Gut bacteria may help combat nematode infestations in sheep

SHEEP FARMERS in Australia and New Zealand have a problem. Their charges are susceptible to which cause them to waste away and can, in severe cases, kill them.Over the years, the worms have once used to attack them. But a second approach is to breed countermeasures into the sheep themselves. This can be done by counting the number of worm eggs in animals’ droppings and selecting as sires and dams those that have the fewest, on the assumption that these are the sheep with the least worm-friendly guts, and that this property will show up in their offspring as well. That works. But how, has been obscure. A study just published in , by Erwin Paz of the University of Western Australia and his colleagues, throws light on the matter. It suggests that what is being bred for is a propensity to develop a worm-hostile gut microbiome.