舍饲滩羊产肉力变化规律的研究

为了研究滩羊产肉力及其变化规律,试验选择二毛滩羊、断奶滩羊及9月龄、周岁、成年滩羊公母羊进行了产肉力和屠宰性能的测定。结果表明:随着年龄的增长,滩羊宰前活重、胴体重、净肉重、骨重等几项指标的变化趋势相同,即成年滩羊>周岁滩羊>9月龄滩羊>断奶滩羊>二毛滩羊,年龄因素对舍饲滩羊屠宰率、净肉率、胴体净肉率的影响均差异不显著(P>0.05);净肉率以成年公羊和9月龄母羊较高,且9月龄母羊高于成年公羊;公羊间眼肌面积差异显著(P<0.05)且呈现一定的规律,即9月龄公羊>断奶公羊>二毛公羊>成年公羊>周岁公羊。说明舍饲滩羊在9月龄之前屠宰,既可以提高产肉率,又可以减少胴体脂肪重。     

12月龄丹巴黄羊与藏山羊屠宰性能比较

为了比较12月龄丹巴黄羊与藏山羊的屠宰性能,屠宰了丹巴黄羊公、母羊和藏山羊公、母羊各3只,测定其屠宰性能、胴体体尺及胴体分割等指标。结果表明:1)丹巴黄羊公、母羊的宰前活重、体长和体高等指标显著高于藏山羊公、母羊(P0.05),胸围和管围等指标高于藏山羊公、母羊;2)丹巴黄羊公羊的胴体重、净肉率及骨重等屠宰指标显著高于丹巴黄羊母羊、藏山羊公羊及母羊(P0.05),屠宰率、肉骨比、净肉率和胴体产肉率等指标在公母羊间及类群间差异不显著(P0.05);3)胴体体尺指标除大腿肌肉厚在公母羊间及类群间相对一致外的7项指标均存在一定的差异,丹巴黄羊公羊的胴体分割的5项指标均显著高于丹巴黄羊母羊、藏山羊公羊及母羊(P0.05)。     

岷县黑裘皮羊的52项生理生化指标研究

岷县黑裘皮羊是甘肃省的优良地方品种,现纯种在1 000只左右,数量急剧减少,为保护这一国家二级保护动物,为育种和保种提供科学依据,本试验以岷县黑裘皮羊24月龄母羊和24月龄公羊为研究对象,测定了3项生理指标和23项血液生理指标和26项血液生化指标。结果显示:(1)岷县黑裘皮公羊的体温为39.45℃、母羊为39.28℃,差异显著(P0.05),在呼吸频率和心率上公、母羊差异不显著(P0.05)。(2)PLT和与之相关的MPV、PDW公、母羊无显著差异(P0.05)。(3)公、母羊Ca含量在2.1～2.13 mmol/L范围内,低于正常水平,说明放牧时饲草成分中矿物质不足。(4)性别因子对成年岷县黑裘皮羊的生理生化指标影响较小。     

皮山红羊脂尾性状特征及其与体重、体尺的相关性分析

皮山红羊是新疆和田地区的优良地方遗传资源,现存数量少,急需扩繁和选育,为掌握皮山红羊体重与体尺的相关性,试验以成年的皮山红羊为研究对象,通过SPSS 27.0软件分析公母羊的尾体积差异,根据尾体积大小进行分型;利用Persons法分析各性状间的相关性,利用逐步回归法估计公母羊体尺性状的模型决定系数,并构建多元线性回归方程。结果表明,公羊尾体积显著大于母羊(P<0.05),且公母羊尾型均可以分为小尾型、中尾型、大尾型;皮山红羊公羊的平均体尺指数与平均体重均高于母羊。公羊体重(y)与尾长(x₅)的相关系数最大,为0.792,母羊体重(y)与胸围(x₃)的相关系数最大,为0.895。公、母羊体重与体尺指标的最佳回归方程分别为：yy_公=2.343x₅+0.364x₃-4.265(R²=0.710,P<0.01)、y_母=0.785x₃+0.395x₁₀-0.319x₁₁     

无角美利奴羊与其亲本羊血液生化指标的比较

所测定的２２项血液生化指标中，亲本公羊与无角美利奴公、母羊之间分别有１２项和１１项的测定值差异极显著或显著，其中４项与羊的生产性能相关显著，占与生产性能显著相关的８项血液生化指标的１／２。亲本母羊与无角美奴利公、母羊之间分别有１１项和１０项差异极显著或显著，其中１项与羊的生产性能相关显著，占与生产性能显著相关的３项血液生化指标的１／３。可见亲本母羊对无角美利奴羊生产性能的影响大于亲本公羊。     

成年公藏羊去势后死亡原因分析与防治方法

<正>成年公羊的去势常用于淘汰的试情公羊和羊群中疏于去势的公羊。据各地兽医人员反映和我们自己实践,成年公羊去势后死亡率达15%~80%,损失很大。公藏羊也不例外,我们试验中去势公藏羊20只,死亡3只,死亡率达15%。现将我们所做的一批成年公藏羊手术结果和近年来采取的防止受术公藏羊死亡的措施,介绍于下。1试验动物公藏羊,20只,其中试情公藏羊14只(3~5     

成年贾洛羊的生理生化指标测定

本试验以四川省的一个地方藏绵羊类群——贾洛羊为研究对象,选择36月龄公、母羊各5只,测定其生理指标、血液生理指标及血液生化指标。结果显示:36月龄贾洛羊的体温、呼吸频率及心率等生理指标在公、母羊间无显著差异;WBC、RBC、HGB、HCT、MCV、MCH、MCHC、PLT、RDW-SD、MPV、PCT、PDW和RDW-CV等血液生理指标在公、母羊间差异不显著(P0.05);公羊的ALP和GLU等血液生化指标显著高于母羊(P0.05),母羊的CHOL显著高于公羊(P0.05),ALT、AST、TP、ALB、GLO、LDH、A/G和CHE等生化指标在公、母羊间差异均不显著(P0.05)。     

简阳黑山羊资源调查及种质特性测定

为进一步挖掘简阳黑山羊遗传资源潜力,笔者开展了简阳黑山羊资源调查和种质特性测定工作.调查结果显示:简阳市现存栏简阳黑山羊15394只,其中公羊2434只、母羊9018只;6月龄体重公羊为30.67 kg,母羊为24.70 kg;周岁体重公羊为48.67 kg,母羊为35.57 kg;成年体重公羊为70.87kg,母羊为...     

24月龄的贾洛羊生理生化指标测定

试验以四川省的1个西藏羊地方类群!贾洛羊为研究对象,选择其24月龄的公、母羊各5只,测定其生理指标、血液生理指标及血液生化指标。结果表明:24月龄贾洛羊的体温、呼吸频率及心率等生理指标在公、母羊间无显著差异;母羊的MPV血液生理指标显著高于公羊(0.01P0.05),公羊的PDW指标显著高于母羊(0.01P0.05),WBC、RBC、HGB、HCT、MCV、MCH、MCHC、PLT、RDW-SD、PCT和RDW-CV等指标在公、母羊间差异不显著(P0.05);ALT、AST、TP、ALB、GLO、ALP、LDH、A/G、GLU、CHE和CHOL等血液生化指标在公、母羊间差异不显著(P0.05)。试验建立了24月龄段贾洛羊的生理指标和血液生理生化指标的参考值,为以后加强贾洛羊的饲养管理、疾病诊断、适应性及选育等提供参考依据。     

辽宁绒山羊优秀种公羊的标准与利用

真正的好公羊,应当具有高的个体育种值、好的遗传基础和理想的表现型,既能适应群体提高的要求,又是建立高产群体的育种动力。具体来说,好公羊的标准除个体表现的规定要求之外,还应有两个要求,一是为群体着想的要求,一是为下一代着想的要求。1公羊个体标准理想的表现型,不是指绒多、绒细、个头大几项指标的孤立表现,而是要求各个性状的结合既有群     

Social Dominance and Courtship and Mating Behaviour in Rams in Non-Competitive and Competitive Pen Tests

A group of 19 Merino rams was used to determine: (i) if body weight, age and testis characteristics are different between high (HR) and low-ranked (LR) rams, and (ii) how the competition between HR and LR rams for oestrous ewes affect their courtship and mating behaviour. Hierarchy was determined using the food competition test. The five first and five last ranked rams were individually exposed to oestrous ewes in pen tests, and the frequency of different courtship behavioural units, mounts and mates, and the time from test onset to each mate was recorded. The sexual behaviour of the five first ranked and the five last ranked rams was also tested in competition, pairing a HR and a LR ram. Age, body weight, body condition score, scrotal circumference, and testis firmness and resilience from HR and LR were not different. The display of courtship behavioural units was lower when rams were tested in competition but was not affected by the rank of the rams. The number of mates per test from HR rams was lower than that observed in LR rams when tested alone. While the number of mates decreased in LR rams in competition tests, it was not affected in HR rams. In summary, there was no relation between social rank and body weight, age or testis characteristics. LR rams were more effective than HR rams when mating oestrous ewes without competition. However, in competitive tests, although all rams modified their courtship strategies, LR rams were more affected by the presence of dominant rams than HR rams were by the presence of LR rams.     

苏尼特羊体重与体尺的相关性分析

[目的]分析内蒙古自治区锡林郭勒盟地方特色肉羊品种苏尼特羊体重与体尺指标的关联程度。[方法]随机选取5~6月龄发育及健康状况良好的苏尼特羊公羊247只、母羊260只,对羊只的体重（Y）、尾长（X₁）、尾宽（X₂）、体高（X₃）、体长（X₄）、胸围（X₅）进行生产性能测定,数据整理后使用SPSS 26.0统计学软件对体重与体尺指标进行相关性分析和多元线性回归分析,最终建立最优回归模型。[结果]影响苏尼特羊公羊和母羊体重的主要体尺指标为尾宽、体高、体长和胸围,且与体重均呈极显著（P<0.01）相关;逐步回归分析建立了多元线性回归模型,公羊的最优线性方程为：Y=0.57X₅+0.325X₄+0.241X₂-35.795,R²=0.834;母羊的最优线性方程为：Y=0.577X₅+0.246X₄+0.205X₂-31.94,R²=0.799。[结论]回归方程中胸围、体长、尾宽与体重相关性均较高,皆可作为苏尼特羊的体重预测模型。     

Relationship between sexual behavior classifications of rams and lambs sired in a competitive breeding environment

The objectives for this study were to 1) determine the relationship between sexual performance class and lambs sired in a competitive mating environment, and 2) determine whether the male-oriented ram test is valid. Fifteen 2- to 3-yr-old whitefaced rams classified as female-oriented, with high or low sexual performance, or classified as male-oriented were used in a multiple-sire breeding arrangement. Five groups of approximately 200 ewes each were exposed for 21 d to 3 rams per group consisting of 1 ram from each class. Rams were blocked for sexual class, and those with close genetic relationship were assigned to different pens. Genomic DNA was prepared from blood collected from 15 rams, 934 ewes, and 1,757 lambs. Up to 4 microsatellite markers were used to determine a lamb's sire. Of 884 ewes with identifiable lambs (known sires), 178 ewes had single lambs, 408 had multiples sired by 1 ram, and 298 had multiples sired by more than 1 ram. The sexual partner preference test used to identify male-oriented rams did not absolutely reflect their sexual performance during competitive breeding. In contrast to only mounting and servicing males in preference tests before breeding, male-oriented rams sired 480 lambs from 330 ewes. Serving capacity tests predicted sexual performance of high and low sexual performance rams. High performance rams impregnated more ewes (499 vs. 258; P < 0.05) and sired more lambs (756 vs. 357; P < 0.05) than did low performance rams, respectively. Low performance and male-oriented rams did not differ for ewes impregnated or lambs sired. We conclude that 1) sexual partner preference tests used to classify male-oriented rams were not absolute in reflecting their breeding performance in a competitive breeding environment; 2) serving capacity tests predicted that high performance rams would breed more ewes than low performance rams and sire more lambs than either low performance or male-oriented rams; and 3) under the conditions of this study, low performance and male-oriented rams did not have an adverse impact on the overall breeding outcome. Combined, low performance and male-oriented rams sired 81 more lambs than did high performance rams, but this required twice as many rams to obtain approximately equal breeding results. Therefore, we suggest that serving capacity tests should be used to select high performance rams, reduce number of rams with marginal sexual performance, and make decisions on ram numbers needed.     

Immunization with Brucella melitensis Rev 1 against Brucella ovis infection of rams

The efficacy of Brucella Melitensis Rev 1 vaccine (Rev 1) for the prophylaxis of Brucella ovis ram epididymitis was evaluated. Twenty-nine 3-month-old rams were vaccinated with 2 X 10(9) Rev 1 and 14 were revaccinated with 5 X 10(8) at 14 months of age. Six rams remained unvaccinated as a control group. All rams were challenged with 5 X 10(8) B. ovis at 21 months of age. Before being slaughtered 8 weeks later, only one vaccinated ram developed epididymitis while four of the six control rams developed testicular alterations. Genital and selected extragenital organs and lymph nodes were removed at slaughter and inoculated on selective media. B. ovis was isolated from 26.6% of the vaccinated rams, 21.4% of the revaccinated rams and 100% of control rams. Portions of epididymis, testes and vesicular glands were also used for pathological studies. More severe lesions were observed in control rams than in vaccinated ones. In conclusion, these results show that vaccination of young lambs, followed or not by revaccination, is a suitable method for the prophylaxis of B. ovis infection of rams.     

Isolation of Actinobacillus seminis from rams in the United Kingdom.

Actinobacillus seminis was isolated from the semen of five rams on four farms. Four of the rams had abnormal semen and three were also infertile. The isolates of A seminis showed similar phenotypic profiles and electrophoretic protein patterns to the type strain of A seminis but were distinct from Histophilus ovis previously isolated from rams with epididymitis in Scotland. The infection appeared to be subclinical but two of the five rams had palpable abnormalities of their testes. Three rams were treated with antibiotics but the infection persisted. No gross lesions were found in the genitalia of two of three rams examined post mortem but one had necrotic abscesses in the testes and epididymis. A seminis was isolated from the seminal vesicles and epididymis of one ram without gross lesions but not from the genitalia of the other two. On one farm the infection in a recently purchased ram led to the detection of another case as a result of the bacteriological screening of 11 stock rams not in contact with the initial case. These five subclinical cases, which included a supposedly healthy stock ram, suggest that A seminis infection may be widespread and should be considered in cases of infertility.     

Immunolocalization of 3beta-hydroxysteroid dehydrogenase in normal and hyperplastic ram prostates

The enzyme 3beta-hydroxysteroid dehydrogenase (3beta-HSD) is essential in the synthesis of all steroids by cleaving dehydroepiandrosterone to androstenedione. In the present study, 3beta-HSD immunoreactivity was investigated in the prostate of Akkaraman breed rams aged older than 3 years. Five normal and five hyperplastic ram prostates were processed for immunohistochemistry. Prostate hyperplasia was determined by histopathological evaluation of 375 ram prostate and confirmed with significantly (P<0.01) increased number of cells expressing proliferating cell nuclear antigen (PCNA) immunoreactivity in the glandular epithelia. The 3beta-HSD immunoreactivity with a variable intensity and pattern of distribution was present in the glandular epithelia and endothelia of blood vessels in normal and hyperplastic ram prostates. While immunoreactivity was focally present in some glands, some sections had a homogenous distribution. The presence of 3beta-HSD immunoreactivity indicates that steroids are locally synthesized in the ram prostate. No differences in the distribution pattern of 3beta-HSD immunoreactivity and the percentage of immunoreactive cells were observed between normal and hyperplastic prostates (P>0.05), suggesting that locally produced steroids have little or no effect on the pathogenesis of the ram prostate hyperplasia which affects a very small proportion of the ram population (5 out of 375).     

Heritability and repeatability of sexual performance scores of rams

Sexual performance has been subjectively measured with a libido test during screening of rams before public sale and breeding at the U.S. Sheep Experiment Station from 1990 to 2000. The objective of this study was to determine whether sexual performance was genetically influenced. Sexual performance scores ranged from 1 to 6 with scores increasing from sexually inactive to highly sexually active in the presence of estrous ewes. The overall average score was 3.5+/-0.02. Records from four breeds (Columbia, n = 807; Polypay, n = 1,668; Rambouillet, n = 1,208; and Targhee, n = 1,002) were combined into one analysis because breeds had similar phenotypic variances. Total number of records was 4,685, which included a second sexual performance test on 1,212 rams in the following year. Variance components were estimated using a REML algorithm. Fixed effects were breed of ram, selection line within breed, and year by breed. A permanent environmental effect for ram was included to account for repeated observations on individual animals. Age and weight of the rams at time of the libido test were linear covariates and were breed-specific. Adjusted means for sexual performance scores did not differ among breeds (P > 0.05). Age was a significant effect (P < 0.01), with sexual performance score increasing 0.05 units for each month of age. The additive genetic variance was estimated as 0.54. The estimate of variance due to ram permanent environmental effects was 1.19. The residual variance was estimated to be 0.67. The heritability estimate was moderate (0.22+/-0.04) and repeatability was high (0.72). These results imply that one screening for sexual performance provides a reliable measure of sexual performance and that favorable response to selection for ram serving capacity may be expected.     

Sexual performance of rams as determined by maturation and sexual experience

The purpose of this study was to compare the sexual performance of rams that differed in age (maturation) and sexual experience. Twenty-four ram lambs (8 mo of age) and 21 rams (20 mo of age) were individually exposed to four females in hormonally induced estrus for 30 min on five occasions, 7 d apart. Half (12) the ram lambs and nine of the yearlings were sexually naive at the start of testing (had been denied access to females since weaning); the remaining males were sexually experienced. The sexual performance of the virgin rams was poorer during the initial exposure to females than in subsequent tests, whereas the sexual behavior of the sexually experienced males did not change over the days of testing. Sexually naive ram lambs and rams exhibited an improvement in sexual performance between Tests 1 and 2; during Test 3 to 5 the sexual performance (ejaculations per test) of sexually naive and experienced rams was similar. The only effects of age (maturation) on sexual performance during the last three test days were a higher frequency of mounts without ejaculation plus mount attempts (P less than .03) and a greater number of mount interactions per ejaculation (P less than .02) by ram lambs. In conclusion, one or two relatively brief exposures to estrous females can bring the sexual performance of virgin rams up to levels comparable to that of experienced males. Also, ram lambs in good condition exhibit acceptable levels of sexual performance.     

Sexual performance of rams in serving capacity tests predicts success in pen breeding.

The purpose of this study was to determine the extent to which sexual performance (serving capacity) tests can be used to predict the sexual behavior and reproductive success of rams in the context of pen mating. Standard serving capacity tests were used to select four low (LP) and four high-performing (HP) rams from a population of 94 yearling males. Each selected ram was then exposed to approximately 30 estrus-synchronized ewes for a 9-d period. Ejaculations observed and mounting marks left on ewes confirmed the greater (P less than .001) sexual activity of the HP rams in the field. In addition, ewes exposed to HP rams had a higher lambing percentage, more lambs born, and more live lambs born per ewe. Ram classification was not related (P greater than .60) to the number of lambs born per ewe lambing (prolificacy). It was concluded that serving capacity tests, properly conducted, can be used to predict ram mating performance and thus aid in establishing more efficient ram-to-ewe stocking rates.     

Evolution of nematode community in grazing sheep selected for resistance and susceptibility to Teladorsagia circumcincta and Trichostrongylus colubriformis: a 4-year experiment

Field trials were undertaken to compare nematode population dynamics in two experimental flocks of rams selected for high and for low faecal egg counts (FECs) following two doses with 20000 infective larvae, 12000 Teladorsagia circumcincta (Tcirc) and 8000 Trichostrongylus colubriformis (Tcol) separated by a treatment. The selection was done by dosing 200 ram lambs (INRA 401 breed) and FECs proceeded with egg identification on days 28 and 35 post-each-infection. The 30 lambs with the lowest FECs constituted the group of permanent resistant rams (R), the 30 with the highest values the group of susceptible ones (S). Each group grazed separated pastures from April to November, this during 4 consecutive years. The contamination (number of eggs deposited) was estimated every 3 weeks on each pasture. The larval populations was measured by successive groups of tracer lambs. The infection of the permanent rams was done by slaughtering eight R and S rams on mid and end of each grazing season. Each autumn, new R and S ram lambs were selected to complete the R and S groups before turning out in spring. On third year, a third species (Haemonchus contortus, Hcon) was added to compare its behaviour with the two others.The regulation of parasite populations were studied by comparing what happens in R rams and pasture to S ones. The selected R ram lambs had a FEC of Tcirc 50% lower than S ones. This induced a similar lowered pasture contamination, a 25% decrease of infective larval population in years 2 and 3, and the worm burdens in R rams were the half of that in S rams after 2 years. The FEC of Tcol was 75% lower at the selection and induced similar difference in pasture contamination, but 65 and 96% reduction in L3 population, respectively, after 1 and 2 years. The worm burden was reduced by 99%. Adding Hcon species during the third year, in year 4, the L3 population was half in R pasture compared with S one, and R rams had 60% less worms of this species than S ones.This selection without any drench prevent outbreaks observed in young tracer lambs on S pasture. The comparison of selected resistant rams to selected susceptible ones and not to unselected controls gave more rapid information about the tendency of the regulation of the communities of nematode parasites.