Investigation of effect of year and season factors on calving difficulty, using poisson regression model in Simmental x South Anatolian red crossbred cattle

GÜRCAN Ismayil Safa; ÖZEN
2014 Ankara Üniversitesi Veteriner Fakültesi Dergisi  
Dystocia is an economically important problem in the cattle industry because it is a major causes of calf mortality. This problem has received increased attention by the cattle industry because of the utilization of some of the incompetible sire breeds in crossbreeding programs. The aim of this study was to investigate the effect of year and season on cattle dystocia using poisson regression methodology. Only first-calf heifer data record, including a total of 1787 birth records over three
more » ... rds over three years, from January 2010 to November 2012, of Simmental x South Anatolian crossbred from a private farm, were collected. Poisson regression model provides an adequate fit for this data, however there might be acceptable level of underdispersion. According the result of the Chi-Square tests, the differences between year 2010 and 2012, 2011 and 2012 were found statistically significant (p<0,001). In addition the differences between seasons winter and summer, autumn and summer, spring and summer were found statistically significant (p<0,001).
doi:10.1501/vetfak_0000002605 fatcat:plqadbyygve4tdiu5szdcfy6dq