The improvement of the milk production in the sheep breeds and populations from various climatic areas

The researches made aimed to create certain sheep populations with high milk productions using the method of crossbreeding and selection, and also assuring optimum conditions of foddering and exploitation. During the experiments there were aimed: testing the capacity of combining of the local sheep with specialized breeds, establishing the optimum variants of crossbreeding, creating the first link of some populations (lines, breeds) specialized for milk, the milk productions at the half-breeds and the evolution of the body weight at the F1 and R1 half-breeds. The milk production of the F1 half-breeds, at the first lactation was superior to the local breeds as follows: F1 Lacaune x Prolific Line-Palas half-breeds _ made a total production of 176.43 ± 8.97 liters besides 146.78 ± 9.99 liters at the Prolific Line, the production of milked milk of 104.50 ± 9.39 liters besides 87.66 ± 8.48 liters at the Prolific Line; F1 Lacaune x Þurcanã half-breeds_made the total milk production of 152.74 ± 9.69 liters besides 116.92 ± 2.16 liters at the Þurcan breeds, and the production of milked milk was of 94.50 ± 1.46 liters and respectively of 69.0 ± 0.96 liters; F1 Awassi x Þigaie half-breeds_ made a total production of 218.0 ± 4.7548 liters besides 132.43 ± 2.4786 liters a the Þigaie breed, and the production of milked milk was of 162.44 ± 4.9408 liters, respectively of 80.0 ± 1.6634 liters. The results regarding the dynamics of the body weight at the R1 half-breeds from the five genotypes comparatively to the half-bred breeds (local) reveals that the specialized breeds have an improving effect upon the growing and development of the body weight in the interval of birth -9 months. The general conclusion is that through crossbreeding with specialized breeds and especially with Lacaune breed, the milk production of the half-breeds since the first lactation grows significantly in comparison with the local breeds. The method of improvement through crossbreeding is fast and efficient, the half-breed sheep perfectly adapting themselves to the climatic conditions from Romania.