Age of Turnout: The effects of early turnout on calf health

Early turnout to grass can be hugely beneficial in terms of improving daily live weight gain and calf health whilst also reducing rearing costs. However, the turnout phase is again another time in the calves' lives when we are introducing them to a new environment, therefore there are a few things we can do to make this time a little less stressful.

The first consideration that will vary is the age of the calf at turnout, and this will depend on the type of system. Spring calving systems and beef rearing systems will see some calves being turnout as young as 8-10 weeks old whereas autumn and all-year-round systems will be turning out calves at up to 9 months old for the first time. One aspect that doesn’t change however is the need to achieve performance targets.

Calves should to be at least 8 weeks of age at first turnout when weaned. Any time before this would be detrimental to the performance as the rumen is not developed enough to be completely reliant on achieving their nutritional requirements solely off grass. This point also highlights the significance of feeding adequate straw/hay and concentrates prior to weaning in order to maximise rumen development.

Cold, wet weather can also be a big challenge for calves therefore it’s advisable to watch the weather forecast and aim to turn calves out where there are 3 or 4 dry days in a row forecasted. A field that provides some shelter is also favourable.

A rotational grazing system is one of the best options for optimising calf health post turnout as it allows for calves to be moved to a fresh paddock every 2-3 days.

A leader follow system also works well where older heifers follow the calf group grazing down the paddocks. This means that the calves don’t have to work as hard to reach their DM intake requirement whilst the older livestock maintain the quality of the regrowth in the paddocks.

It is important to consider the type of grass when selecting paddocks for calves. Turning calves to a rich pasture sward can cause digestive problems which subsequently can negatively impact DLWG. Fibrous grass will help slow the forage passing through the rumen allowing for better nutrient uptake from grass.

Re-seeds are a good option as they are essentially ‘clean’ paddocks which will have a lower parasite burden meaning that it will have a beneficial effect on calf health.

Turning the calves out will feel like a big relief in terms of labour, however, it’s very important that the time saved from feeding and bedding is invested in checking and monitoring the calves' performance out on grass. This period can be crucial for ensuring that the calves reach 60% of their mature weight by mating.

A calf will require approximately 3% of its body weight in kg of dry matter. Therefore it’s important to consider how much the whole group require, so they can continue to meet DLWG targets which can still be as high as 800g/head/day on grass alone.

In addition, it is advised to continue feeding concentrates out in the field for at least 5 weeks post-turnout to help with the transition, subsequently reducing stress. Depending on the growth targets required, it may be necessary to keep concentrating for longer than this period. Another option is grouping the smaller, lighter calves together and continuing to feed through the summer months. Weighing calves on a regular basis will be a good indicator of whether the calves are on track to meet weight targets by mating.

Another aspect to consider is a health plan. Turning calves out onto pasture for the first time means that they will come into contact with lots of new unfamiliar parasites. Becoming infected by these parasites can again cause poor performance and reduced growth rates significantly. Working with your vet and creating a worming/vaccination programme can help reduce the impact.

Read more: Parasites at Pasture