单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,家禽数量性状的遗传,肉用性状（meat trait）的遗传,蛋用性状（egg trait）的遗传,繁殖力和生活力的遗传,饲料报酬(feed remuneration),家禽数量性状的遗传 肉用性状（meat trait）的遗传,1,肉用性状（meat trait）的遗传,体型大小（body size）或体重（body weight）,出壳体重（day-old weight）,生长期体重（grower weight）：6-7周龄体重h,2,=0.42-0.46,成年体重（adult weight）h,2,=0.55-0.65,肉用性状（meat trait）的遗传 体型大小（body,2,肉用性状（meat trait）的遗传,生长速度（growing rate）,累积生长（accumulate growing）,绝对生长（absolute growing）,相对生长（relative growing）,早期生长速度h,2,=0.4-0.5,肉用性状（meat trait）的遗传生长速度（growin,3,肉用性状（meat trait）的遗传,Genetic parameters of growth curve in chickens(S. Mignon-Grasteau and C. Beaumont, 2019, 7,th,WCGALP,11-3),Gompertz function of growth curve:,By using data of 464 chickens from a slow growing meat-type line, which were weighed every two weeks from 4 to 16 weeks, the Gompertz curve fitted well the data (R,2,=0.99), the greatest difference being an overestimation of body weight at 10 weeks (3.6% in males and 2.8% in females).,肉用性状（meat trait）的遗传Genetic par,4,肉用性状（meat trait）的遗传,肉用性状（meat trait）的遗传,5,肉用性状（meat trait）的遗传,Conclusion:,This study confirmed that males and females chickens can be distinguished by their growth curve parameters, females being more precocious than males. Genetic parameters of the Gompertz function parameters showed moderate heritabilities, making it possible to select directly on the form of the growth curve.,肉用性状（meat trait）的遗传Conclusion:,6,肉用性状（meat trait）的遗传,屠宰率（dressed percentage）,h,2,=0.2-0.6,肉用性状（meat trait）的遗传屠宰率（dressed,7,肉用性状（meat trait）的遗传,Genetic and phenotypic parameters of growth and carcass traits of a male line of broilers raised in tropical conditions (C. Argento1 et al 2019, 7,th,WCGALP 4-34),The dataset information came from a male selection line of broilers owned by Agroceres-Ross Melhoramento Gentico de Aves Ltda. and raised in tropical conditions in farm located close to 22S and 48W, at altitude around 700 m above sea level.,Growth data came from 27,231 male and female birds submitted to selection and dataset had information on 5 generations of pedigree;,Carcass data came from 9,463 full sibs of broilers from selection, that were processed at the experimental slaughterhouse. Those animals were slaughtered around 42 days of age, from 2019 to 2019.,肉用性状（meat trait）的遗传Genetic and,8,肉用性状（meat trait）的遗传,Traits measured:,W35: weight at 35 days of age,us1: ultrasound measurements on breast muscle depth (measured next to middle line);,us2: ultrasound measurements on breast muscle depth (measured transversally);,FC: feed conversion;,LWS: live weight at slaughter;,HCW: hot carcass weight ;,Breast: deboned and skinned chilled breast weight;,Legs: chilled whole leg weight.,Software: SAS, MTDFREML,肉用性状（meat trait）的遗传Traits meas,9,肉用性状（meat trait）的遗传,肉用性状（meat trait）的遗传,10,肉用性状（meat trait）的遗传,肉用性状（meat trait）的遗传,11,肉用性状（meat trait）的遗传,Conclusions:,The animal model REML method seemed to be effective to estimate genetic parameters even in data of selected poultry.,The growth and carcass traits of the selected male line analyzed can be used as selection criteria, since no important genetic antagonism was observed.,Economic studies should be applied to the traits analyzed, to identify which combination of them would maximize profit.,As an indicator of carcass merit at slaughter (42 days of age), live weight seemed to be a good and easy to measure selection criterion, that can be widely used, as it has good genetic correlation with the other traits and medium heritability.,肉用性状（meat trait）的遗传Conclusions,12,肉用性状（meat trait）的遗传,肉鸡部分性状的遗传力,肉鸡部分性状的遗传和表型相关,肉用性状（meat trait）的遗传,13,蛋用性状（,egg trait,）的遗传,产蛋量（,egg production,）,入舍蛋鸡产蛋量（,egg production H.H-hen-housed,）：以开产时入舍母鸡数为基数（包括开产后死亡、淘汰母禽在内），在一定利用期内的产蛋量。入舍母鸡,72,周产蛋量,h,2,=0.05-0.1,饲养只日产蛋量（,egg production H.D-hen-day,）：根据每天平均饲养母禽数计算在一定时间内的平均产蛋量。饲养只日,72,周产蛋量,h,2,=0.23-0.27,。,蛋用性状（egg trait）的遗传 产蛋量（egg pro,14,蛋用性状（,egg trait,）的遗传,影响产蛋量的因素：,1、,性成熟期,(sex maturity),：又称开产日龄,(age at first egg),，指母禽产第一个蛋的日龄。有时用早熟性（,earliness,）来描述性成熟的早晚。,度量方法：,个体，见第一个蛋的日龄；群体，蛋禽为达,50%,产蛋率的日龄，肉用禽为达,5%,产蛋率的日龄。性成熟期的,h,2,=0.3,蛋用性状（egg trait）的遗传影响产蛋量的因素：,15,蛋用性状（,egg trait,）的遗传,2、,产蛋强度（,laying intensity,）：指某一时间内母禽的产蛋率（,laying rate,），可用一定时间内该禽群的产蛋百分率表示。,h,2,=0.1,3、,产蛋持久性（,laying persistency,）：一般以生物学年的长度表示，即从开产开始，经产蛋高峰期、产蛋下降期到停产换羽为止所用的时间。,蛋用性状（egg trait）的遗传2、产蛋强度（layin,16,蛋用性状（,egg trait,）的遗传,4、,就巢性（,broodiness,）：即抱性，为质量性状。,5、,休止性（,pause,）：又称冬休性（,winter pause,）。,产蛋持久性,产蛋强度,休止性,就巢性,性成熟期。,蛋用性状（egg trait）的遗传4、就巢性（broodi,17,蛋用性状（,egg trait,）的遗传,蛋重（,egg weight or egg size,）,测量方法：国外一般,32-36,周龄中连续测定,3,天；我国学者建议,295-300,天内取,5,天平均蛋重。,h,2,=0.2-0.7,。,蛋用性状（egg trait）的遗传蛋重（egg weigh,18,蛋用性状（,egg trait,）的遗传,蛋品质（,egg quality,）,蛋壳品质（,shell quality,）,蛋壳形状（,shell shape,）：用蛋形指数（,egg index,）衡量，即纵径,/,横径或横径,/,纵经。,h,2,=0.25-0.5,蛋壳颜色（,shell color,）,h,2,=0.3-0.9,蛋用性状（egg trait）的遗传蛋品质（egg qual,19,蛋用性状（,egg trait,）的遗传,蛋壳品质（,shell quality,）,蛋壳结构（,shell texture,）：用三个指标，即蛋壳强度,(shell strength),、蛋壳厚度,(shell thickness),和蛋壳平滑性,(shell smoothness),衡量。,蛋壳强度用强度测定仪测定，分四级，正常应在,2-3,级之间。,蛋壳厚度可用厚度测定仪或千分尺测量，正常在,244-373nm,间，,h,2,=0.3,；也可用蛋比重（,specific gravity of eggs or egg density,）间接测量，正常比重在,1.070-1.080,间，,h,2,=0.3-0.6,。,蛋用性状（egg trait）的遗传蛋壳品质（shell q,20,蛋用性状（,egg trait,）的遗传,2、,蛋白品质（,quality of egg white,）,可用浓蛋白高度或转换成哈夫单位（,Haugh unit,）表示。,HU=100,lg(H-1.7,W,0.37,+7.57),浓蛋白高度,h,2,=0.15-0.55,；哈夫单位,h,2,=0.1-0.7,蛋用性状（egg trait）的遗传2、蛋白品质（quali,21,蛋用性状（,egg trait,）的遗传,3、蛋黄品质（,yolk quality,）：,用两个指标度量，即蛋黄颜色和蛋黄占全蛋的比例。,蛋黄颜色用罗氏比色扇测定，共分15级（由浅黄到深黄），正常应为12级以上。h,2,=0.15,正常蛋蛋黄约占全蛋30-35%（壳，10-12%；蛋白，55-60%）h,2,=0.1-0.4,蛋用性状（egg trait）的遗传3、蛋黄品质（yolk,22,蛋用性状（,egg trait,）的遗传,4、,血斑或肉斑（,blood spots or meat spots,）,种蛋容许率,2%,，,h,2,=0.1-0.5,蛋鸡部分性状的遗传力,蛋用性状（egg trait）的遗传4、血斑或肉斑（bloo,23,蛋用性状（,egg trait,）的遗传,Estimation of genetic parameters for clutch traits in laying hens(Y. Akbas et al., 2019,7,th,WCGALP 04-15),Genetic Stock.,egg production data of a commercial sire line at 6th generation.,Data.,The data collection period was from the 22nd to 40th weeks of age. Hens were artificially inseminated. In total 1980 animals were used from 43 sires and 8 dams per sire.,Traits recorded:,EN, egg numbers to 40 weeks of age for each individual.,CN, clutch number.,CS, average clutch size. Clutch size consists of number of days with consecutively laid eggs. At least one-day-break of oviposition was taken as the end of a clutch.,DELAY, mean delay of pause days between clutches.,ASM,Age at sexual maturity.,BWSM, body weight at sexual maturity age,蛋用性状（egg trait）的遗传Estimation o,24,蛋用性状（,egg trait,）的遗传,Statistical Analyses.,Model:,Y,ijkl,is any trait considered in this study,is the overall mean,f,i,is the fixed effect of the i,th,tier,s,j,and,d,k(j),are random effects of the sire and dam within sires,is the regression coefficient,x,is age at sexual maturity as a covariate,e,ijk,is the residual effect,.,Variance components for the traits were estimated by Restricted Maximum Likelihood (REML).,蛋用性状（egg trait）的遗传Statistical,25,蛋用性状（,egg trait,）的遗传,Results:,蛋用性状（egg trait）的遗传Results:,26,蛋用性状（,egg trait,）的遗传,蛋用性状（egg trait）的遗传,27,蛋用性状（,egg trait,）的遗传,Higher heritability estimates from dam component as compared to estimates from sire component suggest that some maternal and non-additive effects are significant for the traits.,CS, EN and CN are highly correlated traits with each other. CS has genetic correlations of -0.98, 0.82 and 0.58 with CN, EN and DELAY, respectively.,CN is negatively correlated with other traits considered.,High heritability of CN and CS indicate that these traits may be used in the selection index of laying hens because those traits are also highly correlated with EN.,蛋用性状（egg trait）的遗传Higher herit,28,繁殖力和生活力的遗传,繁殖力（,reproductive capacity,）家禽繁殖后代的能力。,1、,受精率（,fertility percentage,）,h,2,=0.05,繁殖力和生活力的遗传 繁殖力（reproductive ca,29,繁殖力和生活力的遗传,孵化率（,hatchability,）,h,2,=0.1-0.15,繁殖力和生活力的遗传孵化率（hatchability）,30,繁殖力和生活力的遗传,生活力,(viability),在一定外界环境条件下的生存能力。,1、,育雏率（,brooded percentage,）,h,2,=0.05,繁殖力和生活力的遗传 生活力(viability)在一定,31,繁殖力和生活力的遗传,2、存活率（,survival,）：,h,2,=0.05-0.1,繁殖力和生活力的遗传 2、存活率（survival）：h2=,32,饲料报酬,(feed remuneration),饲料消耗比（,feed consumption ratio,）,h,2,=0.2-0.6,饲料转化效率（,feed utilization efficiency,）：饲料营养物被家禽转化用于生产产品的百分率。,Genetic evaluation of feed efficiency traits in a white leghorn population(,R.C. Hazary,et al., 2019, 7,th,WCGALP, 10-18,),饲料报酬(feed remuneration) 饲料消耗比（,33,饲料报酬,(feed remuneration,Population and selection method.,Two White Leghorn populations viz. IWK and Control maintained as closed flock at Experimental Farm, Project Directorate on Poultry, Hyderabad, India was utilized in the present study. The IWK line was previously selected for increased egg production up to 64 weeks of age using a family index. The Control line was maintained as a random bred pedigreed population. Both lines were reproduced simultaneously and were reared under identical conditions of feeding and management,饲料报酬(feed remunerationPopulati,34,饲料报酬,(feed remuneration,Traits measured.,The individual traits measured included body weight (g) measured at four weekly interval starting from 20 weeks of age; average egg weight (g) at 24,28,32,36 and 40 weeks of age; egg production upto 20, 21-24,25-28,29-32,33-36, 37-40 and upto 40 weeks of age; feed consumption (g) from 21-24,25-28,29-32,33-36,37-40 and 21-40 weeks of age and age at sexual maturity (days). Utilizing the above information feed consumed per day (g), feed consumed per dozen egg (g) and feed consumed per kilogram of egg mass (g) were derived in the entire test periods as well as on over all period.,Residual feed consumption was only estimated in 21-40 weeks period as difference between expected feed consumption and actual feed consumption.,饲料报酬(feed remunerationTraits m,35,饲料报酬,(feed remuneration,饲料报酬(feed remuneration,36,饲料报酬,(feed remuneration,饲料报酬(feed remuneration,37,饲料报酬,(feed remuneration,饲料报酬(feed remuneration,38,饲料报酬,(feed remuneration,CONCLUSION,The results clearly show that the line selected for increased egg production is more efficient in utilization of feed as compared to control.,Residual feed consumption is a lowly heritable trait in this line suggesting that it cannot be utilized as a selection criterion to enhance efficiency of egg production.,It will be more appropriate to select on the basis of feed consumed per kilogram egg mass production that will not only take care of egg production because of its favorable association with egg production but also for egg weight since it is one of the component traits.,Genetic correlations of part period egg production with feed efficiency traits in the selected line were in general negative indicating that any attempt to improve feed efficiency would result in improvement in egg production efficiency.,饲料报酬(feed remunerationCONCLUSI,39,饲料报酬,(feed remuneration),剩余饲料消耗（,residual feed consumption,）：实际耗料量与据总产蛋量、体重和体增重计算出的理论耗料量之差。,h,2,=0.42-0.62,例：据,NRC,标准，,ME11.7MJ/kg,的日粮，理论耗料量为：,E(FC)=46.5B,W,0.75,+0.7,EM,+1.97,BWG,RFC=FI-E(FC),饲料报酬(feed remuneration) 剩余饲料消耗,40,饲料报酬,(feed remuneration),Residual food consumption as a tool to unravel genetic components of food intake(M. Tixier-Boichard et al., 2019, 7,th,WCGALP, 10-06),The concept of residual food consumption (RFC) was first proposed by Byerly (1941) as an approach to limit food costs in the laying hen.,The possibility to select on the fraction of total food intake which is not explained by maintenance requirements and production was, indeed, an appealing way to modify food efficiency without any change in production.,This was first investigated in poultry, for the laying hen rather than for the broiler, and, later, in mammals.,Extensive data have been obtained since 30 years on responses to selection on RFC in the laying hen, including metabolic studies, and, more recently, QTL detection.,饲料报酬(feed remuneration)Residua,41,饲料报酬,(feed remuneration),Prediction equation,.,The classical prediction equation is a linear multiple regression of observed food intake (FI) on two types of components (1) body weight (BW) or metabolic body weight, corresponding to maintenance requirement, (2) body weight gain (BWG) which may be partitioned in protein gain and fat gain, and/or exported product such as egg output, corresponding to production needs. An intercept is generally included.,RFC=FI-E(FC),E ( FC) = a + b,1,W G + b,2,EM + b,3,BW,0.75,E (FC) = Expected feed consumption. (gm/d),WG = Weight gain ( gm/d),EM = Egg mass production ( gm/d),BW,0.75,= Metabolic body weight (g),b,1, b,2, b,3,= Multiple regression coefficient,a = Constant.,Fixed effects may be added in addition to the covariables, in order to take into account effects of season, litter, or sex.,饲料报酬(feed remuneration)Predict,42,饲料报酬,(feed remuneration),Metabolic body weight is obtained as a power of body weight, the most frequently used value being 0.75.,In the laying hen, the power value may vary in the range of 0.5 to 1 without affecting the efficiency of the prediction, and body weight has been shown to be an important source of variation in food intake.,In the growing pig, however, performance recording is often done at a fixed body weight, and in that case, metabolic body weight does not contribute significantly to variation in food intake, but backfat thickness, and/or loin eye area have been considered as additional predictors of FI.,饲料报酬(feed remuneration)Metabol,43,饲料报酬,(feed remuneration),Another type of predictor to be added could be heat production. Indeed, from the point of view of bioenergetics, metabolizable energy is a function of (1) heat production, (2) energy retained as protein and (3) energy retained as fat. Thus, heat production is an obvious component of food efficiency.,When heat production was added in the prediction equation of food intake in the laying hen, the residual variation was significantly decreased, and this decrease depended on the ambient temperature and on the feather cover of hens, which is also an important parameter for heat dissipation.,饲料报酬(feed remuneration)Another,44,饲料报酬,(feed remuneration),Efficiency of the prediction equation,.,The residual variation in food intake which is not explained by variation in body weight and production level may represent from 10% to 50% or more of the total variation, according to species, breed, sex, age, and environment.,Regression coefficients on the different predictors will vary according to the same factors.,Patterns of energy exchange during growth may be compared between species, using metabolic weight as a reference, for instance, maximal energetic efficiency was shown to be reached at 20% of mature body size for mammals, whereas this maximal value was sustained to a higher degree of maturity for broilers chickens or quails.,This may have implications regarding the most suitable period to measure RFC during growth, according to species.,饲料报酬(feed remuneration)Efficie,45,饲料报酬,(feed remuneration),Within all species, RFC depends on the breed, for example:,Island-Red (RIR) layers and White Leghorn (WL) layers showed different regression coefficients, explained by different maintenance requirements, RIR showed higher body weight, % body fat, and % yolk in the egg, resulting in a higher energy content in the egg mass.,Differences,were also observed within breed between selected lines, for instance:,In pigs, the Landrace breed was found to have a higher RFC as compared to Yorkshire and Duroc breeds or to Large White breed.,Crossbreeding effects on RFC are not well documented ; one study on laying hens, obtained from crossing high and low RFC lines, showed no reciprocal effect and a negative heterosis, moderate but significant (- 3.6%), on RFC.,饲料报酬(feed remuneration)Within,46,饲料报酬,(feed remuneration),The effect of sex has not been studied to the same extent across species.,In pigs, data are generally obtained on boars only.,In cattle, both sexes have been measured but data have generally been pooled to estimate genetic parameters.,In the laying hen, selection has generally been done on female RFC records, but, in adult male chickens of a commercial white-egg laying strain, the regression on BW and BWG only, explained only 53% of total variation in FI, much less than that usually observed with a full model in females.,In the single experiment where RFC was measured and selected independently in adults of each sex the genetic correlation between the male RFC and the female RFC was 0.19, not significantly different from zero.,饲料报酬(feed remuneration)The eff,47,饲料报酬,(feed remuneration),Age at measurement is a factor to be considered at two levels: (1) time of measurement as compared to sexual maturity, and (2) length of recording period.,In chicken lines selected on RFC of the laying hen, a low phenotypic correlation (0.34) has been found between adult RFC and food efficiency of the growing chick, and no difference was found between food efficiency of growing chicks from two lines divergently selected on adult RFC. In these lines, divergence on RFC was shown to take place precisely at the time of sexual maturity.,Independent studies of the length of recording period in the laying hen showed that a short period, such as 4 weeks, starting after the peak of lay, was a good compromise between accuracy of prediction and cost of measurement. A slight decrease in the regression coefficient on egg mass and a marked decrease of the coefficient on body weight gain were found with increasing age in laying hens.,饲料报酬(feed remuneration)Age at,48,饲料报酬,(feed remuneration),The most relevant environmental factors to be considered for the efficiency of RFC estimation are temperature and food composition.,High ambient temperature is known to decrease RFC in pigs and genotype x environment interactions are to be expected when lines with high or low RFC are compared at two temperatures in the laying hen.,A low energy diet has been shown to decrease RFC, and a high protein content is expected to decrease RFC. Differences between laying hens divergently selected on RFC were maintained when protein content of the diet was modified, but performance of high RFC hens was more affected by a lower protein content than performance of low RFC hens.,Food spillage must be avoided, obviously, to measure,ad lib.,food intake, but differences in feeding behavior between lines or between individuals may cause some difficulty in the design of food recording systems.,饲料报酬(feed remuneration)The mos,49,饲料报酬,(feed remuneration),Genetic variability of RFC,饲料报酬(feed remuneration)Genetic,50,饲料报酬,(feed remuneration),Heritability would appear, however, to be slightly lower for RFC measured in growing animals (broilers) than in adults (laying hen) within the same species.,RFC is always positively correlated with total food intake, across species, start weight and weight gain.,Genetic correlations of RFC with its phenotypic predictors are of great interest in laying hens, correlations between RFC and BW or egg mass are generally low, and in the desirable direction.,In broilers, RFC was not correlated with its predictor, start weight and weight gain.,饲料报酬(feed remuneration)Heritab,51,饲料报酬,(feed remuneration),Correlated responses to selection on RFC,Heat production (HP).,Anatomical measurements related to heat dissipation, such as shank and wattle length in the laying hen, were modified by selection on RFC.,Significant differences were always found between high and low RFC lines, representing a 23% increase of total HP for females.,Sampling White Leghorn hens on extremely high or low RFC, in a single generation, revealed a difference ranging from 10 to 30% in total HP across two replicates.,The main component of the difference in HP was found to be Diet-Induced Thermogenesis (DIT), activity-related HP, and not basal metabolic rate.,饲料报酬(feed remuneration)Correla,52,饲料报酬,(feed remuneration),Behav