FAT-CONTENT, FATTY-ACID COMPOSITION AND VITAMIN CONTENT OF MARES MILK

Changes in the fat content and fatty acid composition as well as the v itamin content of mare's colostrum and milk during the first 45 days o f lactation were studied. Milk samples (300-800 cm(3)) from 29 lactati ng mares, were collected daily at the beginning of the lactation, and weekly from 5 to 45 days postpartum. Colostrum and early milk samples were obtained by hand, without oxytocin administration, while the foal nursed. Later milk samples were taken from mixed milk of the totally- milked udder. Each sample was analysed for total solids, fat content a nd fatty acid composition by conventional methods and Packard gas chro matograph. The total solids and the fat content of the colostrum and m ilk were 24.25 to 26.28% and 2.85 to 2.93% on the first day of lactati on, 12.15 to 12.78% and 2.05 to 2.17% on the 2nd to 5th day and 10.37 to 10.61% and 1.04 to 1.32%, respectively, on the 8th to 45th days of lactation. The concentrations of octanoic, decanoic, dodecanoic, miris tic and palmitoleic acids increased with time while stearic, oleic, li nolic and linolenic acids decreased. The fatty acid composition of mar e's milk fat was very different from that of cow's milk fat. Mare's mi lk fat contained octanoic, decanoic, dodecanoic, linolic, linolenic, s tearic, miristic and palmitic acids, in ratios of approximately 9.6, 3 .1, 2.1, 4.4, 224, 0.2, 0.6 and 0.5 times those of concentrations in c ow's milk. On the basis of the differences in fatty acid composition, a new method for determining the amount of cow's milk mixed with mare' s milk was developed. Content of vitamins A, D-3, K-3 and C of colostr um (0.88, 0.0054, 0.043, 23.8 mg/kg) was found one and half time - twi ce higher than that of normal milk (0.34, 0.0032, 0.029, 17.2 mg/kg). There was no significant difference in vitamin E content (1.342 and 1. 128 mg/kg). Vitamin content of mare's milk was very similar to that of cow's milk.