Management Notes for May 2019

Date published: 03 May 2019

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).

An ideal chop length promotes good consolidation in the clamp and provides enough fibre for the cow to ruminate


Prepared by: Christopher Breen

When should grass be cut for silage?

As a guide you should cut before 50% ear emergence in the sward. For swards based on early perennials cut around 10 May. Swards based on mid-season varieties will be ready to cut around 20 May. Cut late varieties in the first days of June. Walk your crops before these dates and check for ear emergence so that you can plan a cutting date. Each weeks delay after 50% ear emergence results in an extra 2 kg of concentrates to achieve the same milking performance.

Cut grass at the first spell of good weather. A bright day is ideal to increase the sugar content of the grass giving improved fermentation. Sunshine also promotes a more rapid wilt, reducing the amount of water ensiled. It is important that grass is mown dry, cutting wet grass means a longer wilt time and a reduction in nutrients. Mowing grass later in the day is more preferable than starting at 9am when dew may still be a problem.

Wilting grass 

  • To speed up the wilting process spread the cut crop over the entire field straight after mowing.
  • Aim for a target grass dry matter (DM) of 30% at harvesting.
  • A rapid wilt prevents excessive sugar and protein losses.
  • In ideal wilting weather a crop will be ready to lift within eight hours if it has been spread out.


  • Ideal chop length promotes good consolidation in the clamp and provides enough fibre for the cow to ruminate.
  • Set chop length at 25 mm for grass with a DM of 30%.
  • When grass is wetter, less than 20% DM, consider a longer chop length of 50 mm.

Clamp management

The purpose of ensiling grass is to preserve and minimise the loss of nutrients thus improving silage feeding value. Silage fermentation can be divided into two phases:

Phase 1 - elimination of oxygen by chopping grass to the correct length, ensiling at recommended dry matters, filling the silo quickly and distributing grass evenly in the silo.

Phase 2 - production of lactic acid by micro-organisms in the grass. Lactic acid is the primary acid responsible for lowering pH, producing silage and making it stable. Undesirable micro-organisms can dominate if the pH does not drop rapidly. Where weather allows, wilting grass to 25-30% DM before ensiling can eliminate this problem.

The key is to remove air and make the clamp as air tight as possible. Ensure the ensiled grass is spread in shallow layers and rolled continuously. Always cover the silo at night. At the end of harvest apply an effective cover and weight the cover, paying particular attention at the shoulders of the pit.

Use of an additive

Effective silage fermentation produces high levels of lactic acid reducing the crop pH. Silage additives can help this process. A variety of additives are available including bacterial inoculants, enzymes, non-protein nitrogen sources, acids and sugar sources. It is important to emphasise that none of them are a substitute for good silage making techniques and management, but they should help make a good situation better.

May jobs checklist

  • Graze swards down to 1,600 kg DM per hectare to maintain sward quality.
  • Check silos and carry out any maintenance in advance of silage making.
  • Check there is adequate storage in tanks to collect effluent produced.
  • Calibrate parlour and out of parlour feeders to ensure accurate feeding.
  • Spray docks/weeds if conditions are suitable and they are at the right stage for control. If spraying silage ground for docks, generally allow an interval of at least 21 days between spraying and harvest. As this depends on the product used always read the label.


Prepared by: Nigel Gould


Lamb performance at grass

Parasite control and maximising grass dry matter intakes are key in driving lamb performance at grass. It is possible to achieve target daily live weight gains of 280-300 g per day for twin lambs on the ewe where grassland management is high. As daily gains decrease to 180-200 g per day post-weaning at 14 weeks of age it is important to target high grass quality pre-weaning to improve feed efficiency.  It is vital to have a parasite control plan in place over the grazing season. Use an appropriate product to which there is no resistance built up on farm. Faecal samples can be taken and analysed to identify anthelmintic resistance. Where resistance to a particular active ingredient is identified a product containing an alternative ingredient must be used.


May is the month often associated with the start of the Nematodiris threat. The disease, caused by the Nematodiris battus worm, can result in high levels of mortality and stunted growth. It has a different life cycle to other sheep worms. The development of the infective larvae takes place within the egg and infection passes from one year’s lamb crop to the next. Lambs are most susceptible after six weeks of age when dependency on the ewe’s milk reduces and the intake of grazed grass increases. Younger lambs suckling ewes with poorer milk yields are also susceptible. As cold weather delays hatching a sudden increase in temperature can trigger a mass hatch. If this coincides with the period of increased grass intake consequences can be severe. The risk can be reduced by grazing ground which wasn’t grazed by lambs the previous spring. SCOPs, an industry led initiative, which promotes best practice in the control of parasites, provides a live Nematodiris forecast. This predicts hatch date based on temperature data from across the United Kingdom and can be used, along with your sheep grazing history, to identify risk periods on your farm. This can be accessed on the SCOPS website. Provided there isn’t a resistance issue on farm, a white drench (Group 1- Benzimidazoles) will control Nematodiris.


Maintain grass quality to maximise performance

The grazing season provides an opportunity for inexpensive weight gain from grazed grass. Maximise yield and quality to maximise animal performance. Peak grass growth occurs in the May-June period. Good grassland management is vital to ensure grass covers are grazed down tight to avoid a build-up of dead material at the base of the sward. Monitor the grazed area and be prepared to ‘pull out’ paddocks where covers are strong. If cutting is delayed on these paddocks to increase yield, it may lead to grass shortage later.


Breeding season in spring calving suckler cows

As the calving season ends for spring calving suckler herds attention switches to the breeding season. Target body condition score of 2.5+ and a rising plane of nutrition to achieve a calving interval of 365 days. Replacement heifers should be bred two to three weeks before the main herd. Where a stock bull is used, record heats observed and monitor repeat heats to identify infertility or sub-fertility. Sub-fertility is now recognised as an issue and although a bull may be fertile at the start of the season he may experience periods of sub-fertility.

Where artificial insemination (AI) is used heat detection can often be the primary barrier to success. Cows and replacement heifers need to be observed two to three times daily. If this is not practical there are options available which may increase heat detection rate. The most successful is the use of a vasectomised bull fitted with a chin-ball harness. This contains a type of paint, clearly marking any cows in standing heat. As the vasectomy needs to be carried out at least six weeks before the bull is used, this rules out this option, if not already carried out. Tail paints and scratch card/ink-well based patches are another option, however the success of these varies from farm to farm. Where heat detection is a problem and labour availability is limited, a synchronisation programme using fixed-time AI may be considered in consultation with your vet. Research at AFBI has shown a large variation in conception rate to synchronisation on farms. The key to success is having cows in optimum body condition score and adhering strictly to the recommended timing of AI in the particular programme protocol.


Prepared by: Liz Donnelly

Quality Assurance – revised standard

Red Tractor recently revised one of the animal medicine and husbandry procedures standards. The revised standard, AM.b, requires you to now download and save or print a copy of the ‘Practical Guide to Responsible Use of Antibiotics on Pig Farms’. You and any employees that inject pigs must read the document. If the document, which must also be signed by all who read it, is not available at inspection a non-conformance will be issued.

The practical guide offers advice on using antibiotics when your vet recommends them to be appropriate for your farm and health of your pigs. It stresses that ventilation, nutrition, water supply, housing, hygiene and biosecurity are well managed as they are crucial in controlling disease and reducing the need for antibiotics.

Where antibiotics are necessary the guide recommends how to use them responsibly to safeguard animal health and welfare. When used along with optimum management the measures aim to preserve the effectiveness of antibiotics for use in human and animal medicine. 

Benchmarking carcase quality

For the first four months of 2019 the average carcase weight of Northern Ireland pigs slaughtered was 90.2 kg. The average P2 was 12.1 mm, the weight variation 7.61 and the probe variation 2.06. How do these figures compare with those for your herd? A simple way of checking is to view the Pig Grading Information System (PiGIS) benchmarking reports. These reports, as well as providing information on the carcase quality of your pigs over any time period, allow you to compare your figures with, for example the top 10% or 25% of pigs slaughtered. If you are not one of the many pig farmers who already use PiGIS to monitor carcase quality you can register to use it through DAERA Online Services.

Food Chain Information

The Food Chain and Quality Assurance Scheme Information section on the pig movement document requires you to answer four questions. If the answer to question 2 ‘Are the Food Chain Information Statements on the reverse of the document satisfied?’ is ‘no’ you need to provide the factory with more information. This is particularly relevant if any pigs are showing signs of a disease or condition that may affect meat quality. The vet at the factory uses the information at ante-mortem to check if the batch of pigs is fit for slaughter. When answering this question record the number of all pigs with abnormalities. If there are several pigs with different abnormalities, for example tail bitten, hernias, lameness you need to note all of these pigs, not just some of them! Also record the colour of mark used to identify these pigs. The more information you can provide for the vet the better!

Something of interest!

If you are a regular reader of the pig management notes you will know that I often write about things of interest that I see during farm visits. During a recent visit to a County Down farm I saw a very simple and easy to access way of keeping the numerous templates/policies/booklets etc. required for Quality Assurance. Each document is kept on a clip board, with all the clip boards displayed on a frame on the wall in the farm office (see photograph). Clips used to attach plastic piping to a timber frame leave enough space between the pipe and frame for the clip boards to slide down behind the pipe. This means the farmer (and inspector) can see at a glance where the documents are. It is a much more professional and impressive way of keeping paperwork than storing it in a biscuit tin or box!


Prepared by: Leigh McClean


Good growing conditions mean winter cereals are a bit further ahead than we have been used to in recent years. It is important to inspect crops regularly at this time of year to get key spray timings right and maintain the good yield potential crops possess. 

Winter barley disease control

Apply T2 fungicide three to four weeks after T1, ideally when the flag leaf and the first few awns have emerged. For crops that pose a high lodging risk include plant growth regulator (PGR) in the mix and apply earlier before awns emerge when the final PGR is more effective at shortening the straw.

The best performing fungicides contain an SDHI and Triazole, (for example Aviator, Adexar) Strobulurin (for example Priaxor) or a mix with three different modes of action, for example Ceriax or Concorde and Rubric.  Prothioconazole with a Strobilurin, for example Fandango or Mobius also gives good protection if the crop is clean. Inclusion of Chlorothalonil at T2 provides best control of Ramularia normally only evident towards the end of the growing season.  

Winter wheat disease control

Prepare for a timely T2 treatment at flag leaf emergence no later than four weeks after the T1 spray. A well applied T2 spray will give a bigger yield response in wheat than any other spray timing.

Triazoles continue to lose their activity against Septoria and remain most effective when used in a protectant situation as part of a mixture with an SDHI. You must use SDHIs responsibly as part of fungicide programmes which minimise potential selection for resistant Septoria strains. Only use SDHIs where necessary, never apply  more than twice in a season, keep up dose rates and always use in combination with a multisite protectant, for example Bravo or Phoenix and a Triazole fungicide.


For recently sown spring cereals the option still exists to apply residual herbicides more commonly used on winter cereals pre or early post-emergence as extensions of minor use (EAMUs). These herbicides provide a different mode of action and improve annual meadow grass control. 

If crops are too far forward for the residual option, aim to apply a mixture of at least two broad spectrum herbicides whenever most of the weeds are at the two to four leaf stages. This ensures weed competition is removed at an early stage of crop development and may allow product dose rates to be reduced.   

It is also good practice to prevent disease becoming established at this stage by tank mixing a fungicide with your herbicide. As Rhynchosporium is the most damaging disease in our current spring barley varieties, product choice should reflect this. Products previously mentioned for winter barley are equally effective on spring barley, although at a lower rate.

Nitrogen top dressing is best applied once tramlines are visible at the two to three leaf stage (GS 12 to 13). Later applications than this may green the crop but add little yield.


As planting progresses it is important to ensure good quality seed beds are produced. Check periodically to ensure correct planting depth and spacing are being achieved.

Have plans in place for early weed control to ensure key timings are not missed. Where pre-emergent products are used checks crops regularly to ensure herbicides are applied on time to avoid crop damage.

Notes to editors: 

  1. Follow DAERA on Twitter and Facebook
  2. All media enquiries to DAERA Press Office or tel: 028 9052 4619.

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