Variability of Production Traits in First Lactation Romanian Spotted Breed Heifers

Ninety-five first lactation cows of the Romanian spotted breed were used, to study the production traits of the breed and its potential for genetic improvement, in the Buziaş farm, Timiş County. The data were statistically subjected to analyses of variance, for phenotypic parameters: milk, fat and protein yield, fat and protein percentage. Average milk yield per lactation over a standard 305-day lactation length was 3920.63 ± 571.99 kg (ranging from 2598.1 to 5298.7 kg), while fat and protein yields averaged 153.45 ± 22.68 kg (ranging from 98.44 to 208.11 kg) and 126.46 ± 21.08 kg (ranging from 76.51 to 177.35 kg), respectively. A good fat percentage of milk (3.81% ± 0.35) and protein (3.19% ± 0.31) was registered. Milk and fat yield were strong and positive correlated (r = 0.9511). A stronger correlation was registered between milk and protein yield (r = 0.9748). For fat and protein percentage, correlations with milk yield were very low positive, ranging from 0.0648 to 0.0812. Results obtained show that in the studied heifers herd there is a nucleus of positive variants for milk, fat and protein yield, which can be selected to form a valuable dairy cows herd.