Transitioning calves from a milk-based diet to a grass-based diet can be tricky; calves being turned out to lush grass can have digestive upset post-turnout.
To reduce the chances of this happening, calves should be turned out into a strong cover, with access to straw and concentrates for up to four weeks post-turnout.
Rotational grazing
When grazing, calves should be moved every three days, with best practice being to operate a ‘follow the leader’ system, according to Teagasc.
This system allows young calves to graze a paddock with bulling/in-calf heifers to then graze/clean up afterwards.
When calves initially turn out to grass, they will have an intake of 2.5kg/dry matter (DM)/day, with this increasing to 5kg/DM/day by housing.
If you have 40 calves, they will require 360kg of DM for three days grazing (3kg/DM x 3 days x 40 calves).
Reducing worm build-up
The removal of grass for silage or reseeding is a good way to reduce worm build-up in paddocks.
Ideally, the replacement grazing block should be at a stocking rate that allows for paddocks to be removed for silage.
Reseeding is not only a good way to improve grass quality on the replacement grazing block, but it also helps to reduce parasite build up.
Monitoring health
Monitoring parasite burden in calves with pooled faecal sampling is still currently an option for farmers to identify worm burdens.
Under the new EU legislation being introduced in January 2022, all wormers will become prescription based – with blanket treatment of stock no longer possible.
Dosing is recommended for worm burdens that are above 200 eggs/g, using the recommend dose by your vet.
Weighting replacements will help identify calves that are not meeting weight gain targets and can also help identify animals that may have other health issues.
Discuss a plan
Your vet is an important part of the overall solution to reducing and controlling parasite issues with your replacement stock.
This will become even more true as we look ahead to January 2022, with the reduction in antibiotic usage on farms becoming a reality.
Having your vet walk through the replacements and the land they will be grazing will help in the development of a plan to treat and control parasites.
It will also help with the development of a herd health plan and determine which vaccinations may be best suited to your herd.