Presentation on theme: "Estrus Detection Dr. Ray Nebel Dept. of Dairy Science Virginia Tech."— Presentation transcript:
1 Estrus DetectionDr. Ray NebelDept. of Dairy ScienceVirginia Tech
2 Estrus Detection Estrus Behavior Evaluation of Estrus Detection Factors Affecting Estrous BehaviorMethods to Enhance Efficiency of Estrus Detection
3 Estrous Behavior Primary sign of estrus Secondary signs of estrus “Standing to be mounted”Secondary signs of estrusAttempting to mount other cowsMucous dischargeSwelling & reddening of the vulvaRestlessness, bellowing, chin resting, trailing other cows
4 What Causes Cows to Express Estrus? High blood level of estrogen in presence of a low level of progesteronepre-ovulatory follicle in absence of a functional corpus luteumInvoluntary expressionedema & hyperemia of vulva, mucus secretionsVoluntary expressionInfluenced by environment
5 Days of the Estrous Cycle walkingTime eatingmilk yieldMounting activityStanding to be mountedEstrusonsetovulationDays of the Estrous Cycle
6 Variation in Estrus Activity (Duration) ( Intensity)Beef heifers: 8 h 19 stdDairy cows:Holstein: 7 h 7 std(17 Herds) 5 h 7 stdJersey: 5 h 7 stdDairy heifers:Holstein: 11 7 h 7 stdJersey: 6 h 17 std
7 Factors Affecting Estrus Behavior Influence of HerdmatesEnvironmental TemperatureFooting SurfaceFoot and Leg ProblemsNutrition and Level of Milk Production
8 Calving Interval Days to First Service Estrus Detection Breeding SeasonMax. Number of ServicesEstrus DetectionConception Rate
9 Evaluation of Estrus Detection Pre-ServicePost-1st Service
10 Pre-service Estrus Detection Efficiency Days in estrous cycleX 100((Days 1st Service - VWP) + 11)21X 100 = 41.2%( ) + 11
12 Characteristics of Herds with Inefficient Estrus Detection Very few estrus periods observed or recorded before first serviceAverage days to first service greater than 20 days beyond the VWPExcessive interval between services. Average interestrual interval greater than 30 days.
13 Characteristics of Herds with Inefficient Estrus Detection More than 15% of the cows open at pregnancy examination 35 to 45 daysPalpation confirms cows are cycling normally but estrus periods are not detectedLess than 50% heats observed on DHI 202 Herd Summary
15 14 12 10 8 6 4 2 Seasonal effects on standing activity for cows Holsteins14Jerseys121086Mean No. of Standing Events42Dec.-Feb.March-MayJune-Aug.Sept.-Nov.Seasonal effects on standing activity for cowsby breed.
16 Seasonal effects on standing activity for heifers 40HolsteinsJerseys3530252015Mean No. of Standing Events105Dec.-Feb.March-MayJune-Aug.Sept.-Nov.Seasonal effects on standing activity for heifersby breed.
17 Estrus Detection Aids Record systems and estrus expectancy chart Pressure-sensitive mount detectorsKamar and BeaconTailhead chalk, paint, or crayonEstrus-detector animalsvasectomized or surgically altered bulls, androgenized females
19 Automated Estrus Detection Systems 24-h continuous surveillanceAccurate and automatic identification of cows in estrusOperational for productive life of the cowReduce or eliminate labor requirementsHighly accurate ID of estrusSenger, 1994
20 Available Estrus Detection Systems PedometryIntegrated with milking systemWalking activity increases 2 to 5 timesCompared to within cow baseline within defined period of timeHeatWatchelectronic pressure sensing systemRadio Frequency Data TransmissionTransmitter/sensor glued to tailheadSoftware - “standing list”, “suspect list”, individual cow files
22 When is the beginning of Standing Heat!? Why is it important to know the beginning of standing heat?How many times per day are cows visually observed?
23 24 - 32 h Onset of Estrus Ovulation Sperm Viability 12 to 30 h Ova viabilitysperm transport6 h8 to 12 hhOnset of EstrusOvulation
24 Timing of AI for Dairy Cows ID in Estrus by HeatWatch System %PregnantInterval from first standing event to AI2661 inseminations, 17 herds
25 18:00-18:00-24:0024:0021%21%24%24%12:00-12:00-18:0018:0000:00-30%21%21%30%22%06:0027%27%00:00-22%06:0031%31%24%24%06:0006:00-12:0012:00Time of first standing event (estrus onset) for Holstein and Jersey cattle as determined by the HeatWatch® estrus detection system
26 Timing of Insemination HeatWatch5 to 16 hrs after 1st standFrequency of visual observationEvery 4 to 6 hours “AM-PM” guidelineTwice or less daily - within 6 hrs
27 Management Requirements for Enhanced Estrus Detection Improved Cow IDCow InteractionNutrition & HealthProvide Good Footing SurfaceUtilize RecordsEmployee ResponsibilityEstablish an Aggressive Program
28 If a Cow is Mounted and No One Sees It, Did It Happen?