DNA polymorphism of insulin-like growth factor-binding protein-3 gene and its association with birth weight and body weight in cattle

Insulin‐like growth factor‐binding protein‐3 (IGFBP‐3) is a protein that binds the majority of insulin‐like growth factors in circulation for regulation of its action on growth and metabolism of the animals. Animals belonging to Hariana, Holstein‐Friesian (HF) and their crossbreds (HF × Hariana) were studied using polymerase chain reaction‐restriction fragment length polymorphism and nucleotide sequencing of the IGFBP‐3 gene. A 651‐bp fragment of the IGFBP‐3 gene spanning over a part of exon 2, complete intron 2, exon 3 and a part of intron 3 was amplified and digested with HaeIII restriction enzyme. Three patterns of restriction fragments were observed in HF and crossbred cattle revealing polymorphism in both the populations. The frequency of AA, AB and BB genotypes was 0.65, 0.32 and 0.03 in crossbreds and 0.29, 0.65 and 0.06 in HF respectively. The allelic frequency of the A and B allele was 0.81 and 0.19 in crossbreds and 0.62 and 0.38 in HF cattle respectively. Only one restriction pattern (AA genotype) was observed in all the animals of Hariana breed of Bos indicus showing the absence of polymorphism. Nucleotide sequencing revealed a C → A mutation in the intron 2 region of the IGFBP‐3 gene as the cause of the polymorphism. Least squares analysis revealed a significant effect (p < 0.05) of genotypes on birth weight and body weight (weight at 12, 18 and 24 months of age) of the animals. Animals of AB genotype showed higher birth weight and body weight than the animals possessing AA genotype.     

四川西门塔尔牛血红蛋白及血清运铁蛋白多态性研究

235头血样,采用醋酸纤维薄膜电泳及聚丙烯酰胺凝胶双垂直板电泳检测血红蛋白(Hb)及血清运铁蛋白(Tf)的多态性。研究获得Hb及Tf的基因频率和基因型频率;Hb~A和Tf~D为优势基因,HbAA型和TfAD型为优势基因型。     

Genetic evaluation of retail product percentage in Simmental cattle.

The objective of this study was to estimate genetic parameters required for genetic evaluation of retail product percentage (RPP) in Simmental cattle. Carcass weight (HCW), subcutaneous fat thickness (FAT), longissimus muscle area (REA) and kidney, pelvic, and heart fat (KPH) records were available to compute RPP on steers (n = 5171) and heifers (n = 1400) from the American Simmental Association database; animals were sired by 561 Simmental bulls and out of 5886 crossbred dams. Genetic parameters were estimated using residual maximal likelihood and a four trait animal model for the components of RPP including fixed harvest contemporary group effects, random animal genetic effects, and a linear covariate for age at harvest. Heritability estimates were 0.51 +/- 0.05, 0.36 +/- 0.05, 0.46 +/- 0.05, and 0.18 +/- 0.05 for HCW, FAT, REA and KPH respectively. Non-zero genetic correlations were estimated between HCW and REA (rg = 0.51 +/- 0.06) and between REA and FAT (rg = -0.43 +/- 0.08), but other genetic correlation estimates among the component traits were low. As a linear function of its components, heritability and genetic correlations involving RPP were estimated using index methods. The heritability estimate for RPP was 0.41, and genetic correlations were -0.17, -0.83, 0.67, and 0.01 with HCW, FAT, REA and KPH respectively. Therefore, RPP was strongly associated with muscle and fat deposition, but essentially independent of carcass weight and internal body cavity fat. Genetic evaluation of RPP would be straightforward using multiple trait index methods and genetic regression, although the inclusion of KPH would be of marginal value.     

Analysis of genotype by environment interaction for milk yield traits in first lactation of Simmental cattle

The breeding goal for Simmental cattle is derived for intensively managed dairy farms. Its suitability for extensive farms was addressed by analysing possible genotype by environment interaction (G × E) between the management levels for first lactation milk yield traits. A first analysis was performed with the data collected from 300 000 purebred daughters of 278 second crop bulls born in Bavaria in 1993 and 1994. The farms were classified by herd‐year‐effect, using the sum of fat and protein yields into two levels of management, either with 33 or 10% quantiles, corresponding to approximately 100 000 cows and 30 000 cows, respectively. The comparison was based on ‘daughter yield’ deviations (DYD). Correlations between DYD of extensive and intensive environments were 0.90, 0.91 and 0.87 for milk, fat and protein yield (kg) for 33% quantiles, respectively. Corresponding correlations for 10% quantiles were 0.85, 0.83 and 0.77. Despite high correlations, 50 out of 149 sires showed significant differences between DYD in different environments. Bulls with higher DYD for milk yield on intensive farms were superior in all environments. For the second analysis extensive and intensive farms in northern and southern Bavaria were chosen at random. Approximately 20 000 cows in each management class were used for the estimation of genetic parameters. In both regions phenotypic and additive‐genetic variances were higher in the intensively managed herds. Likewise heritabilities were higher for fat and protein yield, but not for milk where higher heritabilities were observed in 33% quantiles. Genetic correlations between extensive and intensive environments were 0.97 and above (33% quantiles). Ten per cent quantiles led to lower genetic correlations (0.90–0.95). Although no serious re‐ranking effects of sires were evident, the scale effect and the differences in genetic parameters should be taken into consideration in practical breeding.     

河北省西门塔尔牛体重体尺性状遗传参数分析

［目的］本研究旨在探究河北省西门塔尔牛体重和体尺性状的遗传参数,为育种提供参考。［方法］本研究以2015～2021年河北天和肉牛养殖有限公司266头西门塔尔牛的体重体尺性状为研究材料,包括体重性状及体高、十字部高、体斜长、胸围、腹围和管围等6个体尺性状,使用DMU软件采用AI-REML结合EM算法并配合动物模型对体重、体尺性状进行了遗传参数估计。［结果］结果表明：体重、体高、十字部高、体斜长、胸围、腹围和管围的遗传力分别为0.41、0.41、0.45、0.45、0.48、0.31和0.66。体重与体尺之间的遗传相关范围为0.20（体高）~0.79（胸围）,表型相关范围为0.14（十字部高）~0.23（胸围）;体尺性状间的遗传相关范围为-0.70（腹围和管围）~0.92（体高和十字部高）,表型相关范围为-0.10（腹围和管围）~0.94（体高和十字部高）。［结论］体重与体尺性状均属于高遗传力性状,体重及体尺性状间除管围外其他体尺性状间均呈较强的遗传正相关,在选育过程中加强对这些性状的选育,有利于提高西门塔尔牛的生长发育性能。     

Tag-SNP selection using Bayesian genomewide association study for growth traits in Hereford and Braford cattle

The aim of this study was to perform a Bayesian genomewide association study (GWAS) to identify genomic regions associated with growth traits in Hereford and Braford cattle, and to select Tag-SNPs to represent these regions in low-density panels useful for genomic predictions. In addition, we propose candidate genes through functional enrichment analysis associated with growth traits using Medical Subject Headings (MeSH). Phenotypic data from 126,290 animals and genotypes for 131 sires and 3,545 animals were used. The Tag-SNPs were selected with BayesB (π = 0.995) method to compose low-density panels. The number of Tag-single nucleotide polymorphism (SNP) ranged between 79 and 103 SNP for the growth traits at weaning and between 78 and 100 SNP for the yearling growth traits. The average proportion of variance explained by Tag-SNP with BayesA was 0.29, 0.23, 0.32 and 0.19 for birthweight (BW), weaning weight (WW205), yearling weight (YW550) and postweaning gain (PWG345), respectively. For Tag-SNP with BayesA method accuracy values ranged from 0.13 to 0.30 for k-means and from 0.30 to 0.65 for random clustering of animals to compose reference and validation groups. Although genomic prediction accuracies were higher with the full marker panel, predictions with low-density panels retained on average 76% of the accuracy obtained with BayesB with full markers for growth traits. The MeSH analysis was able to translate genomic information providing biological meanings of more specific gene products related to the growth traits. The proposed Tag-SNP panels may be useful for future fine mapping studies and for lower-cost commercial genomic prediction applications.     

青贮甜高粱和全株饲用玉米配比料饲喂西门塔尔肉牛的效果比较

[目的]饲草在肉牛养殖中发挥着重要作用,通过牛体增重对比不同饲草及其配比喂养西门塔尔肉牛效果,以确定较优的青贮甜高粱和全株饲用玉米的配比.[方法]在冬季温室养殖条件下,设计5组配比的青贮甜高粱和全株饲用玉米饲喂西门塔尔肉牛,定期称量牛体增重,并分析各试验组养殖效益.[结果]试验结果显示,青贮甜高粱和全株玉米喂养西门塔尔...     

饲养密度对西门塔尔公牛增重和动物福利的影响

[目的]为了研究饲养密度对西门塔尔公牛增重及抗氧化能力的影响。[方法]试验选择黑龙江省某种牛场健康的11～13月龄西门塔尔公牛24头,并按照体重分层随机分组,每组8头,组间始重无显著差异,Ⅰ组、Ⅱ组、Ⅲ组饲养密度分别为8 m²/头、10 m²/头、12 m²/头,试验预饲期10 d,试验期40 d,共50 d。[结果]在试验结束时,Ⅰ组、Ⅱ组、Ⅲ组试验牛体重无显著差异(P>0.05)。Ⅰ组、Ⅱ组、Ⅲ组试验牛均表现随投料后时间延长,趴卧率逐渐增高,Ⅲ组试验牛晨饲后和晚饲后2 h的趴卧率显著高于Ⅰ组、Ⅱ组(P<0.05)。在试验开始时,Ⅰ组血液CREA水平显著高于Ⅲ组(P<0.05),其他指标差异不显著(P>0.05)。试验结束,Ⅰ组血液CREA和HSP-70水平显著高于Ⅱ组和Ⅲ组(P<0.05),其他指标差异不显著(P>0.05)。[结论]在相同增重水平下,西门塔尔公牛由420 kg育肥至490 kg,饲养密度为8 m²/头时,牛舍空间利用效率更高,但长期饲养有威胁...     

An efficient empirical Bayes method for genomewide association studies

Linear mixed model (LMM) is one of the most popular methods for genomewide association studies (GWAS). Numerous forms of LMM have been developed; however, there are two major issues in GWAS that have not been fully addressed before. The two issues are (i) the genomic background noise and (ii) low statistical power after Bonferroni correction. We proposed an empirical Bayes (EB) method by assigning each marker effect a normal prior distribution, resulting in shrinkage estimates of marker effects. We found that such a shrinkage approach can selectively shrink marker effects and reduce the noise level to zero for majority of non‐associated markers. In the meantime, the EB method allows us to use an ‘effective number of tests’ to perform Bonferroni correction for multiple tests. Simulation studies for both human and pig data showed that EB method can significantly increase statistical power compared with the widely used exact GWAS methods, such as GEMMA and FaST‐LMM‐Select. Real data analyses in human breast cancer identified improved detection signals for markers previously known to be associated with breast cancer. We therefore believe that EB method is a valuable tool for identifying the genetic basis of complex traits.     

利用西杂牛和秦川牛做受体进行奶牛胚胎移植的对比试验

[目的]为了选择奶牛胚胎移植的理想受体。[方法]通过利用不同品种的本地黄牛～西杂牛84头和秦川牛77头做受体,进行荷斯坦奶牛胚胎移植效果的对比试验。[结果]西杂牛的同期发情率、受体可用率、受胎率都显著高于秦川牛（P〈0．05）,而且难产率低,奶水充足。[结论]表明西杂牛是奶牛胚胎移植的理想受体。     

中国西门塔尔牛CAPN1基因SNPs及其与经济性状关联分析

本研究旨在分析CAPN1基因部分SNPs与中国西门塔尔牛经济性状的关联性.试验选取同龄、同场的135头中国西门塔尔牛为材料,利用PCR-RFLP方法检测CAPN1 316和CAPN1 4751 2个SNPs位点的多态性,并进行方差分析.结果发现,CAPN1 316 SNP位点与大理石花纹显著相关(P＜0.05),杂合子AB基因型个体的大理石纹评分显著高于AA和BB基因型个体(P＜0.05);CAPN1 4751位点与大理石花纹和剪切力显著相关(P＜0.05),大理石花纹性状中杂合子AB基因型个体评分显著高于AA基因型个体,剪切力性状中BB基因型个体显著高于AA基因型个体.结果表明,CAPN1 316和CAPN1 4751位点适合用于中国西门塔尔牛眼肌、肌肉大理石花纹的分子标记选择.     

长途运输应激对西门塔尔牛体重、血液生化指标和细胞因子含量的影响

为研究长途运输应激对西门塔尔牛体重、血液生化指标和细胞因子含量的影响,随机选取12头、平均体重（292.1±38.2）kg的西门塔尔牛,在最高气温30℃下,经过36 h、1 450 km的敞篷卡车运输,运输前后称重并采集颈静脉血样,测定其体重及血液生化指标的变化情况。结果表明：①与运输前体重相比,经36 h、1 450 km运输后,试验牛平均体重极显著降低（P<0.01）,由292.1 kg降低到262.8 kg,体重损失10.03%。②与运输前相比,运输36 h时西门塔尔牛血清皮质醇（COR）含量显著提高（P<0.05）、血糖（GLU）水平极显著增高（P<0.01）,运输后7~14 d下降到运输前水平（P>0.05）;运输应激对血清胆固醇水平无显著影响（P>0.05）。③运输应激极显著提高了西门塔尔牛血清C-反应蛋白（CRP）含量（P<0.01）,显著提高血清白细胞介素-6（IL-6）、γ-干扰素（IFN-γ）和肿瘤坏死因子-α（TNF-α）的含量（P<0.05）,运输后7~14 d下降到运输前或更低水平（P>0.05）;运输应激对血清白细胞介素-1β（IL-1β）含量无显著影响（P>0.05）。综上所述,长途运输可显著降低肉牛的体重和抑制机体免疫机能,经长途运输后的西门塔尔牛需要约14 d的恢复期。     

Breed and heterotic effects for mature weight in beef cattle

Cow mature weight (MWT) is heritable and affects the costs and efficiency of a breeding operation. Cow weight is also influenced by the environment, and the relationship between the size and profitability of a cow varies depending on production system. Producers, therefore, need tools to incorporate MWT in their selection of cattle breeds and herd replacements. The objective of this study was to estimate breed and heterotic effects for MWT using weight-age data on crossbred cows. Cow’s MWT at 6 yr was predicted from the estimated parameter values—asymptotic weight and maturation constant (k)—from the fit of the Brody function to their individual data. Values were obtained for 5,156 crossbred cows from the U.S. Meat Animal Research Center (USMARC) Germplasm Evaluation Program using 108,957 weight records collected from approximately weaning up to 6 yr of age. The cows were produced from crosses among 18 beef breeds. A bivariate animal model was fitted to the MWT and k obtained for each cow. The fixed effects were birth year-season contemporary group and covariates of direct and maternal breed fractions, direct and maternal heterosis, and age at final weighing. The random effects were direct additive and residual. A maternal additive random effect was also fitted for k. In a separate analysis from that used to estimate breed effects and (co)variances, cow MWT was regressed on sire yearling weight (YWT) Expected Progeny Differences by its addition as a covariate to the animal model fitted for MWT. That regression coefficient was then used to adjust breed solutions for sire selection in the USMARC herd. Direct heterosis was 15.3 ± 2.6 kg for MWT and 0.000118 ± 0.000029 d⁻¹ for k. Maternal heterosis was −5.7 ± 3.0 kg for MWT and 0.000130 ± 0.000035 d⁻¹ for k. Direct additive heritabilities were 0.56 ± 0.03 for MWT and 0.23 ± 0.03 for k. The maternal additive heritability for k was 0.11 ± 0.02. The direct additive correlation between MWT and k was negligible (0.08 ± 0.09). Adjusted for sire sampling, Angus was heaviest at maturity of the breeds compared. Deviations from Angus ranged from −8.9 kg (Charolais) to −136.7 kg (Braunvieh). Ordered by decreasing MWT, the breeds ranked Angus, Charolais, Hereford, Brahman, Salers, Santa Gertrudis, Simmental, Maine Anjou, Limousin, Red Angus, Brangus, Chiangus, Shorthorn, Gelbvieh, Beefmaster, and Braunvieh. These breed effects for MWT can inform breeding programs where cow size is considered a key component of the overall profitability.     

中国肉用西门塔尔牛育种目标性状的选择及其经济权重的测算

为了选育中国西门塔尔牛肉用品系,本研究从中国肉用西门塔尔牛育种实践出发,确定了适应当前中国肉用西门塔尔牛的育种目标性状和选择性状。采用差额法计算出各目标性状的边际效益,并通过各目标性状表型值的遗传标准差校正边际效益,得到相应育种目标性状的经济权重。结果表明,中国肉用西门塔尔牛近期的育种目标性状主要包括生长发育性状（断奶重、育肥期日增重、18月龄体重）、胴体性状（胴体品质、屠宰率、净肉率）及繁殖性状（初产年龄、产犊间隔和留群时间）。在现有市场和生产条件下,上述育种目标性状的边际效益分别为17.93元/kg、16.2元/kg、7.17元/kg、297.99元/级、497.82元/%、594.46元/%、-3.62元/d、-26.55元/d、232.75元/y,3类性状中生长发育性状、胴体性状及繁殖性状的经济权重之比为31.49%：15.86%：52.65%,约为2：1：3,繁殖性状占总经济权重最高,其次是生长发育性状和胴体性状。综上所述,在中国肉用西门塔尔牛育种过程中,繁殖性状具有最重要的地位,需加强繁殖性状的选择力度。     

Allelic frequencies and association with carcass traits of six genes in local subpopulations of Japanese Black cattle

Marker‐assisted selection (MAS) is expected to accelerate the genetic improvement of Japanese Black cattle. However, verification of the effects of the genes for MAS in different subpopulations is required prior to the application of MAS. In this study, we investigated the allelic frequencies and genotypic effects for carcass traits of six genes, which can be used in MAS, in eight local subpopulations. These genes are SCD, FASN and SREBP1, which are associated with the fatty acid composition of meat, and NCAPG, MC1R and F11, which are associated with carcass weight, coat color and blood coagulation abnormality, respectively. The frequencies of desirable alleles of SCD and FASN were relatively high and that of NCAPG was relatively low, and NCAPG was significantly associated with several carcass traits, including carcass weight. The proportions of genotypic variance explained by NCAPG to phenotypic variance were 4.83 for carcass weight. We thus confirmed that NCAPG is a useful marker for selection of carcass traits in these subpopulations. In addition, we found that the desirable alleles of six genes showed no negative effects on carcass traits. Therefore, selection using these genes to improve target traits should not have negative impacts on carcass traits.     

慢性冷热应激对放牧西门塔尔牛抗氧化功能及HPA轴、SAM轴激素分泌的影响

为研究慢性冷热应激对放牧条件下西门塔尔牛生理指标、抗氧化功能及下丘脑-垂体-肾上腺皮质轴(HPA)、交感-肾上腺-髓质轴(SAM)激素分泌的影响,选取内蒙古锡林郭勒盟苏尼特左旗某家庭牧场体质量相近、体况健康的西门塔尔牛20头,试验期间测定试验牛生理指标,于试验期最后一天清晨进行颈静脉采血并制备血清,采用ELISA方法检...     

Selection of Objective Traits and Estimation of Economic Weights for Chinese Simmental Beef Cattle

In order to breed a beef line in Chinese Simmental cattle,this research defined breeding objective traits and selected traits according to real breeding condition of Chinese Simmental beef cattle.Using the balance method to calculate the marginal benefit of each objective trait and getting the corresponding economic weight of breeding objective traits through the standard value of the error corrected marginal benefit of breeding objective traits.The results showed that breeding objective traits mainly included growth traits (including weaning weight,fattening daily gain,18th month weight),carcass traits (including carcass quality,dressing percentage,pure meat percentage) as well as reproductive traits (including age at first calving,calving interval,stay group time).In the current market and production conditions,the marginal benefit of the breeding objective traits were 17.93 yuan/kg,16.2 yuan/kg,7.17 yuan/kg,297.99 yuan/grade,497.82 yuan/%,594.46 yuan/%,-3.62 yuan/d,-26.55 yuan/d and 232.75 yuan/y,respectively,and the ratio of relative economic weights of three kinds of traits was 31.49%:15.86%:52.65%,similar to 2:1:3,and reproductive traits occupied larger economic weight,was better than growth traits and carcass traits.The results indicated that reproductive traits played an important role in the process of breeding in Chinese Simmental beef cattle,and we needed to strengthen the selection of reproductive traits.     

Genome-wide association study identifies genomic loci associated with flight reaction in cattle

Lower flight reaction is closely related to higher production in cattle, but the genetic basis of lower flight reaction is not clearly understood. Here, we sampled a total of 45 Brahman cattles and 166 Yunling cattles with flight distance (FD), and 73 Brahman cattles and 288 Yunling cattles with crush score (CS) and flight speed (FS), whereas there were 45 Brahman cattles and 161 Yunling cattles with all three traits. The FD, CS and FS in Brahman cattle were significantly lower than those in Yunling cattle. The flight reaction traits had negative correlation with conformational traits (e.g., body weight, withers height and body length). Based on SNPs derived from a subset of 162 whole genomes (25 Brahman genomes and 100 Yunling genomes with FD, 30 Brahman and 131 Yunling genomes with CS and FS), genome-wide association study with mixed linear model was performed to test potential associations between flight reaction traits and genomic variants. We identified five, two and two genomic loci suggestively associated with FD, CS and FS, respectively. Five out of five candidate genes for FD (LOC789753, LRP6, CTIF, SLC9A9 and ZEB1) were reported to be related to Alzheimer's disease representing cognitive impairment in human, which was consistent with the finding that cognitive-behavioural intervention decreased the FD of cows to human. In CS, a very strong association locus was assigned to CDH8, a cadherin involved in synaptic adhesion, axon outgrowth and guidance, whose deletion was associated with autism spectrum disorder. In FS, a very strong association locus was assigned to GABRG2, a gamma-aminobutyric acid (a major inhibitory neurotransmitter in brain) receptor, whose polymorphisms were associated with suicidal behaviour in schizophrenia patients. Our findings will provide targets for molecular-marker selection and genetic manipulation of cattle improvement to meeting the growing demand for lower flight reaction to human.     

海原县不同杂交代西门达母牛外貌及生产性能的差异

文章通过对宁夏海原县部分肉牛养殖企业和养殖户调研发现,目前西门达尔母牛牛群结构处于不同杂交代,F1代比例在0.48%(4/834),F2代平均在8.15%(68/834),F3代平均49.76%(415/834),F4代平均41.61%(347/834)。不同代数西门达尔杂交母牛,在繁殖性能上存在较大差异:品种越纯,性成熟期越长,尤其是生殖系统发育不全的母牛比例越高(3%～5%),产后恢复和配种时间越长。针对生产性能的差异,应采取相应的技术措施加以提高。     

我国肉用西门塔尔牛群体生长发育性状遗传参数估计及其遗传进展

旨在对我国国家肉牛遗传评估中心收集的于2000-2019年出生的6 837头肉用西门塔尔牛的各阶段体重和日增重数据进行遗传参数估计,并估计其在2007-2017年取得的遗传进展。本研究利用REML算法估计我国肉用西门塔尔牛各性状遗传力,通过ASREML软件计算所有个体的育种值,再估计各性状的遗传进展。结果显示,我国肉用西门塔尔牛初生重、6月龄重、12月龄重、18月龄重和24月龄重的遗传力估计值分别为0.44、0.42、0.35、0.38和0.46,初生至6月龄日增重、6~12月龄日增重、12~18月龄日增重、18~24月龄日增重的遗传力估计值分别为0.47、0.32、0.36、0.39。我国肉用西门塔尔牛在2007-2017年初生重、6月龄重、12月龄重、18月龄重和24月龄重的平均每年遗传进展为0.46、2.65、4.31、4.12和2.44 kg,初生至6月龄日增重、6~12月龄日增重、12~18月龄日增重、18~24月龄日增重的平均每年遗传进展为0.014、0.016、0.009和0.007 kg·d^-1。本研究对我国肉用西门塔尔牛群体生长发育性状的遗传参数做了系统评估分析,并评估了我国肉用西门塔尔牛取得的遗传进展,为下一步我国肉牛遗传改良计划的实施提供理论依据。