Study on days open in a romanian black and white cow population from he western romania

The aim of the paper was to study the length of days open in Romanian Black and White cows according to county and parity. Researches were carried out on 3167 lactations obtained from 1200 cows reared in Timiş and Caraş-Severin counties. Average days open was 163.5 days (5 months and 11 days) for cows in Timiş County and 122.7 days (4 months and one day) for cows in Caraş-Severin County. The difference of 40.8 days in the favor of cows from Timiş County was significant (p<0.001). The longest period of days open was obtained in primiparous cows both in Timiş and Caraş-Severin, being 174.6 days (5 months and 22 days) and 139.0 (4 months and 17 days), respectively. The shortest length of days open was obtained for both counties in the third parity, being 150.8 days (5 months and 4 days) and 112.9 (3 months and 21 days), respectively. In Timiş County, primiparous cows had a significantly longer days open (p<0.05) compared to cows in second, third, fourth and seventh and over parities. There were no significant differences (p>0.05) for days open between parities for cows in Caraş-Severin County.