DEALING WITH AFTER EFFECTS OF DROUGHT

• Some parts of the country are still suffering from drought and its after-effects.
• Every week, The Farmers Journal provides information on the soil moisture deficit for all areas around the country.
  • 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.
  • This information should be used to size up the growth potential of your farm and the actions you need to take.
  • PastureBase is proving very accurate in predicting the following week’s potential grass growth.
• In these circumstances, measure grass twice every week.
• Remember, there is a void for grass supply for seven to 12 days when rain comes, and the following actions must be considered:
  • Feed more meals, the amount can be calculated based on the amount of grass you have but it could rise to 3-6kg, or even higher. Research from Teagasc Moorepark (from last drought) showed dairy ration and soya hulls to be best.
  • Where high meals are fed (4kg), feed a 16% protein ration.
  • Think of zero grazing silage ground from an outside farm (cheap).
  • Feed baled silage where silage is plentiful. 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 and winter feed later on. Cows not in calf, high cell count cows fall into to this category also.
  • It might seem like a rather radical suggestion but once-a-day milking (OAD) may be a good option: it reduces the demand for grass/feed, cow body condition will be maintained, milk yield will decrease 26% (milk solids/cow decrease by 20%), and workload will be reduced.
• Should you apply nitrogen (N)?
  • Yes. When rain comes, immediately apply 20-35 units per acre as we are now in the period where we must try to build up autumn grass.
• When the drought is coming to an end with the arrival of rain – this is very important advice – you MUST be very pro-active:
  • Apply N immediately, remembering that it will take three to four weeks to have adequate pre-grazing covers.
  • So, you must continue feeding meal/silage so that the rotation is 30-35 days.
  • If you don’t do this, you will have to house stock in Sept/Oct, which could put pressure on winterfeed stocks.
• Some of the suggestions made in this section will be appropriate for anyone who is tight on grass.
  • Refrain from topping/cutting silage bales, 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.
• Water availability is essential for animal welfare and performance:
  • Water is the animals’ most important nutrient.
  • When temperatures increase from 18oC to 30oC, water consumption increases by 29%.
  • Cows provided with shade during summer consume 18% 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 1-3.5 gallons/minute.
  • As cows consume water up to 14 times per day, it is important to have water available within 300m and it should be available at or near milking parlour.

AUGUST GRAZING ADVICE

• It is important to list out the targets for the remainder of the autumn grazing period, see Table 1.
• Advice is very much tied up with how farmers have come out of the drought.
• For starters, rotation length is very important – 25 and 30 days for August 15 and September 1, respectively.

Table 1: August-September target grass covers (kg DM/ha) per cow and average farm cover (AFC) and rotation length.

• Over the last number of years average farm cover (AFC) has been below target on the August 15 on 50-60% of farms, so it is important to focus the advice.
• Farms with adequate grass supply:
  • These farmers, recently, have had above average growth rates which is likely to continue.
  • They have the opportunity to graze leafy, high-quality grass at covers of 1,500-1,600Kg DM.
  • There may be an opportunity/need to remove some paddocks for bales if pre-grazing yield becomes greater than 1,600kg DM/ha.
  • Ensure tight grazing to 4cm, to maintain high quality regrowths so as to avoid a stemmy ‘butt’ in the last two rotations.
• Farms with low grass supply:
  • Many farms are in this situation for various reasons; it is now most important to do something about it from early August.
  • Reduce demand by:
    • Supplementing with meal, silage or zero graze grass from outside blocks.
    • Remove stock from milking platform:
      • Replacements.
      • Calves.
      • Sell off cows due to be culled – lame, not in calf, cows with high SCCs, poor yielders, etc.
    • Add silage ground back into the milking platform.
  • Feeding silage will reduce grass intake more than meal.
  • Hold rotation length at 25 days.
  • If herd demand is 50kg (some supplement fed) and growth rate is 30kg DM/day recorded/projected, there is/will be a deficit of 20kg DM/ha/day. The result is that the AFC will decrease by 140kg DM/ha/week.
    • Therefore, demand must be reduced to 30kg DM.
    • Feeding an additional 7-8kg DM of supplement (mostly silage, if available) will hold AFC at a stocking rate of 3LU/ha (7x3 =21kgDM/ha).

STRATEGIES TO BUILD AUTUMN GRASS

• This is one of your key management tasks in August.
• You will not build autumn grass unless you plan it because grass growth will be decreasing while demand will remain the same. The options are:
  • Reduce demand on the milking platform as outlined above.
  • Strategically use N as per Table 2.
  • Grass build-up starts in August:
    • In the south on August 10.
    • In the north on August 15.
  • Increase grazing rotation length from 20 day in late July to 30 days in late August.
  • Plan a third-cut-graze from late July to grazing on September 10.
  • Ensure P and K levels are optimum.
• Before using N, take stock of how much N you have used so far this year relative to what you are allowed to use and score the clover content of each paddock.
  • Overuse of N will result in penalties.
  • Because of the drought or not using much N on outside blocks you may be able to use slightly more than that recommended in Table 2; whatever extra N you have would best be used in August as growth rates are better than September.
  • To encourage clover growth, follow the N recommendations.

Table 2: Recommended rates of N for different stocking rates

*SW= Soiled water

• Study Table 2 and decide what level of N you can use for your own farm.
• Farmers stocked at less than 2.24 cows/ha should only put on N once, in late August, over the next two months.
  • All other farmers should apply 17 units/acre in August (protected urea).
  • Response is much better in August.
• This N should all be blanket spread as there is no reduction in grass yield for August-September blanket-spread applications.
• The August N should be applied early in the month as you will grow 10-15% more grass because growth rates are higher early in the month than in late August.
• The targets from now August 1 to year end are (according to Teagasc Moorepark) include:
  • Three grazing rotations per paddock, if you wish to achieve the advised 10 annual grazings in the year.
  • Not more than 150kg meal/cow.
  • Achieve at least 150kg milk solids (MS) per cow.
• It is now an opportune time to review how your grassland management KPIs compare with Moorepark targets to August 5 so as to grow 16 tonnes DM/ha, spreading 212kg N and feeding 500kg meal to produce 480kg MS/cow.
  • To achieve this standard, you must have the following by early August:
    • 10,650kg DM grown = 67% of annual amount.
    • Seven grazings complete = 70% of annual amount.
    • 170kg N used = 80% of annual amount.
    • 350kg meal fed = 70% of your annual amount.
    • 330kg MS/cow sold = 69% of your annual amount.
  • Use the percentages to extrapolate your yearly achievement from your present figures.
• The following possible ways to build up grass should be applied:
  • Reduce stocking rates by taking away calves or cattle, selling cull cows, drying off very poor yielders. Stock cows at 2.9 cows/ha for grazing.
  • 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. An alternative to meal is to feed good quality round bales and this is the preferred option for high stocked farms.
  • Apply more nitrogen (stay within your limits) in August as you get a better response than in September.
  • Graze out pastures well (3.5-4.0cm) as there is a temptation to leave too much after each grazing in August.
  • Set up a third cut-graze bank of grass.
  • Protect regrowth by not having cattle or cull cows grazing after cows or spending more than 24 hours in each paddock.
• It’s a very good idea to set up this third-cut-graze plan because:
  • It brings in a bank of high-quality grass for grazing in September.
  • Allows you use 2,000-3,000 gallons (16-24 units N) of slurry per acre on it at closing, saving bag N.
  • Allows you to put on 55-65 units of N discount the slurry N) to cover the six-week closed-up period and the extra N 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% of the milking platform for this purpose by stocking the cows at 2.9-3.0 cows/ha for grazing.
  • These fields should have been cut for silage or topped or very well grazed out (skinned) leaving no butt, apply the slurry plus 25-35 units of N per acre and leave for six weeks and it should result in seven to 10 days’ grazing in late September.
  • An interval of seven 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 will not be necessary to do any of the above to build up grass. It will happen naturally.

RESEED: EARLY AUGUST

• With plenty of winter feed made this year, and N restrictions in operation, it is an opportune time to reseed underperforming fields.
  • Consult your PastureBase data to identify these fields.
• Reseeding with perennial ryegrass and white clover will pay for itself in 2 years by growing much more quality grass.
  • You will have more spring and autumn grass (500-800 kg DM/ha).
  • You will grow 2-3 tonnes/ha more grass compared with old grasses, worth €500 per year more profit per hectare.
  • Silage quality will be 5-8 DMD units better.
  • Less stem/seed-heads and topping during summer.
  • New grasses respond 25% better to fertiliser than old grasses.
  • At high stocking rates, trials have shown an increase of 7.7% in milk production with perennial swards over old permanent swards.
  • The return on money invested in reseeding is an amazing 96%.
• Every day extra you keep grass in the cow’s diet is worth over €2/day in profit.
  • Perennial ryegrass is the best way to grow more grass in the shoulders of the year.
• Reseeding must be done in August:
  • September is too late as it results in weed grasses dominating with poor perennial establishment (50-80% 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.
  • 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 (neglected in most situations).
  • Apply lime, up to three tonnes/acre (required pH is 6.3-6.7) if necessary and three to four bags 10:10:20 (more if Index 1) plus 1 bag CAN before sowing.
  • Sow the seed, only 1cm deep if clover included, lightly chain harrow in, or use a ring roller, but it must be rolled after sowing.
  • Watch out for pest attacks in autumn sown crops, particularly, slugs, leatherjackets, fruit fly, and rabbits.
  • Spray for weeds, particularly docks with clover-safe spray 4-5 weeks after sowing when the docks are the size of a 20cent piece.
  • Graze early, at 600-700kg DM/ha, and often to promote tillering. It would be a good idea to roll again before this grazing to prevent pulling by stock.
• Being a bit old fashioned, but from experience, and where there are no stones, I favour shallow ploughing (less than 15cm).
• 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,
• Consider red clover?
  • Very high production for the three to six years, delivering an annual production of 13-16 tonnes DM/ha.
  • It fixes more than 300kg N/ha (240 units/acre).
  • But it has a high requirement for P and K.
  • Very suitable for a four-cut silage system with zero grazing in the autumn, outside silage blocks.
  • White clovers are more persistent in sward, with a recommendation to oversow every five to six years and reseed every 10+ years.
• Consider multi-species and learn from the experience on your farm. Many farmers are quite happy with their contribution to farm.

WEIGH REPLACEMENTS

• Replacement heifers are key to profitable dairy farming, and quality heifers will result from achieving weight targets evenly throughout their lifetime.
• Why?
  • They will reach optimum service weights.
  • They will have earlier onset of puberty.
  • Greater milk production in first lactation.
  • Every 50kg extra first calving liveweight resulted in 300kg extra milk in the first lactation.
  • They will survive longer in the herd if they don’t calve down too light or too heavy relative to their mature weight.
• Table 3 lists out the weights of heifers and weight gains expected.

Table 3: Liveweight targets (*) for replacements relative to mature cow weight to achieve optimum first-calving weight.

*Because most R2s (replacement heifers = 1-2 years) are calving down at one year and 11 months, these targets must be 5% better.

**Average weight gain from weaning to six months (R1s = replacement 0-1-year-old).

• Two messages arise:
  1. Light animals must be managed to achieve targets on November 1.
  2. Heavy, 20kg+ over target, must be managed so that so that they do not get too fat/heavy because they will struggle to go in calf and will milk less over their lifetime.
• The appropriate actions are obvious. Act now.
• This message essential for farmers who rear their own as well as contract rearers.

Gentle reminders:

• Most of the work is done now, so take a two-week holiday and trust whoever you have left in charge to manage in your absence:
  • Give clear instructions.
  • Take the two weeks so that you totally relax and give yourself some head space.
• Mastitis/SCC financial losses:
  • Over €60 per cow per year.
  • Anyone over 150,000 SCC should consult their milk quality adviser.
  • Do a milk recording now to monitor individual cow SCC levels which can be used for drying off management.
• Intensive dairying removes approximately 0.5 tonnes/acre of lime annually; now is a very good time to lime paddocks as the rotation length will be 30+ days.
• Animal health reminders:
  • Keep a close eye on calves for symptoms of hoose and stomach worms.
  • Lame cows should not be walked long distances to paddocks.
  • Replacement R2s should get the first of their leptospirosis vaccines in late August. Make sure to have ordered this vaccine in time for the cows’ and heifers’ September due date.
• If worried about your financial position, you should do a simple financial plan:
  • Estimate the amount of sale you will take in between now and Christmas.
  • Do the same for likely spending and subtract from sales.
  • Generally, farmers find this reassuring and removes some financial stress.
• Do an autumn rotation plan on PastureBase to make the management of grazing easy from mid-September.

Quote of the month

“The farmer is the only man in our economy who buys everything at retail, sells everything at wholesale, and pays the freight both ways.”

JF Kennedy.