Influence of varying ranges milk urea nitrogen on chemical, hygienic and physical quality traits of cow milk

The aim of our research was to investigate theinfluence of predetermined value ranges incow milk components on milk quality regarding chemical, physical and hygienic aspects. It also aims to identify optimal values o be used in dairy cow farm management, with potential economic efficiency impact, through a morerational use of ration protein. The predetermined value ranges of milk urea were structured between <22 mg/dl and >40 mg/dl, milk urea nitrogen (MUN) within values <10 mg N/dl and >19 mg N/dl, protein from <3% to >3.5% and somatic cell count (SCC) with values between <100 SCC/ml x 10(3) and >400 SCC/ml x 10(3) and investigated urinary excretion nitrogen losses. We analyzed 1591 samples of milk obtained during spring period, which were processed and interpreted statistically. Milk samples were obtained from 1591 head Friesian - Black Spotted Breed raised in Transylvania, Romania with a body weight of 645-680 kg, milk production of 9.981 kg / year with a UNIFEED feeding system. The results of this research show that the optimal value range for milk urea isbetween 23-31 mg/dl, with milk urea nitrogen (MUN) between 10-15 mg N/dl and urinary excretion losses (UEN) between 197-270 g N/day/head.