Genetic correlations among growth, feed, and carcass traits of broiler sire and dam populations.

Genetic correlations based on sire variance and covariance components were estimated for broiler traits. Data were collected from various selected and control strains of sire and dam populations during five generations of selection. Results of analyses of variance for each of the strains within generations and populations were pooled across strains and generations. Correlations between body and carcass weights were all above .8. Weight gain (WG) had similar correlations with these traits with the exception of body weight at 28 days (.57 in site and .69 in dam populations). Body and carcass weights and WG had high correlations with feed consumption (FC) (greater than .7); however, values for feed efficiency (FE) varied: -.58, -.23 for 28-day body weight; -.17, .16 for 42-day body weight; .25, .43 for WG; and .53 in the dam population for carcass weight. Correlations of body and carcass weights and WG with abdominal fat weight (AFW) and percentage (AFP) were generally small to moderate with values being about half as large for AFP as for AFW. Feed consumption and FE were negatively correlated (-.51, -.22) in both populations. In the dam population, FC was positively correlated with AFW and AFP (.42, .55) but FE was negatively correlated with these traits (-.41, -.70). Abdominal fat weight and AFP were highly correlated (.99, .97). Values tended to be similar not only for these populations but also for this and other studies. Simultaneous genetic improvement of growth rate, FE and carcass leanness is feasible in broilers. Selection for WG, FE, and AFP should be effective.

[1]  B. Leclercq.  Genetic selection of meat-type chickens for high or low abdominal fat content , 1988 .

[2]  A. Cahaner.  Experimental divergent selection on abdominal fat in broilers — parental female and male type lines and their crosses , 1988 .

[3]  F. Leenstra.  Fat deposition in a broiler sire strain , 1987 .

[4]  I. Nir,et al.  Weight and Fat Content of Adipose and Nonadipose Tissues in Broilers Selected For or Against Abdominal Adipose Tissue , 1986 .

[5]  Z. Nitsan,et al.  Evaluation of simultaneous selection for live body weight and against abdominal fat in broilers. , 1985, Poultry science.

[6]  L. W. Mirosh,et al.  Genetic variation of abdominal fat, body weight, and carcass weight in a female broiler line. , 1984, Poultry science.

[7]  A. Fortin,et al.  Relationships Between Carcass Fatness and Feed Efficiency and Its Component Traits in Broiler Chickens , 1983 .

[8]  W. Becker,et al.  Genetic correlations between six- and seven-week-old broilers. , 1983, Poultry science.

[9]  A. Fortin,et al.  GENETIC CHANGES IN MEAT-TYPE CHICKENS IN THE LAST TWENTY YEARS , 1981 .

[10]  L. W. Mirosh,et al.  Abdominal and carcass fat in five broiler strains. , 1981, Poultry science.

[11]  B. Leclercq,et al.  Selecting broilers for low or high abdominal fat: initial observations. , 1980 .

[12]  L. W. Mirosh,et al.  Prediction of Fat and Fat Free Live Weight in Broiler Chickens Using Backskin Fat, Abdominal Fat, and Live Body Weight , 1979 .

[13]  R. Pym,et al.  Selection for food conversion in broilers: Direct and correlated responses to selection for body‐weight gain, food consumption and food conversion ratio , 1979 .

[14]  R. Pym,et al.  Selection for food conversion in broilers: Body composition of birds selected for increased body‐weight gain, food consumption and food conversion ratio , 1979 .

[15]  K. Washburn,et al.  Influence of genetic differences in feed efficiency on carcass composition of young chickens. , 1975, The Journal of nutrition.

[16]  S. P. Wilson.  Genetic aspects of feed efficiency in broilers. , 1969, Poultry science.

[17]  R. Rouvier,et al.  ÉTUDE DE LA COMPOSITION ANATOMIQUE DU POULET. I. — VARIABILITÉ DE LA RÉPARTITION DES DIFFÉRENTES PARTIES CORPORELLES CHEZ DES COQUELETS « BRESSE-PILE » , 1967 .

[18]  E. S. Merritt.  Estimates by sex of genetic parameters for body weight and skeletal dimensions in a random bred strain of meat type fowl. , 1966, Poultry science.

[19]  J. H. Smith,et al.  A Genetic Analysis of Growth and Egg Production in Meat-Type Chickens , 1962 .

[20]  C. H. Thomas,et al.  The Relationship Between Feed Conversion and Ether Extract of Broilers , 1958 .

[21]  B. B. Bohren,et al.  An Analysis of Feed Efficiency among Breeds of Chickens and Its Relationship to Rate of Growth , 1954 .

[22]  W. L. Blow,et al.  Efficiency of Selection for Broiler Growth at Various Ages , 1953 .