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 Knowledge for the CommonWealth

Seven Steps to a Successful Heat Detection Program

Dairy Pipeline: October 1997

by Ray L. Nebel
Extension Dairy Scientist, Reproduction
Virginia Tech

Eight times out of ten, the area of reproductive management that needs improvement is heat detection. Research from Virginia Tech revealed that an increase in heat detection from 40 to 50 percent increased income $34 per cow per year. There are very few farms that could not reduce the average days in milk and culling rate by spending a little more time and effort on heat detection.

1. Establish a proactive aggressive program: Use time efficiently. Cows should be observed at times and at a location where they are likely to express estrus. Establish a hormone program to induce estrus in cows not detected by 60 days in milk. Interval between voluntary waiting period (50 to 60 days) and average days to first service should be less than 20 days. Less than 20% of the cows should be open at monthly pregnancy exam.

2. Utilize records: All heat periods detected should be recorded. A 50% conception rate means half the cows bred will become pregnant and half will return to heat in 18 to 24 days. Breeding wheels, calendars, and heat expectancy charts are inexpensive and effective tools.

3. Cow interaction: Watch for sexually active groups of cows. Cows in heat and cows that will be in heat in the next 48 hours commonly congregate together. Cows usually alter their normal routine of behavior when approaching heat.

4. Minimize sore feet: A cow with sore feet and legs usually does not mount or permit other cows to mount her. Trimming hoofs on a regular basis and treating infected or sore feet as soon as possible is important.

5. Timing and location is everything: Visual observations should be where cows have a good footing surface with few obstacles to hinder interaction. Cows should be observed many times (3 to 4) during the day because the average heat period lasts for only 8 hours.

6. Use aids wisely: Heat detection aids, such as Kamar or Beacon heatmount devices should be used to supplement not replace visual detection. Pedometer based systems and the HeatWatch electronic heat detection system requires management decisions on suspect cows and interpretation of information for timely insemination.

7. Induced heat or ovulation prufusrufusrograms: Inducing heat and(or) ovulation with hormonal treatments that include GnRH and PGF2a increases the probability of detecting estrus or allows AI without estrus detection (timed insemination). To achieve accurate and efficient heat detection requires extra effort and organization, it doesnít just happen.

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