Effect of intravenous histidine or histidine peptide infusion on milk protein yield in lactating goats with an induced histidine deficiency

Abstract

Studies involving infusion of stable isotope labelled peptides have shown that the mammary gland has the ability to utilise peptide-derived AA for milk protein synthesis (Backwell et al., 1994a) and that peptides may be involved in the supply of phenylalanine to the mammary gland in vivo (Backwell et al., 1994b). The aim of the present experiment was to compare milk production responses to systemic (jugular vein) provision of histidine as free AA or as a peptide (glycyl-histidine) in lactating dairy goats with an induced histidine deficiency.