一水肌酸及其组合添加物对生长育肥猪胴体组成与肉质相关指标的营养调控研究

本试验旨在研究饲粮添加一水肌酸(CMH)及其组合添加物对生长育肥猪胴体组成、肉质性状及代谢分子指标的影响,为进一步完善CMH在肉质营养调控中的应用提供参考。选择60～70 kg体重"杜×大×长"阉公猪100头,随机分为5组(每组20个重复,每个重复1头猪),分别饲喂基础饲粮(对照组)、CMH饲粮(在基础饲粮中添加0.5 g/kg的CMH)、CMH+α-硫辛酸(ALA)饲粮(在基础饲粮中添加0.5 g/kg的CMH和0.1 g/kg的ALA)、CMH+牛磺酸(Tau)饲粮(在基础饲粮中添加0.5 g/kg的CMH和0.1 g/kg的Tau)和CMH+L-苹果酸(LMA)饲粮(在基础饲粮中添加0.5 g/kg的CMH和0.5 g/kg的LMA),饲养50 d后统一屠宰,采集样品并测定指标。结果表明:与对照组相比,饲粮添加CMH及其不同组合添加物均显著降低生长育肥猪背膘厚度(P0.05),有提高背最长肌水分和降低脂肪含量的趋势(P0.05); CMH+ALA饲粮和CMH+LMA饲粮显著增加生长育肥猪眼肌面积(P0.05); CMH饲粮和CMH+ALA饲粮显著降低生长育肥猪背最长肌滴水损失和压榨损失(P0.05); CMH饲粮和CMH+Tau饲粮显著提高生长育肥猪背最长肌肉色亮度和黄度值以及蒸煮损失(P0.05),显著降低肉色红度值(P0.05); CM H饲粮、CM H+ALA饲粮和CM H+Tau饲粮显著提高生长育肥猪背最长肌琥珀酸脱氢酶和肌酸激酶活性、总抗氧化能力和肌酸储备量(P0.05),显著降低背最长肌乳酸含量(P0.05),并以CM H+ALA饲粮改变程度最大; CM H饲粮和CM H+ALA饲粮显著提高生长育肥猪背最长肌肌酸转运蛋白基因相对表达水平(P0.05),后者改变大于前者且显著提高背最长肌肌红蛋白和肌球蛋白重链Ⅱa基因相对表达水平(P0.05)。综合上述结果可知,饲粮添加CMH、CM H+ALA或Tau或LM A均能够降低生长育肥猪背膘厚度,其中CM H+ALA组合添加综合表现出更好的胴体和肉质改善作用,比单独添加CMH进一步提高了肌酸转运储备、氧化代谢能力、肌红蛋白表达和氧化型肌纤维比例等。     

发酵豆粕对肥育黑猪生长性能、胴体性状、肉品质和肌内氨基酸含量的影响

为研究发酵豆粕对肥育黑猪生长性能、胴体性状、肉品质及肌内氨基酸含量的影响,试验选择50头(78.9±2.0) kg肥育黑猪(杜洛克♂×苏紫黑猪♀),随机分为对照组和发酵豆粕组,每组5个重复,每个重复5头,对照组饲喂基础饲粮,发酵豆粕组饲喂在基础饲粮中添加8%发酵豆粕的饲粮。预试期7 d,正试期56 d。结果表明,与对照组相比:1)试验组肥育黑猪生长性能无显著变化(P0.05);2)试验组肥育黑猪眼肌面积显著增加(P0.05);3)试验组肥育黑猪背最长肌的肌肉红度a*极显著增加(P0.01),肉色评分显著升高(P0.05),背最长肌肌肉滴水损失显著降低(P0.05),同时肌肉剪切力极显著降低(P0.01);4)试验组肥育黑猪背最长肌缬氨酸、谷氨酸和组氨酸含量显著高于对照组(P0.05)。由此可见,饲粮中添加发酵豆粕可以改善肥育黑猪胴体性状和猪肉品质,提高猪肉营养价值。     

山竹醇对生长育肥猪生长性能、肌肉抗氧化能力和肌纤维类型组成的影响

本试验旨在研究饲粮中添加山竹醇对生长育肥猪生长性能、肌肉抗氧化能力和肌纤维类型组成的影响。试验选取80日龄左右、健康状况良好且体重[(35.50±1.50) kg]相近的"杜×长×大"三元杂交公猪48头,随机分为4组,每组12个重复,每个重复1头猪。试验期90 d,试验期间,对照组全程饲喂基础饲粮,试验Ⅰ、Ⅱ、Ⅲ组分别在屠宰前30、60、90 d持续饲喂在基础饲粮中添加400 mg/kg山竹醇的试验饲粮。试验结束时,每个重复随机选择6头试验猪进行屠宰,取其背最长肌样品,检测其抗氧化指标、肌纤维类型组成、过氧化物酶体增殖物激活受体γ辅激活因子-1α(PGC-1α)与p300活性以及肌纤维类型和肌肉生长相关基因的mRNA表达量。结果显示:1)与对照组相比,各试验组生长育肥猪全程平均日增重(ADG)、平均日采食量(ADFI)和料重比(F/G)均无显著影响(P0.05)。2)与对照组相比,生长育肥猪屠宰前60和90 d饲喂添加400 mg/kg山竹醇的饲粮均可以显著提高背最长肌中总超氧化物歧化酶(T-SOD)、谷胱甘肽过氧化物酶(GSH-Px)、过氧化氢酶(CAT)活性(P0.05),显著降低背最长肌中丙二醛(MDA)含量(P0.05)。3)与对照组相比,生长育肥猪屠宰前60和90 d饲喂添加400 mg/kg山竹醇的饲粮均可以显著提高背最长肌中Ⅰ型肌纤维的比例(P0.05),显著降低背最长肌中Ⅱ型肌纤维的比例(P0.05)。4)各组生长育肥猪背最长肌中肌球蛋白重链(MyHC)-Ⅱx的mRNA表达量无显著差异(P0.05);与对照组相比,生长育肥猪屠宰前60和90 d饲喂添加400 mg/kg山竹醇的饲粮均可以显著提高背最长肌中MyHC-Ⅰ和MyHC-Ⅱa的mRNA表达量(P0.05),显著降低背最长肌中MyHC-Ⅱb的mRNA表达量(P0.05)。5)与对照组相比,生长育肥猪屠宰前60和90 d饲喂添加400 mg/kg山竹醇的饲粮均可以显著降低背最长肌中p300活性(P0.05),显著提高背最长肌中PGC-1α活性(P0.05)。综合以上结果得出,生长育肥猪屠宰前60或90 d饲喂添加400 mg/kg山竹醇的饲粮可以提高肌肉的抗氧化能力,增加背最长肌中Ⅰ型肌纤维的比例,且具有生理阶段效应。     

发酵饲料对育肥猪生长性能、胴体性状、肉品质、血清生化指标和代谢产物的影响

本试验旨在研究发酵饲料对育肥猪生长性能、胴体性状、肉品质、血清生化指标和代谢产物的影响。试验选取体重约60 kg的三元杂交健康猪24头,随机分为2组,分别为基础饲粮组(对照组)和发酵饲料组(试验组),每组4个重复,每个重复3头猪。对照组饲喂基础饲粮,试验组饲喂80%基础饲粮和20%发酵饲料。预试期6 d,正试期29 d。结果表明,与对照组相比:1)试验组育肥猪的生长性能和胴体性状指标无显著差异(P 0.05); 2)试验组育肥猪背最长肌的pH45 min、红度值、肉色评分和粗脂肪含量显著提高(P0.05),背最长肌肉剪切力显著降低(P0.05); 3)试验组育肥猪的血清中总蛋白和尿素氮含量显著升高(P 0.05); 4)试验组育肥猪的血清中L-焦谷氨酸含量显著降低(P0.05),但血清中黄嘌呤、丁子香酚、丙烯酰胺和对-香豆酸的含量均显著升高(P0.05)。由此可见,饲喂发酵饲料可改变机体代谢,增加育肥猪背最长肌肉色评分及嫩度,改善肉品质。     

白藜芦醇对生长肥育期宁乡猪肉品质的影响

本试验旨在研究饲粮中添加白藜芦醇对生长肥育期宁乡猪肉品质的影响。选用体重(43±1) kg的宁乡猪24头,随机分为2个组,每组6个重复,每个重复2头(公母各占1/2)。对照(CON)组饲喂基础饲粮,白藜芦醇(RES)组饲喂在基础饲粮中添加300 mg/kg白藜芦醇的试验饲粮。试验期80 d。饲养结束后,每栏取1头体重接近平均体重的猪进行屠宰,并采集背最长肌、股二头肌及腰大肌样品,用于肉品质指标检测。结果表明:1)饲粮中添加白藜芦醇对宁乡猪的生长性能和肌肉主要营养成分含量均无显著影响(P0.05)。2)与对照组相比,白藜芦醇组宁乡猪宰后24 h背最长肌的红度(a~*)显著提高(P0.05),宰后24 h背最长肌和股二头肌的黄度(b~*)有降低趋势(0.05≤P0.10)。3)与对照组相比,白藜芦醇组宁乡猪背最长肌的磷酸果糖激酶(PFK)活性极显著降低(P0.01),股二头肌的丙酮酸激酶(PK)活性和乳酸(LA)含量显著降低(P0.05);肌肉pH无显著变化(P0.05)。4)与对照组相比,白藜芦醇组宁乡猪背最长肌的谷胱甘肽过氧化物酶(GSH-Px)活性、总抗氧化能力(T-AOC)及股二头肌的GSH-Px活性均极显著提高(P0.01),股二头肌的丙二醛(MDA)含量极显著降低(P0.01)。由此可见,饲粮中添加白藜芦醇可以提高宁乡猪肌肉的抗氧化能力,降低宰后肌肉的糖酵解速率,对肉品质具有一定的改善作用。     

饲粮能氮水平对不同品种猪肉质性状及相关基因表达的影响

本试验旨在研究饲粮能氮水平对不同品种猪肉质性状以及肌纤维类型和细胞因子相关基因表达的影响。选取巴马香猪和长白猪共96头(48头/品种),随机分为4组(每组24头猪),分别为长白猪饲喂NRC饲粮组、长白猪饲喂我国地方猪标准(GB)饲粮组、巴马香猪饲喂NRC饲粮组、巴马香猪饲喂GB饲粮组。试验从5周龄开始,至出栏时结束。分别于保育期、生长期和肥育期末,每组选择8头体况相近猪只屠宰,采集肌肉样品分析。结果表明:生长阶段显著影响了试验猪背最长肌熟肉率和肌球蛋白重链(MyHC)Ⅱx、MyHCⅡb及白细胞介素-15(IL-15)mRNA表达水平(P0.05),且随生长阶段呈增加趋势;与长白猪相比,巴马香猪的背最长肌熟肉率、MyHCⅠmRNA表达水平显著升高(P0.05),而滴水损失显著降低(P0.05);与NRC饲粮相比,GB饲粮显著提高了生长期长白猪和巴马香猪的p H45 min(P0.05),显著上调了保育期和肥育期猪背最长肌MyHCⅠmRNA表达水平(P0.05);与GB饲粮相比,NRC饲粮显著上调了生长期猪背最长肌MyHCⅠmRNA表达水平(P0.05)。由此可见,品种和生长阶段均可显著影响肉质性状及相关基因的表达,饲粮能氮水平则主要通过与生长阶段产生互作效应影响肉质性状及肌纤维类型相关基因的表达。     

一水肌酸对肥育猪胴体组成及肌肉系水力的影响

本研究旨在观察一水肌酸(creatine monohydration,CMH)对肥育猪生长性能、胴体组成和系水力的影响及其机理探讨。选用体重70 kg左右的杜长大三元杂交猪48头,按试验要求随机分为2组,每组设3个重复,每个重复8头猪,分别饲喂含CMH为0或0.25%的日粮,饲养试验时间为30 d。结果发现,CMH对猪日增重无显著影响(P>0.05);CMH显著提高了肥育猪的眼肌面积(P<0.05),而对屠宰率、瘦肉率、胴体直长、胴体斜长、腹脂重、脂肪率、背膘厚、皮肤比率、骨骼比率等无显著影响(P>0.05);CMH还使试验组猪的背最长肌率显著提高(P<0.05),股二头肌率有提高趋势但差异不显著,而对其他骨骼肌重率无明显影响(P>0.05);CMH使肥育猪宰后24 h背最长肌和半膜肌的滴水损失明显降低(P<0.05)、pH显著提高(P<0.05),而肌肉中乳酸含量显著降低(P<0.05)。结果提示,饲料中添加一水肌酸可通过降低肌肉中乳酸的积累,提高肌肉的pH,从而降低宰后肌肉的滴水损失,改善肉质。     

饲喂乳酸菌制剂对肥育猪生长性能、肉品质及风味物质含量的影响

试验旨在研究饲粮中添加乳酸菌制剂对肥育猪生长性能、肉品质及风味物质含量的影响。选取平均体重为(55±2)kg的杜×长×大三元杂猪240头,随机分为3个处理组,每组4个重复,每个重复20头试猪,公、母各半。对照组饲喂基础饲粮(玉米-豆粕型),2个试验组饲粮分别在基础饲粮中添加0.3%乳酸菌干粉和0.3%乳酸菌菌液,这2种制剂中乳酸菌含量均为1.2×10~9 CFU/g。试验期57 d,在饲养试验结束时,每个重复选择2头(1公1母)接近平均体重的试猪进行屠宰,测定胴体性状、肉品质和风味物质含量。结果表明:饲粮中添加乳酸菌干粉和乳酸菌菌液均对肥育猪的平均日增重、平均日采食量及耗料增重比无显著影响(P0.05),对肥育猪胴体直长、斜长、背膘厚、皮厚及眼肌面积也无显著影响(P0.05),对肌肉的肉色、大理石纹、pH、滴水损失率及剪切力无显著改善(P0.05);与对照组相比,饲粮中添加乳酸菌菌液显著降低背最长肌中次黄嘌呤含量(P0.05),但2个试验组肌苷酸、谷氨酸和肌内脂肪均无显著差异(P0.05)。综上所述,饲喂乳酸菌制剂对肥育猪生长性能、胴体性状和肉质无显著影响,但可降低肌肉中次黄嘌呤含量,有利于改善猪肉的风味。     

德氏乳杆菌对育肥猪胴体性状及肉品质的影响

本试验旨在研究无抗生素饲粮中添加德氏乳杆菌对育肥猪胴体性状、肉品质及背最长肌营养成分的影响。试验选用健康、平均体重为(65.34±3.64)kg的"杜×(长×大)"育肥猪120头,随机分为2个组,每组6个重复,每个重复10头猪(公母各占1/2)。对照组饲喂无抗生素基础饲粮,试验组饲喂在无抗生素基础饲粮中添加0.1%德氏乳杆菌的饲粮。试验期42 d。结果表明:2组育肥猪的胴体性状差异不显著(P0.05);与对照组相比,试验组育肥猪的脾重率和胰重率显著升高(P0.05);宰后45 min时2组育肥猪的肉品质差异不显著(P0.05),宰后24 h时,与对照组相比,试验组育肥猪肉的黄度显著升高(P0.05),剪切力显著降低(P0.05);与对照组相比,试验组育肥猪背最长肌中甘氨酸、丙氨酸和风味氨基酸含量显著升高(P0.05),葵酸和棕榈酸含量显著降低(P0.05),棕榈油酸、亚油酸和多不饱和脂肪酸含量显著升高(P0.05)。结果提示,无抗生素饲粮中添加0.1%德氏乳杆菌对育肥猪的胴体性状、肉品质及肉中营养成分具有一定改善作用。     

饲粮添加L-肉碱对生长育肥母猪生长性能、胴体品质和肉品质的影响

本试验旨在研究饲粮添加L-肉碱对生长育肥母猪生长性能、胴体品质和肉品质的影响。选取体重[(30.42±3.24) kg]相近的PIC商品母猪420头,随机分为2组,每组7个重复,每个重复30头。对照组饲喂基础饲粮,试验组在基础饲粮的基础上添加100 mg/kg L-肉碱。试验期共计105 d。结果表明:1)与对照组相比,试验组生长育肥母猪各阶段平均日增重、平均日采食量、料重比和存活率均无显著差异(P0.05)。2)与对照组相比,饲粮添加L-肉碱显著提高生长育肥母猪背膘厚度、背最长肌长度和重量(P0.05),显著降低下颌脂肪指数(P0.05),显著降低背最长肌剪切力、滴水损失、肌纤维直径和面积(P0.05),显著提高背最长肌肌纤维密度(P0.05)。3)与对照组相比,饲粮添加L-肉碱提高生长育肥母猪背最长肌肌内脂肪含量(P0.05),但显著降低背最长肌亚油酸、花生酸和花生三烯酸含量(P0.05)。4)与对照组相比,饲粮添加L-肉碱显著提高生长育肥母猪背最长肌脂肪酸合成酶(FAS) mRNA相对表达量(P0.05),显著降低背最长肌肌球蛋白重链Ⅱb(MyHCⅡb) mRNA相对表达量(P0.05)。综上所述,饲粮添加100 mg/kg L-肉碱对生长育肥母猪生长性能无显著影响,但可以影响背最长肌肌内脂肪沉积和肌纤维性状,并改善胴体品质和肉品质。     

Feline intracranial neoplasia: retrospective review of 160 cases (1985-2001)

The purpose of this study was to determine the frequency of different tumor types within a large cohort of cats with intracranial neoplasia and to attempt to correlate signalment, tumor size and location, and survival time for each tumor. Medical records of 160 cats with confirmed intracranial neoplasia evaluated between 1985 and 2001 were reviewed. Parameters evaluated included age, sex, breed, FeLV/FIV status, clinical signs, duration of signs, number of tumors, tumor location(s), imaging results, treatment, survival times, and histopathologic diagnosis. Most of the cats were older (11.3 +/- 3.8 years). Primary tumors accounted for 70.6% of cases. Metastasis and direct extension of secondary tumors accounted for only 5.6 and 3.8% of cases, respectively. Twelve cats (7.5%) had 2 or more discrete tumors of the same type, whereas 16 cats (10.0%) had 2 different types of intracranial tumors. The most common tumor types were meningioma (n = 93, 58.1%), lymphoma (n = 23, 14.4%), pituitary tumors (n = 14, 8.8%), and gliomas (n = 12, 7.5%). The most common neurological signs were altered consciousness (n = 42, 26.2%), circling (n = 36, 22.5%), and seizures (n = 36, 22.5%). Cats without specific neurological signs were common (n = 34, 21.2%). The tumor was considered an incidental finding in 30 (18.8%) cats. In addition to expected relationships (eg, meninges and meningioma, pituitary and pituitary tumors), we found that lesion location was predictive of tumor type with diffuse cerebral or brainstem involvement predictive of lymphoma and third ventricle involvement predictive of meningioma.     

The Prevalence and Intensity of Helminth and Coccidial Infections in Dairy Cattle in Central Kenya

A survey of gastrointestinal parasite infections of young (<6 months old), immature (6–12 months old) and adult (>12 months old) dairy cattle on 16 farms in Kiambu District, Kenya was conducted during a dry season (September 1991 to January 1992) and during a wet season (March to July 1992). The survey was based on monthly coproparasitological examination of cohorts and worm counts in tracer calves. The effects of age, sex, farm and season on the prevalence and intensity of helminth and coccidial infections were determined. Faecal egg and oocyst counts revealed that the overall prevalences were: strongyles (including trichostrongyles) (85.5%), liver flukes (Fasciola gigantica) (34.0%), coccidia (30.9%) and tapeworms (9.6%). Eight species of the protozoan Eimeria were identified, the most prevalent species being E. bovis and E. zuernii. The most prevalent nematode genera were Haemonchus, Cooperia, Oesophagostomum and Trichostrongylus. Season, farm and age of the animals had a significant (p<0.05) influence on the intensity of infection with strongyles, liver flukes and coccidia, whereas the sex of the animals had no significant (p>0.05) effect on the prevalence or intensity of infections. A higher intensity of infection with strongyles and coccidia was found in the wet season than in the dry season (p<0.05). The age-specific intensity was in the following order: for strongyles, immature animals of 6–12 months of age had the highest egg counts, followed by young calves and adults. Calves had significantly (p<0.05) higher oocyst counts than immatures or adults. Liver fluke egg counts did not differ significant (p>0.05) between immatures and adult cattle.     

Hypothalamic dopamine is required for salsolinol‐induced prolactin secretion in goats

The aim of the present study was to clarify the relationship between hypothalamic dopamine (DA) and salsolinol (SAL) for the secretion of prolactin (PRL) in goats. SAL or thyrotropin‐releasing hormone (TRH) was intravenously injected into female goats treated with or without the D₂ DA receptor antagonist haloperidol (Hal), which crosses the blood‐brain barrier, and the PRL‐releasing response to SAL was compared with that to TRH. PRL‐releasing responses to SAL, Hal, and Hal plus SAL were also examined after a pretreatment to augment central DA using carbidopa (Carbi) and L‐dopa. The PRL‐releasing response to Hal alone was greater than that to SAL or TRH alone. The PRL‐releasing response to Hal plus SAL was similar to that of Hal alone. In contrast, the PRL‐releasing response to Hal plus TRH was greater than that to TRH or Hal alone. The treatment with Carbi plus L‐dopa inhibited SAL‐ and Hal‐induced PRL secretion. The inhibition of the PRL‐releasing response to SAL disappeared when SAL was injected with Hal. These results indicate that the mechanisms underlying the SAL‐induced PRL response differ from those of TRH, and suggest that hypothalamic DA and its synthesis is associated in part with SAL‐induced PRL secretion in goats.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

Laboratory diagnosis of respiratory diseases of cattle

The authors describe the procedure of laboratory diagnosis for bovine respiratory diseases: direct diagnosis by isolation and for identification of bacteria or viruses and indirect diagnosis by serological methods. They specify the restraints and limits of this diagnosis and the significance results which are obtained and connected with knowledge of anamnestic information.     

The effect of peri-parturient anthelmintic treatment on the productivity of dairy cattle in subtropical western India

Trials with fenbendazole (Panacur, Hoechst India Ltd) were carried out on two commercial farms in subtropical western India to study the response and economics of nematode treatment in adult dairy cows. Milk yield, lactation length, time to first oestrus and worm egg output were monitored in treated and control groups. Treatment reduced the egg count considerably. Treated cows produced 142 litres more milk over 100 days (p<0.05), with extension of lactation length and advancement of time to first oestrus. The economic gain in terms of milk yield far outweighed the cost of anthelmintic used.     

An Evaluation of the Acceptability as Forage of Some Nutritive and Antinutritive Components and of the Dry Matter Degradation Profiles of Five Species of Ficus

The suitability of five species of Ficus, F. mucoso, F. thonningii, F. polita, F. religiosa and F. benjamina, for feeding ruminant livestock was studied. The nutritive and antinutritive components were determined and the acceptability of the forages to livestock was assessed using a cafeteria method in 8 adult small ruminants. Also, the degradation potential of the dry matter of the five Ficus species was investigated using 3 fistulated sheep. The crude protein (CP) content of the Ficus species varied significantly (p < 0.05), ranging from 130 to 180 g/kg DM. The content of neutral detergent fibre (NDF) also varied significantly (p < 0.05), ranging from 650 to 710 g/kg DM. The organic matter (OM) contents did not differ significantly (p > 0.05), having a mean value of 916 g/kg DM. The concentrations of tannin, saponin, phytic acid and oxalic acid were low. The acceptability of the forage was similar for four of the species but poor for F. polita. The extent of DM degradation varied significant among the Ficus species, the ranking order being F. benjamina > F. thonningii > F. mucoso > F. religiosa > F. polita.