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1.
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。 相似文献
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本文从太行肉牛选育实践出发，研究确定了适应当前太行肉牛育种的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，太行肉牛近期的育种目标性状主要包括生长发育性状（12月龄重、育肥期日增重、生长能力）、繁殖性状（初产年龄、产犊间隔和留群时间）及胴体性状（胴体品质）。在当前市场和生产条件下，上述育种目标性状的边际效益分别为：33.37元/kg、2.63元/g、24.59元/kg、12.43元/d、13.37元/d、338.10元/年和1 050元/级。生长发育性状、繁殖性状及胴体性状的经济权重之比为70.98%、22.56%、6.46%，近似于7:2:1。生长发育性状权重最高，其次为繁殖性状和胴体品质。在太行肉牛育种过程中，生长发育性状和繁殖性状权重较大，应加大选择力度。 相似文献
3.
鲁西黄牛是中国优良的地方品种,为了更有效的制定适宜的育种方案,加快鲁西黄牛肉用品系的选育,本研究在鲁西黄牛青年公牛体系和核心群育种方案的基础上,分别设定开放和闭锁核心群育种方案,采用确定性模型评估了开放和闭锁核心群育种体系的育种效果。结果表明,开放与闭锁核心群育种方案相比,综合遗传进展提高了0.80％;育种产出量提高了9.39％;育种效益提高了10.64％;世代间隔延长了0.90％,开放核心群体系优于闭锁核心群体系。这充分说明,在鲁西牛核心群育种方案中,开放核心群育种体系优于闭锁核心群育种体系。 相似文献
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为了定向选育乳肉兼用牛蜀宣花牛,确定其育种目标性状,计算各目标性状的边际效益,经表型值的遗传标准差校后,确定了各育种目标性状的经济权重。结果表明:蜀宣花牛的各个育种目标性状的边际效益分别为产奶量(kg)3.00元、乳脂率(%)35.00元、乳蛋白率(%)38.05元、初生重(kg)1.46元、育肥期日增重(g)1.58元、屠宰率(%)60.69元、首次产犊日龄(d)-1.80元、产犊间隔(d)-1.79元、使用寿命(d)0.27元。乳用性状、肉用性状、功能性状3类相对经济权重比例分别为70.17%∶14.56%∶15.29%,近乎于3∶1∶1。说明蜀宣花牛的产奶量占的经济权重最大,且改善乳品质和提高屠宰性能所获得的经济效益最大,需加强乳用性状的选择力度。 相似文献
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为了加快我国瘦肉型猪育种的研究进展,制定出符合我国瘦肉型猪育种现状的经济权重。本研究依据中国杜长大三元杂交猪育种现状,选择了适合中国当前杜长大三元杂交体系的目标性状;以生物经济模型为基础模拟猪的生产流程,计算生产周期各阶段成本和收入;先采用差额法计算目标性状的边际效益,再通过各性状的遗传标准差校正得到各育种目标性状的经济权重。结果表明,目前中国瘦肉型猪育种的繁殖、生长和胴体品质性状主要包括窝产活仔数、母猪断配间隔、饲料转化率、达100 kg体重日龄、达100 kg体重背膘厚。在我国现有生产水平和市场条件下,上述各性状的边际效益分别为：19.52、-1.07、-286.95、-8.41、-13.20元。通过计算不同品种的经济权重,得到杜洛克的饲料转化率、达100 kg体重日龄、达100 kg体重背膘厚相对经济权重分别为：50.42%、34.50%、15.08%;长白和大白群体窝产活仔数、母猪断配间隔、饲料转化率、达100 kg体重日龄、达100 kg体重背膘厚的相对经济权重分别为：16.82%、0.22%、39.56%、31.42%、11.98%和32.77%、0.41%、33.22%、24.43%、9.17%。结果显示,目前,在中国瘦肉型猪育种过程中,饲料利用效率应作为育种的主要目标性状,对于不同品种应选择最适合的性状进行育种。 相似文献
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肉用型牛新品种——辽育白牛的培育 总被引：3，自引：1，他引：2
辽育白牛是以夏洛来牛为父本,以辽宁本地黄牛为母本级进杂交后,形成含夏洛来牛93.75%、本地牛6.25%血统,适应当地气候和饲养条件的肉牛新群体。初生重平均：公犊43.6kg,母犊40.3 kg。成年体重：种公牛平均1 084 kg,母牛平均为497 kg,其BPI（肉用指数）分别为7.3和3.9 kg/cm,达到肉用型牛BPI标准。目前育种基础群共有辽育白母牛4 200余头,核心群共有1 100余头,制冻精种公牛9头。辽育白牛共8个家系。外貌整齐,遗传性能稳定,具有生长快、产肉多、耐粗饲、繁殖力良好等优点。 相似文献
8.
湘西黄牛生产性能的研究 总被引：2，自引：0，他引：2
分析测定了湘西黄牛公牛258头和母牛625头各不同年龄的体重、生长指数、屠宰性能及母牛的繁殖性能.结果湘西黄牛公牛初生、6、12、18、24、36、48、60月龄的体重分别为15.86、113.7、161.5、183.63、231.43、280.03、323.23、353.25 kg;母牛体重分别为14.16、102.5、152.46、169.04、208.46、250.86、278.44、295.64 kg.成年牛体长指数为113.6,胸围指数为135.9,体躯指数为119.7.未经育肥的公牛和母牛的屠宰率、净肉率、骨肉比分别为45.5%、36.52%、1∶4.45和42.91%、34%、1∶4.6;经育肥的公牛分别为48.9%、38.56%、1∶4.82.母牛初配年龄为24.03月,发情周期21.07 d,妊娠期281.02 d,繁殖率68.21%,成活率95.35%,泌乳期215.5 d.为进一步开发利用湘西黄牛遗传资源提供了基础资料. 相似文献
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鲁西黄牛肉用品系的选择方案评估 总被引：2，自引：0，他引：2
在现行鲁西黄牛肉用品系青年公牛体系和二阶开放核心群育种方案的基础上,根据不同可利用记录作为不同的选种标准。通过超声波扫描周岁活体牛眼肌面积和背膘厚,测定犊牛断奶后第28、42和56天血浆中IGF-Ⅰ平均浓度,将它们作为胴体性状选择的早期记录,设定4种选择方案,采用确定性模型从遗传和经济角度评估这些方案的育种效果。结果表明,以现行方案（方案1）为参照,超声波选择方案（方案2）、IGF-Ⅰ选择方案（方案3）以及超声波和IGF-1组合方案（方案4）的指数准确性、遗传进展和育种效益分别提高了0.19、39.05%、63.60%,0.01、25.55%、14.90%和0.21、40.68%、64.08%。以上数据说明,将超声波活体扫描和IGF-Ⅰ浓度测定应用到育种方案中可获得相对理想的育种效果。 相似文献
11.
Selection of Objective Traits and Estimation of Economic Weights for Chinese Simmental Beef Cattle 总被引：1，自引：0，他引：1
XUE Jing-long ZHU Bo ZHANG Wen-gang XIA Jiang-wei GAO Hui-jiang LI Jun-ya ZHANG Guo-liang 《中国畜牧兽医》2016,43(8):2120-2127
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. 相似文献
12.
Crowley JJ Evans RD Mc Hugh N Kenny DA McGee M Crews DH Berry DP 《Journal of animal science》2011,89(11):3372-3381
Most studies on feed efficiency in beef cattle have focused on performance in young animals despite the contribution of the cow herd to overall profitability of beef production systems. The objective of this study was to quantify, using a large data set, the genetic covariances between feed efficiency in growing animals measured in a performance-test station, and beef cow performance including fertility, survival, calving traits, BW, maternal weaning weight, cow price, and cull cow carcass characteristics in commercial herds. Feed efficiency data were available on 2,605 purebred bulls from 1 test station. Records on cow performance were available on up to 94,936 crossbred beef cows. Genetic covariances were estimated using animal and animal-dam linear mixed models. Results showed that selection for feed efficiency, defined as feed conversion ratio (FCR) or residual BW gain (RG), improved maternal weaning weight as evidenced by the respective genetic correlations of -0.61 and 0.57. Despite residual feed intake (RFI) being phenotypically independent of BW, a negative genetic correlation existed between RFI and cow BW (-0.23; although the SE of 0.31 was large). None of the feed efficiency traits were correlated with fertility, calving difficulty, or perinatal mortality. However, genetic correlations estimated between age at first calving and FCR (-0.55 ± 0.14), Kleiber ratio (0.33 ± 0.15), RFI (-0.29 ± 0.14), residual BW gain (0.36 ± 0.15), and relative growth rate (0.37 ± 0.15) all suggest that selection for improved efficiency may delay the age at first calving, and we speculate, using information from other studies, that this may be due to a delay in the onset of puberty. Results from this study, based on the estimated genetic correlations, suggest that selection for improved feed efficiency will have no deleterious effect on cow performance traits with the exception of delaying the age at first calving. 相似文献
13.
Forabosco F Bozzi R Boettcher P Filippini F Bijma P Van Arendonk JA 《Journal of animal science》2005,83(9):2043-2051
The objectives of this study were 1) to propose a profit function for Italian Chianina beef cattle; 2) to derive economic values for some biological variables in beef cows, specifically, production expressed as the number of calves born alive per year (NACY), age at the insemination that resulted in the birth of the first calf (FI), and length of productive life (LPL); and 3) to investigate the relationship between the phenotypic profit function and type traits as early predictors of profitability in the Chianina beef cattle population. The average profit was 196 Euros/(cow.yr) for the length of productive life (LPL) and was obtained as the difference between the average income of 1,375 Euros/(cow.yr) for LPL and costs of 1,178 Euros/(cow.yr) of LPL. The mean LPL was equal to 5.97 yr, so the average total phenotypic profit per cow on a lifetime basis was 1,175 Euros. A normative approach was used to derive the economic weights for the biological variables. The most important trait was the number of calves born alive (+4.03.cow(-1).yr(-1) and +24.06 Euros/cow). An increase of 1 d in LPL was associated with an increase of +0.19 Euros/(cow.yr) and +1.65 Euros/cow on a lifetime basis. Increasing FI by 1 d decreased profit by 0.42 Euros/(cow.yr) and 2.51 Euros/cow. Phenotypic profit per cow had a heritability of 0.29. Heritabilities for eight muscularity traits ranged from 0.16 to 0.23, and for the seven body size traits between 0.21 and 0.30. The conformation trait final score can be used as an early predictor of profitability. The sale price of the animal and differences in the revenue and costs of offspring due to muscularity should be included in a future profit function. 相似文献
14.
I. Komlósi M. Wolfová J. Wolf B. Farkas Z. Szendrei B. Béri 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2010,127(2):143-153
A bio‐economic model was used to estimate economic values of 15 milk production, functional, growth and carcass traits for Hungarian Holstein‐Friesian cattle. The calculations were carried out for the situation in Hungary from 2000 to 2007, assuming no production quotas. The marginal economic values were defined as partial derivatives of the profit function with respect to each trait in a production system with dairy cow herds and with sales of surplus male calves. The economic weights for maternal and direct components of traits were calculated multiplying the marginal economic values by the number of discounted expression summed over a 25‐year investment period for 2‐year‐old bulls (candidates for selection). The standardized economic weight (economic weight × genetic standard deviation) of the trait or trait component expressed as percentage of the sum of the standardized economic weights for all traits and trait components represented the relative economic importance of this trait or trait component. The highest relative economic importance was obtained for milk yield (25%), followed by productive lifetime of cows (23%), protein yield and the direct component of a cow’s total conception rate (9% each), the maternal effect of the total conception rate of cows and the somatic cell score (approximately 7% each), fat yield (5%) and mature weight of cows and daily gain in rearing of calves (approximately 4% each). Other functional traits (clinical mastitis incidence, calving difficulty score, total conception rate of heifers and calf mortality) reached a relative economic importance between 0.5% and 2%. Birth weight and dressing percentage were least important (<0.5%). Based on these results, the inclusion of productive lifetime and cow fertility in the breeding programme for Holstein‐Friesian cattle in Hungary is advisable. 相似文献
15.
F Ruvuna J F Taylor J P Walter J W Turner R M Thallman 《Journal of animal science》1992,70(4):1091-1097
A model was developed for the economic evaluation of embryos for producing bull lines for use in commercial beef production. The fundamental concept underlying the model is that a cloned and sexed embryo of known genetic characteristics for beef traits is used to produce a bull. After reaching physiological maturity, the bull is used in natural matings. Equations relating feed energy requirements and growth rates based on NRC requirements and costs and returns discounted to present value allow investigation of expected economic merits of progeny from different embryo bull lines. The model has the flexibility to determine optimal embryo characteristics for different production environments. Model sensitivity to variation in progeny sex ratios, growth rates, yield and quality grades, and herd fertility characteristics was examined. Net present values (NPV) per embryo transferred were determined at the optimal marketing age of progeny produced from mating the bull to 30 cows per year for 5 yr. Relative to the lowest NPV of $18,209 for progeny with an expected quality grade of Select and yield grade of 4 at 400 d, increments in NPV ranged from $329 to $22,708 depending on differences in expected progeny carcass grade characteristics. The difference between NPV for 100% male and 40% male sex ratios was $7,518. The NPV differences between progeny growth rates of 1.6 and .9 kg/d holding herd conception rate constant at .9 and .5 were $8,311 and $4,611, respectively. The model evaluates relative economic values of embryo lines for producing bulls, accommodating interactions among progeny characteristics, and environments. 相似文献
16.
Genetic relationships between calving and carcass traits for Charolais and Hereford cattle in Sweden 总被引：1，自引：0，他引：1
The objective of this study was to estimate genetic correlations between calving difficulty score and carcass traits in Charolais and Hereford cattle, treating first and later parity calvings as different traits. Genetic correlations between birth weight and carcass traits were also estimated. Field data on 59,182 Charolais and 27,051 Hereford calvings, and carcass traits of 5,260 Charolais and 1,232 Hereford bulls, were used in bivariate linear animal model analyses. Estimated heritabilities were moderate to high (0.22 to 0.50) for direct effects on birth weight, carcass weight, and (S)EUROP (European Community scale for carcass classification) grades for carcass fleshiness and fatness. Heritabilities of 0.07 to 0.18 were estimated for maternal effect on birth weight, and for direct and maternal effects on calving difficulty score at first parity. Lower heritabilities (0.01 to 0.05) were estimated for calving difficulty score at later parities. Carcass weight was positively genetically correlated (0.11 to 0.53) with both direct and maternal effects on birth weight and with direct effects on calving difficulty score. Carcass weight was, however, weakly or negatively (-0.70 to 0.07) correlated with maternal calving difficulty score. Higher carcass fatness grade was genetically associated with lower birth weight, and in most cases, also with less difficult calving. Genetic correlations with carcass fleshiness grade were highly variable. Moderately unfavorable correlations between carcass fleshiness grade and maternal calving difficulty score at first parity were estimated for both Charolais (0.42) and Hereford (0.54). This study found certain antagonistic genetic relationships between calving performance and carcass traits for both Charolais and Hereford cattle. Both direct and maternal calving performance, as well as carcass traits, should be included in the breeding goal and selected for in beef breeds. 相似文献
17.
This study was conducted to determine the economic weights of most preferred traits in young breeding Nguni bulls and first parity cows. Fifty-four farmers from low-input cattle production enterprises participated in the choice experiment. Sixteen individual animal profiles were formulated from four traits of three levels each using a fractional orthogonal design of SPSS 14.0 (2005). 120 pair-wise choices were deduced for each breeding animal class. A total of 6480 (54×120) observations were obtained for each class of the animals. Data was subjected to multinomial logit (MNL) models using econometric software NLOGIT 4.0.1 Version (2007). All computed economic values for bull traits were significant (p<0.05). The economic weights of bull traits were poor body condition score (−0.99±0.095), good body condition score (0.45±0.073), over-conditioned (base level), low tick infestation (0.57±0.103), medium tick infestation (0.58±0.084), high tick infestation (base level), high aggression and mating behavior (4.41±0.095), average aggression and mating behavior (2.53±0.094), and low aggression and mating behavior (base level). The economic weights of first parity cow traits were poor body condition score (−0.06±0.055), good body condition score (1.08±0.061), over-conditioned (base level), low tick infestation (1.50±0.059), medium tick infestation (0.83±0.067), high tick infestation (base level), age at first calving of ≤27 months (2.37±0.068), age at first calving of 27–36 months (1.30±0.076), and age at first calving of >36 months (base level). Farmers were willing to pay R37,939 (US$4864) for a bull with high aggression and mating behavior score and R17,185 (US$2203) for a first parity cow of less than 27 months old. Enterprise ownership and demographics factors of the farmers were significant in determining economic weights within trait levels. Economic weights were high for reproductive efficiency of the breeding animals followed by the high adaptive characteristics. The choice experiment procedure can be the tool for determining importance of animal characteristics under low-input production systems. It is recommended to make use of the economic weights of preferential traits in designing selection models. 相似文献
18.
A general bio-economic model for beef cattle production was used to define breeding objectives for Charolais cattle to be utilized in a variety of linked production systems. Economic weights were calculated for 16 traits (some with both direct and maternal components) in three production systems (pure-breeding and terminal crossing with beef or dairy cows) and two marketing strategies (sale or fattening of weaned surplus calves). Economic weights for the total breeding objective were calculated as weighted averages, where weights were numbers of cows expected to be mated with Charolais bulls in each production system and marketing strategy. Results suggest that the direct component of calving performance and cow longevity were of primary economic importance in all systems. Conception rate of cows and weaning weight reached about 50% of the standardized economic weight of calving performance in purebred systems with sale of weaned calves, whereas in purebred systems with fattening the economic importance of the direct component of cow conception rate, losses at calving, mature weight of cows, weaning weight, and fattening traits were of equal importance (each approximately about 20% that of calving performance). In terminal crossing systems, weaning weight was important when calves were sold at weaning, and fattening traits were important for systems selling fattened animals. The bio-economic model performed well under the conditions of this demonstration and could easily be customized for other applications. 相似文献
19.
T. O. Rewe P. Herold H.-P. Piepho A. K. Kahi A. Valle Zárate 《Tropical animal health and production》2010,42(3):327-340
The objective of this study is to describe the present organisational structure of Boran cattle breeding and develop a model
breeding programme using a deterministic approach under the current structure of the Boran Cattle Breeders Society. A breeding
unit of 13,000 cows supplying bulls to a commercial population of 39,000 cows was assumed. Selection criteria used were growth
and reproduction traits while breeding objective traits targeted were growth, carcass, reproduction, survival, milk yield
and feed intake traits. Higher selection intensity was possible for breeding sires resulting in higher genetic gains compared
to dams even though selection accuracies were generally low. Annual genetic gains were positive except for dressing percentage,
cow survival rate, and age at first calving. However, a reduction of age at first calving by 9.5 days obtained a return of
Ksh 49.76. The overall monetary genetic gain obtained was Ksh 84.89 with a profit per cow per year of Ksh 377.98. The basic
breeding programme could be expanded to accommodate a larger population of Boran cattle. The implications of the results are
also discussed. 相似文献