Covariances Among First-Lactation Milk Records of Cousins

Covariances among first-lactation milk records of cousins.

Covariances among first-lactation milk records expressed as deviations from herdmate averages of Holstein cows related as cousins of varying degree, as daughterdan1, as full and maternal sibs, and as aunt-niece of varying degree were examined to dete~nine whether genetic maternal effects are important. The multiple regression of the expected coefficients of additive direct, additive maternal, d...

Genetic covariances among relatives for dairy lactation records.

Linearity of heritability of Holstein first-lactation milk production.

The regression of daughter on dam first-lactation milk deviations from herd-mate averages was found to be linear from an analysis of 47,400 Holstein pairs. The linear equation was y=-25 .6 + .210 (x -27.6) and the quadratic equation was y-----25.6 + .208 (x -27.6) + .0000222 (x~-44131.4) with correlation coefficients, .18258 and .18268, respectively. These results suggest that selection respons...

Human milk IgA concentrations during the first year of lactation.

AIMS To measure the concentrations of total IgA in the milk secreted by both breasts, throughout the first year of lactation, in a cohort of Gambian mothers of infants at high risk of infection. SUBJECTS AND METHODS Sixty five women and their infants were studied monthly from the 4th to 52nd postpartum week. Samples of milk were obtained from each breast by manual expression immediately befor...

Hypopituitarism in first cousins.

There is still much difficulty in elucidating the aetiological causes of dwarfism as it presents itself in children. After Erdheim in 1916 attributed dwarfism to a lack of pituitary secretion, it was for many years a common habit to implicate a pituitary deficiency in alJ dwarfs whatever their clinical features. A reaction to this unscientific approach was to be expected, and it has been so ext...