THE CHEMICAL COMPOSITION OF BOVINE MAMMARY SECRETIONS INDUCED BY THE SUBCUTANEOUS IMPLANTATION OR ORAL ADMINISTRATION OF SYNTHETIC OESTROGENS

The only study so far recorded of the chemical composition of milk produced by ruminants artificially brought into lactation by treatment with synthetic oestrogens, carried out by Folley, Scott Watson & Bottomley [1941b], showed that the milk from virgin goats receiving regular udder inunctions with 1 % diethylstilboestrol ointment underwent changes qualitatively similar to those occurring after parturition during the transition from colostrum to normal milk. These changes, which took place more gradually in oestrogen-treated than in normal parturient animals, follow the initial secretion of fluids characterized by high fat and non-fatty solid (S.N.F.) contents, coupled with a high total nitrogen value, an abnormally low casein number and a high globulin number. No parallel study has hitherto been made upon artificially induced mammary secretions in the bovine, though Folley [1936] investigated the effect of natural oestrogens on milk composition in established lactation in this species and observed increases in fat and s.n.f. values. Similar results were obtained with synthetic oestrogens [Folley et al. 1941]. EXPERIMENTA