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August 2013

on .


  • How do you deal with drought conditions and the carry over effect?
  • Use all the techniques available to build up grass from the second week of August.
  • Use Nitrogen early in the month for greatest benefit.
  • Meals, carefully used, have a part to play!
  • Now is a great chance to reseed.
  • Small replacement heifers must be separated out and fed meals.

Overcoming Drought

Some parts of the country are suffering drought conditions after a dry few months.

How do you define drought? On Page 58 of the Irish Farmers Journal every week they give the 'Soil Moisture Deficits' across the whole country. On June 20, it ranged from 27mm in Donegal to 69mm in the south-east of the country. That means there is a rain or water shortage of 49mm (over 2 inches) and hopefully it has not dis-improved since. At levels between 50-75mm, grass growth is restricted, but new research shows that it sets in at lower levels on light soils. Above 75mm drought conditions exist where no growth takes place. Recent rain hasn't made up the deficit. This information should be used to size up the growth potential of your farm and the actions you need to take.

What should you do to compensate for poor growth due to drought? Carry out a grass budget every week (even twice/week).

The first principal is to lengthen the grazing rotation to 30-35 days. This will allow grass to grow adequately when growth rates are half normal. There is a bit of a risk with this strategy in that where there are reasonable covers of grass the drought can often burn this off. So, you must be alert to eat off this grass before this happens.

But how do you extend rotations when grass is getting scarce? Feed more meals (see the quota debate later), the amount can be calculated based on the amount of grass you have but it could rise to 3-6kg, or even higher. Pulp or barley would do fine.

Where high meals are fed (4kg), feed a 16 per cent protein ration. Feed maize (some farmers may have it) as it would be ideal with grass. Graze silage ground. Think of zero grazing silage ground from an outside farm (cheap). If grazing silage ground (heavy covers) pre-cut it. Only cut one day's feed at a time, being very careful to estimate the quantity made available to herd for the day. Remember, a cow will eat 18kg DM per day and from this you calculate the herd demand.

Feed baled silage. If it is very good, milk yield and protein will decrease very little (Moorepark).

Reduce stocking rate now, if you have too many cattle sell them now, as it will reduce the demand for grazed grass now and winter feed later on.

What might seem a rather radical suggestion would be to go on once per day milking (OAD), as it reduces the demand for grass/feed, cow body condition will improve, milk yield will decrease 26 per cent (MS/cow decrease by 20 per cent), reduced work load and less quota penalty stress worries. It is appropriate to anyone seriously over quota and/or whose cows are thin, with too many cows to fill the quota.

Should You Apply Nitrogen?

Yes, if some grass growth has taken place since last nitrogen was spread (20-35 units of CAN would be advised).

No, if little or no growth occurred since last spreading - soil moisture deficit of over 60mm.

When the drought is coming to an end with the arrival of rain, it is then you need to be very pro-active: Apply N immediately, remembering that in August you will have very little grass for one month. So, you must continue feeding meal/silage so that the rotation is near 35 days. If you don't do this you will have to house stock in Sep/Oct and available winter-feed supplies won't allow that.

Some of the suggestions made in this section will be appropriate for anyone who is 'tight' in grass.

Refrain from topping, as grass shortage means paddocks will be well grazed out. A few seed heads may look bad but in an overall context they have no adverse effect.

The New Zealand approach to drought is different to the above suggestion. They would keep grazing out paddocks until all grass is used up.

This overcomes the dilemma as to the length of the drought and the steps you need to take to overcome it. It ensures that no grass is wasted by leaving too much grass post grazing or in dung-pads.

Also, because there is a void for grass when rain comes, you can then feed meal/silage as a supplement. Water availability is essential for animal welfare and performance:

Water is the animals' most important nutrient. When temperatures increase from 18-30 degrees, water consumption increases by 29 per cent.

Cows provided with shade during summer consume 18 per cent less water per day. Cows will drink at least 5-6 times their milk yield per day, more if eating meal or very dry roughage. Limiting water availability severely and rapidly depresses performance,

Drinking rates vary from 1 to 3.5 gallons/minute. As cows consume water up to 14 times per day it is important to have water available within 300 meters and it should be available at or near milking parlour.

Build-up From August 1

This may seem a contradiction in the context of above discussion, and as I am writing this on July 15 the drought may not persist. But that is what must happen.

Grass is the cheapest feed available to the dairy farmer but from now on the demand for grass per hectare is greater than the growth rate. The following table shows that from early September growth rates drop off very fast.



(17-19kg DM)

Target AFC


Growth Rate(AV)




August 15





Sept 15





Oct 15





Nov 15





Nov 22-26





Every day you keep grass in the cow's diet it increases your profit by Ä2.80 per cow per day. There are other benefits also:

You will shorten the winter, which is vital this year because winter-feed is tight;

Less slurry will have to be stored and spread;

Animal health will be far better;

Labour requirement will be reduced; and,

At low stocking rates (<2.2 cows/ha) no meals will be required in the autumn.

Nationally, we only utilise 6.5t DM/ha and this is one of the best ways of growing and using more grass to achieve the standards of 12-14t/ha being achieved by some farmers.

Therefore, innovative thinking and a commitment to building up grass is now required by all serious farmers.

Interestingly, some dairy farmers in discussion groups have increased grass utilisation from 7.4t to over 12t DM per hectare. Each extra tonne of dry matter utilised is worth Ä200/ha in net profit. If you are now convinced that grass budgeting is worthwhile talk to your Adviser or join a Discussion Group.

Build Grass

The grass year starts now. Get your grassland management wrong during the next month and you will be short in autumn and spring.

Grass build up starts in August and it will be very difficult on dry farms this year:

In the South on August 10 and in the North on August 15.

Rotation length must be 28-30 days, depending on growth rates, coming up to late August and 30-35 days in mid-September.

Some or all of the following ways to build up grass should be applied:

Reduce stocking rates by taking away calves or cattle to an outside farm, sell cull cows, drying off very poor yielders or high SCC cows.

Reduce second-cut silage (particularly if you have enough pit silage).

Introduce meals (expensive option), but will be necessary at high stocking rates. A grass budget will tell you when to start but early rather than too late.

Introduce baled silage; this is a cheap alternative to meals with no loss of milk or percentage protein and must be the 1st supplementary option, if enough winter feed is available.

Apply more nitrogen (stay within your limits) in August as you get a better response than in September, see later in notes.

Graze out pastures well (4.0cm) as there is a temptation to leave too much after each grazing in August. It is a terrible mistake to leave a 'butt' of grass as you are wasting grass and preventing autumn tillering.

Set up a 'third-cut/graze' bank of grass.

Protect regrowths by not having cattle, cull cows grazing after cows or cows spending more than 24 hours in any one paddock.

I strongly favour this 'third-cut/graze' idea because it brings in a bank of high quality grass for grazing in September and it is like trying to save money when things are tight. If you run short of money in these circumstances you, at least, have money in the bank for the 'rainy day'.

It also allows you spread 2,000-3,000 gallons (16-24 units N) of slurry per acre on it at closing.

It also allows you put on 60-70 units of Nitrogen (discount the slurry N) to cover the six-week closed-up period and the extra Nitrogen(over grazing requirement) will grow extra grass which will feed 10-12 cows for one extra day for every acre closed up.

The way you do it is set aside 10-15 per cent of the farm for this purpose by leaving at least 0.8 – 0.95 acres/cow for grazing.

These fields should be topped or very well grazed out (skinned) leaving no butt, apply the slurry plus the Nitrogen and leave for six weeks and it should result in seven-10 days grazing starting from September 12-14.

An interval of three to five days should be allowed between spreading slurry (spread first) and applying nitrogen, so as to avoid losses of N by denitrification. If grazing grass is tight during this period, some of this area can be grazed.

However, at low stocking rates (2.2 cows/ha or less) because the demand will be low, 40-45kg DM/day, it may not be necessary to do any of the above to build up grass. It will happen naturally:

Definitely feed no meals;

Graze out tight to 4-4.5cm;

There's no need of 'third-cut/graze'; and,

For sure protect regrowths.

When Grass Is Tight, Use Nitrogen!

Now is the time to take stock of how much Nitrogen you have used so far this year relative to what you are allowed to use. Overuse will result in penalties, but use what you are allowed.

Farmers stocked at less than 2.24 cows/ha should only put on Nitrogen once, late August, over the next two months. All other farmers should apply 28 units/acre in August (Urea okay if wet). And another 28 units in mid-September.

Response is much better in August (12kg DM) than in September (8kg DM of grass per kg N applied),

Even though the rules allow you to apply N up to late September this year, but because the response is too low from mid-September on it is advisable to apply the last N in early September.

This Nitrogen should all be blanket spread as there are no losses in grass yield for August-September blanket spread application. As the benefit is greatest the earlier in the month you spread it, this must be a priority this year. Don't delay!

The August Nitrogen should be applied early in the month as you will grow 10-15 per cent more grass because growth rates are higher early in the month than late August.

Sulphur will still improve grass yield in August/September on light soils, deficient in sulphur by 3-20 per cent.

Meal Feeding in August

This depends on:

Your stocking rate (none required at less than 2.2 cows/ha);

Building up autumn grass;

The type of cow you have (some cows respond poorly to meals);

The cost of meal;

The milk price, so high this year it will force guys to bad decisions;

And combining all - the economic response; and,

Quota position, but, as we will have a quota problem this year be very careful.

Look up your EBI report – the Predicted Difference (PD) page. It tells you the genetic ability of your herd to milk. This is given in the form of PD for milk in kg. (A great figure to know). Get your adviser to help you with this. If you haven't this information, then, chances are you will make a bad decision and lose money. Therefore, join Herd Plus through ICBF.

Table 2: The Response (kg milk/kg meal) in August by cows of different genetics to milk with plenty of grass (Moorepark research).

PD for Milk

+ 150kg


+ 30kg

Milk yield/kg meal/day

1.07 kg



Value of extra milk/day (milk price = 39c/kg)



21.84 cents

Cost of 1 kg.
meal (Ä250/ton)

25 cents

25 cents

25 cents

Economic Gain
by Feeding Meal


+15.56 cents


Table 2 shows you how to lose money or make money, but these responses are not achieved above 2-3kg meal/day.

This means that for a farmer with a herd with a PD for milk of 150kg, for every kg of meal fed (costing 25c) he will get 1.07kg milk (worth 41.73c) in August.

Therefore, he has a margin of 16.73c/kg meal fed.

However, if the PD for milk in your herd is 30kg or less, then the response is only 0.56kg milk (worth 21.84c) per kg of meal (costing 25c). Therefore, you are losing 3.16c/kg meal fed. These cows are more likely to be New Zealand, British Friesian, Jersey or stock-bull type animals. You are losing money. Don't feed meals now.

There are several, more profitable options, open to you to fill your quota, particularly, quality grass at this time which is worth an extra 2.25L/cow/day.

Citrus Pulp as the sole concentrate should not be fed at rates above 2-3kg. Small replacement heifers should get 1-2kg Meal(18 per cent P). The same advice for small in-calf heifers.


Reseeding with perennial ryegrass, even though costing Ä250+ per acre, will pay for itself in two years by growing much more quality grass. You will have more spring and autumn (500-800kg DM/ha). In a full year you will grow up to 50 per cent more grass. Silage quality will be 5-8DMD units better. There is less stem/seed-heads and topping during summer. At high stocking rates, trials have shown an increase of 7.7 per cent in milk production with perennial swards over old permanent swards.

Reseeding must be done in August. September is too late as it results in weed grasses dominating with poor perennial establishment (50-80 per cent of the sown grasses). Clover will only prosper if sown in August. Anecdotal evidence of September/October reseeds doing well is false because even weed grasses look green.

It is important to do the job correctly and the following must be adhered to:

Kill off old grasses and weeds with Round-up/Gallup.

Leave for six-to-seven days before eating off or baling and then ploughing or tilling with one or two pass system, leaving a fine, firm seed bed by rolling prior to sowing (essential).

Apply lime (required ph is 6.2-6.7) if necessary and three bags 10:10:20 plus one bag CAN before sowing.

Sown the seed, only 1cm deep if clover included, lightly chain harrow in or use a ring roller, but it must be rolled after sowing (more important than ever this year).

Spray for weeds, particularly docks with Legumex, three-to-four weeks after sowing.

Graze early, at 600-700kg DM/ha, and often to promote tillering.

The next big decision is which varieties of grass to sow. It is best to take independent, professional advice on this as it is an investment that will influence your profit for the next 10-20 years. In principle, put in three varieties and clover for grazing mixes, and even in silage ground being cut twice. Sow 14-15kg/acre to ensure thick establishment.

Grazing Mix: Silage/Grazing Mix:

4kg AberGain (T) 4kg AberGain (T)

5kg Glenveagh (D) 4kg AberChoice (D)

5kg AberChoice (D) 5kg Tyrella (D)

0.5kg Avoca Clover 1kg Alice Clover

0.5kg Chieftain Clover

'In-calf Project' 2013-2014

There is merit in scanning all cows now, 30 days after last service. Because of grass, winter-feed and quota shortage, identifying non-pregnant cow will allow you dry off and cull earlier. Replacement heifer management, seriously neglected on many farm, needs remedial action based on current weights: Target weights(kgs) on August 1 are;


Jersey/Holstein Cross




In-calf Hfs



There is only one way to know for sure if you are under target and that is to get a weighing scales (between a few friends, it will pay for itself in a few years);

Any animals under the targets must be separated out and managed separately with either super grass quality or fed 1-2kg meal.

It is likely that the calves will need a worm dose during August. Order your requirements for Salmonella vaccine now for cows and incalf heifers.

Bits and Pieces

Deal with lame cows as they will lose body condition, will milk poorly and have high SCC levels.

A footbath, Formalin/Bluestone should be use three times/month. Repair roadways if they are not good, as the problem will persist.

Herd Health issues must be kept constantly under review.

High SCC levels are a major concern and are easy to control with good practices, viz, good machine, good milking routine and milking chronically infected cows last or cull them.

Move calves onto aftergrass after dosing to minimise worm infection. As liver fluke has become a major issue for cows, even on dry land, we must do everything in August to prevent its development by not having access to wet areas (tractor wheel tracks, around water troughs/gateways.

A sudden drop in milk yield could indicate a Lepto attack.

Keep an eye out for four-month abortions - due to Neospora (caused by dogs).

Take a holiday. Everyone, even farmers who think it isn't cool, need a break from the constancies of work. It will cost a few euro to get the work done while away but it will be worth it, and maybe you could rotate the holiday work with a neighbouring farmer or friend.

Will you know or have enjoyed your children by the time they move away to work? Get a contractor to do some of the work. On holidays leave the mobile on the 'off' button so that you remove yourself to a relaxed frame of mind.