Question 1 • When is the best time to inseminate for highest fertility? 6-24 hours after the start of standing heat Question 2 • The hormone estrogen causes physical and psychological changes known as heat in a cow or heifer. • What is the single, surest sign of heat? Standing to be mounted by another animal. Question 3 • Name secondary heat signs. • Nervousness • Mounts other cows • Swollen vulva • Marks from the mounting animal • Bawling • Hair worn on the tailhead • Pacing • Mucus flowing from the vulva Question 4 • When you checked your cows today, you noticed bloody mucus smeared on one of your cows’ tail and buttock. • Should you inseminate her immediately? No • Why or Why not? The bloody discharge indicates she was in estrus and you should observe her for heat in about 17 days. If inseminated chances of pregnancy are considerably reduced. Question 5 • Describe the various kinds of heat detection aids that are available. Patches that change color or raise a flag when the animal is mounted. Chin ball markers on detector animals mark estrous animals with ink. Electronic heat detection devices that monitor mounting activity. Daily chalking of tail heads. Milk progesterone tests. Good records and proper identification. Question 6 • Heat detection aids should be used only as supplement to good visual observation. • How much time out of your daily routine must you spend on heat detection if using visual detection? At least 30 minutes twice a day. Question 7 • Well-fed heifers normally show their first heat period at nine to eleven months, and then cycle about every 21 days after that except when pregnant. • Are all heats of cows and heifers fertile heats? No heifers may not be old enough or weigh enough. Cows may not have had enough rest since calving. A small percentage of cows will show signs of heat even though pregnant. Question 8 • When is the bet time to inseminate heifers? When the heifer is of a size that she could deliver a calf. • How long should you wait before inseminating cows that have calved? Cows need a minimum of 40 days to recover after calving. Question 9 • The old a.m.-p.m. rule states that cows first observed in heat in the morning should be inseminated late that afternoon, and that cows first observed in heat in the afternoon should be inseminated the following morning. • Does once-a-day insemination produce effective results? Yes • Why or why not? There is no advantage to breeding twice a day. Most cows ovulate between 17 and 38 hours after the onset of standing heat. Question 10 • Considering the difficulties in precisely determining the onset of heat, what is the most practical rule-of-thumb to follow in inseminating based on first observation of heat? Inseminate anytime after observing standing heat. Question 11 • What are some of the management practices to be considered when planning a once-aday or twice-a-day insemination program? For Dairy - how long will the cows be locked up? How long standing on cement? Body temp during heat stress. Inseminator fatigue. For Beef - number of cattle handled. Inseminator fatigue. Are cattle sorted after being observed in heat when using heat synchronization.