Fertiliser: A typical response to nitrogen across a growing season is 30kg of grass per kilo of nitrogen applied. So if 200kgN/ha is normally applied, that should grow 6t of grass per hectare.
Across a 40ha farm that’s 240t of feed grown by nitrogen. Not having access to some or all of this nitrogen has big repercussions.
Background nitrogen in the soil will help to bridge a gap for a period.
There is also organic nitrogen in slurry and soiled water but that’s won’t replace artificial nitrogen per se, because these have always been used to grow grass.
Granted, low-emission slurry spreading will retain more nitrogen versus splash plate.
Farms must have enough feed all year round. I am concerned that if nitrogen is restricted, that won’t be possible. There are lots of long term solutions but very little else, other than reducing stocking rate to match grass growth – through early culling of poor performing cows, selling beef cattle or contract rearing young stock. Other options include doing deals now with tillage farmers to contract grow winter feed such as taking three or four cuts of red clover/hybrid ryegrass instead of them sowing a cereal crop.
Calves: Back on farm, I’m hearing of a good few cases of scour in calves. There are a few articles on calf health in this week’s Focus. The phrase “a touch of scour” should send alarm bells ringing.
The reality is scour is caused by really nasty germs that will kill calves if they can. At the first sign of scour affected calves should be isolated and any calves that have been exposed to them should be kept away from healthy calves.
The priority should be to nurse sick calves back to health and to prevent healthy calves from getting it.
Electrolytes replace fluids lost through scouring and should be fed in addition to milk. Keeping sick calves well-nourished is the best way of ensuring a good outcome. It’s not easy and help will be required to deal with sick calves. If in the middle of an outbreak, talk to a vet or other expert on ways to prevent spread and the best treatment for sick calves.
Bloat: I’m also hearing of some bloat issues in calves fed milk replacer. This often occurs where calves are fed with a computerised feeder. Ususally it’s because the machine isn’t calibrated correctly and the concentration of powder to water is higher than it should be.
This increases ‘osmality’ of the milk, meaning that it takes longer for the calf to digest. The result is that it sits in the abomasum and bloat occurs when bacteria start to feed and multiply rapidly on the milk there.
This can also happen to calves fed whole milk and to calves fed milk replacer manually. It can also be farm specific, as the type of bacteria is a big factor. High feeding rates are definitely a risk factor, so if experiencing problems consider reducing the concentration of powder in every litre of mixed milk. Make sure to calibrate computerised feeders to ensure that the correct amount of powder is being used per litre.