Effect of the artificial insemination campaign on the reproductive status of the Zebu cows and their calves

José Darío Delgado Corona

ABSTRACT
From an experience conducted at a farm of the Livestock Production Enterprise San Juan with Zebu animals and analyzing the results of the 1999-2000 campaign with the ones obtained in the 10 previous years of that farm, it is decided to start the AI campaign in a group of units of the genetic farm of the enterprise, which has a total area of 3 650,24 ha without irrigation or fertilization with lixiviated yellow Quartzitic Ferralitic soils. The farm has more than 2 000 cows in reproduction. The campaign consists in inseminating the animals in the rainy season when there is a higher pasture availability. The objective of this work was to compare the reproductive and productive indicators as well as the increase of the live weight at weaning between the campaign and the traditional insemination system. The indicators to be taken into consideration were: cows under AI plan, quantity of parturitions, pregnant cows, newly-calved cows, cows inseminated at first estrus, other estruses, total inseminations, technical efficiency and empty cows; the age and live weight of the calves at weaning were also analyzed. The results suggest that the campaign system improves the indicators of empty cows and the live weight at weaning of the calves, as well as the need to make a transformation of the pasturelands, planting sugarcane, Pennisetum purpureum cv. CT-115 and trees in the farms that benefit the physical status of the animals in the dry season (DS) and make it possible that they start the rainy season (RS) under better body conditions for the campaign to have better results, and for the calves to reach a higher live weight at weaning; and to make adequate planning for the weaning in the corresponding months, because the quantity of animals that are weaned per months, in addition to the clearing of the areas that are infested with weeds and the application of herbicides for their elimination.