Effect of Mummified Fetuses on the Prolificacy of Holsteins

Breed and clinical records of 2,607 cows for 30 years, from a Holstein herd which was supervised by one man for 25 years, were used in this study. Mummified fetuses were produced by 1.1% of the cows, with gestations ranging from 131 to 342 days, involving 0.43% of the parturitions. These cows were above the herd average in reproductive periods and in average age. Heritabflity was estimated at 16% when service sire was excluded. Mummified fetuses resulted in 0.6% of the cases when hulls, postulated as heterozygous, were mated to daughters of other heterozygous bulls. There is no evidence that mummified fetus is transmitted as a single recessive in a simple Mendelian way. Editor.