Knowing when a heifer or cow is ready to breed is important for breeding purposes. There are definite rules one must follow to make sure it is ready.
Remember these two important terms:
Heifers are female cattle that have not yet had a calf. A heifer will no longer be a heifer after giving birth. Then it will be called a cow, that is, an adult female bovine that has had a calf. The heifers remain so from birth until the first calving.
Steps
Method 1 of 2: Reproduction of the heifers
Step 1. Depending on the breed, most heifers will begin to show the first signs of heat between 9 and 22 months of age
The speed of reaching sexual maturity is determined by genes and race. The rate of growth, being physical growth, is not directly linked or determined by sexual maturity. Physical maturity is reached when bones and muscles stop growing and fat begins to accumulate
Step 2. It is usually best to wait at least 15 months of age before breeding
Although precocious breeds reach puberty even at 7-9 months, it is best to wait 13-15 months before breeding them. This is to let them grow more, which will increase the pelvic area and be stronger to support the pregnancy. Heifers that breed too early tend to have too small a pelvic area to give birth, so some require a Caesarean section or the calf needs to be pulled. It can be expensive, because the calf often has to be bottle fed to get enough milk.
Sometimes, however, some heifers that are bred too early manage to do without human help, both during pregnancy and during lactation
Step 3. The heifer must be at least 60-65% of average weight for maturity before it can reproduce
This is to allow her to raise a calf while she continues to grow too.
Step 4. There are two ways to successfully breed a heifer:
- Choose a bull with a good (and low) number of offspring to breed with her (and other heifers like her), or
- Take into account her period of estrus so that you can artificially inseminate her (or have her inseminated by a technician).
- A heifer can only be successfully inseminated during periods of heat. It is important to calculate the times correctly for a successful artificial insemination. She must be inseminated 12 hours after the first signs of heat, and remember that artificial insemination has a success rate of 60-70%.
- Using natural insemination, the bull will know when the heifer is ready and when it is not receptive. It is best to leave the bull with the heifers for 60-80 days to allow him to inseminate all of them. Use a one-year-old bull to reduce injuries and increase the chances of the heifer giving birth to a small, tame calf.
Method 2 of 2: The cow
Step 1. A cow must be re-inseminated after having had a calf
The optimal time for her to reproduce is 45-60 days after giving birth. To have her give birth at the same time of the previous year, let her rest for 80-90 days before letting her reproduce again. It usually takes longer to return to normal cycle if she is weakened or if her fertility is reduced due to age, inadequate diet, or the environment.
- The time it takes to get her to reproduce again will be longer the worse her condition or the leaner or fatter than normal she is. Age and health conditions determine the time required for the new insemination.
- The reason why time has to pass between delivery and the new insemination is that it takes time for the uterus to retract to its normal size. It also takes time for the cow's ovaries and hormone system to normalize. Even if a cow shows signs of heat 14 to 18 days after calving, these periods are quite short and unpredictable. This is because it takes the ovaries time to return to normal and start producing eggs again.
Step 2. As mentioned earlier in step 5 on heifers, a cow can be artificially or naturally inseminated
- Artificial insemination follows the same principles listed above for heifers to have a high success rate.
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With cows there is no need for a bull to facilitate calving, at least not as with heifers. Either way, pay attention to the bull you select for your cows. For some breeds of bulls, the bull must have a low EPD to reduce the likelihood of problems during calving. For example, Charolais bulls are known to give birth problems with English breed cows, producing larger calves than they should be for those breeds. If you don't pay attention to the numbers (EPDs, "Expected progeny differences") of that breed, you will have a lot of problems, and you will have a lot to do next season helping the cows to give birth.
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On the other hand, if you don't pay attention to the numbers you can also have problems with crosses of the same breed. Beware of bulls that have a high EPD count, no matter what breed they are.
Also remember to select the bull based on the missing characters in your herd, and not the other way around
Advice
- You will always know when a heifer or cow is ready to mate by watching when they go into heat.
- The normal period of estrus lasts 24 hours and happens every 17-24 days.
- Check the shape of the heifer's hindquarter before deciding on its breeding. A wide, long, deep thigh is a sign that the heifer is ready.
- Heifers should be mated when they have had at least three periods in heat since the onset of puberty, regardless of breed.
- The better the cow's health score after calving, the sooner she can be inseminated again.
- Heifers should be in the same good condition as cows 30 days before insemination. Females should have a Cdn BCS score of between 2.5 and 3.5 (3 to 5 on the American scale) before the breeding season.
Warnings
- A lone cow or heifer that does not have access to other specimens in the herd is a danger to you, especially when it goes into heat. You may be in for a nasty surprise if he decides to mount you.
- Watch out for bulls during the breeding season. They can be protective of their harem if they don't understand that you are not representing a competitor.
- Artificial insemination has only a 60-70% chance of success if you decide to use it on all your cows or heifers. However, the better it is conducted, the higher the chances of success.
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