Management Notes for August 2020

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).

Bumblebee at work

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).

DAIRYING

Prepared by: Christopher Breen

Reseeding

August is the traditional time for reseeding. Before any work starts consider:

• If any drainage repair is needed
• If ploughing is necessary or if soil compaction is an issue that needs addressed
• Using soil analysis to determine correct lime and fertiliser requirements
• Sowing grass varieties with similar heading dates which are suitable for  intended use
• Using a maximum of four grass varieties

Minimal cultivation and stitching-in techniques can be used to establish new or renovate existing swards.

• Minimal cultivation - if the old sward contains scutch grass or is heavily infested with docks, it should be destroyed before cultivation. Following hard grazing (3-5 cm) or silage cutting, spray off the regrowth. About a week later (follow specific product recommendation) drill the seed into a shallow tilth prepared by harrowing the surface and rolling afterwards.
• Stitching in – use this technique to improve swards with a significant proportion of perennial ryegrass. It is particularly suitable for open silage swards or stony ground. Most drills will sow grass seed into existing swards. Minimise competition from the existing sward by hard grazing or mowing for silage immediately before reseeding. Graze with light stock after reseeding to keep the existing sward from overwhelming the new seedlings.

Inspect all reseeds for signs of pest damage, particularly frit fly and leatherjackets.

Close up dry cows

The last four weeks of the dry cow period are the most critical in terms of establishing the subsequent lactation. If dry cows have been grazed, they should be housed for the last four weeks of pregnancy. A low calcium diet will stimulate the cow to mobilise calcium from her own body reserves coming up to calving reducing the risk of milk fever - the Dietary Cation-Anion Balance diet. It is important to feed forages which are low in potassium (K) (grass/silage grown from soil low in K or wholecrop) to minimise milk fever risk. A mineral analysis can determine the level of milk fever risk for the forage or forages being fed.

Body condition of the cows dictates the amount and quality of feeding. Ideally cows should be in condition score 3. If cows are too fat or too thin, alter their feed to allow them to achieve this condition score at calving. Fibrous silage and straw are good for keeping the rumen expanded and working. During the close-up stage energy requirement increases to around 120 MJ per day. At this stage think about increasing the energy density of the diet potentially through feeding 1.0-2.0 kg pre-calver concentrate.

Improve cow housing

The next month provides a last opportunity to make any housing changes before the winter. Assess your dairy unit with a view to improving cow comfort and easing management. Size cubicles for the largest cows in your herd. Suggested dimensions for a 600 kg cow are:

The bed should slope 100 mm from front to back and the kerb depth should be between 150 mm and 200 mm. Trials show that cow lying time increases with the softness of the bed so try kneeling on the cubicle bed. If you feel any discomfort it needs upgraded.

Don’t overlook simple issues that have a bearing on feed intake, milk yield and fertility. These include ventilation, condition of floors, feed space, cow flow, provision of adequate water and lighting.

August jobs checklist

• To maintain sward quality, top grazing swards containing dead grass or seed heads
• Reseed fields that are not performing well. Apply lime where necessary and the appropriate fertiliser based on soil analysis results
• Check if there are any areas that would benefit from drainage. Consider drainage before reseeding swards

Information and guidance during the Covid-19 pandemic.

BEEF AND SHEEP

Prepared by: Nigel Gould

BEEF

Weaning calves

As weaning is a stressful time for calves it can result in a check in performance. Measures taken to reduce the cow-calf bond and boost the immune system in advance of weaning will reduce the severity of the growth check.

Introduce creep grazing to allow calves access to the higher quality grass ahead of the cows. The cows can then be used to clean out paddocks. This can be done at low cost by raising part of the electric fence. Alternatively, the gate propped slightly ajar and held securely will create a funnel effect between the gate and gate post. This allows the calves access to creep grazing. Creep grazing can also facilitate supplementary feeding of concentrates pre-weaning. Offering concentrate for four to six weeks before weaning reduces the calf’s dependency on the cow. This helps to avoid the growth check at weaning. It is important the concentrate doesn’t simply replace quality grazed grass in the diet. Generally 2.0-3.0 kg of concentrates per calf per day is offered, depending on calf type. Heifer calves and native bred steer calves are prone to laying down excess fat on the higher feeding levels. Well conformed continental type bull calves are generally good convertors of concentrate to lean muscle without excess fat deposition. In this case, a response of 1.0 kg additional live weight gain per 4.0-6.0 kg of concentrate is achievable. A simple concentrate mix can be offered provided quality ingredients are used. It should have a crude protein of 16% and a metabolisable energy of 12.5 MJ/kg dry matter. An example of a mix is: 57.5% barley, 25% beet pulp, 15% soyabean meal and 2.5% minerals/vitamins. Keep troughs clean and concentrate fresh at all times to minimise spoilage.

Some farmers are now using devices such as nose flaps to successfully reduce the cow-calf bond. These are fitted to the noses of calves and prevent suckling while calves remain with their dams. It removes milk from the calf’s diet while retaining the comfort of the dam. The calves can then be fully weaned after a short period of time. Gradual weaning, where a proportion of cows are removed from the group while their calves remain in the field with the other cows and calves, may also reduce calf stress at weaning.

Pneumonia in calves can be more common around weaning time due to a suppressed immune system. Vaccination can reduce incidences of pneumonia as long as good management is still practiced. Vaccination generally requires two doses of the vaccine administered three weeks apart. The initial dose is required up to six weeks pre-weaning for some products to achieve maximum immunity by weaning time.

Treat internal parasites two weeks pre-weaning where possible. Calves with lungworm burdens in particular will be put under increased stress if dosing coincides with weaning.

SHEEP

Prepare the flock for breeding

Although it may seem a long way off for most flocks, consideration should be given to both ewes and rams well in advance of breeding. Rams should have a target body condition score (BCS) of 3.5-4.0 at breeding to allow for some condition loss during breeding. Thoroughly inspect rams now, paying particular attention to testicles and feet to allow time for corrective action and treatment. If a ram is to be vasectomised for use as a teaser, the procedure needs to be carried out at least six weeks before being required. If purchasing a ram, speak to the seller about his pre-sale diet. If a high level of concentrate was being fed, it is necessary to gradually adjust the diet before he is put out to the ewes.

Continue to monitor ewe BCS. Ideally group ewes according to BCS and feed accordingly. Hogget ewes which have reared lambs or other ewes in poor body condition should be closely monitored and offered the best quality grass. If BCS fails to improve, consider culling as there may be a hidden reason for the poor performance.

Information and guidance during the Covid-19 pandemic.

PIGS

Prepared by: Liz Donnelly

The five facts of heavy pigs!

Heavier pigs at slaughter does not necessarily mean more profit. The average deadweight of pigs in Northern Ireland at present is almost 92 kg and this figure is rising. As the average weight is 91 kg this means there are units selling pigs that are killing out much heavier than 91 kg. When pig price is good relative to feed cost, there is a real temptation to take pigs to heavier weights as the price received per pig looks very attractive. But this may not be the best approach for all units. Below are five facts to consider:

• Fact 1 - as pigs get heavier they get fatter. It is therefore critical to check factory returns carefully to determine the number of pigs probing over the upper P₂ value.
• Fact 2 - higher slaughter weights means more overweight pigs. As overweights are severely penalised by the factory it is important there are not too many, as this will have a real impact on the price received. The Pig Grading Information System (PiGIS) allows you to easily check the effects of probe and weight and helps you select an optimum slaughter weight to maximise price. If you are not already using PiGIS you can access the programme through DAERA online services;  https://www.daera-ni.gov.uk/services/daera-online-services
• Fact 3 - feed conversion may get worse as pigs get heavier. The most important factor in producing heavy pigs is the cost of feed. You need to know how feed conversion changes at different slaughter weights for your pigs. Industry averages only give an indication. Although not easy to calculate every effort should be made to determine the Feed Conversion Ratio of your pigs.
• Fact 4 - heavy pigs can become overstocked, leading to reduced performance and more variation in the weight of pigs in the pen. The result of this is that it takes longer to clear pens and there is a higher risk of tail biting.
• Fact 5 - pig factories in the Republic of Ireland, Great Britain and across Europe have had to reduce throughput or temporarily close due to Covid-19 infection in workers. As Covid-19 is still present, there is potential for the slaughter of pigs to be disrupted in our local plants. Could you keep your pigs for an extra week or two if slaughter numbers were reduced by the factory?  By reducing slaughter weights you can release space and ease any pressure there may be on the system.

Environmental enrichment

Providing the right type and amount of enrichment in the right way is one way of reducing stress in pigs. Pigs need to root and explore their environment. If they can’t they become stressed and may start to tail bite. Other stressors that can cause tail biting include overstocking, inadequate feeder space, high ammonia, poor health and genetics.

Providing wood as enrichment is becoming popular with both pig farmers and the pigs themselves. Pig farmers like wood because it is easily available, relatively inexpensive, is an organic product, can be suspended by a chain or put in a dispenser and suits fully slatted systems. The photograph below shows how popular wood is with pigs. A new piece of wood was put into this dispenser five days before the photograph was taken. It is obvious from the photograph that the pigs are making good use of the wood. The wood used is spruce which is a soft wood. It is important to use soft wood as the pigs can chew and manipulate it much easier.

If using wood check there are no sharp edges and the wood is not splintering as this could cause the pigs harm. The size of wood should also be proportional to the size of the pigs, with smaller pieces of wood more suitable for younger pigs. There is no point giving small pigs a large block of wood which they can’t chew!

Information and guidance during the Convid-19 pandemic.

HORTICULTURE

Prepared by: Kieran Lavelle

Bumping off bumblebees

The practice of using commercial bumblebee hives to pollinate crops has been increasingly adopted by growers to increase yield and fruit quality. Since 2008 these hives have been based on a bumblebee species that exists in Ireland, Bombus terrestris, although local populations can be genetically distinct from imported colonies. Although commercialisation of bumblebee hives is strictly regulated within the EU, inappropriate disposal techniques can have a serious impact on local pollinating insects and native bees. Recent work shows these hives can spread bee parasites and compete with local populations for nectar and pollen. One of the biggest issues is that the new queens that emerge from these hives can interbreed with local populations, affecting the unique genetic profile of the indigenous, wild bumblebees.

The risk of hybridisation caused by interbreeding can be eliminated if proper disposal techniques are used. Bumblebee colonies have evolved so new queens emerge as the colony withers and dies. They then mate, overwinter and set up new colonies the subsequent year. The timeframe from delivery of a hive to a new queen potentially emerging takes around 18 weeks, with the hive being most effective for eight weeks after delivery. Some growers do not dispose of the hive after this eight week period, but let it die naturally. This gives the colony the chance to complete the natural cycle and create new queens which can escape into the local environment.

Colonies should be disposed of after this eight week period. By ensuring the colonies are disposed of before queens emerge, you can make a valuable contribution towards the protection of our unique and valuable native pollinating insect population.

Botrytis in ornamental production

Botrytis or grey mould is a destructive fungal plant pathogen which affects a range of crops. It can attack all parts and can render crops unmarketable. It is a relatively ‘weak’ pathogen and needs the presence of wounds or weakened tissue to establish an infection. Once established, it can generate a vast amount of spores that are quickly distributed. Although viewed as a cool season pathogen capable of infecting crops at temperatures as low as 0^oC, warmer temperatures above 18^oC in combination with high humidity can greatly encourage disease development.

You should remove plant trash, disinfect surfaces and immediately remove heavily infected plants. If any pruning of plants is required, this should be carried out early in the day allowing wounds to dry quickly. Over fertilisation can lead to soft growth which offers an easier route for botrytis to enter the plants. If using overhead irrigation, water in the morning to reduce free moisture on the leaf surface. High humidity is conducive to the development of an infection. Reduce relative humidity around the plant canopy by using pipe heat to create convection currents lifting warm, humid air from around the crop. An alternative is to use Horizontal Airflow Fans (HAF) or Vertical Airflow Fans (VAF) to create air currents in the crop canopy. Although HAF fans are seen as the industry standard, research shows VAF are more effective than HAF for creating air movement in plants grown on benches or the floor. Regardless of how airflow is directed, aim to recirculate twice the air volume of the structure every hour. You can check if there is an even distribution of air by using air temperature as an alternative to measuring air speed with aerometers, which can be challenging to assess. The objective in a greenhouse is to ensure the temperature (both vertically and horizontally) does not vary more than 1^oC. Another benefit of using fans to drop relative humidity is cost saving, with Grow Save showing fans cost about one third less to control humidity compared to pipe heat.

If using fungicides rotate products with different FRAC codes to minimise resistance developing in Botrytis.

Information and guidance during the Covid-19 pandemic.

Notes to editors: 

1. The department may take photographs and videos at announcements and events to publicise its work. Photographs, interviews, videos or other recordings may be issued to media organisations for publicity purposes or used in promotional material, including in publications, newspapers, magazines, other print media, on television, radio and electronic media (including social media and the internet). Photographs and videos will also be stored on the department’s internal records management system. The department will keep the photographs and recordings for no longer than is necessary for the purposes for which they have been obtained. The department’s Privacy Policy is available on our website.
2. Follow us on Twitter and Facebook.
3. All media queries should be directed to the DAERA Press Office: pressoffice.group@daera-ni.gov.uk

Share this page