What should I feed my spring-calving cows and heifers this winter?

Calving may seem like a long way away for spring-calving suckler herds, but winter management is key to the success of the calving period next spring.

Although grazing conditions are still favourable across many parts of the country, farmers are starting to think about winter diets as they close up paddocks for the winter.

Drought conditions played havoc with the silage-cutting season this year and, by the end of August, silage supplies on many farms were looking grim.

However, a good back end weather wise has seen contractors and farmers take to the fields and this has allowed farmers to reduce some – if not all – of the fodder deficit.

The main problem that this presents is that silage that was harvested in latter weeks will not be of the same quality as silage that was harvested in June or July – mainly due to shorter days and a lower sugar content.

Therefore, there is a huge difference between feeding silage with a dry matter digestibility (DMD) of 72% compared to a silage DMD of 55-60%; so, knowing the value of baled silage – or silage in the pit – is extremely important. This can be done through silage testing.

At this time of year, the key area that suckler farmers need to look at is the body condition score (BCS) of their cows.

Body condition score

The herd should be body condition scored at housing and cows penned according to BCS. If possible, cows should be split into three groups. These are: thin (BCS 2.0-2.5); target (BCS 3.0-3.5); and fat (BCS >3.5).

According to Teagasc, cows with a BCS >3 can afford to lose between 0.5 and 1.0 BCS through restricting the allowance of good-quality silage. Essentially, this is a silage of 70-75% dry matter digestibility (DMD).

Reducing intake to cows that don’t require as much silage can also help reduce feed demand on farm; this is something that will benefit farms with a silage deficit.

According to Teagasc, achieving target BCS at weaning and calving can lead to a winter feed saving of 1.0-1.5t of grass silage.

Looking at this in terms of cost, this is equivalent to a €35-40 or more saving per cow (approximately €2,000 annually for a herd of 50 cows).

Farmers can feed moderate-quality (65% DMD) silage ad-lib or dilute the energy of the diet by incorporating straw. However, straw is in scarce supply this year on many suckler farms and this may not be an option.

If farmers have access to straw, Teagasc says, good-quality straw plus 2-3kg of concentrates (including minerals and vitamins) is also suitable for dry cows in good body condition.

If farmers have a lower-quality silage (<60% DMD), these cows can be fed silage ad-lib along with 1-1.5kg of concentrate.

Important BCS targets for spring-calving suckler cows:
  • Housing: 3.0-3.5;
  • At calving: 2.5;
  • At turnout: 2.0+;
  • Breeding: 2.0-2.5.

Prioritising thin cows

Thin cows need to be prioritised and allowed free access to good-quality silage and/or supplemented with concentrate, where good-quality silage is not readily available.

A clean supply of water should always be made available to the cows.

Research from Teagasc shows that as BCS increases above moderate levels, calving difficulty can increase. This occurs as over-conditioned cows have increased calving difficulty due to fat being deposited in the pelvic area.

genomics

It also shows that very thin cows have increased calving problems. This is due to insufficient strength to withstand the birth process and giving birth to weak, non-vigorous calves.

In-calf heifers

Winter feeding management of in-calf heifers – due to calve next spring is critical.

Good-quality silage (72-75% DMD) is sufficient for these heifers. However, if feeding silage – with a DMD value of 65%, these heifers will need to be supplemented with 1.5-2kg of meal. Concentrate levels will need to be increased if feeding a silage with a lower DMD.

Looking ahead to next spring, as calving approaches, cows should be offered an appropriate dry-cow mineral for at least six weeks prior to calving.

In terms of cost, keeping the wintering period as short as possible (weather depending) will maximise the time at grass and increase liveweight gains; it will also reduce costs by lowering the silage and meal requirements.