Over the next six weeks, the livestock team will feature advice on different feeding systems for various types of cattle on Irish farms.

To start the series, the focus will be on feeding autumn cows over winter, along with managing dry cows in spring-calving herds.

When it comes to winter feeding of cows, there are two basic starting points for every farm.

Firstly, cows should be body condition scored (BCS) to assess fat cover, as animals at differing BCS levels have different feed requirements.

And secondly, get silage analysed for feed value. Grass silage is the staple feed on almost every cattle farm during winter. Yet, there is huge variation in the quality of silage on livestock farms, which ultimately affects cattle performance.

Autumn cows

For autumn-calving herds, winter feeding should be geared to keep cows milking and go back in-calf again. Get it wrong and calves will be lighter at weaning, unless fed higher levels of purchased concentrate.

Also, when scanning cows, there will be a higher barren rate, or an extended calving period next year. Either way, profitability will be undermined.

Feed periods

As the nutritional requirement of autumn cows changes during winter, split winter feeding into three phases as follows.

1 Pre-calving feeding

By mid-October, the majority of autumn cows will have calved already. But there are plenty of autumn herds with cows still to calve during late October and November. These cows are most likely housed for pre-calving management.

First off, cows should be penned based on age and body condition. Keep first-calving heifers separate from mature cows.

This will prevent bullying at the feed face and stop younger cows being underfed.

Silage quality

Dry cows should be offered silage of average quality, which is fodder around 66% to 68% DMD, in order to maintain body condition.

Cows in optimum condition (BCS 3) and set to calve within the next two to three weeks should be fed silage to appetite.

With cows so close to calving, the calf will be more or less fully developed. Trying to restrict silage intakes at this point will not reduce calf birth weight, nor will it alter BCS of cows.

Instead, cows will be more prone to metabolic problems, such as milk fever. Colostrum quality will be poor and cows can be lethargic at calving, thereby increasing assistance required.

Pre-calving minerals

Autumn cows should also be fed pre-calving minerals. If minerals have not been fed, there is still time to do so for late-autumn-calving cows. Feeding 150g/head on a daily basis will cut down on calving problems, such as cows holding the placenta, and calves will be quicker to stand and suck.

2 Calving and breeding

Most suckler cows will hit peak lactation around 50 to 70 days post-calving. This usually happens at the same time as cows are coming back in heat and bred again.

Therefore, these cows have an increased requirement for energy and protein in the diet. Ideally, cows should be offered high-quality silage (70+ DMD) on an ad-lib basis, so keep the feed passage filled.

But there is only so much silage cows can eat, so offer concentrates to supplement fodder quality and increase dry matter energy intake.

Concentrates

For cows on 70% to 72% DMD silage, feed 2kg/day during the breeding period. For silage at 73% to 74% DMD, reduce concentrates to 1.5kg/day and 1kg/day for cows on 75% to 76% DMD forage.

If cows only have access to average silage (66% DMD), increase supplementation rates to 3kg/day.

Cows should be on a steady, consistent diet during the breeding period to maximise conception rates.

Therefore, keep cows on the same concentrate and silage allocation until breeding has finished.

Budget

Do a quick fodder budget. If high-quality silage is limited, target this to autumn cows during the breeding season.

Feeding an extra 1kg/head of concentrate will stretch silage reserves, replacing 4kg to 5kg/day of fodder for every cow fed.

Restricting suckling

Restricting calves to suckling their dam twice per day will help bring cows back in heat much faster. It will also reduce the nutritional stress on cows, helping maintain BCS and reducing silage intake. Calf performance will not be compromised.

3 Post-breeding management

Once breeding has finished and cows are settled in-calf, concentrate levels can be reduced or cut from the diet, depending on silage quality.

For cows on 70% to 74% DMD, feed 1kg/day of concentrate.

For cows on silage above 74% DMD, there is little need for concentrate feeding, unless fodder is limited and the aim is to stretch reserves.

If cows are on average-quality silage, continue to feed 2kg/day until turnout. Once autumn-calving cows go back to grass, concentrate feeding can be cut from the diet.

Managing spring-calving cows through the dry period

When managing dry spring-calving cows over winter, pen the first-calving heifers together and group older cows separately also.

In most herds, these groups account for small numbers of cows. Mature cows should also be penned according to BCS.

Cows at BCS 2.5 to 3.0 are in the optimum condition and should be wintered on average- to good-quality silage (66% to 69% DMD) to maintain BCS.

Changing BCS

Thin cows – animals below BCS 2.5 – need to gain condition. Cows above BCS 3 are carrying too much flesh and need to lose condition.

In both instances, the time to alter BCS in cows is mid-gestation. For March-calving cows, this should take place from October to the end of December.

Changing from BCS 2 to BCS 3 is the equivalent of gaining 60kg to 80kg liveweight, or 10% of mature cow body weight, depending on breed type.

Moving from BCS 4 to BCS 3 is the equivalent of losing the outlined liveweight.

Gradual change

BCS should be changed in a gradual manner. Taking a liveweight gain of 1kg/day, it will take anywhere from eight to 10 weeks to alter BCS by one unit.

Given this time frame, thin cows should be separated from the main herd for supplementary feeding now.

Cows carrying too much condition should also be separated and have silage restricted. However, when restricting silage, make sure there is adequate space at the feed face for all cows to eat at the same time. If not, dominant cows will eat to appetite, while shy cows will be underfed.

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