he aim of this paper was to study the influence of the calving interval on the days in milk and total milk production traits in Romanian Black and White cows raised in the Didactical Station farm. Researches were carried out on 125 lactations, divided into three classes according to the calving interval length. The classes were up to 350 days, from 351 to 450 days, and above 450 days. Total days in milk increased from 260.3±17.03 when calving interval was below 350 days to 331.6±5.28 when calving interval was 351-450 days. The maximum days in milk was obtained for a calving interval equal or longer than 450 days (431.3±8.55).Milk yield per whole lactation increased from 4823.4±368.18 kg when calving interval was up to 350 days to a maximum of 5280.4±129.35 kg for a calving interval between 351 and 450 days. For a calving interval over 450 days the milk yield was 5043.6±114.86 kg. In conclusion, lactation length was significantly influenced (p<0.001) by the length of calving interval, while milk production indices were not (p>0.05).

calving interval; days in milk; milk production; Romanian Black and White

Presentation: oral