Activity of selected aminopeptidases of whole milk in cows as related to feeding season (autumn/winter vs spring/summer)

摘要

Aminopeptidases play a crucial role in animals metabolism Their activity in degrading proteins and peptides is also important in milk processing industry. Activity of AlaAP, LeuAP and ArgAP was determined in whole milk of Polish Red cows (mean yield 4200 kg per lactation) at the end of autumn/winter (A/W) and then at the end of spring/summer (S/S) feeding season — 23 and 19 cows, respectively. Feeding was typical of seasons: silages, hay, and concentrates during A/W, or grazing and concentrates during S/S. The activity of all three enzymes was found significantly higher in milk of cows at the end of S/S than at the end of A/W season.