Genetic Parameters of Atypical Progesterone Profiles in Holstein-Friesian Cows using Data from Four European Experimental Research Herds

Abstract Text:

Compromised fertility is a major problem in dairy herds. An objective way to classify estrus cycles is to analyze milk progesterone. The objective of this study was to estimate genetic parameters for measures of normal estrus cycles, delayed cyclicity, prolonged luteal phases and cessation of cyclicity in 1122 Holstein-Friesian cows with 1618 lactations. The heritability was moderate for delayed cyclicty (0.24) and commencement of luteal activity (0.23), but was low for prolonged luteal phase (0.02), luteal phase length (0.09) and inter-ovulatory interval (0.06). Little and no genetic variation was detected for inter-luteal interval and cessation of cyclicty, respectively. Moreover, delayed cyclicity and commencement of luteal activity were strongly genetically correlated with milk yield in early lactation (0.57±0.14 and 0.63±0.09, respectively) which may imply a deterioration of these traits with selection for higher milk yield.

Keywords:

dairy cow
progesterone profile
fertility
genetic parameters