Effect of excess nitrate on Xalda sheep

Abstract

This study analyzed potential causes of a 40% mortality rate observed in a flock of endangered Xalda sheep, indigenous to the province of Asturias in northern Spain. We found that productive and reproductive parameters of the flock were also severely affected. In order to diagnose the cause of mortality and illness in the sheep, we examined the animals and their living conditions. We found high concentrations of nitrate in animal serum, well water and the surrounding pastures. Based on these findings and the absence of a geological source for nitrogen in the paddock, we believe that inappropriate management of manure in neighboring dairy farms resulted in nitrate toxicity in the Xalda sheep. This study highlights the importance of good practices in manure management and the need to monitor nitrate toxicity in pastures. It also highlights the importance of anthropogenic factors on the conservation of animal genetic resources.