trace elements

Bijeenkomst: EGF2015
Auteur: De Haas M.J.G., Den Boer D.J., Bussink D.W. and Van der Draai H.
ISBN: 978-9090-289-61-8
Jaar van uitgifte: 2015
Producttype: Paper
Well-supplied trace elements are necessary for production and animal health. The Water Framework Directive requires a reduction of the output of heavy metals. The tool ‘Spoorwijzer’ (Trace element guide) is used to calculate the supply of Zn, Se, Cu and Co of different groups of dairy cattle. Zn and Cu are necessary for animal health. Zn is amply supplied on most conventional Dutch dairy farms. Young stock, dry cows and end-lactation cows receive little or no concentrate feed, causing low supply of Se, Cu or Co. Using tailor-made mineral mixtures on a number of farms did not have a negative effect on production and animal health. The surplus per ha on these farms was decreased by 52% for Zn, 28% for Cu, 22% for Se and 56% for Co. It is concluded that Zn is not necessary in mineral mixtures on Dutch conventional dairy farms. Considerable cost reduction is possible by using tailor-made mineral mixtures. In conclusion, the studies found that using tailor-made mineral mixtures is positive for high-output dairy farming and eco-efficient farming.

Bijeenkomst: EGF2015
Auteur: Simić A., Dželetović Ž., Vučković S., Geren H. and Mandić V.
ISBN: 978-9090-289-61-8
Jaar van uitgifte: 2015
Producttype: Paper
Intensive livestock production is concentrated in the northern part of Serbia, particularly in the vicinity of Belgrade. This area is very important for forage production, but the main power stations of the Serbian power supply system are located in this region and these produce high emissions of fly ash. Forage plants are exposed to the pollution effects of fly ash, and some agricultural systems are located very close to the Nikola Tesla A (TENT-A) power station. A study of three forage plants (Medicago sativa, Phalaris arundinacea, Melilotus officinalis) was done on ‘TENT-A’ ash deposit in order to analyse bioaccumulation of maximally exposed plants. Plant samples were collected at tillering stage and concentrations of 10 elements were analysed. The results show lower concentrations of trace metals in the herbage shoots than in the ash, which had excessive contents of As, Ni and Cr. None of the examined species accumulated a high amount of the above-mentioned elements, even though they were from different families, with different morphology and dry matter yield. Alfalfa had the highest concentrations of As and Ni among the species that were analysed.