Changes in the secretion rate and production of colostrum by ewes over the first 24 hpost partum

Abstract

AbstractAn experiment was conducted to examine the changes in colostrum secretion rate and colostrum composition in ewes over the first 24 h post partum. Sixteen mature Suffolk × Cambridge ewes, which had produced one to four lambs, were used. Colostrum yield was estimated within 1 h of parturition and colostrum secretion rate measured between 3 and 6 h, 9 and 12 h, 15 and 18 h and 21 and 24 h post partum. Samples of colostrum were taken at each milking and the composition analysed. The mean yield (g) of colostrum at 1 h was 801 (s.d. 568·9) with a range from 35 to 2450 g. Mean secretion rates, in g/h, at 3 to 6 h, 9 to 12 h, 15 to 18 h and 21 to 24 h were 120 (s.d. 67·0), 104 (s.d. 55·2), 112 (s.d. 49·8) and 109 (s.d. 41·1) respectively. At 1 h, mean concentrations, in g/l, of total solids, fat, protein, ash and IgG were 367 (s.d. 76·9), 132 (s.d. 43·7), 203 (s.d. 43·2), 9.6 (s.d. 2·4) and 116 (s.d. 30·2) respectively. Corresponding values at 24 h were 242 (s.d. 38·8), 122 (s.d. 39·5), 71 (s.d. 11·2), 6.8 (s.d. 1·0) and 15 (s.d. 12·5).Sequential samples were taken throughout the milking process within 1 h of paturition from a further eight Dorset-cross ewes. There were no significant differences in the composition of colostrum due to stage of milking, although there was a suggestion that fat content was higher in the final sample than the first (140·1v.104·1 g/l, P = 0·084). It is clear that there is a large amount of variation in the secretion rate and composition of colostrum produced by ewes over the first 24 h post partum. However, a single sample taken between 3 and 12 h post partum would be a good indicator of 24 h yield (r = 0·88) and composition (total solids, r = 0·90 and IgG, r = 0·93).