Farming in Mount Temple, Moate, Co. Westmeath, Irvine Allen – a participant in the Teagasc Green Acres Calf to Beef Programme – is just winding down the busy calf-rearing period on his midlands-based farm.

Some 96 calves arrived on the holding between February 24 and March 3, consisting of 87 Friesian bull calves and nine Aberdeen Angus types – which were all sourced direct off dairy farms.

Calves were split with a proportion reared on an automatic feeder, while the remaining 35-40 were ‘bucket reared’ – receiving 6L/day of milk replacer in two 3L feeds.

The bucket-reared calves were then moved onto a once-a-day (OAD) feeding system. Similarly, the calves on the automatic feeder received 6L/day.

Irvine pays particular attention to both the weight of the calf and how much concentrate is consumed prior to weaning (at least 1kg/day), with the decision whether to wean or not based on these two parameters.

Weaning commenced on April 14 and the lightest calf on that date was 87kg, while the heavier calves were up on 100kg.

The majority of calves are now weaned and are currently grazing quality grass – aiming for covers hovering around 1,000kg DM/ha. As these calves were born early in the year, Irvine will continue to feed concentrates at grass (at a rate of 1kg/day), but will stop feeding in mid-June.

Commenting on the rearing period, Irvine said: “I’ve had a great year; I’ve a 0% mortality rate and the best thrive I got was around the weaning period, when calves were doing between 0.98/kg/day and 1.2kg/day over that two-week period.”

Like Irvine, other farmers in the Green Acres programme, and indeed farmers across the country, are either going through or planning for weaning.

Basically, what we’re looking for during the calf-rearing period is for a calf to double its birth weight. Taking a 40kg calf a birth, this animal should weigh at least 80-85kg after the first 56 days on the farm. To achieve this, we’re looking for an average daily gain (ADG) of 0.7-0.8kg/day.

So, monitoring performance by weighing with a scales or weigh-band is important. Ideally calves should be weighed at birth, on arrival to the farm, and again between six and ten weeks.

For successful weaning, the main target is to have calves eating at least 1kg calf starter/day for three consecutive days prior to weaning.

This generally occurs by eight weeks of age, depending on the level of milk feeding, age at concentrate introduction and water availability. Stress should be avoided at weaning with water available at all times.

Calves are generally turned out to grass after weaning. Farmers should aim for top-quality grass with covers of 1,000kg DM/ha. At grass, a nut ration of 16% crude protein is sufficient providing grass quality is good.

Early, spring-born calves should be supplemented with 1-2kg of concentrate/day until May or June. At this point, grass intake is increasing and concentrate supplementation is no longer required.

Calves should remain on a grass-only diet until early September. At this stage, farmers should reintroduce concentrates at 1kg/day until housing, as grass supply and quality deteriorates.

Calves born in April/May will go to grass later in the summer and should receive 1-2kg concentrate/day for the entire grazing period.