23/10/2026
In this series we’ve been looking at the effects of worm and liver fluke coinfections in dairy cattle and the subsequent effects on the Australian dairy industry.
In Part 2 of this 3-part series we put the spotlight on worms and which ones in particular can cause problems. Of the main culprits - small brown stomach worm, barber’s pole worm, nodule worm and small intestinal worm - the small brown stomach worm (Ostertagia ostertagi) is arguably the most significant. In young cattle, it causes loss of appetite, weight loss and watery diarrhoea. In adult cattle, the signs are less obvious, as inhibited larvae induce a strong immune response that diverts energy away from milk production and can result in a drop in milk yield of up to 0.7 - 1.1 kg/cow/day¹. A national bulk milk tank survey of Australian dairies reported that 92% of all farms tested had small brown stomach worm burdens high enough to be causing production losses.
Always talk to your vet about treatments for control of worms in your dairy herd.
1.Charlier et al. A survey to determine relationships between bulk tank milk antibodies against Ostertagia ostertagi and milk production parameters. Veterinary Parasitology, 2005.
AU-RUM-0093-2026
