Effect of Whey Protein Concentrate on Postprandial Changes in Plasma Concentrations of Retinol and Triglyceride in Preruminant Calves

Abstract

Four Holstein male calves were used to study the effect of whey protein concentrate (WPC) on postprandial changes in plasma retinol and triglyceride concentrations. Suckling tests were conducted on the calves using Holstein cow whole milk mixed with Vitamin A acetate, with or without WPC, at weekly intervals from immediately after birth to 6 weeks of age. A catheter was inserted into a jugular vein and blood samples were taken from just until 8h after the feeding of the whole milk at 0800h. Plasma retinol and triglyceride concentrations were determined by HPLC and enzymatic methods, respectively.The concentrations of plasma retinol increased gradually following the feeding of both milk. However, no significant effect of WPC on plasma retinol was found. On the other hand, the plasma concentration of triglyceride in the calves fed the milk with WPC were significantly higher than that of the calves fed the milk without WPC 8 h after the feeding. This suggests that WPC participates in milk fatty acid metabolism and not in retinol transport in preruminant calves.

Effect of β-lactoglobulin on plasma retinol and triglyceride concentrations, and fatty acid composition in calves

“…In the second phase of the present study, the concentrations of plasma triglyceride in calves at 10 d of age were significantly higher in those given the β-lg diet than in the control calves during the period from 7 to 11 h after feeding. In a previous study, we clearly showed that preruminant calves fed whey protein concentrate (WPC) had significantly higher concentrations of plasma triglyceride than control calves (Kushibiki et al 1997). Because β-lg is a major protein in WPC, this response may be partly dependent upon the higher β-lg content of a milk diet (Kushibiki et al 1997).…”

“…In a previous study, we clearly showed that preruminant calves fed whey protein concentrate (WPC) had significantly higher concentrations of plasma triglyceride than control calves (Kushibiki et al 1997). Because β-lg is a major protein in WPC, this response may be partly dependent upon the higher β-lg content of a milk diet (Kushibiki et al 1997). On the other hand, β-lg of ruminants isolated from milk by non-denaturing methods contains several bound lipids, mainly triglyceride and long-chain fatty acids (Perez et al 1989).…”