Concentração da glutamina e composição do leite em vacas holandesas durante a lactação

Abstract

The objective of this research was to measure the concentration of glutamine (GLN) plus glutamate (GLU) in milk and blood of dairy cows, milk composition ([Lactose], [Fat], [Protein], [Total solids]) and somatic cell count (SCC) in different periods of lactation, and the concentration of these amino acids in the blood of their calves Samples of blood and milk were collected from 21 Holstein cows during five months of lactation (first, second, third, fifth and tenth) and serum samples from 28 calves in first three months of life. The results were analyzed by ANOVA, with 5% of significance and the Tukey test, with the same level of significance. There was not statistical difference (P>0,05) in [GLN + GLU] in the blood of the cows and calves, neither in the concentration of these amino acids in the milk; [Lactose], [Fat] and CCS also were not affected (P>0,05). It was observed higher protein content (P<0,05) in the fifth and tenth months of lactation (~ 3,61% in both) relative to the first, second and third months; the total solids was higher in the tenth month (~12,92%) related to the first and second months of lactation (~ 11,83% and ~ 11,81%, respectively). The period of lactation did not affect [glutamine] plus [glutamate], neither in the concentration of these amino acids in milk. SCC, [lactose] and [fat] did not change, and only [protein] and [total solids] were significant different. There was no correlation with age of calf and [glutamine] plus [glutamate].