中互作和能量对腿肌率的影响极显著(P<0.01);对半净膛率和全净膛率的影响,均是能量>互作>蛋白质,且影响均不显著(P>0.05);对胸肌率的影响,是能量>蛋白质>互作,且影响不显著(P>0.05)。③第7组(低能高蛋白组)在生长性能和经济效益方面均较佳。因此,推荐5￣10周龄仔鹅日粮能量、蛋白质水平分别为10.50MJ/kg、17%。