Wednesday, 31 July 2019 16:36

Nitrate poisoning

Written by  Sarah Jones, business development manager, Eurofins Agri-Testing, independent scientific laboratory

Nitrate poisoning usually occurs in late autumn or winter when nitrate levels in the feed are high, particularly during a flush of growth after a dry period.

Cattle are most susceptible to nitrate poisoning, and the onset of symptoms is rapid. Feed testing by a laboratory prior to grazing will accurately identify nitrate levels and help manage the risk of nitrate poisoning. 

It all depends on what is absorbed versus what is used by plants. 

When plants are growing well they quickly take up nitrate from the soil. Under good conditions (plenty of sunshine) the nitrate taken up by the plant converts to nitrite and then finally into plant protein. If plant nitrate uptake from the soil is greater than conversion to plant protein, then nitrate can accumulate to abnormal levels. When this feed is consumed it causes nitrate poisoning. 

Common symptoms of nitrate poisoning include animals appearing staggering and weak, gasping for breath, collapse and coma leading to death. In severe cases, if an animal ingests a toxic amount of nitrate in an hour, it can start to show signs of poisoning shortly afterwards. By the time an animal starts showing symptoms of poisoning it can be too late to reverse the situation. 

Don’t let hungry stock graze on feed with high nitrate levels. 

Supplement extra feed like hay or silage, feed only low levels initially as rumen can adapt to higher nitrate levels, and avoid fertiliser applications or keep them low.

An accurate indication of nitrate levels in the feed can be obtained by getting samples tested by a laboratory.  Planning testing ahead of grazing is required to ensure that you receive your results prior to the stock starting to eat the pasture or crop.   

Laboratory testing results showing nitrate levels under 5.0 g/kg DM is considered safe to feed under all conditions and do not feed >17.5 g/Kg DM. A feed with nitrate levels between 5 – 17.5 g/Kg DM can be fed under certain restrictions. 

• Sarah Jones is business development manager, Eurofins Agri-Testing, independent scientific laboratory.

More like this

Reviewing 50 years of NZ use

Nitrogen is an essential nutrient for plant growth, and nitrogen fertiliser has long been critical to maintaining the high productivity of grazed pasture systems in New Zealand.

More N available than thought

Paul Hunter farms 240ha of well-drained Mairoa ash soils at Mulroy Farm, situated south of Te Awamutu in the Waikato.

Oz farmers study N usage

Australian dairy farmers are backing a new five-year research project looking into reducing the reliance on nitrogen fertilisers used in pasture production.

Featured

Govt urged to reduce ETS units

The Climate Change Commission wants the new Government to reduce NZ Emissions Trading Scheme (ETS) auction volumes as son as possible.

Dairy sheep, goat woes mount

Dairy sheep and goat farmers are being told to reduce milk supply as processors face a slump in global demand for their products.

Alliance's Pure South cuts win gold

Meat co-operative Alliance Group has bagged four gold medals at the Outstanding NZ Food Producer Awards, achieving top honours for every cut entered.

Dairy demand on the rise

There is increasing evidence that dairy demand is on the upswing, according to Rabobank senior agricultural analyst Emma Higgins.

Fert use tumbles as prices spike

Fertiliser use in New Zealand over the 18 months is about 25% down from what it consistently was for the previous decade or more, says Ravensdown chief operating officer Mike Whitty.

National

Machinery & Products

JD unveils its latest beast

John Deere has unveiled its most powerful tractor ever, with the launch of the all new 9RX Series Tractor line-up…

Biggest Quadtrac coming to NZ!

In the biggest announcement that Case IH Australia/New Zealand has made around its tractor range, its biggest tractor is about…

A different shade of blue for Norwood

Norwood and ARGO Tractors, the Italian manufacturer of Landini and McCormick tractors, have announced an agreement that gives Norwood exclusive…

Kubota tests diesel engines

Kubota last month used the UK LAMMA Show to test the water with its new 200hp, four-cylinder 09-series diesel engines.

Claas rings up some big numbers

The Claas Group finished fiscal year 2023 with a substantial leap in sales that reflected the high demand for agricultural…

» Latest Print Issues Online

The Hound

Too late?

OPINION: Your canine crusader reckons moves by the new government to try and breathe new life into the country's ailing…

Going rogue!

OPINION: This old mutt suggests the new government is going to have to move fast to rein in a number…

» Connect with Rural News

» eNewsletter

Subscribe to our weekly newsletter