绵羊母性对产仔成活率的影响

绵羊母性正常是保证初生羔羊存活的必要条件,而导致初生羔羊伤残或死亡的,基本都为母性异常。研究绵羊母性,对产羔季节实行科学饲养管理,提高羔羊的成活率具有重要意义。一、时间及方法 1982年12月至1985年2月对3个产羔期进行观察统计,对饲养管理条件一致、品种相同的分娩母羊,按设计要求,把羔羊出生后母羊拒绝羔羊哺乳,顶撞、踢蹴羔羊的,羔羊出生后哞叫或哺乳而母羊毫无反应的母性异常者,加以统计分析。     

雷州山羊不同母性行为对羔羊体重的影响

试验旨在研究山羊不同母性行为对羔羊体重的影响,选用健康、产期相近的雷州山羊6只,其中3只初产、3只经产,经产母羊此次产羔均为第3胎。羔羊出生后,连续1周采用24 h监控系统全事件记录母羊的母性行为时长。产羔后利用布条对羔羊进行编号和区分,在出生和生产第10天对羔羊进行称重。结果表明:初产母羊对羔羊的舔舐和嗅闻与经产母羊相比显著升高,而寻找羔羊、待在一起和哺乳时长显著降低;经产羔羊平均日增重较初产羔羊显著升高,且单羔的平均日增重是双羔的1.8倍;母羊不同哺乳时长、平均中断或拒绝哺乳次数均与羔羊日增重及10日龄重存在显著相关性。综上,母羊胎次及产仔数通过影响母羊与羔羊亲子联系的建立及母性行为的表达间接影响羔羊日增重。     

限位环境对妊娠母猪母性的影响

限位环境在带来生产便利的同时也限制了母猪的母性表达。从中枢控制、基因表达、激素调节等角度阐明母性行为的发生机制,分析限位环境应激对母猪行为、生理、心理等方面的影响导致的母性减弱,并总结限位母猪常见疾病对母性的影响;通过对限位环境中母性表达影响因素的分析,探究其在妊娠母猪中的作用机制,将有助于改进母猪的育种和管理。     

饲养方式影响母猪母性行为的研究进展

哺乳动物的母性行为主要包括做窝行为、哺乳行为、护仔和抚育行为。在畜牧生产中,母性行为的好坏会影响母猪对仔猪的哺育和母仔之间的交流,对母猪的生理、心理健康和仔猪的生长发育都有直接影响,进而影响猪场的生产成绩和经济效益。随着现代集约化养猪的兴起,养猪业发展迅速,经济效益得到了提高。但是,现代集约化饲养对于母猪表达其母性行为,以及仔猪学习如何正常表达行为产生了诸多限制因素。综述了现代集约化饲养和开放式饲养模式对母猪母性行为的影响,以及给养猪生产带来的影响。     

黑头杜泊羊与和丰本地绵羊杂交后代羔羊生产性能及肉品质研究

为了客观评价黑头杜泊羊与和丰本地绵羊杂交后代羔羊的生产性能和肉品质,挑选杂交后代羔羊和本地绵羊羔羊各60只作为研究对象,测定其生产性能和肉品质的各项指标.结果表明:初生、1月龄杂交后代羔羊的体重显著高于本地绵羊羔羊(P<0.05),2月龄、3月龄、4月龄杂交后代羔羊的体重均极显著高于本地绵羊羔羊(P<0.01).4月龄...     

山羊母性也会影响产仔成活率

村养殖技术农山羊母性是否正常是初生羔羊存活或伤残的必要条件,研究山羊母性,对产羔季节实行科学饲养管理、提高羔羊成活率具有重要意义。(一)方法据对饲养管理条件一致、品种相同的分娩母羊观察,把羔羊出生后母羊拒绝哺乳羔羊,顶撞、踢蹴羔羊的和羔羊出生后咩叫,或哺乳而母羊毫无反应的母性异常者,加以统计分析。用这些母羊的产仔数、产羔成活数及产仔成活率等指标同母性正常的相对指标进行比较,找出母性对产仔成活率的影响关系。(二)结果观察分娩母羊共362只,其中母性异常的母羊为116只,异常组产仔数为122只,产仔成活89只,产仔成活率为73…     

现代肉羊生产几项关键技术的探究

1肉用绵羊的生产指标体系近10年来,用从国外引进的肉用绵羊品种,选择性早熟、多胎、高产的地方良种小尾寒羊和湖羊与当地的本地绵羊进行杂交生产肥羔羊,为我国肉羊生产开辟了一条新路子。事践证明,杂交羔羊育肥生长速度快、饲料     

影响母猪母性行为的因素

母猪母性行为是受激素、遗传、环境等多方面因素影响和调控的复杂过程.仔猪的成活率与母猪的母性存在着直接影响关系,比如一些母猪的异常母性行为会导致仔猪被母猪咬死、踩死、压死现象.在现代规模化养猪生产中,往往只重视仔猪挤压死亡情况的产生,不重视母性行为对仔猪死亡率的作用.本文就激素、环境因素和遗传因素对母猪母性行为的影响进行论述,目的是为降低仔猪死亡率.     

The effect of ewe maternal behaviour score on lamb and litter survival

The study was carried out on a commercial New Zealand sheep farm with high ewe reproductive rates and lamb survival produced through intensive selection in its Coopworth flock for maternal ability.Heritability and repeatability estimates were derived for ewe maternal behaviour score (MBS) and litter survival (LIS). Heritability estimates were derived for lamb survival as a trait of the lamb (LAS) for all lambs, for twin (LAS2) and for triplet (LAS3) lambs.MBS and LIS were measured on 1954 dams, for a maximum of four parities: 1997, 1998, 1999 and 2000. MBS was measured at tagging on a 5-point scale (1=poor, 5=excellent) when the dam's lambs were between 12 and 36 h old. The mean MBS in this study was 3.3 and increased with litter size. LIS was measured from birth to weaning. Mean litter survival was 83%. LIS increased significantly as MBS increased (P<0.01). LIS decreased as the size of the litter increased (P<0.01). Age of dam was a nonsignificant effect on LIS (P>0.05).LAS was measured from birth to weaning on 4171 Coopworth lambs. Mean LAS was higher for lambs born as twins compared to lambs born as singles and lowest for lambs born as triplets (P<0.01). LAS was lower for lambs born to dams aged 2 years. This effect was significant for all lambs, regardless of litter size at birth and for the triplet lamb data set (P<0.01). The effects of age of dam and sex of lamb on twin lamb survival were not significant (P>0.05). Ewe lamb survival rate was higher when compared to ram lambs in the full data set, however the relationship was reversed for the triplet lamb data set where ram lamb survival was greatest (P<0.01). LAS decreased as the MBS of its dam increased (P<0.01). The relationship was significant for lambs in the full data set and the twin data set (P<0.05).MBS and LIS were under minimal genetic control. The heritability and repeatability for MBS were both 0.09. The heritability and repeatability for dam LIS were 0.0 and 0.11. Heritability for LAS over all lambs attributed to direct effects was 0.14, while the heritability attributed to maternal effects was 0.11. The heritability for twin (LAS2) and triplet (LAS3) lamb survival differed. Heritability attributed to direct and maternal effects were 0.0 and 0.21, respectively, for twin lambs and 0.08 and 0.16, respectively, for triplets.The genetic correlation between maternal and direct effect for LAS was −0.74. It is possible that the genes that regulate physiological and biochemical processes for survival are incompatible with the genes that enhance ewe-lamb bonding. For example, the genes that regulate the physiological factors to reduce gregariousness at parturition may in fact be the same genes that encourage isolation in the neonate from its littermates and dam.There is minimal genetic variation in this flock for lamb survival and maternal traits. Low genetic variation suggests that selection will be ineffective, and that farmers must consider environment and management techniques for improving lamb survival.     

Genetic and environmental effects on growth to 1 year and viability of lambs from a crossbreeding study of D'man and Sardi breeds.

Genetic effects were estimated for growth to 1 yr and viability to 90 d of 882 lambs from a diallel cross of Sardi (S), D'man (D), and D'man x Sardi (DS) male and female parents. Sardi direct genetic effects were significantly higher than those of D'man for weights at birth and up to 2 mo, but the difference decreased thereafter and was in favor of D'Man at 6 mo. Sardi maternal ability was better than that of D'man for weights at all ages. Estimates of individual heterosis were small and negative for weight at birth, weight at 1 mo, and lamb viability and positive for other body weights; the estimate was significant for 12-mo weight. Estimates of maternal heterosis were small and did not approach significance for any trait. Epistatic recombination effects were generally small, but negative for all traits and significantly so for viability to 30 d. In general, the results, combined with those on reproduction and total lamb production of ewes of these groups, reported elsewhere, indicate that a population produced by inter se mating of animals 50% D, 50% S breeding is expected to have higher total lamb production than either purebred.     

Genetic background of maternal behaviour and its relation to offspring survival

Maternal behaviour is becoming increasingly important in animal production. Selection for increased litter size at birth in pigs and sheep puts higher demands on the ability of dams to raise large litters. In pig production, the use of loose housing systems for lactating sows increases the importance of good maternal behaviour. Extensive production systems (e.g., ecological farming and outdoor production), where there is a small degree of supervision of the animals, also leaves a greater responsibility with the mother to care for her young. The environment provided by the dam is important for the survival and growth of the offspring in many species. Several behaviour traits of the mother play a role for the offspring's chances of survival and a good start in life. Examples of such behaviour traits are responsiveness towards signals from the offspring (pigs), aggressive behaviour towards the offspring (pigs and sheep), nursing behaviour (pigs and sheep), and fear behaviour (pigs, sheep, and cattle). Some of these traits are in part genetically controlled, and thus possible to improve by selection. Behaviour traits are, however, often difficult to observe and record on a large scale. By studying behaviour, we can gain further understanding about factors affecting survival of the young, and increase our chances to improve maternal behaviour. Improved maternal behaviour would increase the welfare for both mother and young.     

羔羊代乳粉在新疆肉羊生产中的应用前景

羔羊代乳粉在羔羊早期断奶和肉羊产业化生产中起着重要的作用。在新疆当前羊肉供需不平衡,羊肉价格过高的情况下,在肉羊产业中使用羔羊代乳粉,发展肥羔肉和优质小羊肉生产,建设集约化、规模化、产业化的养羊业,是解决这种矛盾的有效途径之一。     

Variations in the concentrations of the immunoglobulins IgG1, IgG2, IgM and IgA in sheep. 2. Changes in the blood of lambs of different breeds and crossbreeds during the course of the rearing period

The sera of 188 lambs from seven breed groups were analyzed for the concentrations of IgG1, IgG2, IgM and IgA by radial immunodiffusion using monospecific antibodies. From each lamb, 14 blood samples were drawn before and 5 samples after weaning. The following results were obtained: 1. Immunoglobulins could not be detected in sera drawn before the first intake of colostrum. 2. In normally suckling lambs, the peak concentrations of maternal immunoglobulins are attained at 0-18 hrs after birth. They can be assessed in a single blood sample drawn between 18 and 24 hrs. 3. The half-life times of maternal immunoglobulin in lamb sera are 11 days for IgG1, 7 days for IgG2, 6 days for IgM and 18 hours for IgA. 4. The absolute peak heights relate to the amounts of colostrum ingested before 12-18 hrs after birth. 5. The decline of maternal immunoglobulins in lamb sera over-laps with the onset of lamb immunoglobulin synthesis. Renewed rises of concentrations are observed for IgG2 after week 2, for IgM after week 3 and for IgG1 after week 7. The concentrations of IgA remain at the low levels characteristic for the serum of grown sheep. 6. The role of immunoglobulin synthesis in suckling lambs is only briefly and to a small extent reduced after weaning.     

Estimation of additive and non-additive genetic parameters for reproduction, growth and survival traits in crosses between the Moroccan D'man and Timahdite sheep breeds

Genetic breed differences, heterosis, recombination loss, and heritability for reproduction traits, lamb survival and growth traits to 90 days of age were estimated from crossing D'man and Timahdite Moroccan breeds. The crossbreeding parameters were fitted as covariates in the model of analysis. The REML method was used to estimate (co)variance components using an animal model. The first estimation of crossbreeding effects for Timahdite and D'man breeds shows that breed differences in litter traits are mainly of maternal genetic origin: +1.04 lambs, +1.88 kg, +0.60 lambs, and +2.23 kg in favour of D'man breed for litter size at lambing, litter weight at lambing, litter size at weaning, and litter weight at 90 days, respectively. The breed differences in lamb growth and survival are also of maternal genetic origin for the majority of traits studied, but in favour of the Timahdite breed: +3.48 kg, +45 g day⁻¹ and +0.19 lambs for weight at 90 days, for average daily gain between 30 and 90 days of age, and for lamb survival to 90 days, respectively. The D'man direct genetic effect was low and negative for survival and birth weight of lambs during the first month of life. All traits studied showed positive heterosis effects. Recombination loss effects were not significant. Therefore, crossbreeding of Timahdite with D'man breeds of sheep can result in an improved efficiency of production of saleable lambs. Heritability estimates were medium for litter size but low for the other reproduction traits. Direct heritabilities were low for body weights and lamb survival at 90 days and the corresponding maternal heritabilities showed, however, low to moderate estimates. For litter traits, the estimates of genetic and phenotypic correlations were positive and particularly high for genetic correlations.     

羔羊代乳粉研究进展及其在肥羔生产中的应用前景

文章从羔羊代乳粉的研究进展及其在羔羊早期断奶中的应用等几个方面进行了阐述,分析了肥羔生产的产业优势及产业现状,认为羔羊代乳粉是肥羔规模化、工厂化、产业化生产的主要技术条件,应用前景广泛.     

Effects of alternative lamb production systems, terminal sire breed, and maternal line on ewe productivity and its components.

The 4 yr productivity of 25% (QF; n = 533) and 50% (HF; n = 531) Finnsheep ewes exposed to either Suffolk or Columbia rams in one of three production systems was monitored to test the effects of system, terminal sire breed, maternal line, and their interactions on annual market lamb production. Ewe lambs and yearlings were randomly assigned to either a high-input accelerated lambing system (HIGH), a high-input annual system (MED), or a low-input annual system (LOW). Nursery facilities were available for weak lambs or those born in triplet or more births for the HIGH and MED but not for the LOW systems. Accelerated lambing protocol required early weaning. Sex-adjusted lamb weaning weights were corrected to within-system mean ages of 42 d for HIGH and 70 d for MED and LOW. The HIGH ewes weaned 1.55 lambs per year compared with 1.46 for MED and 1.18 for LOW (P less than .01). However, because of early weaning, HIGH yielded the lowest weight of weaned lamb per year. The MED ewes weaned 5.9 and 11.1 more kilograms of lamb per year than the LOW and HIGH ewes, respectively (P less than .01). The HIGH system may be economically feasible if young lambs could be inexpensively grown to feeder or market lamb weight. The HIGH ewes did not, however, increase lamb numbers in proportion to increased exposures compared with the annual systems. Breed-group effects for ewe productivity (kilogram of lamb weaned per ewe per year) were consistent across management systems, although some interactions among breed group and system were present for components of productivity. Suffolk rams yielded an advantage of 1.6 kg of weaned lamb per exposure over Columbia rams (P less than .05) due to a 3% better lamb survival (P less than .01) and heavier weaning weight, especially in the LOW system. The HF ewes weaned .1 more lambs per exposure than QF ewes (P less than .01); .06 of the lambs were nursery-reared. However, lambs from HF ewes had a 2% lower survival rate (P less than .05) and were 1.4 kg lighter at weaning (P less than .01), so overall productivity among HF and QF ewes was similar.     

The effect on wool production of changes in management designed to increase output of lamb from hill land in the United Kingdom

A system of management designed to increase the economic efficiency of the production of weaned lamb from hill land through the use of pasture improvement and controlled grazing has resulted in considerable increases in the outputs of both lamb and wool. In two examples quoted the weight of weaned lamb produced increased by 51 and 94%; these changes were accompanied by increases in wool output of 31 and 84%, respectively. The additional outputs of both products are attributable to a combination of increased numbers of ewes and higher levels of individual animal performance.The increase in output of wool which may be expected from changes in management directed at increasing lamb production is relatively small, ranging from 4.6 to 6.5 kg per 100 kg increase in weaned lamb in the Scottish Blackface to 11.6 kg per 100 kg increase in weaned lamb in the South Country Cheviot. Evidence is presented to show that the magnitude of the increase in wool production is likely to be determined genetically by the response to improved nutrition of both lamb and wool production.     

Inheritance of active and acquired immunity traits in sheep

Six hundred sixteen ewes of six strains were inoculated twice with ovalbumin in Freunds' incomplete adjuvant. To quantify the humoral immune response to the foreign antigen, blood samples were collected from all ewes 1 wk post-second injection. Blood samples were also collected between 4 and 40 h of age from their 709 lambs, to examine genetic differences in ability of lambs to acquire maternal anti-ovalbumin antibodies. Titers of anti-ovalbumin antibodies were determined using kinetic enzyme-linked immunosorbent assay (ELISA) techniques. Strain did not affect ewe immune response, but sire within strain was highly significant. In pregnant ewes, anti-ovalbumin antibody titers in 12- and 30-mo-old ewes were higher than those in 21-mo-old ewes. Number of lambs in utero did not significantly affect ewe immune response. Heritabilities of anti-ovalbumin titer from a paternal half-sib analysis were .27 +/- .17 for all ewes and .57 +/- .25 for only the pregnant ewes. The effect of strain of lamb on lamb anti-ovalbumin titer approached significance, and sire within strain was highly significant. Lamb anti-ovalbumin antibody concentration increased as time from birth to blood sampling increased to 18 h but declined thereafter. The size of the litter in which a lamb was born had a highly significant effect on the lamb's acquired immunity, with titer decreasing as litter size increased. The heritability estimate for lamb anti-ovalbumin antibody concentration from a paternal half-sib analysis was .38 +/- .11; it was .28 +/- .15 from the sire variance component of a full-sib analysis. When lamb titer was considered a maternal trait (lambs nested within their maternal grandsires within strains), the maternal grandsire variance component was negative. The average anti-ovalbumin antibody concentration of lambs that died between blood sample collection and 120 d of age was less than the average antibody concentration of lambs that survived (P less than .01).