Absorption of colostral IgG1 by the newborn lamb: influence of the length of gestation, birthweight and thyroid function.
The relationships between the length of gestation, the birthweight, thyroid and adrenocortical function, and the absorption of colostral IgG1 were studied in 18 Romanov lambs born spontaneously between 135 and 145 days of gestation. All the lambs were bottle-fed in accurately standardised conditions with a bovine colostrum pool. Negative relationships were observed between the maximum plasma IgG1 levels and the length of gestation, the birthweight, or the plasma thyreostimulin levels near birth and between the times at which the maximum plasma IgG1 levels occurred and the length of gestation, or the plasma thyroxine levels near birth. The half-lives of bovine IgG1 in the plasma of the lambs were also related to the plasma thyroxine level at birth. These results suggest that maturity of the newborn lamb, assessed by the length of gestation and the hormonal status, could greatly influence the acquisition and maintenance of colostral immunity.
D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism* / Q000502:physiology; D001724:Birth Weight; D003126:Colostrum / Q000276:immunology*; D005865:Gestational Age; D007074:Immunoglobulin G / Q000378:metabolism*; D012756:Sheep / Q000378:metabolism* / Q000502:physiology; D013961:Thyroid Gland / Q000502:physiology*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood
D007074:Immunoglobulin G; D013972:Thyrotropin; D013974:Thyroxine