| Presuckle colostrum and 36 h postpartum lamb serum immunoglobulin G(,1) (IgG(,1)) concentrations were measured in ewes and lambs from Polypay, Rambouillet, Targhee, Columbia, Finnish Landrace, and Finn cross sires. Significant effects in colostrum included dam's sire breed, dam's sire, age of ewe, number of lambs born. A fetal stimulus may exist to increase the mass of IgG(,1) in colostrum available for multiple births. Significant effects in lamb serum IgG(,1) concentration were lamb's sire within breed, birth type, and regressions of lamb serum IgG(,1) on dam's colostral IgG(,1) and on day born. Sire breed, sex of lamb, and age of dam were not significant. The heritability of IgG(,1) by paternal half-sib analyses was .19 for colostrum and .18 for lamb serum.;Immunoglobulin G(,1) concentration was measured in presuckle colostrum and calf serum obtained at 36 h and at weaning from inbred and straightbred Angus, Brangus, Hereford, Red Angus, and Simmental cattle. Line of sire of dam, sire of dam within line, age of dam, and linear regression of colostral IgG(,1) concentration on inbreeding of dam were not significant. Sire, line of sire of dam, sex of calf, and calving score were significant in 36 h serum IgG(,1) concentration, while only line of sire of dam was significant for IgG(,1) in calf serum at weaning. Age of dam was not significant in either analysis. IgG(,1) concentration in the newborn calf decreased with increasing calving difficulty. Level of inbreeding has no influence on IgG(,1) concentrations except when 36 h calf serum was considered a trait of the dam. The heritability of IgG(,1) concentration was .17 in colostrum, .60 in 36 h calf serum, and .28 in calf serum at weaning. |
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