• Previous Article
• Next Article

Research Article

Effect of daily yield of cows and date of first insemination on services per conception

Anna Sawa , Małgorzata Jankowska, Agata Augustyniak

Department of Cattle Breeding, UTP University of Science and Technology in Bydgoszcz, Mazowiecka 28, 85-084 Bydgoszcz, Poland

1. Acta Sci. Pol. Zootechnica, 17(1), 2018, 9‒14
2. DOI: 10.21005/asp.2018.17.1.02

Abstract. This study analysed the effect of daily milk yield (28,078 test-day records up to 30 days before first insemination, during the period up to 150 days of the first and second lactation), season of first insemination and reproductive rest period on fertility of 17,618 cows measured as number of services per conception. Data were analysed using the GLM and FREQ procedures of the SAS package. The number of inseminations needed for pregnancy increased with increasing daily milk yield of the cows, especially when the first insemination was performed in summer or when reproductive rest period was shortened to  ≤ 60 days after calving.

Keywords: cows, services per conception, daily milk yield, insemination date