羊人工授精三级网点的建立

由精液供应站，精液转运站和输精点组成的羊人工授精三级网点，能更充分地利用优良种公羊精液，扩大配种范围，加速羊群改良。本文对三级站点的任务要求及应配备的设施和人员作出具体的论述。     

现代生物技术在山羊繁殖中的应用

讨论了几种有关山羊繁殖的生物技术进展，主要包括山羊的人工授精，胚胎克隆和胚胎移植，体外胚胎生产和转基因等。     

戴云山羊新品系繁殖性能研究

试验系统研究了经连续4个世代选育的戴云山羊新品系的繁殖性能。结果表明,各世代配种率、受胎率均在90％以上;头胎母羊产羔数在1．32～1．48头之间、经产母羊产羔数在1．89～2．12头之间;头胎初生重为1．69～1．77kg,经产为1．47～1．58kg。遗传改良效果为：各世代母羊的配种率与受胎率都得到了一定的改善;产羔数提高约0．2头;各世代羔羊的初生重随着产羔数的增加而减少。     

Contribution of Reproduction Management and Technologies to Genetic Progress in Horse Breeding

Reproductive technologies aim at improving fertility with the ultimate result of improving genetic selection. In equidae, the respective contribution of different methods of horse management and breeding to genetic progress remain difficult to evaluate as breeding strategies affect the number of offspring per mare or stallion whereas different selection methods (based on pedigree, performance, genomics or progeny’s performance) will be applicable at different ages, leading to different accuracy in the estimation of the breeding value. Here, a mathematical model was applied to evaluate theoretical genetic progress depending on breeding conditions in horses. The model showed that for breeding systems ranging from 0.6 to 2 foals/year/mare and from 10 to 150 foals/year for stallions, when selection of the best animals is strictly made by a truncation, the genetic progress is accelerated by (1) increasing the number of offspring per year, (2) the start of reproduction as soon as the age of 2 in both sexes, and (3) reducing the number of years of use for stallions from 10 to 5 years. The calculation showed that using all ways of improvement could provide an increase in genetic progress of up to +270% and +226% in mares and stallions, respectively, above the basal reference situation of 100%. In the Selle Français breed, the observed reproductive management parameters (10 years generation interval, 10 foals/stallion and 0.55 foals/mare) are close to the worst conditions of the model. In addition, the best mares are not selected for breeding. In conclusion, new reproductive technologies, genomic selection, and breeding younger animals will increase genetic gain.     

药物诱发山羊同期发情和人工授精效果观察

2002年和2003年,在都兰县巴隆乡托托村人工授精配种站对639只柴达木绒山羊进行了同期发情和人工授精试验。试验山羊颈部皮下注射三合激素(ITC)1.0ml,成年山羊的同期发情率在80%以上,初配羊为69.5%,低于成年母羊(P<0.05)。成年山羊采用子宫颈深部输精,输入辽宁绒山羊1∶1稀释精液0.1ml,情期受胎率达到64.8%,初配母羊采用阴道输精,情期受胎率为19.4%,低于成年母羊(P<0.01)。     

山羊多胎性状候选基因的研究进展

多胎性状是山羊的重要经济性状,直接关系到其产业的经济效益。目前在绵羊中已经找到了影响多胎性能的若干主效基因;在山羊上,国内外对遗传机制的研究主要集中在常规选育和分子标记方面,但是仍未找到控制山羊多胎性状的主效基因。论文就山羊多胎性状候选基因的研究现状进行综述,为其主效基因的筛选及应用提供有益参考。     

辽宁绒山羊改良新疆山羊的效果研究

本试验用辽宁绒山羊与新疆母山羊进行杂交改良,经过9年多的工作,取得了大量数据,证明杂交改良效果好,改良羊与父母本的适应性一样强,杂交羊的产绒量有了明显的提高。杂交1代、2代、3代周岁母羊产绒量分别比当地山羊高76.22克、114.65克、131.05克;分别提高53.99％、81.21％、92.82％,各组平均抓绒量间有极显著的差异(P<0.01)。这项研究结果对提高我区山羊生产将会起到积极作用,具有一定的社会效益和经济效益。     

种鸡人工授精的卫生管理

1环境的卫生 采精环境的卫生状况会影响采出精液的质量,如果环境中灰尘多则在采精过程中容易飘落到精液中,这些灰尘进入精液后会诱使部分精子以头部与其接触,尾部向外做原地摆动(这是精子的趋触性表现),这样的精子尽管能够活动却都丧失了受精能力;     

Genetic Aspects of Reproduction in Sheep

Maintenance of high levels of realized fertility (defined as the percentage of ewes that lamb) and appropriate levels of fecundity are critical for efficient sheep production. The optimal level of fecundity in most situations is well below the maximum attainable level and can be targeted by combining selection among and within breeds with use of an expanding array of single-gene mutations affecting ovulation rate and litter size. The heritability of litter size is approximately 0.10, allowing changes of up to 2%/year from simple mass selection. Mutations in several genes associated with the transforming growth factor β superfamily ( BMPRIB , GDF9 and sex-linked BMP15 ) can increase ovulation rates by 0.7–1.5 ova in heterozygous ewes. However, ewes that are homozygous for BMP15 or GDF9 mutations are sterile, so use of these mutations requires carefully structured breeding programmes. Improvements in fertility may be critical for autumn lambing or programmes that aspire to lamb throughout the year. Selection to improve fertility in spring matings has been successful; selected adult ewes have lambing rates of 80–85% in October and early November. The selected ewes have a dramatically reduced seasonal anestrus, and many ewes continue to cycle during spring and summer. Major genes affecting seasonal breeding have not been identified in sheep. Polymorphisms in the melatonin receptor 1a gene appear to be associated with seasonal breeding in some, but not all breeds. However, functional genomic studies of genes associated with circadian and circannual rhythms have potential to reveal additional candidate genes involved in seasonal breeding.     

绍鸭与法国番鸭杂交的人工授精技术

绍鸭产蛋率高、体型小 ,产肉率低 ;法国番鸭体型大、产肉率高 ,且风味独特 ,营养价值高。目前我国家庭人口较少 ,番鸭鲜食市场需求小。基于这一情况 ,我们尝试将绍鸭与法国番鸭杂交 ,以生产出体型适中、肉质优良的肉鸭。因绍鸭与法国番鸭不能自然交配 ,现将绍鸭与法国番鸭杂交的人工授精技术要点介绍如下 ,供同行参考。1　公番鸭的选择精液质量的好坏决定人工授精的成败 ,要获得高质量的精液 ,必须选择年轻体壮的公番鸭。一般选 2 0 0日龄、体重 4kg左右的健康公番鸭。2　公番鸭的饲养管理为了保持公番鸭旺盛的性欲 ,延长利用时间 ,必须一笼…     

Studies on Reproduction in the Goat: III. The Functional Activity of the Ovaries of the Goat

1. A study of the functional activity in the ovaries was undertaken on 366 organs from pregnant goats and 171 organs from nonpregnant goats. The ovulations were recorded by the presence of corpora lutea in the ovaries.
2. The right ovary appears to be the most active in the goat, since 57 % of the ovulations occurred in the right ovary. In cases of multiple ovulations there appears to be a greater tendency for the first of these ovulations to occur in the right ovary (62.34 %).
3. In almost 50 % of twin pregnancies both ova will be shed from the same ovary.
4. In six cases, five twin pregnancies and one triplet pregnancy, only one, respectively two corpora lutea were found. This can in all probability be taken as an indication of the occurrence of identical twins.
5. The incidence of “ovum loss” or early embryonic mortality was found to be 19.6 %.

     

弯头输精针输配山羊效果的观察

近年来，随着山羊人工授精技术的大力推广，为市场提供了大量的优质肉羊，使养殖农户增收了可观的经济效益。据调查，羊改点输精员使用直头金属输精针，输配山羊往往在进针时较为困难，造成了受胎率不高，为解决输精员进针技术难题，根据山羊生殖器官形态特征，我们采用了自己设计制作弯头输精针输配山羊取得了较好效果，现介绍供同行参考。１材料与方法１．１材料（１）设计制作５０支弯头金属输精针（长１９cm，针体直径２mm、从套注射器端起至针体１７．５cm处处理形成３０度的曲弯头，曲弯头长度１．５cm，按提供尺寸经江苏省泰兴市动物…     

Effects of Artificial Insemination vs Natural Service Breeding on Production and Reproduction Parameters in Dairy Herds

The effects of four combinations of AI and natural service (NS) breeding on production and reproduction parameters were analyzed using Holstein Dairy Herd Improvement herd summary records for years 1999 through 2002. Herds were assigned to breeding systems (BS) by percentage of NS usage as follows: 1) 0%, 2) 1 to 20%, 3) 21 to 89%, and 4) 90 to 100%. Regions were North, Midsouth, and South. Herd sizes were small (<100 cows), medium (100 to 249 cows), and large (>250 cows). The mean percentages of AI and NS usage over 4 yr by BS were 1) 100%, 0%; 2) 92.9%, 7.1%; 3) 54.2%, 45.8%; and 4) 1.0%, 99.0%. Actual calving interval was shorter (P<0.05) for BS4 compared with the other systems. Herds using a combination of AI and NS (BS2 and BS3) had longer actual calving intervals than did herds in BS1 (P<0.05). Days dry and the percentage of dry periods between 40 to70 d were less for BS1 (P<0.05). The percentage of cows leaving the herd was significantly less for BS4. The percentage of cows leaving the herd for reproductive reasons was greater for BS1 (P<0.05). Overall reproductive efficiency as measured by the percentage of cows in milk and herd milk yield was greater (P<0.05) for BS1 and declined as the percentage of NS increased. Actual calving interval, days dry, and percentage of dry periods between 40 to 70 d were less in the North (P<0.05). Percentage of cows in milk and herd milk yield were greater in the North (P<0.05). Herd milk yield was greater (P<0.05) for large-size herds and decreased with declining herd size.     

荔波县牛人工授精及品种改良存在的问题及对策

利用冷冻精液人工授精技术进行牛品种改良是提高牛生产性能的重要措施之一，已在很多地区发挥了很好的作用，现将我县牛人工授精及品种改良存在的问题分析如下，并提出发展对策，供同行参考。     

山羊不同输精方式和精子数目的受胎效果比较

影响山羊人工授精效果的因素主要是人工输精方式和输入的有效精子数目。山羊人工输精方式有子宫颈口法和子宫内法,目前主要采用子宫颈口法。这种方法虽然简单方便,但是精液消耗量大,受胎率低,复配率高。随着腹腔镜的应用,子宫内输精已经得到了普遍的推广和应用。试验通过比较山羊不同人工输精方式和输入的有效精子数目,进一步探讨了子宫内输精的应用条件,为该技术的推广利用奠定基础。1材料与方法1.1材料1.1.1试验山羊和分组选择健壮的2～4岁经产、空怀、发情母羊共123只,随机分为4组,试验处理见表1。1.1.2主要试剂卡那霉素、BSA、HEPES…