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Difficult calving can be eased with preparation |
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By MONETTE TAYLOR | South Central Texas |
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January 17, 2002 -- "As you select those heifers at a yearling age and get them ready for breeding, select those heifers that have a high tailhead. So many producers like those clean rear end heifers that have those tailbones that pull down and look pretty. They look at those others with the big old high tailheads ... and they don't want to pick 'em," said Dr. "Buddy" Faries, Jr., DVM, Texas A&M University Extension Veterinarian, at the Corpus Christi Farm and Ranch Show held Jan. 9 and 10. He said that calving difficulties can be caused by several different things, each of which can be overcome, successfully, with the correct procedures. "First, you have to decide ... is the calf too big, or is the heifer too small. That's really two different things. When it occurs at the same time in the same heifer, there's no way to deliver the calf from the rear end. She would be a candidate for a Caesarean section," said Faries. The scientific word for a difficult delivery is "dystocia," and it usually occurs in first calf heifers and second calf heifers, but can occur in older cows. A lot seems to have to do with the size, weight and breed of the heifer. "When a heifer reaches 12-16 months of age, somewhere in that breeding time, she should be weighing 65 percent of her adult weight," said Faries. "If she doesn't have the genetics, she won't reach that 65 percent weight. Along with the genetics, you have to have the nutrition," he added. He said that an average pregnancy would be 285 days in length, and during that time, the heifer should gain up to 85 percent of her adult weight, which would normally occur between 20-24 months of age. Faries said that he prefers that a calf weigh around 70 pounds at birth because the higher the weight, the more risky the birth process. "Another good reason (for not having too big of a calf) would be related to the strength of the heifer ... how strong is she?" asked Faries. "The strength of the heifer has to be strong enough to lift the calf up out of the hole (bottom of the uterus) all the way up to the top, to the vagina area and to the outside. It takes a lot of strength." As in most births, pushing takes a lot of strength, and the heifer needs to be in good body condition. Lots of heifers and cows are calfing at this time on into March, said Faries, and many of them have gotten thin in the last few months due to the weather conditions. These animals may have difficulties calving, he said. Once the heifer is at her due date, producers were told that the mucous plug at the entrance into the cervix will loosen and fall out, due to the dilation of the cervix. This usually happens one to three weeks before birth, said Faries. When stage one of the calving starts, producers will be able to see signs from the heifers, he said. "When you see that a heifer is not only off to herself, she is uncomfortable, you go ahead and call her in stage one, and she's going to be calving, today," said Faries. Other signs that a heifer/cow is in labor is that she may be laying down, standing up and rolling on her back as she has contractions. The first stage of labor usually lasts from two to six hours, and, according to Faries, should not be allowed to progress more than eight hours without the help of a veterinarian. "Stage two is when she really starts straining. She is laying down, bowing up, pulling her flanks up. She's bellowing, she's defecated, she's urinated, she's really straining. You know she's in stage two," he said. During stage two, you can expect her water to break and it usually amounts to about 20 gallons, he added, and the birth should follow within a four hour time frame. The size and shape of the pelvic bone can either assist or deter the calving process, said Faries. According to these factors, the stretching ability can function only if the "bony ring" of the pelvic bone allows passage. "This bony ring is never round. It is an oval to an oblong shape. It's always taller than it is wide," said Faries. "You never deliver a calf upright. You never have the calf where the back is at the top, because the shoulders and elbows will always hang up on these heifers." Another sign of imminent birth is that the ligaments that hold the top piece of the tail will relax. "You're going to see that her tail head is getting higher, higher and higher, because the ligaments that hold the top piece relax and the lower back will go upward," said Faries. Without this happening, he said you can just about depend on having to do a Caesarean section. If you see that the heifer is going to need a little help in calving, chains can be properly applied, he said. "I never say I'm going to 'pull' a calf ... I'm walking the calf back and forth. When you start pulling, you never ever pull both chains at the same time. You alternate. "You pull on one and it moves an inch or so, and you pull on the other one," said Faries. Another important thing to remember is to pull "up, up, up and down, down, down," he said. Never pull straight out. Also, the correct positioning of the chains is very important. You should put a loop above the ankle and then one-half inch below, he said. Other suggestions were not to allow calving inside a regular chute because you are not able to pull up and down to assist the birth. Once the calf is born, if the membrane is still in place, allow the heifer to open it and remove it or the heifer will not bond to the calf and it will be yours to raise, he said in closing. |
