Neospora caninum and reproductive wastage in extensively managed Queensland beef herds. Issue 9 (27th August 2013)

• Record Type: Journal Article
• Authors: Fordyce, G; Holroyd, RG; Taylor, J; Kirkland, PD
• Is Part Of: Australian veterinary journal. Volume 91:Issue 9(2013)
• Page Start: 385
• Page End: 390
• Publication Date: 2013-08-27
• Subjects: Veterinary medicine -- Australia -- Periodicals; Veterinary medicine -- Periodicals; Veterinary Medicine -- Periodicals; 636.089
• DOI: 10.1111/avj.12097
• Languages: English
• ISSNs: 0005-0423

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="avj12097-sec-0001" sec-type="section"> <title>Objective</title> <p>To compare reproduction in extensively managed, tropically adapted beef cows that were either seropositive or seronegative to <italic>Neospora caninum</italic>.</p> </sec> <sec id="avj12097-sec-0002" sec-type="section"> <title>Design</title> <p>Longitudinal study of cows within management groups.</p> </sec> <sec id="avj12097-sec-0003" sec-type="section"> <title>Methods</title> <p>Compare pregnancy with weaning outcomes for 502 seropositive and 3255 seronegative cows in 25 management groups.</p> </sec> <sec id="avj12097-sec-0004" sec-type="section"> <title>Results</title> <p>We found <italic>N. caninum</italic> in all herds, with an average of 20% of 2640 tested animals seropositive within management group; prevalence varied between 0% and 94%. At 7 of 10 sites assessed, there was evidence of horizontal transmission of <italic>N. caninum</italic>. There was no overall difference in pregnancy rate (79% vs 75%; P > 0.05), reproductive wastage after confirmed pregnancy diagnosis (11% vs 10%; P > 0.05) or weaning rate (67% vs 68%; P > 0.05) between seronegative and seropositive cows, respectively. In one herd where a combination of risk factors for <italic>N. caninum</italic> was present, a significant reduction in pregnancy rate occurred after the 6 months mating (85% vs 69%; P < 0.05). The fetal and calf losses observed were lowest in south‐east Queensland (4.3% of 117 pregnancies), highest in north‐west Queensland (15.5% of 413 pregnancies) and intermediate in north‐east Queensland (10.2% of 1625 pregnancies). Other infectious agents that are known to cause reproductive wastage were endemic in many herds, though none appeared to cause significant fetal or calf loss in this study.</p> </sec> <sec id="avj12097-sec-0005" sec-type="section"> <title>Conclusion</title> <p>Despite a high prevalence of <italic>N. caninum</italic>, there was no apparent effect on beef cattle reproduction, but there is potential to cause reproductive wastage if known risk factors to neosporosis are in effect.</p> </sec> </abstract>