Virus Still a Bighorn Issue

Virus Still a Bighorn Issue

RON DAINES
Sheep Industry News Contributor

Despite decades of research into whether bighorn and domestic sheep transfer pneumonia virus between species, significant gaps remain, said Maggie Highland, a wildlife pathologist with the USDA-ARS Animal Disease Research Unit in Pullman, Wash.

In the meantime, she told the ASI executive committee in Charleston, grazing restrictions owing to pneumonia outbreaks have had a big impact on the domestic sheep industry, Highland said that a critical research finding is that just because a domestic or bighorn sheep has the pneumonia virus doesn’t necessarily mean it will die, which has further complicated the issue. Underpinning her current research is the question of whether bighorn and domestic sheep, raised under equal circumstances, may be able to fight the disease on an equal footing. She initiated her study by collecting lambs at birth from both bighorn and domestic sheep and raising them under equal circumstances: They had no contact with the ewe or other sheep, were hand-raised (she collected colostrum from the ewe then used milk replacer after that) and remained separated by species.

“The first ones are three-years-old and so far they remain free of the bacteria associated with pneumonia,” said Highland. Several parts of the study, including a look at passive transfer of antibodies from ewe to lamb, have been completed but have not been published. A study of intranasal immunization is scheduled to begin this spring.

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