Improving percentage of successful first insemination using electronic detector of oestrus in a herd of Norman dairy cows

The aim of this study was to analyze the field work of a farmer (75 milking Normandy breed cows) during the reproductive season (between the 15 of October and the 15 of February of years 1995-2002), and to compare the visual detection technique with the use of the DEC (electronic heat detector). At the same time the information that the farmer received from the DEC helped him to breed the cows in an optimum moment for AI, which consequently reduced the number of cows that would come back into heat after 3 weeks, as well as reduce the number of cows he would cull at the end of the reproductive season for reproductive reasons. In such a manner he improved his first AI success rate from year to year (1995-49%, 1996-44%, 1997-33%, 1998- 31%, 1999-16%, 2000-58%, 2001-55% and 2002-63%).