1. Colorado Agriscience Curriculum Animal Science Unit 4 – Reproduction and Genetics Lesson 6 Heat Detection

2. What is heat? What is standing heat? –Heat – Signals the time of ovulation and determines proper timing of insemination. –Standing Heat – Best indication of estrus. It is when the female stands still when mounted by a male or another female. Do not breed a female you think is in estrus until you actually see her ridden while she stands completely still. If she is the one riding it is not an indication of standing heat. (Unit 4 Reproduction and Genetics, Lesson 6 Heat Detection T.M.A)

3. Secondary signs of heat –Cattle – Cows are checked for estrus twice daily, in the morning and evening. Secondary signs include restlessness, attempting to mount other cows, and a clear, mucous discharge from the vagina. Do not breed a cow until you actually see standing heat, though. Secondary signs may just be leading up to estrus. –Swine – Gilts’ and sows’ secondary signs of heat include a red, swollen vulva, odd sounds and odd odors. (Unit 4 Reproduction and Genetics, Lesson 6 Heat Detection T.M.B)

4. Signs of Standing Heat –Cattle – Standing heat is exactly what it sounds like it is in cattle. The cow stands to be ridden by another cow in the herd, or if naturally bred, the cow stands to be ridden by a bull. –Swine – Gilts and sows in standing heat assume a rigid stance with ears erect when hands are placed firmly on their backs. (Unit 4 Reproduction and Genetics, Lesson 6 Heat Detection T.M.C)

5. Common Heat Detection Aids Cattle Chin Ball Marker – This device is worn beneath the detector animal’s chin, consists of a dye reservoir with a steel ball valve attached with a strong leather halter. Leaves a giant mark on the ridden cow’s back and rump. Androgenized cows – Females used to detect heat that have been injected with testosterone to stimulate them into exhibiting male-like behavior. Kamar – This plastic device is glued to the tailhead of cows eligible for breeding. Prolonged pressure from the mounting animal turns the white detector red. (Unit 4 Reproduction and Genetics, Lesson 6 Heat Detection T.M.D)

6. When to inseminate livestock after observation of standing heat –Cattle – 12 hours after standing heat. So a cow found in standing heat in the morning should be inseminated in the evening of the same day. –Sows – Insemination is recommended at the end of the first day and at the beginning of the second day of estrus. (Unit 4 Reproduction and Genetics, Lesson 6 Heat Detection T.M.E)