Farm Table says:
Meta-analysis of the effect of pasture allowance on grazing temperate grasslands
What is the problem?
Daily pasture allowance (PA) is a measurement of pre-grazing pasture mass and offered area, and is the major grazing management factor determining pasture utilization per unit area. This study performed a meta-analysis, using previously published papers, to review PA and the effect on pasture intake, milk composition and production, and grazing behavior in dairy cows.
What did the research involve?
Using 56 previously published papers, 97 PA comparisons were used in the final data set. This group was further dived into 3 subsets based on estimated height at which PA was determined. The first subset, PA0, was PA above ground level. PA3 was PA 2.5 – 3.5 cm, and PA5 had PA 4 to 5 cm.
What were the key findings?
Pasture intake, milk production, and milk solids production per kg on PA increase was lowest in PA0 and highest in PA5. Grazing time increased from PA0 to PA3, but not from PA3 to PA5. Intake rate increase from PA0<PA3<PA5, for two reasons; bite mass from PA0 to PA3, and bite rate for PA3 to PA5.
The authors state this as a globally appropriate mathematical method for investigating the effect of PA on different variables, and the effect of PA on these is independent of estimated height. This may be useful for improving grazing management with pasture-based systems.