JUNE 3, 2012
ESTIMATING PASTORAL GRASS INTAKE BY USE OF
ACCELEROMETERS
FRANK OUDSHOORN, OLE JØRGENSEN
RESEARCH, DEPARTMENT OF ENGINEERING
FACULTY OF SCIENCE AND TECHNOLOGY
AARHUS UNIVERSITY
UNI
VERSITET
1. My background
2. Why do we need more detailed knowledge of grass
intake on pasture
3. What methods have been used to calibrate ?
4. What sensors are on the marked that could be used ?
INNOVATIVE GRAZING
FRANK OUDSHOORN
JUNE 3, 2012
2
ATTACHMENT OF THE SENSORS
INNOVATIVE GRAZING
FRANK OUDSHOORN
JUNE 3, 2012
3
SOME RESULTS CHECKING GRAZING TIME ESTIMATION
INNOVATIVE GRAZING
FRANK OUDSHOORN
JUNE 3, 2012
4
13-Sep
12-Sep
11-Sep
10-Sep
09-Sep
08-Sep
07-Sep
06-Sep
05-Sep
04-Sep
03-Sep
02-Sep
01-Sep
31-Aug
30-Aug
29-Aug
28-Aug
27-Aug
26-Aug
25-Aug
24-Aug
23-Aug
22-Aug
21-Aug
20-Aug
19-Aug
18-Aug
17-Aug
16-Aug
15-Aug
14-Aug
13-Aug
12-Aug
11-Aug
10-Aug
09-Aug
08-Aug
07-Aug
06-Aug
05-Aug
FARM DATA 2011
9.0
8.0
2163
2479
7.0
1491
1980
6.0
2408
2084
5.0
2158
2098
4.0
2390
2488
3.0
2473
2406
2.0
2231
2241
1.0
2296
1784
0.0
2473
INNOVATIVE GRAZING
FRANK OUDSHOORN
1978
JUNE 3, 2012
5
IS GRAZING TIME ENOUGH
› We can say something about their eating behaviour
› We can identify individual cow specificity and
possible abnormalty
› We can identify if the pasture is offering too little
However,
INNOVATIVE GRAZING
FRANK OUDSHOORN
JUNE 3, 2012
6
Grass intake relative to total
CORRELATION WITH GRASS INTAKE IS NOT VERY GOOD
Relative grazing time
INNOVATIVE GRAZING
FRANK OUDSHOORN
JUNE 3, 2012
7
MANUALLY COUNTED BITES
Season
spr09
aut09
aut10
Nb of periods
(Nb of cows)
Trial 1
Trial 2
142 (10) 147 (10)
27 (10)
48 (10)
66 (5)
21 (2)
Period length, sec
Trial 1
145 ± 26
95 ± 11
139 
Trial 2
143 ± 25
98 ± 12
141 ± 12
Fz bites/min
Trial 1
52 ± 10
60 ± 9
58 
Trial 2
55 ± 10
48 ± 9
47 ± 12
Cow
Trial
effect a effect a
*
**
***
*
***
**
In order to try and supply extra
information
INNOVATIVE GRAZING
FRANK OUDSHOORN
JUNE 3, 2012
8
INCLUDING BITES WE ARE FINDING GOOD
CORRELATIONS
D1 min graz 30
D1 bites 30
340.0
25000.0
330.0
320.0
R² = 0.9642
20000.0
R² = 0.8645
310.0
15000.0
300.0
10000.0
290.0
5000.0
280.0
0.0
270.0
0.0
5.0
10.0
15.0
20.0
0.0
5.0
10.0
INNOVATIVE GRAZING
FRANK OUDSHOORN
15.0
20.0
JUNE 3, 2012
9
MODELLING TO FIND ACCURACY
INNOVATIVE GRAZING
FRANK OUDSHOORN
JUNE 3, 2012
10
ACCELEROMETER DATA 16 HZ. SHAPE MATCHING
Section of sensor data for dataset # 2, manual bite markings as vertical lines
INNOVATIVE GRAZING
FRANK OUDSHOORN
JUNE 3, 2012
11
DOES BF ESTIMATE GRAZING
Grazing correspondance with increased threshold for bites per second
INNOVATIVE GRAZING
FRANK OUDSHOORN
JUNE 3, 2012
12
THRESHOLD VALUE FOR BITE MOVEMENTS
› when we measure more than 25 bites per minute we
can be sure that 95% of the cows are grazing
according to the IceTag annotations.
We tried to make a control with IGER jaw movement sensors.
Program GRAZE gives annotations for Bite, chew and
unknown.
INNOVATIVE GRAZING
FRANK OUDSHOORN
JUNE 3, 2012
13
Automatic = accelerometer
modelling
INNOVATIVE GRAZING
FRANK OUDSHOORN
JUNE 3, 2012
14
THRESSHOLD BITE FREQUENCY TO DETERMINE
GRAZING
Bite frequency,first 24 hours . Horizontal line indicates a reasonable bite frequency vs grazing threshold
.
INNOVATIVE GRAZING
FRANK OUDSHOORN
JUNE 3, 2012
15
INNOVATIVE GRAZING
FRANK OUDSHOORN
JUNE 3, 2012
16