Abstract

The decline of fertility in the last decades is a major concern in dairy farms being caused by a series of factors analysed in the present paper. Research took place on a number of 950 dairy cows exploited in a semi-intensive system in the North-East area of Romania. On the whole analysed population, the frequency of reproduction disorders were between 12 (in January) and 27% in July, with a greater intensity starting with the end of spring up to winter season. The most frequent reproduction disorders were anoestrus, losses of heat cycles, weak heats undetected in due time, metritis, feeding and others. The batch of the cows with over 85 days of infecundity represented 88.15%, while the batch with one to 27 days infecundity was of only 1.05%, and the batches with 28 to 56 days and 57 to 84 days of infecundity represented 4.25 and 6.55%, respectively from the total of analysed population. The most days of infecundity were recorded at primiparous cows (55.90%) followed by the second-parous ones (32.10%) and multiparous cows (12.00%). The losses by infecundity and sterility over passed the rate of 25% from production. The common feature of the reproduction biotechnologies consist maximization of the genetic process for cattle, of their wealth fare and fertility state, in the conditions of reducing the price cost per product unit.

Key words: Cows, reproductive capacity, biotechnology