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Estrus Detection Dr. Ray Nebel Dept. of Dairy Science Virginia Tech.

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Presentation on theme: "Estrus Detection Dr. Ray Nebel Dept. of Dairy Science Virginia Tech."— Presentation transcript:

1 Estrus Detection Dr. Ray Nebel Dept. of Dairy Science Virginia Tech

2 Estrus Detection l Estrus Behavior l Evaluation of Estrus Detection l Factors Affecting Estrous Behavior l Methods to Enhance Efficiency of Estrus Detection

3 Estrous Behavior l Primary sign of estrus – “Standing to be mounted” l Secondary signs of estrus – Attempting to mount other cows – Mucous discharge – Swelling & reddening of the vulva – Restlessness, bellowing, chin resting, trailing other cows

4 What Causes Cows to Express Estrus? l High blood level of estrogen in presence of a low level of progesterone – pre-ovulatory follicle in absence of a functional corpus luteum l Involuntary expression – edema & hyperemia of vulva, mucus secretions l Voluntary expression – Influenced by environment

5 Days of the Estrous Cycle Estrus onset ovulation walking Time eating milk yield Mounting activity Standing to be mounted

6 Variation in Estrus Activity Beef heifers: 16  8 h 60  19 std l Dairy cows: – Holstein: 7  7 h 7  7 std (17 Herds) 7  5 h 9  7 std – Jersey: 8  5 h 10  7 std l Dairy heifers: – Holstein: 11  7 h 17  7 std – Jersey: 14  6 h 30  17 std (Duration) ( Intensity)

7 Factors Affecting Estrus Behavior l Influence of Herdmates l Environmental Temperature l Footing Surface l Foot and Leg Problems l Nutrition and Level of Milk Production

8 Calving Interval l Days to First Service – Breeding Season – Max. Number of Services l Estrus Detection l Conception Rate

9 Evaluation of Estrus Detection Pre-Service Post-1st Service

10 Pre-service Estrus Detection Efficiency Days in estrous cycle ((Days 1st Service - VWP) + 11) 21 ( ) + 11 X 100 X 100 = 41.2%

11 Post-1st Service Estrus Detection Efficiency (S/P-1)  (ADO - DFS) 21 ( )   ( ) 21 X 100 X 100 = 61.7%

12 Characteristics of Herds with Inefficient Estrus Detection l Very few estrus periods observed or recorded before first service l Average days to first service greater than 20 days beyond the VWP l Excessive interval between services. Average interestrual interval greater than 30 days.

13 Characteristics of Herds with Inefficient Estrus Detection l More than 15% of the cows open at pregnancy examination 35 to 45 days l Palpation confirms cows are cycling normally but estrus periods are not detected l Less than 50% heats observed on DHI 202 Herd Summary

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15 Seasonal effects on standing activity for cows by breed Dec.-Feb.March-MayJune-Aug.Sept.-Nov. Mean No. of Standing Events Holsteins Jerseys

16 Seasonal effects on standing activity for heifers by breed Dec.-Feb.March-MayJune-Aug.Sept.-Nov. Mean No. of Standing Events Holsteins Jerseys

17 Estrus Detection Aids l Record systems and estrus expectancy chart l Pressure-sensitive mount detectors – Kamar and Beacon l Tailhead chalk, paint, or crayon l Estrus-detector animals – vasectomized or surgically altered bulls, androgenized females

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19 Automated Estrus Detection Systems Automated Estrus Detection Systems l 24-h continuous surveillance l Accurate and automatic identification of cows in estrus l Operational for productive life of the cow l Reduce or eliminate labor requirements l Highly accurate ID of estrus –Senger, 1994

20 Available Estrus Detection Systems l Pedometry – Integrated with milking system – Walking activity increases 2 to 5 times – Compared to within cow baseline within defined period of time l HeatWatch – electronic pressure sensing system – Radio Frequency Data Transmission – Transmitter/sensor glued to tailhead – Software - “standing list”, “suspect list”, individual cow files

21 HeatWatch ® Configuration HW Transmitter Receiver Buffer Repeater HW

22 When is the beginning of Standing Heat!? l Why is it important to know the beginning of standing heat? l How many times per day are cows visually observed?

23 Ova viability h Onset of EstrusOvulation Sperm Viability 12 to 30 h 8 to 12 h sperm transport 6 h

24 Timing of AI for Dairy Cows ID in Estrus by HeatWatch System Interval from first standing event to AI % Pregnant 2661 inseminations, 17 herds

25 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 31% 21% 27% 24% 22% 30% 24 %

26 Timing of Insemination l HeatWatch – 5 to 16 hrs after 1st stand l Frequency of visual observation – Every 4 to 6 hours “AM-PM” guideline – Twice or less daily - within 6 hrs

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

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


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