Validation of Calibration Equations Developed ... - Automatic Milking

More documents

Recommendations

Info

1800 1600 1400 - - - - - - - - - - - - Trend line for observations made in grazed parts of the pasture y = -11,536x + 2707,4 R 2 = 0,2279 Yield (kg DM/ha) 1200 1000 800 _______________ Trend line for observations made in non-grazed parts of the pasture y = 17,665x - 1728,6 R 2 = 0,7932 600 400 200 0 0 20 40 60 80 100 120 140 160 180 200 CPM height (mm) 02-sep 08-sep 09-sep 15-sep 16-sep 18-sep Figure 2.3 - Trend lines for observations made in grazed and non-grazed parts of the pasture respectively 8
made with both early and late season calibration equation and with calibration equation without seasonal effects. These calibration equations found by Hansson (2011) is presented below: Log ( Yield ) = 1.8615× Log( Height) - 0.9431 (Early season) Log ( Yield ) = 2.8498× Log( Height) - 3.2233 (Late season) Log ( Yield ) = 2.2993× Log( Height) -1.9731 (Seasonal effects omitted) The analysis was done with a dataset of 27 observations. The calibration equations are only valid within the sward height range 128-263mm in which the calibration trial observations were made. The analysis was therefore repeated with a subset of data, including only height observations within this range. 3 Results There was significant difference between the predicted and actual pasture yield for all calibration equations, see details in Table 3.1. The late season calibration equation predicted yields that were closer to the actual yield, compared to predictions made by the other equations. The early season calibration equation predicted yields with the greatest deviation from the actual yield. Table 3.1 - Results from t-test on all height observations Calibration equation p-value Significance level Mean difference 1 (kg DM/ha) 95% confidence intervals (kg DM/ha) Early 7×10 -10 *** 443 ±96 Late 0.007 ** 133 ±94 Season omitted 2×10 -5 *** 247 ±96 1 The predicted yield being greater than the actual The calibration equations are only valid within the sward height range 128-263mm in which the calibration trial observations were made. The analysis was therefore repeated with a reduced dataset, including only height observations within this range. The difference between the predicted and actual yield was not significantly different for the late season 9
Page 1 and 2: F A C U L T Y O F L I F E S C I E N
Page 3 and 4: Table of content Abstract..........
Page 5 and 6: was determined with low uncertainty
Page 7: Figure 2.2 - Outline for measuremen
Page 11 and 12: According to the results reported b
Page 13 and 14: The results in all suggest that the
Page 15 and 16: References Andersen & Due (2010): P
Page 17 and 18: Tabel 1. Tidsplan for registreringe
Page 19 and 20: Græshøjde, kvalitet og tilbud. Di
Page 21 and 22: Græsvækst. Udstyr: Haldruphøster
Page 23 and 24: Skema Afgræsning 2009-2 Troels Gr
Page 25 and 26: Late part of season Log(Yield) 2.6

Validation of Calibration Equations Developed ... - Automatic Milking

Create successful ePaper yourself

Delete template?

Save as template?