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1.
A joint growth-carcass analysis was conducted to develop equations for predicting carcass quality traits associated with variation in growth path of crossbred cattle. During a four-year period (1994-1997) of the Australian "Southern Crossbreeding Project", mature Hereford cows (r = 581) were mated to 97 sires of Jersey, Wagyu, Angus, Hereford, South Devon, Limousin, and Belgian Blue breeds, resulting in 1141 calves. Data included body weight measurements of steers and heifers from birth until slaughter and four carcass quality traits: hot standard carcass weight, rump fat depth, rib eye muscle area, and intramuscular fat content. The model provides nine outputs: median and mean of carcass quality traits, predicted means, and lower and upper confidence intervals, as well as predicted intervals of carcass quality traits (95%) and economic values for domestic market and export markets. Input to the model consists of sex, sire breeds, age (in days)-weight (kg) pairs and slaughter age (500 days for heifer and 700 days for steers). The prediction model is able to accommodate different sexes across seven sire breeds and various management groups at any slaughter age. Its strength lies in its simplicity and flexibility, desirable to accommodate producers with different management schemes. In general, fat depth and intramuscular fat were found to be more affected by differences in growth rate than hot carcass weight and eye muscle area. Also, export market value was more sensitive to growth rate modifications than domestic market value. This model provides a tool by which the producer can estimate the impact of management decisions.  相似文献   

2.
A joint growth-carcass model using random regression was used to estimate the (co)variance components of beef cattle body weights and carcass quality traits and correlations between them. During a four-year period (1994-1997) of the Australian "southern crossbreeding project", mature Hereford cows (N = 581) were mated to 97 sires of Jersey, Wagyu, Angus, Hereford, South Devon, Limousin, and Belgian Blue breeds, resulting in 1141 calves. Data included 13 (for steers) and 8 (for heifers) body weight measurements approximately every 50 days from birth until slaughter and four carcass quality traits: hot standard carcass weight, rump fat depth, rib eye muscle area, and intramuscular fat content. The mixed model included fixed effects of sex, sire breed, age (linear, quadratic and cubic), and their interactions between sex and sire breed with age. Random effects were sire, dam, management (birth location, year, post-weaning groups), and permanent environmental effects, and their interactions with linear, quadratic and cubic growth, when possible. Phenotypic, sire and dam correlations between body weights and hot standard carcass weight and rib eye muscle area were positive and moderate to high from birth to feedlot period. Management variation accounted for the largest proportion of total variation in both growth and carcass traits. Management correlations between carcass traits were high, except between rump fat depth and intramuscular fat (r = 0.26). Management correlations between body weight and carcass traits during the pre-weaning period were positive except for intramuscular fat. The correlations were low from birth to weaning, then increased dramatically and were high during the feedlot period.  相似文献   

3.
Two analyses, cubic and piecewise random regression, were conducted to model growth of crossbred cattle from birth to about two years of age, investigating the ability of a piecewise procedure to fit growth traits without the complications of the cubic model. During a four-year period (1994-1997) of the Australian "Southern Crossbreeding Project", mature Hereford cows (N = 581) were mated to 97 sires of Angus, Belgian Blue, Hereford, Jersey, Limousin, South Devon, and Wagyu breeds, resulting in 1141 steers and heifers born over four years. Data included 13 (for steers) and eight (for heifers) live body weight measurements, made approximately every 50 days from birth until slaughter. The mixed model included fixed effects of sex, sire breed, age (linear, quadratic and cubic), and their interactions between sex and sire breed with age. Random effects were sire, dam, management (birth location, year, post-weaning groups), and permanent environmental effects and for each of these when possible, their interactions with linear, quadratic and cubic growth. In both models, body weights of all breeds increased over pre-weaning period, held fairly steady (slightly flattening) over the dry season then increased again towards the end of the feedlot period. The number of estimated parameters for the cubic model was 22 while for the piecewise model it was 32. It was concluded that the piecewise model was very similar to the cubic model in the fit to the data; with the piecewise model being marginally better. The piecewise model seems to fit the data better at the end of the growth period.  相似文献   

4.
Information on the genetic diversity and population structure of cattle breeds is useful when deciding the most optimal, for example, crossbreeding strategies to improve phenotypic performance by exploiting heterosis. The present study investigated the genetic diversity and population structure of the most prominent dairy and beef breeds used in Ireland. Illumina high-density genotypes (777 962 single nucleotide polymorphisms; SNPs) were available on 4623 purebred bulls from nine breeds; Angus (n=430), Belgian Blue (n=298), Charolais (n=893), Hereford (n=327), Holstein-Friesian (n=1261), Jersey (n=75), Limousin (n=943), Montbéliarde (n=33) and Simmental (n=363). Principal component analysis revealed that Angus, Hereford, and Jersey formed non-overlapping clusters, representing distinct populations. In contrast, overlapping clusters suggested geographical proximity of origin and genetic similarity between Limousin, Simmental and Montbéliarde and to a lesser extent between Holstein, Friesian and Belgian Blue. The observed SNP heterozygosity averaged across all loci was 0.379. The Belgian Blue had the greatest mean observed heterozygosity (HO=0.389) among individuals within breed while the Holstein-Friesian and Jersey populations had the lowest mean heterozygosity (HO=0.370 and 0.376, respectively). The correlation between the genomic-based and pedigree-based inbreeding coefficients was weak (r=0.171; P<0.001). Mean genomic inbreeding estimates were greatest for Jersey (0.173) and least for Hereford (0.051). The pair-wise breed fixation index (Fst) ranged from 0.049 (Limousin and Charolais) to 0.165 (Hereford and Jersey). In conclusion, substantial genetic variation exists among breeds commercially used in Ireland. Thus custom-mating strategies would be successful in maximising the exploitation of heterosis in crossbreeding strategies.  相似文献   

5.
At the instigation of the South Devon Cattle Breeders' Society of South Africa we studied the genetic relationships of South Devon cattle (South Africa) and Gelbvieh cattle (Germany) with eight other breeds including Red Angus and Black Angus (USA). On the basis of comparisons at ten immungenetic loci Gelbvieh and South Devon cattle are nearly as genetically similar as Red and Black Angus. The results indicate that Gelbvieh and South Devon had a common ancestry on the Continent and are distinct from other British breeds such as Hereford, Angus and Jersey. This study illustrates the application of studies of the genetic similarities of different breeds to the rational development of future breeding and preservation programs.  相似文献   

6.

Background

The major obstacles for the implementation of genomic selection in Australian beef cattle are the variety of breeds and in general, small numbers of genotyped and phenotyped individuals per breed. The Australian Beef Cooperative Research Center (Beef CRC) investigated these issues by deriving genomic prediction equations (PE) from a training set of animals that covers a range of breeds and crosses including Angus, Murray Grey, Shorthorn, Hereford, Brahman, Belmont Red, Santa Gertrudis and Tropical Composite. This paper presents accuracies of genomically estimated breeding values (GEBV) that were calculated from these PE in the commercial pure-breed beef cattle seed stock sector.

Methods

PE derived by the Beef CRC from multi-breed and pure-breed training populations were applied to genotyped Angus, Limousin and Brahman sires and young animals, but with no pure-breed Limousin in the training population. The accuracy of the resulting GEBV was assessed by their genetic correlation to their phenotypic target trait in a bi-variate REML approach that models GEBV as trait observations.

Results

Accuracies of most GEBV for Angus and Brahman were between 0.1 and 0.4, with accuracies for abattoir carcass traits generally greater than for live animal body composition traits and reproduction traits. Estimated accuracies greater than 0.5 were only observed for Brahman abattoir carcass traits and for Angus carcass rib fat. Averaged across traits within breeds, accuracies of GEBV were highest when PE from the pooled across-breed training population were used. However, for the Angus and Brahman breeds the difference in accuracy from using pure-breed PE was small. For the Limousin breed no reasonable results could be achieved for any trait.

Conclusion

Although accuracies were generally low compared to published accuracies estimated within breeds, they are in line with those derived in other multi-breed populations. Thus PE developed by the Beef CRC can contribute to the implementation of genomic selection in Australian beef cattle breeding.  相似文献   

7.
FABP4 is a protein primarily expressed in adipocytes and macrophages that plays a key role in fatty acid trafficking and lipid hydrolysis. FABP4 gene polymorphisms have been associated with meat quality traits in cattle, mostly in Asian breeds under feedlot conditions. The objectives of this work were to characterize FABP4 genetic variation in several worldwide cattle breeds and evaluate possible genotype effects on fat content in a pasture-fed crossbred (Angus-Hereford-Limousin) population. We re-sequenced 43 unrelated animals from nine cattle breeds (Angus, Brahman, Creole, Hereford, Holstein, Limousin, Nelore, Shorthorn, and Wagyu) and obtained 22 single nucleotide polymorphisms (SNPs) over 3,164?bp, including four novel polymorphisms. Haplotypes and linkage disequilibrium analyses showed a high variability. Five SNPs were selected to perform validation and association studies in our crossbred population. Four SNPs showed well-balanced allele frequencies (minor frequency?>?0.159), and three showed no significant deviations from Hardy-Weinberg proportions. SNPs showed significant effects on backfat thickness and fatty acid composition (P?相似文献   

8.
Scrotal circumference (SC) was measured on 7,918 2-yr-old Angus, Charolais, horned and polled Herefords, Limousin, Shorthorn, and Simmental bulls presented to culling committees at six show/sales between 1977 and 1983. Only SC data from bulls within the age range of 24 +/- 4 mo were used. Scrotal circumference data were corrected across breeds for the effects of location-year and sire and were adjusted to a common bull age of 730 d. The adjusted mean SC (+/- SE) for 2-yr-old beef bulls was Simmental, 38.8 +/- 0.10 cm (n = 540); Aberdeen Angus, 37.2 +/- 0.09 cm (n = 629); Charolais, 36.3 +/- 0.09 cm (n = 499); horned Hereford, 36.1 +/- 0.03 cm (n = 3,769); polled Hereford, 35.6 +/- 0.04 cm (n = 2,170); Shorthorn, 34.9 +/- 0.11 cm (n = 231); and Limousin, 32.2 +/- 0.18 cm (n = 80). The authors' recommendations of minimum acceptable SC for 2-yr-old beef bulls are Simmental, 36.0 cm; Angus and Charolais, 35.0 cm; horned and polled Herefords and Shorthorn, 34.0 cm; and Limousin, 33.0 cm.  相似文献   

9.
Profitability of beef production can be increased by genetically improving carcass traits. To construct breeding value evaluations for carcass traits, breed-specific genetic parameters were estimated for carcass weight, carcass conformation and carcass fat in five beef cattle breeds in Finland (Hereford, Aberdeen Angus, Simmental, Charolais and Limousin). Conformation and fat were visually scored using the EUROP carcass classification. Each breed was separately analyzed using a multitrait animal model. A total of 6879–19 539 animals per breed had phenotypes. For the five breeds, heritabilities were moderate for carcass weight (h2=0.39 to 0.48, s.e.=0.02 to 0.04) and slightly lower for conformation (h2=0.30 to 0.44, s.e.=0.02 to 0.04) and carcass fat (h2=0.29 to 0.44, s.e.=0.02 to 0.04). The genetic correlation between carcass weight and conformation was favorable in all breeds (rG=0.37 to 0.53, s.e.=0.04 to 0.05), heavy carcasses being genetically more conformed. The phenotypic correlation between carcass weight and carcass fat was moderately positive in all breeds (rP=0.21 to 0.32), implying that increasing carcass weight was related to increasing fat levels. The respective genetic correlation was the strongest in Hereford (rG=0.28, s.e.=0.05) and Angus (rG=0.15, s.e.=0.05), the two small body-sized British breeds with the lowest conformation and the highest fat level. The correlation was weaker in the other breeds (rG=0.08 to 0.14). For Hereford, Angus and Simmental, more conformed carcasses were phenotypically fatter (rP=0.11 to 0.15), but the respective genetic correlations were close to zero (rG=0.05 to 0.04). In contrast, in the two large body-sized and muscular French breeds, the genetic correlation between conformation and fat was negative and the phenotypic correlation was close to zero or negative (Charolais: rG=0.18, s.e.=0.06, rP=0.02; Limousin: rG=0.56, s.e.=0.04, rP=0.13). The results indicate genetic variation for the genetic improvement of the carcass traits, favorable correlations for the simultaneous improvement of carcass weight and conformation in all breeds, and breed differences in the correlations of carcass fat.  相似文献   

10.
An 11-bp deletion in the bovine myostatin ( MSTN ) gene was identified as the causative mutation for the double-muscling phenotype in Belgian Blue and Asturiana cattle. More recently, this mutation was also identified in the South Devon breed of cattle, in which it has been found to be associated with a general increase in muscle mass. The present study found that the mutant allele was also segregating in a commercial population of Scottish Aberdeen Angus beef cattle. The mutation was found at a low frequency (0.04) with no animals homozygous for the mutation in the sample population (536 animals). The effects of this mutation on various carcass traits of economic interest were then tested. We found that the mutation significantly increased carcass weight, sirloin weight, hindquarter weight, muscle conformation score and eye muscle area, but had no effect on the fat traits.  相似文献   

11.
肉牛杂交优势预测、评估及其应用研究   总被引:22,自引:0,他引:22  
利用微卫星标记技术分析了8个肉 要交样本群体的遗传结构和遗传变异,预测了要种优势。在此基础上肉牛发校组合的实际杂交效果利用个体动物模型进行了评估,并提出了筛选最优杂交组合的分子数量遗传学综合评选新方法。其最优杂交组合的评选结果为,在丰宁、隆化代表区域,以海伏特、利木赞和夏洛来为父本的组合最好;在赞皇代表区域,以利木赞、安格斯和海伏特为父本的组合最好,在抚宁代表区域,以海伏特、利木赞和皮埃蒙特为父本  相似文献   

12.
It has been claimed that the origin of the South Devon breed of cattle is 'unknown' and that biochemical polymorphisms '… indicate that Gelbvieh and South Devon had a common ancestry on the Continent and are distinct from other British breeds such as Hereford, Angus and Jersey' (Kidd et al., 1974).
In fact, historical records indicate that the South Devon evolved largely from native Devon cattle and is a close relative of other English Lowland breeds such as the North Devon and Hereford. Information about crosses from other breeds makes no mention of the Gelbvieh but emphasises the contribution of Channel Island breeds, especially the Guernsey. Data for biochemical polymorphisms in the relevant breeds show agreement with the historical information and with the biogeography of the breeds involved.  相似文献   

13.
It has been claimed that the origin of the South Devon breed of cattle is 'unknown' and that biochemical polymorphisms '. . . indicate that Gelbvieh and South Devon had a common ancestry on the Continent and are distinct from other British breeds such as Hereford, Angus and Jersey' (Kidd et al., 1974). In fact, historical records indicate that the South Devon evolved largely from native Devon cattle and is a close relative of other English Lowland breeds such as the North Devon and Hereford. Information about crosses from other breeds makes no mention of the Gelbvieh but emphasises the contribution of Channel Island breeds, especially the Guernsey. Data for biochemical polymorphisms in the relevant breeds show agreement with the historical information and with the biogeography of the breeds involved.  相似文献   

14.
The relationship of heifer size, calf size and sire on dystocia was studied in approximately one thousand Angus, Hereford X Angus and Charolais heifers bred to Angus, Hereford and Charolais bulls. Heifers were weighed and pelvic measurements taken 35 days post breeding, at midgestation, and on a random group of 135 heifers two weeks prior to calving. Dystocia score, calf birth weight, calf body length, calf hip width and calf sex were recorded at calving.Correlation coefficients for calf traits indicate that birth weight and birth weight to body measurement ratios were the most highly correlated variables with dystocia score. For traits of the dam, pelvic area was the most highly correlated variable to dystocia score, while dam weight had a low and nonsignificant correlation.Sires experiencing a higher than average incidence of dystocia had calves that were larger for all measures of body size. Individual sire differences for dystocia indicate a large number of calves and an accurate randomization of heifers bred to each bull is necessary to make precise judgements as to a bull's potential for siring easy-calving offspring.Calf size measurements were positively correlated with heifer weight and pelvic area; however, correlations tended to be low. Breed of calf, sire, heifer weight I and II and pelvic area I, II and III accounted for only 23.6% of the variation in calf birth weight.Charolais calves were larger (P<.05) and had more dystocia (P<.05) than Hereford or Angus sired calves. Hereford sired crossbred calves were larger (P<.05) and had more dystocia than Angus crossbred or straightbred calves. Angus crossbred calves were larger (P<.05) but had no more dystocia than Angus straightbred calves.Heritability estimates for calf body length (0.35) and calf hip width (0.42) indicate calf skeletal measurements were more heritable than calf birth weight (0.28).Pelvic area measurements were correlated (P<.01) with heifer weight; however, heifer weight I and II accounted for only 37% and 30% of the variability in pelvic area I and II, respectively. Average pelvic area was largest in Charolais heifers, followed by Crossbred and Angus heifers. Pelvic area growth was .275 cm2/day in Angus, .254 cm2/day in Crossbred, and .250 cm2/day in Charolais heifers.Dystocia score was most highly related to calf size and pelvic area I. Pooled over all breeds, a regression analysis showed 37% of the variability in dystocia score being accounted for by the ratio of calf birth weight to calf body length and pelvic erea I. Very little increase in the R2 value occurred by the addition of the other independent variables.Histogram analyses demonstrates that a constant level of dystocia can be maintained only if pelvic area increases in proportion to calf size. However, regardless of the size of calf, heifers that had very small pelvic openings had a high rate of dystocia, just as heifers having very large calves experienced high rates of dystocia even when they had large pelves.  相似文献   

15.
This research developed two real-time PCR assays, employing high-resolution melt and allele-specific analysis to accurately genotype the F94L mutation in cattle. This mutation (g.433C > A) in the growth differentiation factor 8 or myostatin gene has recently been shown to be functionally associated with increased muscle mass and carcass yield in cattle. The F94L mutation is not, like other myostatin mutations, associated with reduced fertility and dystocia. It is therefore a candidate for introgression into other breeds to improve retail beef yield and the development of a simple and accurate test to genotype this specific mutation is warranted. Variations in the efficiency of enzyme cleavage compromised the accuracy of genotyping by published methods, potentially resulting in an overestimation of the frequency of the mutant allele. The frequency of the F94L mutation was determined by real-time PCR in 1140 animals from 15 breeds of cattle in Australia. The mutation was present in Simmental (0.8%), Piedmontese (2%), Droughtmaster (4%) and Limousin (94.2%) but not found in Salers, Angus, Poll Hereford, Hereford, Gelbvieh, Charolais, Jersey, Brahman, Holstein, Shorthorn or Maine Anjou. The low prevalence of F94L in all beef breeds except Limousin indicates the significant potential for this mutation to improve retail yield in Australian beef cattle.  相似文献   

16.
A whole-genome scan for carcass traits [average daily gain during the pre-weaning, growth and finishing periods; birth weight; hot carcass weight and longissimus muscle area (LMA)] was performed on 328 F(2) progeny produced from Wagyu x Limousin-cross parents derived from eight founder Wagyu bulls. Nine significant (P 相似文献   

17.
Muscling in cattle is largely influenced by genetic background, ultimately affecting beef yield and is of major interest to the beef industry. This investigation aimed to determine whether primary skeletal muscle cells isolated from different breeds of cattle with a varying genetic potential for muscling differ in their myogenic proliferative capacity. Primary skeletal muscle cells were isolated and cultured from the Longissimus muscle (LM) of 6 month old Angus, Hereford and Wagyu X Angus cattle. Cells were assessed for rate of proliferation and gene expression of PAX7, MYOD, MYF5, and MYOG. Proliferation rates were found to differ between breeds of cattle whereby myoblasts from Angus cattle were found to proliferate at a greater rate than those of Hereford and Wagyu X Angus during early stages of growth (5–20 hours in culture) in vitro (P < 0.05). The proliferation rates of myoblasts during early stages of culture in vitro were also found to be positively related to the liveweight and carcase weight of cattle (P < 0.05). Gene expression of MYF5 was also found to be significantly down-regulated in WagyuX compared with Angus cattle (P < 0.05). These findings suggest that early events during myogenesis are important for determining liveweight and caracase weights in cattle.  相似文献   

18.
A whole‐genome scan was carried out in New Zealand and Australia to detect quantitative trait loci (QTL) for live animal and carcass composition traits and meat quality attributes in cattle. Backcross calves (385 heifers and 398 steers) were generated, with Jersey and Limousin backgrounds. The New Zealand cattle were reared and finished on pasture, whilst Australian cattle were reared on grass and finished on grain for at least 180 days. This paper reports on meat quality traits (tenderness measured as shear force at 4–5 ages on two muscles as well as associated traits of meat colour, pH and cooking loss) and a number of metabolic traits. For meat quality traits, 18 significant QTL (P < 0.05), located in nine linkage groups, were detected on a genome‐wise basis, in combined‐sire (seven QTL) or within‐sire analyses (11 QTL). For metabolic traits, 11 significant QTL (P < 0.05), located in eight linkage groups, were detected on a genome‐wise basis, in combined‐sire (five QTL) or within‐sire analyses (six QTL). BTA2 and BTA3 had QTL for both metabolic traits and meat quality traits. Six significant QTL for meat quality and metabolic traits were found at the proximal end of chromosome 2. BTA2 and BTA29 were the most common chromosomes harbouring QTL for meat quality traits; QTL for improved tenderness were associated with Limousin‐derived and Jersey‐derived alleles on these two chromosomes, respectively.  相似文献   

19.

Background

Artificial selection for economically important traits in cattle is expected to have left distinctive selection signatures on the genome. Access to high-density genotypes facilitates the accurate identification of genomic regions that have undergone positive selection. These findings help to better elucidate the mechanisms of selection and to identify candidate genes of interest to breeding programs.

Results

Information on 705 243 autosomal single nucleotide polymorphisms (SNPs) in 3122 dairy and beef male animals from seven cattle breeds (Angus, Belgian Blue, Charolais, Hereford, Holstein-Friesian, Limousin and Simmental) were used to detect selection signatures by applying two complementary methods, integrated haplotype score (iHS) and global fixation index (FST). To control for false positive results, we used false discovery rate (FDR) adjustment to calculate adjusted iHS within each breed and the genome-wide significance level was about 0.003. Using the iHS method, 83, 92, 91, 101, 85, 101 and 86 significant genomic regions were detected for Angus, Belgian Blue, Charolais, Hereford, Holstein-Friesian, Limousin and Simmental cattle, respectively. None of these regions was common to all seven breeds. Using the FST approach, 704 individual SNPs were detected across breeds. Annotation of the regions of the genome that showed selection signatures revealed several interesting candidate genes i.e. DGAT1, ABCG2, MSTN, CAPN3, FABP3, CHCHD7, PLAG1, JAZF1, PRKG2, ACTC1, TBC1D1, GHR, BMP2, TSG1, LYN, KIT and MC1R that play a role in milk production, reproduction, body size, muscle formation or coat color. Fifty-seven common candidate genes were found by both the iHS and global FST methods across the seven breeds. Moreover, many novel genomic regions and genes were detected within the regions that showed selection signatures; for some candidate genes, signatures of positive selection exist in the human genome. Multilevel bioinformatic analyses of the detected candidate genes suggested that the PPAR pathway may have been subjected to positive selection.

Conclusions

This study provides a high-resolution bovine genomic map of positive selection signatures that are either specific to one breed or common to a subset of the seven breeds analyzed. Our results will contribute to the detection of functional candidate genes that have undergone positive selection in future studies.

Electronic supplementary material

The online version of this article (doi:10.1186/s12711-015-0127-3) contains supplementary material, which is available to authorized users.  相似文献   

20.
Young stock survival is a trait of crucial importance in cattle breeding as calf mortality leads to economic losses and represents an animal welfare issue. The aim of this study was to estimate genetic parameters and sire breeding values for young stock survival in beef x dairy crossbred calves. Two traits were analysed with a univariate animal model: young stock survival between 1 to 30 days and 31 to 200 days after birth. Breed combinations with Belgian Blue sires outperformed all other sire breeds. The lowest survival rates were found for breed combinations with Jersey dams or Blonde d’Aquitaine sires. The results showed low but significant heritabilities (0.045 to 0.075) for both survival traits. Differences in breeding values between sires ranged from −2.5% to 3.5% and from −5.4% to 4.7% survival from 1 to 30 days and 31 to 200 days, respectively. Based on these findings, we concluded that it is feasible to breed for improved young stock survival in beef x dairy crossbred calves. This will hopefully contribute to increasing the survival rate of the calves and reduce economic losses for the farmers.  相似文献   

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