Heritability and genetic correlations of body weight and surgically removed abdominal fat in Coturnix quail.

Thirty-seven male Coturnix quail were weighed (99 g) and anesthetized. The leaf fat (1.35 g) was surgically removed from these birds at 58 days of age. Ten days later, they were single-pair mated and produced 141 male and 137 female offspring. The offspring weighed 107 g (males) and 114 g (females) at 58 days of age and had 2.53 g (male) and 1.31 g (female) of leaf fat. Estimates of heritability of body weight were .74 +/- .21 (sire-son regression), .69 +/- .22 (sire-daughter regression), .67 +/- .18 (full-sib analysis for males), and .73 +/- .18 (full-sib analysis for females). Heritability estimates of leaf fat were .71 +/- .33 (sire-son regression), .58 +/- .34 (sire-daughter regression), .65 +/- .18 (full-sib analysis for males), and .33 +/- .17 (full-sib analysis for females). Genetic correlations between body weight and leaf fat using the sire-offspring relationship were .77 +/- .10 and .74 +/- .22 for sons and 1.01 and .90 +/- .06 for daughters when estimated by arithmetic and geometric methods, respectively. Corresponding genetic correlations from the full-sib analyses were .82 +/- .08 (males) and .55 +/- .21 (females). Environmental correlations were .80 +/- .11 (males) and .87 +/- .47 (females), and phenotypic correlations were .82 +/- .09 (males) and .64 +/- .28 (females). Males had the highest percent of fat (2.5%) as compared with females (1.2%), a reversal of the broiler chicken relationship. The surgical technique developed in this experiment might be used for estimating abdominal fat in young chicken broilers. It was concluded that Coturnix quail could be used as a pilot animal in abdominal fat research provided due caution was taken of the differences between the two species.