System 1 System 2 System 3

Transcription

1 Crude protein, % Forage mass, lb/acre J J S O N D J F M A Figure 1. Forage mass (lb/acre) produced by system, by month J J S O N D J F M A Figure 2. Crude protein concentration in pastures by system, by month

2 Body weight gains, lb Neutral detergent fiber, % J J S O N D J F M A Figure3. Neutral detergent fiber concentration in pastures by system, by month Body weight gains (lb) by system Grazing days Figure 4. Body weight gains (lb) by system

3 Average daily gains, lb Average daily gains, lb Summer Hay feeding Winter Total Period Figure 5. Average daily gains (lb) by period Figure 6. Average daily gains (lb) by system while System 3 steers were on sorghum-sudan

4 Table 1. Carcass characteristics of steers produced from different systems BW, lb HCW, lb DP, % REA, sq.in. Marbling KPH, % PYG WB, lb SYSTEM SYSTEM SYSTEM BW = weight at harvest REA= Ribeye area, square inches HCW = Hot carcass weight Marbling = 1-199: P. devoid; 2-299: Traces DP = Dressing percent KPH = Kidney, pelvic, and heart fat PYG = Preliminary yield grade WB = Warner-Bratzler tenderness; below 8 lb is tender Table 2. Average soil characteristics for the forage systems used for the project. Field Soil texture ph C N P S K Ca Mg % % mg/kg mg/kg mg/kg mg/kg mg/kg Ryegrass+Clover Loam System 1: Ryegrass Loam System 2: Ryegrass+Clover Silt Loam System 2: Dalligrass+Clover Loam Dallisgrass+Clover Loam Bermudagrass Loam System 2: Bermudagrass System 1: Bermudagrass Loam Sorghumsudan+Ryegrass Loam Soybean+Ryegrass Loam

5 Soil depth (cm) Soil C (%) Bermuda grass Ryegrass + Clover 1 Figure 7. Soil carbon distribution in pasture soil systems Avg. mg CO 2 -C/ day/m CO 2 -C Figure 8. Average rate of CO 2 -C emissions from different forage crop systems over 3 year monitoring.

6 CH 4 -C Avg. mg CH 4 -C/ day/m Figure 9. Average rate of CH 4 -C emissions from different forage crop systems over 3 year monitoring. N 2 O-N Avg. mg N 2 O-N/ day/m Figure 1. Average rate of N 2 O-N emissions from different forage crop systems over 3 year monitoring.

7 Table 3. Revenue, Expenses and Profit per Treatment (Dollars per Animal) Item Steer income Hay income bc ac ab Total income bc ca ab Fertilizer cost bc a a Pesticide cost Livestock cost Other cost 8.96 bc 7.97 a 7.47 a Seed cost bc ac ab Minerals, medication cost b a Diesel cost bc a 5.85 a Repair maintenance bc a a Interest cost Total direct cost(d) Return over total direct cost c c ab Fixed cost (F) bc ac ab Total expenditure (D+F) Return over specified Expenses c c ab Land rent bc ac 72.1 ab Residual return c c ab Notes Superscripts a, b, and c indicate the means differ from those of Systems 1, 2, and 3, respectively at p <.5 Residual Return = Total Return - Direct Expense - Fixed Expense - Land Expense System Table 4. Global Warming Potential as kg CO2 Equivalent per Year Among Systems Kg CO2 Equivalent per Year from Different Sources and Total as GWP NPA EF CH4 F N2O F CO2 F GWP GWP/animal System System System Where, GWP -Net global warming potential (GWP) in kg of CO2 equivalent NPA-nitrogen fertilizer production and application (NPA), EF-CH4 emission from enteric fermentation (EF), CO2 F- the atmospheric CO2 flux. CH4 F- the atmospheric CH4 flux, N2O F- the atmospheric NO2 flux

8 Kg of CO2 Equivalent Dollar Figure 11. Net profit (dollars) per animal per year Figure 12. GWP in CO 2 Equivalent per Animal per Year