The retention of certain minerals in pigs from birth to 90 kg live weight

Abstract

SUMMARYA method of preparation of the whole bodies of pigs, suitable for the analyses of their mineral contents, has been described. Two litters of pigs were slaughtered at birth and another two at 8 weeks of age and each pig was analysed for whole body content, of Ca, P, Mg, Na, K and Cl. From another litter of pigs a gilt and castrated male were slaughtered at 23, 41, 54 and 90 kg live weight and their bodies analysed for the same elements. The data were used to derive a series of regression equations relating mineral contents to empty body weight for pigs at birth, 8 weeks of age and from 23 kg to 90 kg live weight. The regression coefficients, which provide a measure of the amount of a particular mineral retained in g/kg increase in empty body weight were, for pigs at birth Ca, 7·9; P, 6·3; Mg, 0·3; Na, 1·5; K, 1·9; Cl, 4·8; for pigs at eight weeks of age, Ca, 13·3; P, 7·4; Mg, 0·5; Na, 1·6; K, 2·3; Cl, 1·7; and for pigs from 23–90 kg live weight Mg, 0·4; Na, 1·3; K, 2·0; Cl, 1·1. For the older pigs Ca and P retentions (g/kg increase in empty body weight) ranged from 13·5 (Ca) and 7·6 (P) at 23 kg empty body weight to 4·3 (Ca) and 1·0 (P) at 90 kg empty body weight.