Publication Date

1985

Location

Kyoto Japan

Description

To evaluate and compare the key factors for energy efficiency in pasture production between temperate and subtropical grass sward, dry matter production and cattle gain were determined under grazing condition during 1979-1983. Seasonal changes in the biomass of above and underground organs and in surface litter were measured in the two types of the swards of orchardgrass mixed with Italian ryegrass and of Bahiagrass mixed with Vicia sp. In an e_xample of the conversion efficiency measured for the productive growing season in 1980 (Fig.1), Bahiagrass pasture fixed 1.36:% of global solar radiation as the net production including the growth of underground part, while orchardgrass­ltalian ryegrass pasture fixed 0.74 %. The Bahiagrass pasture, however, gave only 0.02 % of solar radiation as cattle gain on average for grazing days based on ground area, while orchardgrass-Italian ryegrass pasture presented 0.05 %. Both the values of efficiency were nearly the same (0. 36 % and O. 34 % ) at the step of digestible energy taken into cattle. The digestibility and the ratio of net energy for growth to digested energy were comparatively low in Bahiagrass pasture and were regarded as important factors for the higher efficiency in Bahiagrass pasture more than its growth attributes relating to photosynthesis. In case of orchardgrass pasture, summer depletion of both plant and cattle growth was regarded as an important problem to be solved and low palatability and digestibility of stem part would be also the problem.

Share

COinS
 

Energy Efficiency of Primary and Secondary Production in Grazed Pasture of Dactylis glomerata as Compared with those of Paspalum notatum

Kyoto Japan

To evaluate and compare the key factors for energy efficiency in pasture production between temperate and subtropical grass sward, dry matter production and cattle gain were determined under grazing condition during 1979-1983. Seasonal changes in the biomass of above and underground organs and in surface litter were measured in the two types of the swards of orchardgrass mixed with Italian ryegrass and of Bahiagrass mixed with Vicia sp. In an e_xample of the conversion efficiency measured for the productive growing season in 1980 (Fig.1), Bahiagrass pasture fixed 1.36:% of global solar radiation as the net production including the growth of underground part, while orchardgrass­ltalian ryegrass pasture fixed 0.74 %. The Bahiagrass pasture, however, gave only 0.02 % of solar radiation as cattle gain on average for grazing days based on ground area, while orchardgrass-Italian ryegrass pasture presented 0.05 %. Both the values of efficiency were nearly the same (0. 36 % and O. 34 % ) at the step of digestible energy taken into cattle. The digestibility and the ratio of net energy for growth to digested energy were comparatively low in Bahiagrass pasture and were regarded as important factors for the higher efficiency in Bahiagrass pasture more than its growth attributes relating to photosynthesis. In case of orchardgrass pasture, summer depletion of both plant and cattle growth was regarded as an important problem to be solved and low palatability and digestibility of stem part would be also the problem.