Short communication: Effects of dietary N-carbamoylglutamate supplementation on the milk amino acid profile and mozzarella cheese quality in mid-lactating dairy cows

摘要

N-Carbamoylglutamate (NCG) is an enhancer ofArg, which is a functional AA and could prevent cardiovasculardisease and improve immunity. The presentstudy was conducted to investigate the effects of supplementingNCG in diets of lactating cattle on the NCGconcentration and AA composition of raw milk andon mozzarella cheese quality. Thirty multiparous cowswith a mean body weight of 669 kg (standard deviation= 71) and days in milk of 176 (standard deviation =55) were blocked based on parity and milk productionand randomly assigned to 1 of 2 treatments: basal diet(CON) and basal diet supplemented with 40 g of NCGper day per cow (NCG). After 8 wk of treatment, rawmilk samples were collected from the 2 groups for AAanalysis and mozzarella cheese-making. Furthermore,the NCG concentration and distribution in milk andmozzarella cheese were detected. The AA concentrationin milk was greater and the NCG concentration in rawmilk was approximately 6 times greater in the NCGgroup than in the CON group. No NCG was detectedin cheese from the CON group, and very little NCG(<1.0 μg/kg) of cheese was detected in the NCG group.Most of the dietary NCG was transferred into whey,stretch water, and brine during cheese production. Nosignificant difference was found between the 2 groupson cheese texture and color except that hardness waslower in the NCG group. Overall, the results indicatedthat dietary supplementation of NCG could improvethe NCG and AA concentrations in raw milk withoutaffecting the quality of cheeses such as mozzarella.