Читать книгу Hobby Farm Animals - Chris McLaughlin - Страница 27

Breed your cows nine to nine and a half months before you want calves. A cow should start cycling, or going into heat, within three weeks to sixty days of having a calf and will cycle about every three weeks after that until being bred again. Many cows will breed back (conceive) on their first cycle, while some will take two cycles; those that take three or more or don’t get bred at all should be considered for culling.

A heifer is usually bred for the first time in the summer after her first birthday, at about fifteen months of age. If a heifer is small for her age, you should give her a little longer or cull her. Slow growth is not a desirable trait in beef-cattle production.

Artificial Insemination

Artificial insemination (AI) allows you to pick from the very best bulls available nationwide, based on detailed statistical information provided by the AI company. In addition to the physical characteristics and growth records of bulls, the company’s catalog will list the expected progeny differences (EPD) numbers. This is the statistical chance that a bull’s progeny will be above or below the breed average for that characteristic. EPDs are given for such factors as low birth weights (a low birth weight is a strong indicator of easy calving) and weaning weights. Use EPDs to select for characteristics you want to see in your herd, such as better milk production.

Making sense of all of the numbers does take some education and practice, so it’s a good idea to start by asking advice from your AI technician. If your budget is a little tight, ask about young sires, whose semen is generally cheaper because they aren’t yet old enough to have produced enough progeny for a statistically credible EPD record.

The advantages of artificial insemination are that you get a wide choice of excellent bulls, and you don’t have to worry about keeping a live bull on your farm. If you have just a few cows, it’s probably also cheaper than a live bull.

The disadvantage of AI is that you have to spot the cows or heifers when they’re in heat, which isn’t always easy to do. Heats can be tough to catch on some cows, or you may have an off-farm job and not be around to check cows as often as you need to. To make things easier, buy a heat-detecting strip. This is a strip with small dye capsule that is glued onto a cow’s rump. When the cow goes into heat and other cows start trying to mount her, the pressure of mounting bursts the capsule and mixes the dye with another fluid so that it changes color. This works pretty well, except when you don’t get it positioned right or it falls off, so take care when applying the strip. Attaching the strip to the cow also involves an extra trip through the chute.

A cow cycles every seventeen to twenty-four days, and heat lasts about thirty-six hours. For best results, a cow should be bred during the twelve hours she’s in a standing heat, which starts about six to twelve hours after the heat cycle begins. A standing heat is so called because, during that time, a cow or heifer will let another mount her. When a cow is in heat but not in standing heat, the others will smell her and try to mount, but the cow won’t stand still. But don’t worry about the timing of AI breeding too much. As one friend who’s bred a lot of cows puts it, if you see a cow in heat, breed her. If you’re a little late, it’s OK.

To spot cows in heat, you should be out in the pasture at least twice a day. In hot weather, your best chance of catching a heat will be before sunrise, at the coolest time of the day. Once you know that a cow is ready to be bred, call your AI technician and then get the cow into the chute. Seventeen days later, start watching the cow carefully to see whether she goes into heat again. If she does, she has to be bred again.

Using a Live Bull

The advantage of using a live bull is that the bull and the cows will take care of the breeding without your involvement. For cattle owners with other jobs or erratic schedules, live breeding saves the headache of scheduling with the AI technician. Cows generally conceive more quickly and at a higher overall rate with a live bull than with AI. If you have enough cows to breed, it will also be cheaper than AI, even if you pay for a high-quality bull.

The disadvantages of using a live bull begin with having to keep a dangerous animal on the farm. On the whole, beef bulls don’t have the bad reputation for maiming and killing their owners that dairy bulls do, but you still need to be careful and cautious and to warn visitors.

If you keep the bull for a couple of years, you’ll need a separate pasture for the heifers not yet old enough to be bred and the cows for which it’s too early in the year to breed. The fences between the pastures must be effective enough to discourage a lovesick bull because a bull can smell a heifer in heat from up to 5 miles away and will come running if he can.

Another disadvantage of live breeding is that you’ll have fewer choices in bull traits than you would with AI because you’ll be limited to whichever bulls are available in your area. That said, there are many excellent bull producers, and a bull from your area will be adapted to your climate. Finally, a good bull is expensive and can only be used for two years because, after that, he would be breeding its daughters.

Choosing a live bull is much the same as choosing cows and heifers, except that your selection has a much greater effect on your herd. A cow has only one calf at a time, but your bull will sire all of the calves. The old saying that “the bull is half the herd” is very true. A bad bull can saddle you with poor animals for a long time. Look for a docile animal with a good build. He should be beefy and masculine through the neck and shoulders, with a bit of a hump, and broad and plump from stem to stern, but not fat. A fat bull will get too tired to breed all of the cows. A mature bull should be able to breed twenty to twenty-five cows in a season. If you have just a few cows, consider buying a yearling bull, which will be less expensive and, if well grown, able to breed up to fifteen cows.

It’s also important to use a bull that’s not a lot bigger than your cows. A big bull siring a big calf in a small cow adds up to calving problems.

Instead of buying a bull, you could ask around about renting a bull either before or after the main breeding season, if you’re willing to adjust your calving calendar. That way, you’ll need to have the bull on your farm for only a couple months.

Another option, if you can find a willing bull producer, is to rent a yearling bull for the summer. Many bull producers like to sell two-year-old bulls, and if you pay them some rent for a yearling for a few months, it cuts their cost of raising a bull to two years. In many areas, you used to be able to get a bull for the summer just for feeding him, but that is happening less and less, and usually not with high-quality animals.

Whatever bull you buy or rent, have its fertility tested. A disturbingly high percentage of beef bulls are infertile, and if you don’t catch the problem before you breed, you’ll have gone to all that expense and trouble and won’t have any calves the next spring—a disaster.

Combining AI and Live Bull Methods

Many serious beef producers use AI followed by a “cleanup” bull for those cows that don’t “settle” with AI. This provides the advantage of getting some top-notch genetics into a herd without having to worry about getting all of the cows bred in time to hit your desired calving window. If you’ve been using AI and having problems getting all of the cows to conceive, this might solve the problem.

A pregnant cow needs proper nutrition for both herself and her calf.