INFLUENCE OF SEASON ON PRODUCTIVE PERFORMANCES AT BROWN BREED EXPLOITED IN NORTH PART OF ROMANIA

Roxana Georgiana Mihalache, I. Gîlcă, Alina Narcisa Postolache, Roxana Nicoleta Raţu, M.M. Ciobanu

Abstract
   The main objective of dairy cattle’s exploitation is the one to find an efficient economical path for increasing of milk production and quality. The results presented in the current study were obtained after an ample research which aimed to complete the information regarding quality of milk gathered from Brown breed cattle exploited in the N-E area of Romania.
   To achieve the proposed targets, research was carried out in according with an experimental design based on considerations regarding milk production and determination of milk quality by specific physical-chemical analysis during four seasons, aiming the following parameters: fat, protein, casein and lactose.
   For fat percentage, the lowest mean value was 3.24% (recorded in spring season) and the highest one 3.98%, (recorded in winter season). There are very significant differences (p<0.001) for fat percentage between seasons: autumn-winter; summer-winter; autumn-spring; summer-spring and insignificant differences (p>0.05) for seasons: spring-winter; autumn-summer.
   For protein percentage were calculated mean values between 3.46% and 3.61%, during spring months, respectively autumn months. The mean values calculated in the current study are in according with the limits from literature.
   Regarding casein percentage, in our own research were calculated mean values between 2.71% (summer) and 2.83% (winter).

Key words: Parameters; Casein; Lactose