HERITABILITY OF CHRONIC INTERSTITIAL NEPHROPATHY AND ITS GENETIC-RELATIONSHIPS WITH LAYING INTENSITY AND BODY-WEIGHT IN MUSCOVY DUCKS

Heritability of chronic interstitial nephropathy was estimated from an alysis of all-or-none traits for 1969 female Muscovy ducks, which were the progeny of 47 sires and 263 dams. Heritability estimates for the sire and dam components were 0.57 and 0.32, respectively. From sire or dam components of variance, genetic correlations with total number of eggs laid were 0.29 and 0.44 and with body weight at 10 wk were 0. 18 and 0.08. Existence of a major gene affecting resistance to the disea se was suspected. These results suggest that selection for resistance against this disease could be effective without excessive losses in la ying intensity or body weight.