Fluorescence was provided by FITC with the same method of labeling indicated for acetylcholinesterase. The experimental results obtained show that 10 min after catechol addition, there is a decrease of fluorescence emission that is correlated to the pesticide concentration. The graphs of Fig. 4B show Fc absolute values.
3.4. Quality of milk production checked as content of urea, lactose and lactic acid
As previously mentioned, the safety and quality of milk are correlated with cow health. Chemical contaminants may indirectly increase the vulnerability to mastitis through the disruption of the endocrine and immune systems. In its turn, mastitis may affect the Vandetanib of contaminants in milk . Animals with mastitis produce milk of poorer quality and may be identified through the unusual production of metabolites such as great quantity of urea and lactic acid and low amount of lactose.
3.4.1. Urease for analyses of urea content
Urease belongs to hydrolase enzyme family and catalyzes the hydrolysis of urea to form ammonia and carbamate. It is produced by bacteria, fungi, yeast and plants where it catalyzes the urea degradation in order to supply these organisms with a source of nitrogen for growth . Urea is a metabolite produced in liver and kidneys from ammonia, deriving from the degradation of crude proteins in the rumen with a concentration in healthy cows between 23 and 35 mg/dL. High concentrations of urea generally accompany typical pathologies of hyperammonaemia (metabolic alkalosis, reduced fertility, lameness, etc.) determining negative quality characteristics. Lower levels of urea in milk are often the result of insufficient protein intake in the diet .