Activity Monitoring in Combined
Timed AI and Heat-Detection
Programs
Jeffrey S. Stevenson, PhD
Dept. of Animal Sciences and Industry
Physiologic Changes during Estrus
• Vaginal cytology and pH
• Electrical resistance of vaginal mucus and genital tissues
• Body temperature
• Pulse and heart rate
• Pheromones and odors
• Blood metabolites and hormones
• Milk yield and feed intake
• Increased physical activity
Challenges of
Heat Detection
Detection of Estrus (Heat)
• Cow problems • Poor footing; sore and wet feet
• Inadequate space for sexual behavior
• High-producing cows show less behavior
• People problems • Limited visual detection
• Chalking/painting tail heads = heat detection
• Occasional visual heats detected
• A.I.-breeding pregnant or luteal phase cows
93
35
40
14
6
7
1
0 20 40 60 80 100
Visual observation
Tail chalk/paint
Bulls
Heat mount patches
HeatWatch
Other
Pedometer
Percentage
Heat Detection Methods on U.S. Dairy Farms
NAHMS (2007)
• Increased activity is a correlated trait
with estrus—increases up to 400% in
93% of estrous periods (Kiddy, 1977).
• Pedometers quantifying either movement or actual steps provided 70 to 80% accuracy (Roelofs et al., 2010).
• Cows housed in free stalls were 2.75 times more active during estrus than during diestrus.
• Relatively little within-cow variation from day to day when cows are NOT in estrus.
Physical Activity
Systems Sold by an A.I. Organizations
System
Company
AfiTag ABS Global
ai24 Semex
ALPRO Genex
Cow Alert Alta
Genetics
CowScout S Accelerated
Genetics
Heatime Select Sires
Select Detect Select Sires
Slide courtesy of Dr. Ray Nebel, Select Sires Inc.
Three Basic Components Sensor
Hardware
Software
Systems that Interface
with Milking Parlor
DeLaval AfiKim
Dairymaster
Slide courtesy of Dr. Ray Nebel, Select Sires Inc.
Systems with Rumination,
Eating, or Chewing
Ai24 or
Heatime
Agis CowManager, SensOor
Slide courtesy of Dr. Ray Nebel, Select Sires Inc.
Heatime Select Detect
Accelerometers
Question
Response
(%)
Agreed that heat-detection rate
had increased 93.1
Agreed that reproductive
management had become easier 92.3
Satisfaction with the system 94.1
Would install the system again 94.5
Survey of 219 German Dairy Farmers1
1 Heatime system (SCR Engineers Ltd., Netanya, Israel); herd size averaged
97 cows.
Source: Michaelis et al. (2013)
Factors Affecting
Physical Activity
Detection
BCS and Parity Affects Peak Activity
Index and Duration of Activity1,2
Item Class
% cows with high
peak activity
index (> 50) P
% cows with long
duration (≥ 8 h)
activity P
BCS
Low (≤ 2.5) 68.3
(138/202)
0.008
65.8
(133/202)
0.02 Moderate
(2.75 to 3.00)
78.8
(578/733)
75.3
(552/733)
High (≥ 3.25) 75.5
(120/159)
74.2
(118/159)
Parity
Primiparous 78.1
(289/370) 0.49
74.3
(275/370) 0.41
Pluriparous 75.5
(545/720)
73.1
(526/720)
1 Total of 1,163 estrus events in 346 lactating dairy cows. 2 Heatime (SCR Engineers Ltd, Netanya, Israel).
Courtesy of R.L.A. Cerri
Madureira et al., 2013
10 20 30 40 50 60 70
No Correlation between Peak of Physical
Activity and Milk Production
Milk yield (kg/day )
Peak o
f A
ctivity
r = 0.0023
Ovulation
Prediction
When does ovulation occur
relative to increased activity?
Select Detect Automated
Activity Monitors (n = 133)
Heatwatch® pressure-sensitive
rump-mounted transmitters (n = 65)
• Lactating Holstein cows were enrolled in the study
beginning at 50 DIM.
• Estrus was induced by 25 mg PGF2α (PG) or 100 µg
GnRH i.m. 7 days before PG or spontaneous estrus
• Ovarian scans begun at 14-16 h and repeated every 3 h.
Experimental Design
HeatWatch, Cow Chips LLC
Transmitter Receiver
Buffer
Repeater HW HW
Daily Activity of Select Detect
Hourly Activity of Select Detect
Cow #3830
HeatWatch First stand at 8:53 p.m. (1/7)
Last stand at 5:56 a.m. (1/8)
Heat duration of 9 hr 3 min
Stood 15x for total of 25 sec
Ovulated 29 hr after first stand
Select Detect Threshold at 10:00 p.m. (1/7)
Ovulated 1:55 a.m. (1/9)
Ovulated 28 hr after threshold
14.9
11.9
37.3 35.8
11.1
26.5 27.4
35.0
0
5
10
15
20
25
30
35
40
< 20 21 - 25 26 - 30 > 30
%
Hours to Ovulation
HeatWatch (n = 65)
Select Detect (n = 117)
Stevenson (2013)
P = 0.407 P = 0.026 P = 0.122 P = 0.800
Proportion of Cows Ovulating
7.7 6.7
27.2
21.1
12.5
25.3
14.8
0
5
10
15
20
25
30
35
40
Estrus duration,h
Standing events,no.
Ovulation afteronset, h
Ovulation afterend, h
HeatWatch
Automated Activity Monitor
Stevenson (2013)
Activity and Estrus Characteristics
Associated with Ovulation Prediction
Onset of Estrus to Ovulation
15
20
25
30
35
15 20 25 30 35 40 45
On
se
t o
f t
hre
sh
old
to
ovu
latio
n, h
Onset of first standing event to ovulation, h
y = 0.616x + 8.536
R2 = 0.516
n = 58
Stevenson (2013)
0
5
10
15
20
25
30
35
0 5 10 15 20
Dura
tion o
f activity,
h
Duration of standing estrus, h
y = 0.233x + 9.649
R2 = 0.020
n = 48
Duration of Estrus
Stevenson (2013)
End of Estrus to Ovulation
0
5
10
15
20
25
30
10 15 20 25 30 35
En
d o
f a
ctivity t
o o
vu
latio
n, h
End of standing estrus to ovulation, h
y = 0.535x + 4.261
R2 = 0.277
n = 42
Stevenson (2013)
Activity Monitor vs.
Heatmount Detector Patches1
Activity system2 Heatmount3
Item % (no. of cows detected / total no. of cows)
Estrus 71 (63/89) 66 (59/89)
Ovulation 95 (60/63) 93 (55/59)
No estrus 29 (26/89) 34 (30/89)
Ovulation 35 ( 9/26) 47 (14/30)
1 Of 112 cows treated with GnRH and PGF 7 d later. Cows
enrolled had a CL, a follicle > 10 mm in diameter, and luteolysis
by 48 h after PGF. 2 Heatime (SCR Engineers Ltd, Netanya, Israel). 3 Estrotech heat-detection patches (Rockway Inc., Spring Valley, WI)
Valenza et al., 2012
Pregnancy
Risk using
Activity
Monitors
36 3841
45
38
32 32 3329
23
05
101520253035404550
0 to 4 5 to 8 9 to 12 13 to 16 17 to 26
Con
ception
rate
(%
)
Interval to AI (h)
1st lactation 2nd+ lactation
268
361
467
607
467
656
254
435
207
297
b c
b
c
ab
d
a
cd
ab Means within 1st lactation group differ (P < 0.05) cd Means within 2+ lactation group differ (P < 0.05).
ab
c
Pregnancy Outcomes in 19 herds
Within Herd Comparison:
Timed AI vs. Activity Monitors
Cows were enrolled randomly at calving in 832-cow dairy
located in central Pennsylvania:
• Timed AI program (n = 414)
• AI according to the activity system (n = 394)
for the first 3 services starting at 50 DIM.
GnRH
AI PGF
7 days
GnRH GnRH
7 days
TAI GnRH-2
PGF GnRH-1
56h
8-
16h
PGF PGF
7 d 11 d 14 d
Presynch 14x11
PD
56h
Distribution of First Services
Total timed AI
program for first
and 2 repeat
inseminations
Conception Risk at First Service1
Lactation
number
n 1 2+
System
effect
Conception risk, %
Select Detect 394 45.9 25.6 35.0
Timed AI 412 45.8 35.8 39.8
Lactation effect 45.8 31.1
1System x lactation number interaction (P = 0.067).
Activity Monitors vs. Timed AI
66
36 35
74 68
75
42 44 42
52
0
10
20
30
40
50
60
70
80
Days at 1st AI CR at 1st AI(%)
Overall CR(%)
HDR (%) Preg at 150DIM (%)
Activity
Timed AI
Proportion Pregnant
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
50 70 90 113 134 154 174 194 214 234 254 274 294
Pro
po
rito
n o
f co
ws n
ot
pre
gn
an
t
Days in Milk
Activity monitors
Timed AI
Median = 115 days
Mean = 134 ± 4
Median = 95 days
Mean = 123 ± 4
Wilcoxon test
P < 0.001
Three Within Herd Comparisons:
Activity Monitors vs. Timed AI
Holstein cows (n = 1,429) in 3 commercial Ontario herds
were enrolled during 1 yr in a randomized controlled
experiment.
Automated activity monitoring system (Heatime, SCR
Engineers Ltd., Netanya, Israel)
vs.
Timed-AI based program:
Herd A Herd B Herd C
Presynch 14x14 Ovsynch 56 CO-Synch 72
Neves et al., 2012
Median Days to Pregnancy
All inseminations
(including visually
based)
Only program assigned
inseminations
Neves et al., 2012
Pregnancy Survival Curve (n = 924 cow-6-month periods)
Neves et al., 2012
Timed AI
Median = 125 days
Automated
activity monitor
Median = 82 days
Pro
po
rtio
n o
f cow
s n
ot pre
gn
ant
Days to pregnancy
Benchmarks Before and After
Activity Monitor Installation1
Berning
Acres
Furseth
Dairy
Goeser
Dairy
Reuter
Dairy
Sturgis
Dairy
Item Bef Aft Bef Aft Bef Aft Bef Aft Bef Aft
Milk (lbs) 82 91 86 87 82 87 85 91 85 82
21-d PR (%) 13 22 15 22 15 23 23 26 13 18
1st CR (%) 28 46 40 45 35 37 36 39 23 28
All CR (%) 23 32 29 33 31 35 33 36 18 20
DIM 182 176 193 178 210 189 183 169 210 183
HDR (%) 51 56 58 69 62 67 65 75 59 63
DFS 89 86 73 72 74 74 75 73 71 70
1 2011 Repro Invitational Panelists, Select Sires.
Betham Brothers Dairy – McBain, MI
June 7, 2010
(before)
June 7, 2013
(after 3 yr)
Herd size 664 981
Rolling herd average, lb 27,705 29,258
Calving interval, mo 13.5 12.8
Days open 132 109
21-day pregnancy rate, % 19 24
First-service CR, % 38 40
Overall CR, % 36 39
Days to first service 71 71
% time inseminated 46 1 1 Prostaglandin injections are administered every 14 days until 100 DIM and
then cows are treated with a CIDR insert (only 5% of cows). Open cows are
pregnancy diagnosis are given PGF if a CL is present.
Take Home Messages
• Time of ovulation relative to start of increased
activity or standing estrus is predictable:
• Standing estrus = 27.2 ± 0.6 h
• Activity monitor = 25.3 ± 0.6 h
• Automated activity monitors increase heat-detection
rates, but may not increase conception risk.
• Activity monitors reduce inter-insemination intervals
and help get cows pregnant at a faster rate.
• Activity monitors add value to the reproductive
management program, but do not identify all heats.
Happy AI-breeding!
Activity Monitoring in Combined Timed
AI and Heat-Detection Programs
16.7
25.8 24.2
33.3 31.1
22.7
17.4
28.8
0
5
10
15
20
25
30
35
0100 to 0600 0601 to 1200 1201 to 1800 1801 to 2400
Onset of activity (
%)
Time when estrus began
HeatWatch (n = 66) Activity Monitor (n = 132)
P = 0.031 P = 0.638 P = 0.257 P = 0.518
Onset of Estrus Activity