ASSOCIATION BETWEEN BRUCELLOSIS AND REPRODUCTIVE FAILURE IN DOMESTIC RUMINANTS: EVIDENCE FROM HERD-LEVEL ANALYSIS

Abstract

Brucellosis is a significant zoonotic disease of worldwide importance, known for its substantial impact on animal production due to reproductive failures and related productivity declines. This study examined the impact of brucellosis on infertility, abortions, and stillbirths. It reduced reproductive efficiency in domestic ruminants, employing a cross-sectional approach supplemented by a prospective follow-up of breeding females in cattle, sheep, and goats. A total of 1,047 animals from 60 herds were assessed using a composite diagnostic methodology that integrated the Rose Bengal Plate Test, indirect ELISA, and PCR confirmation. The overall seroprevalence of brucellosis was 20.1%, with markedly elevated abortion rates in seropositive animals (32.6%) compared with seronegative animals (14.0%). Animals positive for brucellosis demonstrated increased infertility (16.2% versus 7.4%), stillbirth rates (10.4% versus 4.1%), prolonged days open (227.4 versus 213.1 days), protracted inter-parturition intervals (369.1 versus 342.5 days), and a larger number of services per conception (3.5 versus 2.6 services). Multivariable regression analysis established that brucellosis was independently correlated with abortion (AOR = 2.4, 95% CI: 1.7–3.3), infertility (AOR = 1.9, 95% CI: 1.2–2.9), and stillbirth (AOR = 2.6, 95% CI: 1.5–4.4), whereas continuous models indicated significant increases in days open and inter-parturition interval. Vaccination and elevated biosecurity scores protected against infection, underscoring their significance in control methods. These findings underscore brucellosis as a significant barrier to ruminant fertility and production, highlighting the urgent need for integrated surveillance, vaccination, and preventive management within the One Health Framework.