杜洛克约克夏长白种猪的氟烷基因与经济性能之间的相关性研究

本研究采用PCR-RFLP技术检测了长白、约克夏和杜洛克猪群的RYR基因的多态性,分别分析了RYR基因与猪的产仔数(TNB)、初生重(LBW)、仔猪28日龄重(LWT28)、背膘厚(TheBackfatThickness)、死胎数(ND)之间的相关关系。对群体遗传结构分析表明,在约克夏、杜洛克猪群中,有氟烷基因存在;长白猪群中,未发现有该基因存在。通过对RYR基因分型研究,在约克夏和杜洛克猪群中,未发现有隐性纯合基因型(nn)个体,仅存在纯合基因型(NN)个体和杂合型(Nn)个体。不同氟烷基因型(NN,Nn)之间在产仔数方面存在差异性显著(P<0.05)。约克夏猪群中,比较了头胎的平均产仔数,结果发现,Nn个体的产仔数(TNB)比NN个体平均多1.7045头/胎;杜洛克猪群中,Nn个体的产仔数(TNB)比NN个体平均多2.5758头/胎;经产胎次中,平均产仔数分别多0.3898和0.9956头/胎。杂合型(Nn)个体显著高于纯合基因型(NN)个体(P<0.05)。在两层和三层膘厚检测中发现,在杜洛克猪群和约克夏猪群中,纯合基因型个体均低于杂合基因型个体,因此在背膘厚方面两种基因型(NN,Nn)个体存在差异性显著(P<0.05)。在仔猪28日龄重方面,杂合型(Nn)个体则低于纯合基因型(NN)个体,差异性显著(P<0.05);仔猪初生重方面,纯合基因型个体的仔猪初生重与杂合型个体差异不显著(P>0.05);死胎数方面,?     

七个贵州地方猪种RYR1基因突变的分布

兰尼定受体1(Ryanodine Receptor1,RYR1)基因中的单个氨基酸(R615C)是导致猪应激综合征、影响肉质的重要原因。采用RFLP方法,以大白猪、二个杂交猪群(杜洛克×长白猪×大白猪和长白猪×大白猪)为对照,研究了糯谷猪、萝卜猪、柯乐猪、宗地花猪、香猪、关岭猪和黔南黑猪7个贵州地方猪种RYR1基因突变的分布类型。结果表明,从柯乐猪中检测到一例杂合基因型RYR1Nn,杂合基因型的发生频率为2.08%,其余6个贵州地方猪种糯谷猪、萝卜猪、宗地花猪、香猪、关岭猪和黔南黑猪均为正常的基因型RYR1NN,对照组中,外三元、外二元杂交猪和大白猪中均检测到RYR1Nn基因型,杂合基因型的发生频率分别为11.11%、12.12%和5.77%,说明贵州地方猪种中RYR1基因的突变频率低于商品猪,但也存在一定的比例,应加强对地方猪种的利用和保护。     

猪遗传性对其鲜腰排的可口性、颜色和外观特征的影响

本研究是为了确定不同遗传背景猪的猪肉品质特征。试验用猪来源于 :杜洛克 ,皮特兰 (氟烷阴性 ,NN) ,皮特兰(氟烷阳性 ,nn) ,巴克夏猪 ,汉普夏猪 (rn+) ,汉普夏猪 (RN- )和一个合成系。以 10人为一组 ,通过训练 ,评估没烤过的瘦肉和肥肉的外观以及烤猪排的风味和肌理。同时测定 HunterL*、a*和 b*值 ,色泽角度 ,烹调损失和 Warner- Bratzler剪切力。猪的遗传背景不同 ,其猪肉在视觉上颜色有差异。杜洛克、巴克夏、皮特兰 - nn和合成系猪的排骨粉红色最浅。巴克夏猪的排骨瘦肉中大理石纹最多 ,而皮特兰 - nn猪的排骨瘦肉中大理石纹最少 ;皮特兰 (nn)和汉普夏 (rn+)猪的排骨 a*值最高 ,而杜洛克、皮特兰 (NN)和汉普夏 (RN - )猪的排骨 a*值最低 ;就排骨的烹调损失而言 ,杜洛克猪低于汉普夏 (rn+)、皮特兰 (NN)和合成系猪。皮特兰 (nn)和汉普夏 (rn+)猪的排骨剪切力最大。汉普夏 (RN- )猪的排骨肉汁最多 ,其次是汉普夏 (rn+)、皮特兰 (NN)、巴克夏和杜洛克猪。剪切力分别与异味强度、金属味和咀嚼性成正相关 (r分别为 0 .72、0 .94和 0 .6 9) ,与甜度成负相关 (r=- 0 .73)。综上所述 ,遗传背景对所测的许多肉品质特性有重要影响     

部分引进猪种α1-岩藻糖转移酶基因多态性研究

本研究采用PCR RFLP技术对4个引进猪种杜洛克、约克夏、长白猪和皮特兰共计122头猪的FUT1基因进行了多态性分析。结果表明：4个猪种在该FUT1基因座位存在多态性，但抗性基因型AA仅在杜洛克和皮特兰猪中分布。卡方检验结果表明，长白猪与皮特兰间FUT1基因基因型分布差异极显著，长白猪与杜洛克猪之间差异显著，约克夏与皮特兰间差异也显著。     

规模化养猪的关键——合理搭配品种

合理搭配品种对养猪意义极大。目前外国优良四大名猪吉林省都有,这就是丹麦长白猪、英国大约克夏猪(也可以称大白猪或苏白猪)、美国杜洛克红毛猪、美国汉普夏白带猪,其中长白猪用得最早最普遍,汉普夏猪用得最少,近年来约克夏猪也开始受欢迎。有的地方由于长期连续使用长白猪进行级进杂交,商品猪开始变得又长又窄逐渐退化,而约克夏猪粗而短,前期生长较快,用它和长白杂种杂交后代变得粗而宽很受养猪户的欢迎。杜洛克猪由于毛色红、杂交后代不是白色,开始不受欢迎,但杜洛克公猪和长白杂种杂交后其后代绝大多数为白色,因此作为第二父本还是比较理想的。但无论长白还是约克夏、杜洛克,由于生长快、瘦肉率高,要求条件也较高。一旦饲料、气候、管     

大约克、杜洛克及长白猪胴体性能及肉品质比较

选择出生日期相近、生长发育良好、体重100 kg左右的大约克、杜洛克及长白猪各10头屠宰,测定其胴体性能、肉质性状及背最长肌氨基酸、脂肪酸含量。结果表明,长白猪胴体直长比杜洛克高3.31%(P0.05),平均背膘厚大约克比长白低27.48%(P0.01),胴体瘦肉率以杜洛克猪最高(61.17%),分别比大约克和长白猪高3.49%(P0.05)、4.44%(P0.05)。杜洛克a值最高(15.30),分别比大约克和长白猪高12.58%(P0.01)、11.76%(P0.01);a24值杜洛克比长白高7.27%(P0.05);背最长肌剪切力以杜洛克最小(3.15 kg),分别比大约克及长白猪低25.36%(P0.05)、24.28%(P0.05);肌纤维直径以长白猪最细(70.30μm),比杜洛克低12.52%(P0.05);肌内脂肪含量以杜洛克猪最高(2.13%),分别比大约克和长白猪高65.12%(P0.01)、19.66%(P0.05),长白猪比大约克猪高37.98%(P0.05)。背最长肌17种氨基酸和4种脂肪酸含量品种间差异不显著。     

提高仔猪成活率的技术要点

1能繁母猪的品种 我国优良的地方猪品种具有性早熟、产仔多、耐粗饲等特点,但是瘦肉率低,有待于进一步选育与提高。引进的国外猪品种,瘦肉率较高,生长快,饲料转化率高。长白猪平均产仔数11.1头,约克夏猪平均产仔数10.75头。杜洛克猪平均产仔数9.78头,汉普夏猪平均产仔数8.66头,皮特兰猪平均产仔数9.7头。由于品种造成的产仔数低的因素改变起来相当困难,在生产中应多选择一些繁殖能力强的品种猪作种用,以提高产仔数。     

杜洛克、汉普夏、波中回交母猪杂种后代的生产性能比较

据D.L.Kuhlers,S.B.Jungst和J.A.Little(1985)报导,为了测定不同品种的母猪对仔猪断奶前后各种生产性能的影响,试验采用杜长(3/4杜洛克×1/4长白)、汉长(3/4汉普夏×1/4长白)、波长(3/4波中×1/4长白)回交母猪100头,在每头母猪的发情期中与2头约克夏公猪随机交配(共用约克夏公猪9头),计299窝,产仔猪3721头。妊娠期间全部饲养在未     

瘦肉型商品猪杂交组合筛选

试验采用公猪有杜洛克(杜)、汉普夏(汉)、约克夏(约),杂种母猪有约克夏×长白(约长)、约克夏×苏白(约苏)、梅山×长白(梅长),杂交方式为杜×约长、杜×约苏、汉×约长、汉×约苏、约×梅长5种.每一组合配种30窝.从每个组合的后代中挑选12～14头仔猪作肥育试验,180日龄时各挑选4头猪作屠宰测定.试验结果经方差分析,产仔数、180日龄活重,各组合间差异不显著(P>0.05);各组合料肉比为2.95～3.29,90kg屠宰各组合瘦肉率(除约×梅长51.14%外)均高于55%.结果表明,在主要生产性能上各组合差异不显著,杜洛克、汉普夏、约克夏均可作为三元杂交的终端父本.     

不同猪种ESR基因多态性的PCR-RFLP分析

运用PCR-RFLP方法,检测了杜洛克、约克夏、长白猪、皮特兰、梅山猪、二花脸猪、枫泾猪、荣昌猪、苏太猪等9个国内外猪种的ESR基因PvuⅡ位点多态性.结果表明,在约克夏猪、二花脸猪、枫泾猪和苏太猪中检测到了AA、AB、BB 3种基因型,在杜洛克猪、皮特兰猪中检测到AB、BB 2种基因型,在长白猪、梅山猪、荣昌猪中只检测到了AB基因型.在本研究中不同品种的A、B基因频率差异显著,总体上在国外猪群体中A等位基因为优势等位基因,而地方猪种中B等位基因为优势等位基因.     

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.     

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.     

Macrolides and lincosamides

Macrolides and lincosamides are first choice bacteriostatic antibiotics used in veterinary dermatology. The main antibiotics in these classes are erythromycin, lincomycin, clindamycin and tylosin. They are well absorbed if given orally and are able to penetrate well into infected skin. Their spectrum of action comprises bacteria commonly associated with skin infections, including staphylococci. Their main disadvantages are the rapid development of bacterial resistance and occasional gastroenteric upset, most often seen with erythromycin. More recently developed macrolides, such as azithromycin and clarithomycin, are bactericidal, have a larger spectrum of action, a longer endurance, less resistance and may be given once a day instead of two or three times daily.