While the initial days/weeks of calf rearing may appear to be the most labour-intensive stage for farmers, the first season at grass can prove a more difficult phase for them to manage.

Nutritionally, success is measured by developing the calf as best as possible prior to introducing grazed grass. Given that newborn calves are born with undeveloped rumens, the initial objective is to assist such rumen development prior to being weaned off milk. This enables them to become cost-effective forage consumers.

Rumen development begins within the first few days of life and is advanced by exposure to healthy bacteria from the environment and the consumption of solid feeds. Introducing a palatable calf-starter ration/nut from 3 days of ages (18% Crude Protein) is important, along with access to fresh, clean water and high-quality clean straw ad-libitum (no haylage/silage).

Weaning on a weight basis alone can create a false sense of security in terms of how ready calves are for the next stage of nutrition. Weaning shouldn’t be considered until calves are intaking a minimum of 1.5kg concentrate/day in grouped pens – which indicates that the calf’s dry matter intakes can cope with the transition to a 100% solid diet.

Year-on-year, cases of calves suffering from setbacks following their introduction to grass can also prove a major influencing factor.

Nutritionally, spring grass can be high in oils like conjugated linoleic acid, sugars and potentially nitrogen, which young, underdeveloped rumens can find it hard to adjust to. Low covers of grass also have very little fibre, which is a key substrate for good rumen health.

Calves aren’t fully functioning ruminants, which is why additional care and attention is required at so critical a phase in their development.

Greater rumen development in early life can help combat such issues, alongside the following: offering concentrates post-turnout, grazing slightly heavier covers until calves having adapted to grazing, offering a fibre source to ease the transition and/or strip grazing calves to ensure stem content is also being grazed.

For more information and calf rearing advice, contact your local Agritech Sales Advisor here.