Associations between management practices and major reproductive parameters of Holstein-Friesian replacement heifers

• Published in: Animal reproduction science 2018-01, Vol.188, p.114-122
• Main Authors: Fodor, I., Baumgartner, W., Abonyi-Tóth, Zs, Lang, Zs, Ózsvári, L.
• Format: Article
• Language: English
• Subjects: Age at first calving; Dairy heifer; Oestrus detection; Pregnancy diagnosis; Reproductive management
• ISSN: 0378-4320; 1873-2232
• DOI: 10.1016/j.anireprosci.2017.11.015

•The use of heat detection aids reduced age at first calving.•Observing heat in short periods was more efficient than continuous observation.•Sexed semen users achieved younger calving age due to lower age at first service.•Diagnosing pregnancy more than once per week resulted in younger calving age.•Intensive management practices improved reproductive performance in heifers. The aim of this study was to assess the relationship between the reproductive management practices and the performance of replacement heifers on large commercial dairy farms. The individual data of 14,763 heifers, first inseminated in 2014, were analysed from 33 Holstein-Friesian dairy herds in Hungary. The relationships between management practices and major reproductive parameters (age at first service, AFS; age at first calving, AFC; conception risk to first insemination, CR1; and pregnancy status at 20 months of age) were examined by mixed-effects models, with the herd as the random effect. The results showed that farms using oestrus detection aids experienced reduced AFS (p