CONCENTRATIONS OF IMMUNOGLOBULIN IN MAMMARY SECRETION OF RUMINANTS DURING INVOLUTION WITH PARTICULAR REFERENCE TO SELECTIVE TRANSFER OF IgG₁

Abstract

Summary Involution of the mammary gland was initiated by stopping milking in 8 cows in the eighth to tenth month of lactation, in 4 ewes which had been lactating less than 7 weeks and in a further 6 ewes lactating more than 12 weeks. In all animals the concentrations of immunoglobulins in the mammary secretion—IgG1, IgC2, IgA and IgM—increased as involution progressed. In the cows and in those ewes in early lactation there was a transitory increase in selective transfer of IgG1 during the initial phase of involution. Subsequently, the glandular epithelium completely lost its ability to selectively transfer IgG1, and the results indicated that the loss of structural integrity of the epithelium characteristic of advanced involution allowed a ready equilibration of proteins between the secretion and interstitial fluid. There was no suggestion of a transitory increase in selective transfer of IgC1 in those ewes involuted late in lactation.

REVIEW ARTICLE: An integrated view on how the management of the dry period length of lactating cows could affect mammary biology and defence

“…The concentration of all immunoglobulin classes, i.e. IgG 1 , IgG 2 , IgA and IgM, increase markedly by the first week of the dry period (Watson et al., 1972).…”

Immunological Functions of the Mammary Gland and Its Secretion-Comparative Review

“…In other words an antigenic insult results in impairment of the selective transport mechanism, breaching of the epithelial barrier (which would otherwise discriminate in the transfer of protein into secretion) and allows leakage of interstitial fluid into the mammary secretion. It has been observed that following antigenic insult, when signs of acute inflammation have disappeared, but when milk production is still depressed, there appeatsto be an increase in the magnifude of the selective transfer ofIgG 1 into milk (Lascelles 1969;Harmon et al 1976)~_ This appears to be another example of the inverse relationship between selective transport of IgG 1 and de novo synthesis of milk constituents in the gland (Watson et al 1972).…”

The Origin of Antibody in Intestinal Secretion of Sheep

“…Those fractions containing protein were pooled according to their position on the optical density profile, concentrated by dialysis, and their antibody content determined using the above assay techniques. The presence of each class of immunoglobulin was detennined by double diffusion in agar against monospecific antiserum prepared as described by Watson, Brandon and Lascelles (1972).…”