Brucellosis, genital campylobacteriosis and other factors affecting calving rate of cattle in three states of Northern Nigeria.

Peter C Irons,Hassan M Mai,Peter N Thompson

doi:10.1186/s12917-015-0317-9

Abstract

BackgroundReproductive diseases limit the productivity of cattle worldwide and represent an important obstacle to profitable cattle enterprise. In this study, herd brucellosis and bovine genital campylobacteriosis (BGC) status, and demographic and management variables were determined and related to predicted calving rate (PrCR) of cattle herds in Adamawa, Kaduna and Kano states, Nigeria. Serum samples, preputial scrapings, questionnaire data, trans-rectal palpation and farm records were used from 271 herds. The Rose-Bengal plate test and competitive enzyme-linked immunosorbent assay were used for Brucella serology and culture and identification from preputial samples for BGC. A herd was classified as positive if one or more animals tested positive. The PrCR was determined as the number of calvings expected during the previous 6 and next 6 months as a percentage of the number of postpubertal heifers and cows in the herd. A multilevel linear regression model was used to estimate the herd-level effect of Brucella abortus seropositivity, Campylobacter fetus infection and other factors on calculated PrCR.ResultsThe reproductive performance of the cattle herds was generally poor: Only 6.5% of the nursing cows were pregnant and 51.1% were non-pregnant and acyclic; the mean annual PrCR was 51.4%. Brucella abortus and C. fetus infection of herds were independently associated with absolute reduction in PrCR of 14.9% and 8.4%, respectively. There was also a strong negative association between within-herd Brucella seroprevalence and PrCR. Presence of small ruminants, animal introduction without quarantine and the presence of handling facilities were associated with lower PrCR, whereas larger herd size, supplementary feeding, routine mineral supplementation and care during parturition were associated with higher PrCR.ConclusionsBrucellosis and BGC may be largely responsible for the poor reproductive performance of indigenous Nigerian cattle. Farmer education and measures to improve the fertility of cattle herds are suggested.

Highlights

Reproductive diseases limit the productivity of cattle worldwide and represent an important obstacle to profitable cattle enterprise
Reproductive indices reported in nomadic cattle herds in Nigeria include age at first calving of 60 months, calving interval of 17 to 24 months, annual calf crop of 40% and total lifetime number of calves produced by a cow of 2.5 [6]
The purpose of this study was firstly to estimate the reproductive efficiency of cattle herds in Northern Nigeria, as reflected by predicted calving rate (PrCR), and secondly to investigate the effect of brucellosis, bovine genital campylobacteriosis (BGC), and other managemental and environmental factors, on PrCR

Summary

Introduction

Reproductive diseases limit the productivity of cattle worldwide and represent an important obstacle to profitable cattle enterprise. Predicted annual calving rate (PrCR), on the other hand, is a robust indicator of breeding performance and herd fertility, taking into account the number of pregnant animals and estimated ages of foetuses based on trans-rectal palpation, as well as estimated ages of calves in the herd at a single time point [5,15,16]. It is independent of the season in which the data are collected, which can be a confounder when other indices are used in herds with seasonal calving patterns [17]. Single-day examination of a herd and prediction of calving rate may be prone to bias in that it cannot account for future cases of abortion and is dependent on accurate aging of pregnancies

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