As you spread your fertiliser, spare a thought for the animals who will be grazing the grass. While farming publications applaud new innovations helping to improve nutrient management, animal production losses still continue to plague the industry.
Fertiliser nutrients taken up by the plant create their own unique mineral profile for grazing animals, and therein lies the problem- it seems the connection between fertiliser and production problems continues to be overlooked.
Farmers working with Mineral Systems are part of growing group who are looking more closely at the impact of their fertiliser choice on animal performance and losses.
John Heald (Pohuetai Farms, Dannevirke) engaged Mineral Systems to investigate the concerning number of cast ewes at lambing. John, Daniel Preece and their team run 1800 MA Highlander Elite ewes for Focus Genetics, 8000 commercial breeding ewes and a large beef breeding herd and young stock. The five year scanning percentage averages 185% on the two tooth’s and mixed ages ewes and hoggets range from 110% to 145% all counted.
"One of the things we have been trying to achieve is higher survivability in triplets and Hogget lambs by making sure the minor minerals are up to the mark” says John, who is embracing the new focus from Mineral Systems. "One thing is, that if you keep doing the same thing year on year and hope for a good season then production will never improve”.
View overlooking Pohuetai.
Cast ewes can be an indicator of metabolic disease, along with ewe deaths at lambing and an increased number of lambs born dead. Analysis of pasture samples taken from 2014 & 2015 lambing paddocks at Pohuetai indicated a severe metabolic risk was present An extensive sheep and beef system has its own set of challenges when it comes to managing risk, however successful strategies for Pohuetai included;
Understanding the soil characteristics, such as the low Anion Storage Capacity and how this can contribute to high phosphorus herbage levels.
Considering product choice and timing of fertiliser application to minimise the risk of accelerating the phosphorous levels even higher.
Encouraging pasture species into the sward that concentrate high levels of calcium and magnesium yet limit levels of potassium eg. plantain and chicory.
Managing the sulphur levels of the pasture to minimise the effect of high sulphur which can reduce appetite and palatability.
“As our budget tightens up we are looking more closely at what fertiliser is going on the paddocks and asking is it having the right effect? With the help of Pat last season we added 15kg of Boron to our applications and cut back on the sulphur, and now after coming through a cold slow growth winter we are now seeing more clover appearing at this time of the year than we have seen for a few years".
A separate investigation into sporadic deaths in the hogget blocks identified excessive sulphur levels to be the root cause of a diagnosed thiamine deficiency.
Many of the common disease syndromes are mediated by mineral metabolism - particularly calcium, magnesium, selenium, iodine, cobalt and copper. These minerals are commonly deficient in NZ and the levels are antagonised by conventional fertiliser practice.
Analysing pasture and soil samples at critical times of the year when animal losses are highest will provide insight into the risks facing your grazing animals. For John and his team at Pohuetai they are managing the mineral status of their sheep based on knowledge of the risks present on their farm.
“This season most ewes and all the hoggets have had a 4 gram copper cap plus a shot of iodine. With Pat’s background and science now looking at our soil and herbage samples we have more confidence in what we are doing", John Heald.