Publication Date
1993
Description
Grazing trials are limited by financial and logistical constraints that restrict duration and number of treatments to be investigated. Combining data from independent trials may be a feasible way to circumvent these constraints and provide a more meaningful body of information. Datasets were pooled from 12 independent trials conducted during the last 13 springs at 9 locations in 7 USA eastern states (a total of 37 location/ years) to provide combined estimates of steer (Bos taurus) performance on Festuca arundinacea pastures free of or infested with the endophytic fungus Acrenoium coenophialium, and to demonstrate the effectiveness and flexibility of Henderson's mixed model procedure (MMP). The MMP allowed the estimation· of fixed treatment effects over unique environmental and climatic situations (inference spaces) as appropriate predictable functions were defined. The combined analysis was able to detect treatment differences which were not obvious in each discrete study. Spring steer performance generally reflected pasture endophyte rate and clover (Trifolium spp.) incidence.
Citation
Fribourg, H A.; Thompson, R W.; Waller, J C.; and Sanders, W L., "Inference Space Choices in Combined Mixed Model Analyses of Discrete Grazing Trials" (2024). IGC Proceedings (1993-2023). 20.
https://uknowledge.uky.edu/igc/1993/session19/20
Included in
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Inference Space Choices in Combined Mixed Model Analyses of Discrete Grazing Trials
Grazing trials are limited by financial and logistical constraints that restrict duration and number of treatments to be investigated. Combining data from independent trials may be a feasible way to circumvent these constraints and provide a more meaningful body of information. Datasets were pooled from 12 independent trials conducted during the last 13 springs at 9 locations in 7 USA eastern states (a total of 37 location/ years) to provide combined estimates of steer (Bos taurus) performance on Festuca arundinacea pastures free of or infested with the endophytic fungus Acrenoium coenophialium, and to demonstrate the effectiveness and flexibility of Henderson's mixed model procedure (MMP). The MMP allowed the estimation· of fixed treatment effects over unique environmental and climatic situations (inference spaces) as appropriate predictable functions were defined. The combined analysis was able to detect treatment differences which were not obvious in each discrete study. Spring steer performance generally reflected pasture endophyte rate and clover (Trifolium spp.) incidence.
