Bloat is a major risk on all farms at present. I have heard numerous incidences over the last 10 days of cows being found dead in fields and of other cows being affected by it.
In some cases preventative measures don’t seem to be working. It seems that the risk is higher than usual this year because grass covers are lower, meaning there is less fibre in the sward.
Nights are longer and there is a heavy dew under clear skies, meaning dry matter contents are low.
The combination of low dry matter and low fibre seems to make the risk worse and there have been cases of bloat even where water was being dosed with bloat oil and where cows were given a small grass allocation.
A small grass allocation is where the herd is only given enough grass to sustain them for an hour or so, before they get the rest of the field.
The thinking here is that the cows will eat all the grass in this section – both the leaf and the stem, which should help to increase fibre content before the herd move on to the rest of the sward.
The big risk is that when animals go into a field first, they will eat all the nice leafy grass and clover first and this is the big risk for bloat because the gasses these highly digestible feeds release create a frothy layer in the rumen which prevents gasses from escaping and bloat occurs.
Even though the closed season has ended for spreading fertiliser, the market remains open and deals are being done for spring supplies.
Prices for urea seem to have hardened in recent weeks as new products are faced with higher energy prices compared to product that was already in the pipeline.
Fertiliser sales declined by about 25% this year and dry conditions aside, most farmers are happy enough with grass yields.
However, there will have been a good bit of background nitrogen in the soil coming into this year, particularly on farms that would have historically spread high quantities of N.
Over time, that background nitrogen will reduce and grass growth will be more reliant on what nitrogen is applied and what is fixed by clover. It’s something to keep in mind when planning fertiliser use for next season.
Also, the fertiliser register is due to come into effect in January, meaning all fertiliser sales will be assigned to a herd number.
The new rules around nitrate banding come into effect next year. This means that how much organic N each cow in the herd will be assigned will be based on average milk yield per cow over a rolling three year average.
So for next year, that’s 2020, 2021 and 2022 milk yield.
The milk yield per cow is based on total volume sold to the co-op in kilos divided by average cow numbers. Multiply litres of milk by 1.03 to convert to kilos of milk.
Average cow number is all dairy cows in herd, including dry or cull cows. For farmers that are close to either 170kg or 250kg organic N per hectare, what band they are in will be very important because being in a higher band may push them into, or out of derogation territory. Meal feeding rates should be adjusted accordingly.