Estrus DetectionEstrus Detection

Dr. Ray NebelDept. of Dairy Science

Virginia Tech

Estrus DetectionEstrus Detection

Estrus BehaviorEvaluation of Estrus DetectionFactors Affecting Estrous

BehaviorMethods to Enhance Efficiency

of Estrus Detection

Estrous BehaviorEstrous Behavior

Primary sign of estrus– “Standing to be mounted”

Secondary signs of estrus– Attempting to mount other cows– Mucous discharge – Swelling & reddening of the vulva– Restlessness, bellowing, chin

resting, trailing other cows

What Causes Cows to What Causes Cows to Express Estrus? Express Estrus? High blood level of estrogen in

presence of a low level of progesterone– pre-ovulatory follicle in absence of a

functional corpus luteum Involuntary expression

– edema & hyperemia of vulva, mucus secretions

Voluntary expression– Influenced by environment

Days of the Estrous Cycle

-4 -3 -2 -1 Estrus 1 2 3 4 onset ovulation

walking

Time eatingmilk yield

Mounting activity

Standing to be mounted

Variation in Estrus Variation in Estrus ActivityActivity Beef heifers: 16 8 h 60 19 std Dairy cows:

– Holstein: 7 7 h 7 7 std(17 Herds) 7 5 h 9 7 std

– Jersey: 8 5 h 10 7 std Dairy heifers:

– Holstein: 11 7 h 17 7 std– Jersey: 14 6 h 30 17 std

(Duration) ( Intensity)

Factors Affecting Estrus Factors Affecting Estrus BehaviorBehavior Influence of Herdmates Environmental Temperature Footing Surface Foot and Leg Problems Nutrition and Level of Milk

Production

Calving IntervalCalving Interval

Days to First Service– Breeding Season– Max. Number of Services

Estrus Detection

Conception Rate

Evaluation of Estrus Evaluation of Estrus DetectionDetection

Pre-Service

Post-1st Service

Pre-service Estrus Pre-service Estrus Detection EfficiencyDetection Efficiency

Days in estrous cycle

((Days 1st Service - VWP) + 11)

21 (95 - 55) + 11

X 100

X 100 = 41.2%

Post-1st Service EstrusPost-1st Service Estrus Detection Efficiency Detection Efficiency

(S/P-1) (ADO - DFS) 21

(2.5 - 1) (146 - 95) 21

X 100

X 100 = 61.7%

Characteristics of Herds Characteristics of Herds with Inefficient Estrus with Inefficient Estrus DetectionDetection Very few estrus periods observed

or recorded before first service Average days to first service

greater than 20 days beyond the VWP

Excessive interval between services. Average interestrual interval greater than 30 days.

Characteristics of Herds Characteristics of Herds with Inefficient Estrus with Inefficient Estrus DetectionDetection More than 15% of the cows

open at pregnancy examination 35 to 45 days

Palpation confirms cows are cycling normally but estrus periods are not detected

Less than 50% heats observed on DHI 202 Herd Summary

Seasonal effects on the duration of estrus (h) inHolstein and Jersey heifers and cows.

0

2

4

6

8

10

12

14

Dec.-Feb. March-May June-Aug. Sept.-Nov.

Me

an

Est

rus

Du

rati

on

(h

)Cow sHeifers

Seasonal effects on standing activity for cowsby breed.

0

2

4

6

8

10

12

14

Dec.-Feb. March-May June-Aug. Sept.-Nov.Me

an

No

. of

Sta

nd

ing

Eve

nts

HolsteinsJerseys

Seasonal effects on standing activity for heifers

by breed.

0

5

10

15

20

25

30

35

40

Dec.-Feb. March-May June-Aug. Sept.-Nov.

Mea

n N

o. o

f S

tan

din

g E

ven

ts

HolsteinsJerseys

Estrus Detection AidsEstrus Detection Aids

Record systems and estrus expectancy chart

Pressure-sensitive mount detectors– Kamar and Beacon

Tailhead chalk, paint, or crayon Estrus-detector animals

– vasectomized or surgically altered bulls, androgenized females

Automated Estrus Automated Estrus Detection SystemsDetection Systems 24-h continuous surveillance Accurate and automatic identification of

cows in estrus Operational for productive life of the

cow Reduce or eliminate labor requirements Highly accurate ID of estrus

– Senger, 1994

Available Estrus Detection Available Estrus Detection SystemsSystems Pedometry

– Integrated with milking system

– Walking activity increases 2 to 5 times

– Compared to within cow baseline within defined period of time

HeatWatch– electronic

pressure sensing system

– Radio Frequency Data Transmission

– Transmitter/sensor glued to tailhead

– Software - “standing list”, “suspect list”, individual cow files

HeatWatch®

Configuration

HWHW

TransmitterReceiver

Buffer

RepeaterHWHW

When is the beginning When is the beginning of Standing Heat!?of Standing Heat!?

Why is it important to know the beginning of standing heat?

How many times per day are cows visually observed?

Ova viability

24 - 32 h

Onset of Estrus Ovulation

Sperm Viability

12 to 30 h

8 to 12 hsperm transport

6 h

Timing of AI for Dairy Timing of AI for Dairy Cows ID in Estrus by Cows ID in Estrus by HeatWatch SystemHeatWatch System

Interval from first standing event to AI

%Pregnant

2661 inseminations, 17 herds

Time of first standing event (estrus onset) for Holstein and Jersey cattle as determined by the

HeatWatch® estrus detection system

21%

27%

31%

21%

24%

30%22%

24%

00:00-

06:00

12:00

12:00-

18:00

18:00-

24:00

18:00-

24:00

12:00-

18:00

06:00-

12:00

00:00-

06:00

06:00

31%

21%

21%

27%

24%

22%30%

24%

Timing of InseminationTiming of Insemination

HeatWatch – 5 to 16 hrs after 1st stand

Frequency of visual observation– Every 4 to 6 hours “AM-PM”

guideline– Twice or less daily - within 6 hrs

Management Management Requirements for Requirements for Enhanced Estrus DetectionEnhanced Estrus Detection Improved Cow ID Cow Interaction Nutrition & Health Provide Good Footing Surface Utilize Records Employee Responsibility Establish an Aggressive Program

If a Cow is Mounted and No One Sees It, Did It Happen?