为了解杜洛克猪对梅山猪生长育肥性状的改良效果,选择杜×梅杂交一代猪48头(26公、22母),测定体重20～100 kg阶段的平均日增重、体长、体高、屠宰率、胴体瘦肉率、后腿比例、眼肌面积等.结果:阉公猪的全期日增重为(622.30±20.93)g/d,比阉母猪的低18.2 g/d,阉公猪的全期饲料转化率为2.92∶1,比阉母猪的多0.27;宰前体尺中,阉母猪体长、体高和腿臀围均高于阉公猪(P＜0.01),不同屠宰体重组所测定的体尺均达到显著(P＜0.05)或极显著(P＜0.01)水平,体尺随宰前体重的增加而增加;阉母猪的胴体指标优于阉公猪,不同屠宰体重组大部分胴体指标达到显著(P＜0.05)或极显著(P＜0.01)水平.研究结果表明,杜×梅杂交一代商品猪宜公、母分栏饲养,其出栏体重控制在90～95 kg为宜.

为了检测猪KISS-1基因所有外显子的多态性,试验采用混合基因组DNA池和直接测序技术扫描基因所有外显子区域,在此基础上采用PCR-SSCP、PCR-RFLP等技术进行大规模检测,并分析各位点的群体遗传学特性.结果表明:共检测出2个单核苷酸多态性(SNPs),分别为外显子1中G41T和外显子2中G2343C.氨基酸序列比对发现,G41T导致缬氨酸(Val)变为苯丙氨酸(Phe),G2343C导致谷氨酸(Glu)变为谷氨酰胺(Gln).梅山猪、枫泾猪与大白猪3个群体KISS-1基因的2个位点均表现出多态性.

为了研究稀释密度对猪冷冻精液解冻后精子活力的影响,试验选用12头成年健康公猪的精液,按5种不同稀释密度进行稀释,比较不同稀释密度冷冻精液解冻后精子活力.结果表明:随着稀释倍数的增大,猪冷冻精液解冻后精子活力逐渐增大,稀释密度为0.8×108～1.6×108个/mL时解冻后即时和2小时时的精子活力较高.

All exons in progesterone receptor(pgr) gene in Xiaomeishan, Fengjing and Large White pig populations were screened using mixed genome DNA pool and direct sequencing methods. The results showed that only one site exhibits nucleotide polymorphism(SNP), which is in exon1 of pig pgr gene at 1 319 bp with base mutation from C to T(C1319T). This mutation do not cause the change of amino acid residue, which is a synonymous mutation. Based on this mutation, mismatched PCR?RFLP method was established to analyze polymorphism of pgr gene in the above mentioned pig populations. According to PCR-RFLP, three pig populations is divided into AA, AB and BB genotypic types, in which AB types exist in Xiaomeishan and Fengjing pig populations, and BB, AB types in Large White pig population.

Puberty refers to the period that male or female animal discharges gamete in the first time.The onset of ani-mals' puberty is the mark that animal obtained reproductive capacity since it was born.This study demonstrated that the se-cretion amounts of GABA increased in puberty,the combination of high concentration GABA and GABAAR could stimulate the secretion GnRH nerve fiber and promote the onset of puberty.

The polymorphism of exon2 in BMP15 gene was detected in Meishan pig and Large White pig by PCR-RFLP.The result showed that there were allele A and B at the locus of BMP15 gene in these two breeding.The relationship between the polymorphic locus of exon2 in BMP15 gene and the total number of piglets born and survived in first parity,second parity and later parities was analyzed by the least square analysis.The results indicated that there were significant differences in Meishan pigs between different genotype sow of later parities in piglets born and survived.Genotypes of AA sows had the most piglets of 14.28 in number survived,while,BB sows had the least piglets of 12.67 in number born and 12.33 in number survived.There were significant difference in Large White pig between different genotype sows of first parity and later parities in number born,and no significant differences in other aspects,but had a trend of AA>AB>BB.

<正>近年来,随着我国乳品工业的迅猛发展,奶牛业也发展迅速,呈现了养牛热的大好局面。但目前奶牛场在管理方面仍存在着诸多急待解决的问题。本文就现代奶牛场管理中的几个误区进行了分析和讨论,希望对奶牛

以IGF2基因作为控制猪生长性状主基因的候选基因,选用小梅山猪及其杂种作为试验猪群体,采用微卫星DNA标记技术,检测猪IGF2基因紧密连锁的3个微卫星DNA标记的多态性,同时对这3个微卫星DNA标记与生长性状进行关联分析.结果表明:SW256等位基因D对180日龄体重性状有正效应,等位基因B有负效应;SWC9等位基因E对30日龄体重性状有正效应,等位基因F对180日龄体重性状有正效应.

采用PCR-RFLP技术分析了小梅山猪FSHβ基因和PRLR基因的多态性及其与繁殖性状的相关性.结果表明:FSH β基因3个基因型AA、AB、BB在小梅山猪中的频率分别为0.8500(AA)、0.0667(AB).0.0833(BB);PRLR基因3个基因型AA、AB、BB在小梅山猪中的频率分别为0.6441(AA).0.2881(AB).0.0678(BB).FSH β基因对小梅山母猪初产胎次的总产仔数、产活仔数和初生窝重影响显著,并呈现出AA>AB>BB的趋势;PRLR基因对小梅山母猪的各项繁殖性状都没有显著影响.

众所周知,优质原料乳是乳品企业生产优质产品的首要保证.目前,随着国内乳品市场规模的不断扩大,消费者对乳制品的品质要求也不断提高.而个体奶农由于种种原因,其原料乳的质量始终难以得到保证.规模化奶牛场的建设和发展是我国奶牛业健康、可持续发展的方向,因此规模化奶牛场原料乳的质量成了生产优质安全乳制品的重要前提.