Balanced diets key to keeping cows in milk
Waikato dairy farmers are well-placed heading into the peak of summer, thanks to favourable growing conditions late last year that resulted in abundant onfarm feed reserves.
Getting the most production out of this season by keeping cows in milk has to be a key focus. There is a huge opportunity cost associated with drying cows off too early because they have run out of feed. I’m aware of a Bay of Plenty farm that netted an extra $30K last season simply by having enough feed on hand to keep the cows milking. At the current payout this would have climbed to over $80K.
It has been a bumper spring in many districts but pasture cover levels can change quickly, particularly if the summer turns out to be yet another dry one. Maize silage is the ideal supplement to have on hand to complement pasture, as (1) it can be fed in large amounts, and (2) it is cost-effective.
1. Maize silage can be fed in large amounts. The amount of concentrates (e.g. grain or dairy meal) that can be fed is limited because these feeds have the potential to cause acidosis (also known as grain overload). Palm kernel is not highly palatable and for many herds intake peaks at 3-5 kgDM/cow. In contrast maize silage is a highly palatable forage which can be fed at up to 50% of the total dietary intake in the late lactation.
2. Maize silage is cost-effective. Most New Zealand farmers can grow maize silage crops yielding 18-24 tDM/ha for just 16-21c/kgDM. Crops grown on high fertility dairy land (including effluent paddocks) can be grown for 4-5c/kgDM less*.
How much maize silage do you need and what is the likely return?
The maintenance requirement for a pregnant Friesian 12 weeks pre-calving is about 6.5 kgDM. If you were to feed her an extra 6.5 kgDM (= 70 MJME) feed, she would produce about 0.88 kgMS/day. The gross return (from which the cost of feeding out, labour, depreciation and milking costs must be deducted) is as follows:
Feed cost:
6.5 kgDM maize silage at say, 40c/kgDM fed = $2.60
Milk return:
0.88 kgMS, at say $8.62 ($8.30/kgMS + $0.32 dividend) = $7.54
Gross return:
$4.94/cow/day (feeding out, labour, depreciation and milking costs must be deducted)
Most farmers will feed a higher pasture allowance and graze to lower pasture residuals in the late lactation and then use the balance of their maize silage to increase pasture cover levels and put weight on their cows over the dry period. It makes sense to do this, as the energy in maize silage is used 50% more efficiently to put weight on cows than the energy in autumn pasture.
Another key benefit of having an extra stack of maize silage on hand is that it can be fed if it is needed, but can be held over for months or even years if the feed isn’t needed. The interest cost of carrying over maize silage for 12 months is normally about 1c/kgDM.
Running out of feed could be the most expensive mistake you make this season. Revisit your feed budget today and make sure you will have enough maize silage on hand to enable you to milk through, even if the grass doesn’t grow!
*See Pioneer® brand Maize for Silage 2013/14 catalogue, pages 37 and 38, for a full list of assumptions.
• Ian Williams is a Pioneer forage specialist. Contact him at This email address is being protected from spambots. You need JavaScript enabled to view it.
