Management and meteorological factors affect fertility after artificial insemination in Murciano-Granadina goats

Abstract

Over 6 years, 2004 artificial inseminations (AI) were documented from 13 goat farms. We quantified the effect on fertility rate of management factors (farm, year, month, timing and order of insemination, dose of progestagen, prostaglandin, equine chorionic gonadotrophin and prostaglandin doses, age, technician, problems at AI, body condition and buck) and meteorological conditions at AI (mean, maximum and minimum temperatures, mean relative humidity, mean solar radiation, and total rainfall). Meteorological variables were converted to categorical variables to quartiles and deciles. Overall fertility was 56%. Each of the management factors had a significant (P < 0.05) effect on fertility. Non-pregnant goats differed significantly in most of the meteorological variables. Successful inseminations were associated with significantly (P < 0.001) higher mean, maximum and minimum temperatures, and solar radiation, and lower relative humidity, and rainfall, than were failed inseminations. Fertility rates of the highest and lowest deciles were significantly different for each of the meteorological variables. Inseminations performed when meteorological values were in the highest decile of mean (62%), maximum (61%) and minimum temperature (60%), and solar radiation (59%), and the lowest of relative humidity (61%) and rainfall (57%) had a significantly (P < 0.0001) higher proportion of does that became pregnant than when meteorological values were within the opposite decile (47%; 34%; 55%; 46%; 45%, and 43%, respectively). In conclusion, management and meteorological factors affected the success of AI in goats. Although technical factors can be controlled, it remains to be determined whether scheduling the dates of insemination based on forecasted temperatures can improve the success of AI.