Publication Date
1985
Location
Kyoto Japan
Description
The effect of stocking rates on the energy conversion efficiency was examined on a grazing pasture over an eight year period from 1974. Annual stocking rates were in the range of 117-523 animal-unit days (AUD)/ha over eight years. Photosynthetically active radiation, net primary production by herbage plants and the amounts consumed by grazing cattle were measured during the plant growing season (from late March to late November). For estimations of stored energy in cattle, ARC feeding standards (1965) using the daily increment for body weight were adopted. Energy conversion efficiencies from solar energy through plants and animals were calculated as follows: Photosynthetically active radiation amounts did not differ so much over the eight growing seasons and were around 2.6 x 105 - 3.1 x 105 kcal/m2 for a plant growing season. Out of this total, 1.1-3.2% (3.0 x 103 - 9.0 x 103 kcal/m2) was stored as net primary production, with a tendency to decrease with increase of stocking rate. Of the net primary production, 63 - 84% (1.9 x 103 - 7 .1 x 103 kcal/m2) was aboveground production, unaffected by stocking rates. Total animal production increased from 5.8 x 10 to 17 .5 x 10 kcal/m2, but the animal production per 100 kg of cattle body weight at the beginning of each grazing season decreased from 20.0 to 6.7 kcal as stocking rate increased. Over all efficiency of conversion from solar radiation to energy stored in cattle was 0.017 to 0.066%, which increased as stocking rate increased.
Citation
Takahashi, S; Shiyomi, M; Akiyama, T; and Okubo, T, "Energy Conversion Efficiencies in Grazing Grassland at Different Stocking Rates" (1985). IGC Proceedings (1985-2023). 92.
(URL: https://uknowledge.uky.edu/igc/1985/ses6/92)
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Energy Conversion Efficiencies in Grazing Grassland at Different Stocking Rates
Kyoto Japan
The effect of stocking rates on the energy conversion efficiency was examined on a grazing pasture over an eight year period from 1974. Annual stocking rates were in the range of 117-523 animal-unit days (AUD)/ha over eight years. Photosynthetically active radiation, net primary production by herbage plants and the amounts consumed by grazing cattle were measured during the plant growing season (from late March to late November). For estimations of stored energy in cattle, ARC feeding standards (1965) using the daily increment for body weight were adopted. Energy conversion efficiencies from solar energy through plants and animals were calculated as follows: Photosynthetically active radiation amounts did not differ so much over the eight growing seasons and were around 2.6 x 105 - 3.1 x 105 kcal/m2 for a plant growing season. Out of this total, 1.1-3.2% (3.0 x 103 - 9.0 x 103 kcal/m2) was stored as net primary production, with a tendency to decrease with increase of stocking rate. Of the net primary production, 63 - 84% (1.9 x 103 - 7 .1 x 103 kcal/m2) was aboveground production, unaffected by stocking rates. Total animal production increased from 5.8 x 10 to 17 .5 x 10 kcal/m2, but the animal production per 100 kg of cattle body weight at the beginning of each grazing season decreased from 20.0 to 6.7 kcal as stocking rate increased. Over all efficiency of conversion from solar radiation to energy stored in cattle was 0.017 to 0.066%, which increased as stocking rate increased.
