Reproductive potential in female cattle discarded as infertile

Area of Science:

• Veterinary Medicine
• Animal Reproduction
• Dairy Science

Background:

• Infertility is a significant concern in dairy herds, impacting herd productivity and profitability.
• Understanding the causes of infertility in dairy cattle is crucial for improving reproductive management.
• Previous studies have identified various factors contributing to infertility, including genetic, nutritional, and infectious causes.

Purpose of the Study:

• To investigate the reproductive status and genital tract health of dairy cattle culled due to infertility.
• To determine the prevalence of pathological changes in the reproductive organs of infertile dairy cows.
• To assess the conception rates and pregnancy outcomes in relation to genital tract findings.

Main Methods:

• Seventy-four dairy cattle culled for infertility were included in the study.
• Cattle were artificially inseminated for up to three consecutive heat cycles.
• Genital tracts were examined post-slaughter to assess for pathological changes and pregnancy status.

Main Results:

• Of 28 primiparous or never-calved animals, 43% conceived readily with normal pregnancies.
• In mature cows (parity 4-9), 19.6% became pregnant with live embryos, and 15.2% experienced embryonic death.
• Pathological changes in the uterus and/or oviduct were observed in 60% of infertile mature cows, with 40% showing normal genitalia.

Conclusions:

• Genital tract pathologies, particularly in the uterus and oviduct, are significant contributors to infertility in mature dairy cows.
• A notable proportion of infertile dairy cattle, including those never calved, possess normal reproductive organs, indicating other underlying causes.
• Further research is needed to identify non-pathological factors affecting conception and pregnancy maintenance in dairy cattle.