The concentrations of some water-soluble constituents in the milks of cows, sows, ewes and goats

Abstract

The concentrations of lactose, potassium, sodium, chloride and citric acid were determined in milks of cows, sows, ewes and goats. For cows, sows and ewes trends with lactation are reported and for all species correlations between constituents in milks secreted in mid-lactation are given. The results are discussed in relation to the secretion of water-soluble constituents in milk.

Concentration of citrate in the mammary secretion of sows during lactogenesis II and established lactation

“…The concentration of citrate in the milk of the sows declined by ~ 30 % between days 2 and 6 post partum and then remained relatively constant (Figs 1 and 2). These findings are consistent with those of Konar et al (1971) who also observed a decline in the concentration of citrate in sows' milk during the first week of lactation. Studies on the permeability and ultrastructure of the mammary epithelium in a number of animals have suggested that the tight junctions that connect the epithelial cells in the mammary glands are ' leaky' during pregnancy and allow the direct passage of ions and small molecules such as lactose between milk and the extracellular fluid by a paracellular pathway (Pitelka et al 1973;Linzell & Peaker, 1974).…”

“…More recently, Arthur et al (1989) have shown that milk citrate was a useful marker of lactogenesis II in women, and found that changes in citrate in milk provided biochemical evidence of the delay in lactogenesis II experienced by insulindependent diabetic mothers. Although Konar et al (1971) determined the concentration of citrate in sows' milk during established lactation, the concentration of citrate has not been examined in the mammary secretion of this species during the initiation of lactation.…”

The composition of Alpine goats' milk during lactation in Greece

“…A highly significant negative correlation was observed between Na and K which is in accordance with the findings of Storry et al (1983), but is not consistent with the results of Konar et al (1971) who reported that Na was positively but not significantly correlated with K. Significant negative correlation was found between Na and lactose which is in agreement with the results of Storry et al (1983). K was positively correlated with lactose which disagrees with the results of Konar et al (1971) and of Storry et al (1983) who reported that K was negatively but not significantly correlated with lactose. There was a significant positive correlation between K and citrate.…”

Effect of ACTH and oxytocin treatment on lactoferrin and citrate in cows' milk

“…In normal milk the LF concentration is reported to be 0-1-0-3 mg/ml (Bishop et al 1976) and citrate concentration is reported to be 0-9-2-0 mg/ml (Faulkner & Peaker, 1982;Konar et al 1971). Both citrate and LF concentrations in milk undergo dramatic changes during involution and lactogenesis (Peaker & Linzell, 1975;Smith et al 1971).…”