Distribution of Estrus in Hair Ewe during the Season of Low Activity Reproductive Conditions of Northwestern Mexico

摘要

The aim of this study was to determine the presence and duration of estrus in ewes Pelihuey environmental conditions in northwestern Mexico with constant feeding.The study was conducted in the Valley of Mexicali,Baja California,located at 32°NL with arid climate.This study will last for one year (January to December),24 adult sheep were used to measure multiparous Pelibuey estrous changes for a year,under constant feeding.To measure estrous activity,we used two studs,that were introduced twice a day for half an hour each time the sheepfold,females were in heat detected by the male.The month with the highest percentage of females in heat was March (86.36％ ),April (81.8％ ),in February and June showed zeal and 77.3％ in January (50％ )showing significant difference (P＜0.05).For the variable duration of estrus were the months of June and March with 38.9％,35.3％ and 26.3％ respectively,in January the lowest rate that jealousy between 24-36 hours presented with a 20.0％.Was created a completely randomly.Variables expressed as percentages were analyzed with chi-square,continuous variables with analysis of variance.SAS 2004.