|Skinner, Robert - Howard|
Submitted to: Grassland Science in Europe
Publication Type: Proceedings
Publication Acceptance Date: 12/10/2003
Publication Date: 6/21/2004
Citation: Sanderson, M.A., Soder, K.J., Brezezinski, N., Muller, L.D., Skinner, R.H., Wachendorf, M., Taube, F., Goslee, S.C. 2004. Plant species diversity influences on forage production and performance of dairy cows on pasture. Grassland Science in Europe. 9:1-4. Interpretive Summary: Greater plant diversity in grasslands has been linked to increased plant production, greater stability in response to disturbance and reduced weed pressure. Thus, managing complex mixtures of plants to take advantage of variability in land and climate may be one approach to increase productivity of grazing lands. We wanted to know if complex mixtures of forage species would yield more dry matter and reduce weed competition compared with a simple grass-legume mixture. Therefore, we established pastures of 2, 3, 6, or 9 forage species and measured forage and grazing milk cow production for two years. Complex forage mixtures were more productive than simple grass-legume mixtures during drought and also had reduced weed pressure. Individual milk cow performance was similar among simple and complex mixtures. Increasing plant species diversity on pastures may be a simple way to increase forage productivity and stability, while reducing weed competition.
Technical Abstract: We conducted a grazing study to determine if plant species diversity in pastures affects forage and animal productivity and weed invasion. Replicated pastures (1 ha each) planted to mixtures of two, three, six, or nine temperate forage species were grazed with lactating dairy cattle during two years. Herbage yield and vegetation dynamics were measured along with dry matter intake and milk production of Holstein dairy cows. Herbage yield increased with increasing species richness (4800 kg ha-1 for the two-species mixture and 7400 kg ha-1 for the nine-species mixture) in 2002 (a drought year). There were no differences among treatments in 2003, probably because of greater rainfall. Milk production averaged 35.6 kg cow-1 day-1 and grazed dry matter intake averaged 13.7 kg cow-1 day-1 in 2002 with no significant differences among treatments. The six- and nine-species mixtures had fewer weeds than the two-and three-species mixtures. These results indicated that complex mixtures of forages in pastures benefit herbage production without affecting individual animal performance.