From my mainly soil fertility scientist’s perspective, the keys are to
(i) grow nutritious pasture as cost-effectively as possible; encourage clover,
(ii) do whatever you can to get the utilisation of the pasture as high as possible,
(iii) minimise bought-in feed,
(iv) do whatever you can to increase the utilisation of the nutrients in urine, dung and dairy-shed effluent.
(i) Growing nutritious pasture cheaply. If you have reasonably good soil tests already, as most dairy farmers do, you can cut back dramatically on superphosphate – by half or more, or even stopped if Olsen P levels are over 40- for the next 2 years. Potash (K) and sulphur (S) needs to be applied more regularly than P, but rates can be reduced. The most important nutrient to manage well is nitrogen (N). How you do this depends a lot on your soil organic matter status. If you have a soil rich in organic matter, you will not get as big a response to N, so restrict N applications to when you really need to reach a higher feed wedge. Use SustaiN or N-Protect instead of ordinary urea – it really is worth the extra $40-50/tonne. Our ‘ONEsystem’ wetted, nbpt-treated prilled urea is far more efficient again, but only just starting to become available. For N-hungry farms with low pasture N levels (new conversions and most irrigated farms, especially on shallow soils), follow the cows with 20-25 kg N/ha of SustaiN, N-Protect or ONEsystem; limit annual use to no more than 180 kg N/ha.
(ii) Optimising pasture utilisation. You must put the effort into monitoring your pasture production weekly on every paddock and recording this, and monitoring your post-grazing residuals. Leaving the optimum pasture level (typically 1500-1700 kgDM/ha) in every paddock – not more, not less – is vital to gaining optimum DM before the next rotation. If the paddock still has 2000 kg DM when the cows come out for milking, put them back for a few hours afterwards; don’t just put them into a new paddock. It really is worth the effort. Ideally, use a computerised grazing management tool like the LIC ‘Minda’ program. Within a few rotations, you will start to see which are your best and worst paddocks. You can assess whether the poorer ones need resowng, or whether they just need more N than the others. Get advice on optimum modern pest-resistant clovers to have in the mix.
(iii) Minimise bought-in feed. Growing and utilising more grass is always the cheapest way to produce more milk. Alternative forages and bought in feed should only be a means to get over seasonal climatic difficulties and soil limitations eg pugging in winter. As your pasture utilisation improves, more paddocks can be set aside for silage. Try to minimise wastage during feeding out supplements. Check comparative costs and ME content of alternative feeds where they have to be used.
(iv) Optimise the use of nutrients in urine, dung and effluent. Typically, 40-70% of the N in urine is wasted. New technology being developed by Pastoral Robotics Ltd (Spikey) greatly enhances the recovery of the N in urine by the pasture, reducing nitrate leaching in the process. In the meantime, avoid excess N levels in pasture (which leads to higher N content in the urine) by putting N on in small applications, within 3 days of grazing. If dung pats are drying out and not breaking down, you should be introducing the deep-burrowing earthworm (A.longa) and dung-beetles if available. Get effluent on to every possible paddock possible, as low a rate as possible, within the limitations of available equipment and farm layout and topography.
As with any commodity, prices go up and down. With increasing intensification, increased use of bought-in feed and heavy N use, NZ costs of dairy production were increasing towards those of our competitors. However, we have the ability to reduce costs and get through the current low prices more easily than our competitors. Just hang in there.