Publication Date
1997
Description
In four zero-grazing experiments, the effects ofN fertilizer (450 to 300 to 150 kg/ha/yr) on intake and utilization of some grass minerals (Ca, P and Mg), were investigated. Grass was offered ad lib to 12 cows per N treatment. A reduction in N fertilizer resulted in lower mean contents and intakes of Ca and Mg while P content and intake increased in late summer/autumn. The output of these minerals in milk and urine was relatively low. Therefore, a reduced intake of Ca and Mg resulted in a lower faecal output of these minerals. The ratio between intake and requirement varied for Ca between 141% and 210%, for P between 115% and 140% and for Mg between 73% and 97%. Nevertheless, no signs of hypomagnesemia were obtained at the lowest levels of Mg intake as a consequence of a reduction in N fertilizer.
Citation
Valk, H and van Vuuren, A M., "Mineral Intake and Utilization by Dairy Cows Offered Grass Fertilized with Different Levels of Nitrogen" (2024). IGC Proceedings (1993-2023). 22.
https://uknowledge.uky.edu/igc/1997/session17/22
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Mineral Intake and Utilization by Dairy Cows Offered Grass Fertilized with Different Levels of Nitrogen
In four zero-grazing experiments, the effects ofN fertilizer (450 to 300 to 150 kg/ha/yr) on intake and utilization of some grass minerals (Ca, P and Mg), were investigated. Grass was offered ad lib to 12 cows per N treatment. A reduction in N fertilizer resulted in lower mean contents and intakes of Ca and Mg while P content and intake increased in late summer/autumn. The output of these minerals in milk and urine was relatively low. Therefore, a reduced intake of Ca and Mg resulted in a lower faecal output of these minerals. The ratio between intake and requirement varied for Ca between 141% and 210%, for P between 115% and 140% and for Mg between 73% and 97%. Nevertheless, no signs of hypomagnesemia were obtained at the lowest levels of Mg intake as a consequence of a reduction in N fertilizer.
