Management Notes for June 2024

Date published: 14 June 2024

Management Notes are prepared by staff from the College of Agriculture, Food and Rural Enterprise (CAFRE). CAFRE is a College within the Department of Agriculture, Environment and Rural Affairs (DAERA).


Prepared by: Christopher Breen

Growing a low potash (K) silage for dry cows

There are cow health advantages to producing a silage specifically for dry cows. The aim is a low K grass at cutting, as high K silages are associated with metabolic disorders and subsequent poor milk yields in early lactation cows.

Fields previously cut for silage should not receive slurry again. An application of 315 kg per hectare (two and a half bags per acre) of CAN fertiliser (27:0:0) is enough to grow a low K silage for dry cows. Baled silage is suitable for feeding to dry cows.

Leave cutting until early August as stem development coincides with a fall in grass K levels. To avoid mould growth or mycotoxins, the harvested grass dry matter should not rise above 35% before baling. It takes seven hectares to produce enough bales to feed 100 cows in the last four weeks of the dry period. Store the bales separately and use only for dry cow feeding.

Water for cows at grass

Water for cows at grass is extremely important with 100 cows drinking 6,500 litres daily. When the temperature is above 200C this figure can double. Troughs should be large enough so that 10% of the herd can drink at any one time with 30-50% water intake occurring within one hour of milking. Troughs located in the centre of paddocks with fast flow valves and large bore pipes ensure easy access to water. Clean troughs regularly as cows are very sensitive to smell and will not drink dirty water.

Fertility management

For autumn/winter calving herds the end of June is an appropriate time to end the service period; by doing this the last cow will calve by early April next year. Obviously, pregnancy diagnose cows regularly to monitor the number of empties. If there are a significant number, review fertility management. Try to tighten the calving pattern by doing this two weeks earlier each year. These later cows, as well as having a limited opportunity to be served, generally have poorer fertility and are more likely to be culled.

Condition scoring late lactation cows

Cows calved last autumn are over 200 days in milk. At this stage in late lactation, cows should be condition scored with the aim of having them at condition score 2.5 - 3.0 at calving, neither gaining nor losing body condition through the dry period. Condition scoring now will identify thin cows with a score of 2.5 or less. To improve the condition of thin cows, increase their dry matter and energy intake. Consider feeding these cows an extra 1.0 - 3.0 kg of a low protein cereal-based concentrate per day to promote fat deposition and get them dried off earlier. Condition scoring is done by assessing fat cover over the loin, pelvis and tail area:

  • Loin - there should be a slight depression along the cow’s top line and her loin. The shelf at the end of her transverse processes and flank should be filling.
  • Pelvis - there should be a good cover of tissue developing on the plates.
  • Tail area - there should be a good cover of tissue over the pin bones and the cavity at the tail head should be filling.

June jobs checklist

  • Ensure good grazing management by grazing swards down to 1,600 kg dry matter per hectare (4 cm) where possible to maintain sward quality. If high covers remain after grazing, top paddocks to achieve target cover.
  • Think about dry cow winter diets now so that low K silage can be made.
  • If operating under a nitrate derogation, ensure slurry that is spread after 15 June is applied using a low emission technique such as a trailing shoe or dribble bar.
  • Top any grazing swards that contain dead grass or seed heads to maintain sward quality.
  • Calibrate parlour and out of parlour feeders to ensure accurate feeding.
  • Carry out spraying by a suitably qualified operator if conditions are suitable and docks/weeds are at the right stage for control. If spraying docks in silage fields, generally allow an interval of at least 21 days between spraying and harvest. Always read the product label.
  • Assess heifer performance by weighing or weigh-banding them regularly. Use BoVIS to compare the performance of individual heifers against targets to calve at 24 months of age.


Prepared by:  Jack Friar

Weaning lambs and selecting for slaughter

Lambs should be weaned between 12 and 14 weeks of age and offered the best quality grass available on the farm. Lambs born at the start of March should be earmarked for weaning at the end of May/beginning of June. Not weaning at this age can have a negative impact on both lambs and ewes. When lambs reach this age, they are consuming large quantities of grass, resulting in ewes and lambs competing for grass. Consider weaning lambs earlier, at approximately ten weeks, if they are suckling hogget ewes or ewes that are rearing triplets and/or in poor condition.

After eight to ten weeks the proportion of milk in the overall diet is minimal, particularly for these lambs. Having the correct body condition score for the next breeding season starts at weaning, as it can take ten to 12 weeks for a ewe to gain one body condition score.

As mentioned briefly in the May management notes, keep a close eye on weights and grades and act accordingly to ensure you maximise farm profits. Draft lambs for slaughter as soon as they become ‘fit’. Factory specification for carcase weights for spring lambs in most cases are between 19 kg and 21 kg.

The kill out percentage of lambs varies throughout the season. Early spring born lambs which are well conformed, creep fed and drafted straight off the ewe kill out around 50%, whilst later in the season the kill out of weaned lambs can be as low as 42 - 44%. Lambs should not be drafted on weight alone.

Fat class should also be assessed as most factories prefer lambs with a fat class of at least 3 to meet the widest range of customer specifications. Therefore, regularly weigh and handle lambs to avoid lambs being drafted that are overweight, have poor conformation and are over-fat or under-fleshed.

Fly populations on the increase – monitor closely


Autumn calving cows and replacement heifers should be monitored carefully to prevent summer mastitis as fly populations start to increase. Watch out for early signs of mastitis as once you notice a swollen quarter, full recovery is much less likely. The main signs are an animal standing on its own which is often lame, dull, anorexic and can have a significantly raised temperature. To minimise the risk of summer mastitis, consider the following:

  • Avoid areas of the farm with large fly populations. This can be pastures with sandy soil, tree cover and/or water nearby.
  • Watch out for teat lesions.
  • Control flies on cattle, especially around teats.
  • Identify and isolate cases as soon as possible.


Warm, damp conditions provide the ideal environment for blueflies and maggot strike. Closely monitor ewes, rams and lambs and contact your vet to ensure you choose the prevention and/or treatment strategy best suited to your circumstances. Follow product label instructions correctly. Pay particular attention to the length of protection and withdrawal period as some are relatively long and will not suit heavier lambs close to finishing.

Complete a fodder budget

With volatile weather this year leading to difficult grazing conditions, many farms had to keep stock inside for a longer than usual, using up silage reserves. If you were fortunate and were able to get stock out, you may have given them access to fields which would usually have been closed off for silage to relieve pressure on grazing ground. In either case, a winter fodder budget should be completed after the first cut to help plan requirements from second and potentially third cuts.

This will also help you determine at an early stage if additional forage needs to be sourced. AFBI research shows that extra fertiliser, sown early in the season to increase grass yield, is the most cost-effective way to address a potential shortfall.


Prepared by: Andrew Thompson 

Spring 2024 has been difficult, with poor ground conditions making slurry application impossible for some. Recent favourable weather and improvements in ground conditions have allowed some to harvest silage, while others may be considering the first slurry application of the season.

With variable ground conditions, there remains a danger of slurry run off to waterways. Consider the forecast before applying slurry and stay 10 m from a waterway or 3 m if using Low Emission Slurry Spreading Equipment (LESSE) to reduce the risk of runoff.

Adjust slurry application rates to avoid nutrient loss and meet crop nutrient demand. The table below shows available nitrogen, phosphate and potash contained within 1000 gallons of slurry when applied using LESSE. As the availability of phosphate is influenced by the soil phosphate index, use of soil analysis results when planning applications to better meet crop demands.

Nutrients available from slurry when spread using LESSE

  Available nitrogen  

Available phosphate

(P Index 0-1)


Available phosphate

 (P Index 2 & above)

  Available potash  


1000 gallons



1000 gallons



1000 gallons



1000 gallons

6% DM cattle slurry 9 1 5.5 0.6 11 1.2 20 2.2
4% DM pig slurry 17 1.8 6.6 0.7 13 1.4 17 1.8

At a soil index of 2+, applying 3000 gallons per acre (33.68 m3 per hectare) of 6% DM cattle slurry fully supplies the phosphate requirement for a 68-70D silage. Phosphate applications greater than this will over supply crop requirements and risk being lost to the environment.

More help is available on the CAFRE crop nutrient calculator.

CAFRE online Soil Nutrient Health Scheme (SNHS) training is available to all farmers at. This training will help you interpret your soil analysis results and develop a nutrient management plan.

The dry matter of some early first cut silages may be low. Care is therefore needed when dealing with the resultant silage effluent. Ensure effluent is collected by clearing all channels from the silo to your effluent storage. It is also worth considering effluent produced from bales. Effluent from bales stored on an impermeable surface, such as concrete, must also be collected. If field storing bales, ensure they are sited at least 10 m from any open drain or watercourse.

Field boundary maintenance

Many farmers in recent years have planted new hedgerows or rebuilt stone walls on their farms. It is likely most of this work will have been carried out as part of the Environmental Farming Scheme.

Now is a good time to inspect those hedgerows or walls, checking if any maintenance is required. New hedgerows can quickly become overgrown by grasses and weeds and if not kept in check will stunt or in severe cases kill the hedge. If you installed a weed barrier when planting, you will be able to pull or kick back the grasses and weeds that have crept in from the sides. Usually this can be done quickly allowing sunlight to get into the young hedge plants. If you did not install a weed barrier, you may need to hand weed around the plants.

If intending to use a herbicide to control hedgerow weeds and grasses be aware that these chemicals will kill any hedge plants they make contact with.

Similarly, if you have rebuilt stone walls, it is a good time to check if any stones have fallen. Livestock are adept at finding breaks in boundaries such as walls, so now is a good time to carry out any repairs before breaks are made worse by cattle or sheep.

Maintaining hedges and walls is good for both the environment and the landscape. However, if they were planted or constructed as part of the Environmental Farming Scheme you are required to carry out annual management. This management ensures all hedges are weed free and stone walls are maintained. Scheme inspections are conducted to ensure compliance.


Prepared by: Liz Donnelly

National PRRS Control Scheme

The National PRRS Control Scheme is up and running, with an initial focus on farms in the Cookstown area, County Down and west Tyrone. Porcine Reproductive and Respiratory Syndrome or Blue Ear as the disease is commonly known is a devastating disease. As the name implies it causes reproductive failure in sows and respiratory problems in pigs. The virus multiplies in the immune system, destroying a large part of the defense mechanism which allows other infections to take hold.

A key element of the Control Scheme involves taking blood samples from pigs at slaughter and testing them for antibodies to the virus. This part of the Scheme is ongoing with samples being taken from pigs that are thought to be free of the virus. If your pigs have been blood tested, Pig ReGen will contact you, normally by email, with the results. If you receive an email from Pig ReGen, it is extremely important that you read it carefully. If the results show that your herd is positive it is crucial you contact your vet immediately for advice on PRRS control.

Another important part of the Scheme is the completion of biosecurity audits. As we all know, good biosecurity helps prevent the entry and spread of disease on a farm and controls diseases already present. The biosecurity audits will be carried out by your vet who will walk your farm and identify where simple and effective changes can be made to improve external and internal biosecurity.

Gary Anderson, who, as a result of participating in the PRRS Pilot Control Scheme in the Cookstown area, made several changes to biosecurity and management. The changes, which are inexpensive and simple to implement, are aimed at reducing the spread of the PRRS virus on the farm. They include:

  • Changing injection needles between every litter of pigs. This is important as it reduces the risk of passing the virus from a positive to negative pig.
  • Regularly replacing needles when blanket vaccinating sows.
  • Placing a foot dip at the entry to each house and/or room and ensuring they are always used.
  • Encouraging regular washing of hands, especially when moving from one section to another.
  • Having separate colour coded equipment, boiler suits and boots for each section. In practice, this means only driving boards, paddles, buckets and boiler suits of one colour are used in each section.

By implementing and strictly adhering to these simple changes, Gary has improved the control of PRRS and other diseases on his farm.

The Three Tonne sow!

First it was the Two Tonne sow, now it is the Three Tonne sow! Just over ten years ago, the target for the pig industry was to produce on average 2,000 kg of pigmeat per sow per year; the so called Two Tonne sow. This target is now surpassed. In fact, in 2023, on average 2,600 kg or 2.6 tonnes of pigmeat was produced per sow per year for CAFRE benchmarked farms.

Equally impressive is that feed efficiency was also excellent with a requirement of 3.42 kg of feed per kilogramme of pigmeat produced. Although the new target is three tonnes of pigmeat per sow per year, several CAFRE benchmarked farms have already exceeded this figure, with some producing almost 3.5 tonnes of pigmeat.

It you do not benchmark with CAFRE and don’t know how many kilogrammes of pigmeat each sow on your farm is producing, it is very easy to calculate the figure. Simply multiply the number of pigs produced per sow per year by the average carcase weight, for example if you are selling 30 pigs per sow per year at an average carcase weight of 97 kg then you are hitting the target!

As the performance and efficiency of the sow herd continues to improve, how long will it be until the four-tonne sow target is set! This can be achieved by producing, for example 40 pigs per sow year at an average carcase weight of 100 kg! Not possible? The top farmer participating in the CAFRE breeding herd performance project is already weaning 38.5 pigs per sow per year!

Notes to editors: 

  1. Follow DAERA on X formerly called Twitter and Facebook.
  2. All media queries should be directed to the DAERA Press Office: or telephone: 028 9016 3460.

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