Identifying the sources of variation in estrus and ovulation in weaned sows for AI timing and application of fixed time AI

摘要

Estrus and ovulation variability have previously been identified in weaned sows but their origin remain uncertain. Regardless of the source, their variability prohibits accurate prediction for time of ovulation and leaves optimal AI timing to chance when based on detection of estrus. Many studies have reported that variability in ovulation is related to the wean to estrus interval. The factors that can impact estrus and therefore ovulation timing may reside in many environmental and management factors and even includes farm. This variation is important for AI timing and fertility. Defining the extent of the variability for estrus and ovulation is essential for developing methodology to reduce or control variation. Further, this foundational information is essential to help advance technology which can help predict or synchronize ovulation, and use of fixed time and single service AI.