Welcome to the all-new Vetlearn

  • Vetlearn is becoming part of NAVC VetFolio.
    Starting in January 2015, Compendium and
    Veterinary Technician articles will be available on
    NAVC VetFolio. VetFolio subscribers will have
    access to not only the journals, but also:
  • Over 500 hours of CE
  • Community forums to discuss tough cases
    and networking with your peers
  • Three years of select NAVC Conference
    Proceedings
  • Free webinars for the entire healthcare team

To access Vetlearn, you must first sign in or register.

registernow

  Sign up now for:
Become a Member

Veterinarian Technician July 2005 (Vol 26, No 7)

Calving Problems in Beef Cows

by Sarah Peterson, BS, RVT

    Key Points

    • Problems associated with calving lead to millions of dollars in lost revenue every year by beef producers.
    • Dystocia, or difficult birth, is one of the major concerns of beef producers.
    • Technicians play an important role in educating clients about calving difficulty.

    Problems associated with calving are one of the leading causes of death, in both cows and calves, among beef herds. These deaths add up to millions of dollars in lost revenue every year by producers. One of the most common reasons for calving difficulty is fetal-maternal disproportion (the calf is too large to pass through the pelvic area), but problems can also have nutritional, metabolic, genetic, environmental, or other physical causes.

    The main goal of a herd health technician is to help optimize production in order to make the producer's cow-calf operation more profitable.1,a This article focuses on educating technicians about the common causes, treatment, and prevention of calving problems.

    Dystocia

    Dystocia, defined as a difficult birth or "any time a cow is unable to deliver her calf normally,"2 is one of the major concerns of beef producers. An estimated $750 million is lost annually because of dystocia.3 Studies conducted in Montana and Michigan found that 57% and 67.7%, respectively, of all calf losses were related to dystocia.4 Nearly 50% of dystocias occur in first-calf heifers, and about 25% occur in second-calf heifers.5 Not only does dystocia directly reduce the calf crop for the year, but it also has other detrimental effects on the beef production cycle, including delayed rebreeding, more open females (not bred), an extended calving season, and increased labor costs.4 By knowing how to properly assist cows and recommend economical, reliable prevention methods, technicians can help save producers a great deal of money every year.

    There are many causes of dystocia, and they are usually divided into three categories:

    • Calf effects (i.e., heavy birth weight, breed of sire, sex of calf, shape of calf)
    • Cow effects (i.e., age and pelvic size)
    • Fetal placement at birth
      — Presentation (anterior or posterior)
      — Position (dorsosacral, dorsoileal, or dorsopubic)
      — Posture (head or neck back, forelimb flexed, or rearlimb flexed)

    Malpresentation is the second most common cause of dystocia, after heavy birth weight.6

    Although many producers choose to assist in the calving process, the help of an experienced veterinary professional is invaluable. Normal delivery should be completed about 50 minutes after the onset of hard labor.1 Prolonged labor can cause problems for both the cow and calf, including hypothermia, a less vigorous calf that is less likely to suckle properly and will therefore fail to obtain the antibodies from the colostrum, and a fatigued dam that is less likely to mother the calf.7 After this time, the level of assistance needed should be assessed. Vaginal palpation by a veterinarian or technician is useful in determining the location and position of the calf. If vaginal palpation is impossible, rectal palpation can be done; however, rectal palpation is not as useful in determining the calf's position.a Before palpating either region, hands and arms should be cleaned and lubricated, obstetric sleeves donned, and the animal's perianal area cleaned with a mild detergent and warm water.6,a

    Presentation

    Normal presentation of the beef calf is often described as a "diver position." The front feet should emerge first, with the soles of the hooves oriented toward the ground. One foot should be slightly in front of the other, which causes the shoulders to not be squared, thereby facilitating passage through the pelvis. The nose should appear through the vulva next. The remainder of the body proceeds, with contractions, in the shape of a diver.1,a

    If presentation is not normal, such as a leg or head turned back, an experienced veterinary professional can correct it manually through the vagina with the cow standing, so as not to tear or rupture the uterus.a If breech presentation is apparent, and the calf is too large to proceed through the birth canal, a veterinarian should assist in delivery or perform a cesarean section. A copious amount of lubricant should be used in any type of assisted delivery.5 The cow should be monitored postpartum for passage of the placenta. If the placenta is not passed after 12 hours, it is considered retained, and the cow should receive medical attention.1

    Facilities, Equipment, and Delivery

    When pulling the calf during normal presentation, obstetric chains should be used to apply traction to the calf. Laying the cow down often makes the process easier. One of the calf's feet should be about an inch farther forward than the other and should remain so throughout the delivery. Traction should be applied gently and the calf "walked out" by putting more pressure on one leg and then the other. No more than 200 lb of pressure (a moderately gentle pull) should be applied to expose the legs and nose. The nose should follow the legs at about the level of the knee and should subsequently come forward with additional pressure to the legs. The pulling should be done in an upward motion. Once the legs are delivered, a straight outward motion should be used to pull with similar action as before after the shoulders have become exposed.8,a No more than 600 lb of pressure (a hard but not dangerous pull) should be applied to deliver the remainder of the calf. If progress is not made in 30 minutes, a veterinarian should be consulted.

    If assistance is necessary, it is important for the well-being of the cow and calf as well as the person assisting to have access to the proper facilities. The cow should be restrained with her head low in a head gate or tied to a stationary object, such as a wall or secure post. She should not be placed in a chute because she needs plenty of room to lie down. To eliminate slippage, the flooring should not be slick; slippage can lead to obturator paralysis, muscle trauma, hip luxation, or fracture. Clean, dry straw is recommended, and plenty of space should be available for the puller to stand and move back as the calf progresses outward.7

    Proper placement of the obstetric chains, including a loop above the fetlock and a half-hitch knot at the level of the pastern, helps reduce the amount of pressure on the leg and lessen the chance of fracture while pulling. Improperly placed chains can lead to fractured limbs in the calf. Handles are often attached to the chains to aid in pulling and provide traction for the puller's hands. A fetal extractor (i.e., calf jack) can also be attached to the obstetric chains to assist in pulling and provide additional traction. As a general rule, no more pressure than can be applied by two strong men should be used when employing a fetal extractor. These instruments can be very dangerous in inexperienced hands and may cause tears in the vagina or perianal region and possibly paralysis. Injury to the calf, such as femoral fracture or rib fracture, can also occur during this process, and a quick-release mechanism on a fetal extractor proves to be an invaluable accessory in these instances.5

    Selection of Breeding Stock

    Because dystocia occurs most commonly in first-calf heifers, careful heifer selection is important in the breeding herd. The cause of dystocia is often thought to be that heifers are much smaller than mature cows. However, heifers also generally have smaller calves than mature cows. This is because "mature, multiparity cows have a fully developed skeletal structure and body size compared with their heifer counterparts and are, therefore, capable of giving birth to heavier calves."9 Overall body size is highly correlated with pelvic size, which determines the size of the calf that can be delivered successfully.1,9 However, larger heifers do not always have larger pelvic areas.

    The area of the pelvis can be determined by multiplying the height and width of the heifer's pelvis during rectal palpation. By culling cows that have pelvic areas in the bottom 10% of a heifer herd, or those smaller than 140 cm2, the incidence of dystocia can be decreased significantly. These measurements should be obtained at the time of first breeding to eliminate the problem heifers and the money wasted by breeding them.1,9

    Pelvic area should also be used to estimate the deliverable calf size. The measurements obtained before breeding should be divided by 2.1 to estimate the birth weight of a calf that a heifer can deliver successfully. If measurements are calculated at the time of the pregnancy examination, 2.7 should be used as the value because the heifer has had more time to develop.1,9

    When selecting bulls, birth weight expected progeny difference (EPD) has proven to be an accurate indicator of the size of calf that a bull will produce. The EPD estimates the genetic value of an animal as a parent and is used to compare bulls within a breed. For example, if the breed average body weight EPD for an angus bull is +2.7, then a bull with a body weight EPD of +1.4 will produce calves that weigh 1.3 lb less at birth than the average angus bull's progeny. This management practice has the potential to greatly reduce the incidence of dystocia in breeding herds. By having a general understanding of EPDs, a veterinary technician can be a great asset to a herd health practice or breeding operation.

    Nutrition

    Nutrition of the dam is another important aspect in preventing dystocia. Both obese and undernourished cows may have calving problems.4 Body condition score (BCS) is a good method of determining the nutritional needs of an animal. BCS in beef cattle is based on a 1 to 10 scale — "1" being highly emaciated and "10" being grossly obese. At the time of rebreeding, mature cows should have a BCS of 5 to 5.5 to ensure breeding success and proper calf growth during gestation, whereas a heifer should have a BCS of 6 at the time of first breeding and should weigh 65% to 70% of her mature body weight.1 Before calving, heifers should have a BCS of approximately 6.5 to 7.a

    Vaginal Prolapse

    Vaginal prolapse is a condition that occurs more commonly in older cows in the last third of gestation. The tissue surrounding the birth canal can become relaxed because of an increase in the hormone relaxin. Because of increased pressure in the abdomen, the vagina may be pushed out. If this tissue becomes trapped outside the body, it will swell and become inflamed. The bladder may also be pushed out, rendering the animal unable to urinate.2

    To treat this condition, the tissue must be put back into place using the Buhner method, which is a series of sutures made in the vulva to hold it in place. Before replacing the tissue, it must be cleaned and disinfected so bacteria are not introduced into the birth canal. Because replacing the tissue can be painful, epidural anesthesia may be necessary to complete this procedure. Most importantly, the sutures must be removed before calving. If the sutures are not removed, more complications can arise because the calf will not be able to exit the birth canal without tearing the tissue surrounding the vulva.2

    Technicians need to encourage clients to cull cows that have vaginal prolapse before calving because prolapse may occur again during the next pregnancy as a result of weakened tissue surrounding the birth canal. Many cows are genetically predisposed to this condition, which provides another valid reason to cull the cow. However, obese animals, animals eating from a high-legume pasture, and cows used frequently for embryo transfer are also at a higher risk. Cows should not be allowed to gain too much weight in the last trimester of pregnancy.2 Feeding high-quality grass hay along with a trace mineral supplement should provide enough nutrients to meet the requirements of the cow yet not allow her to gain too much weight or become too thin.

    Injury to the Birth Canal

    Bruises and lacerations of the birth canal are common problems associated with calving. Although dystocia can cause injury to the birth canal, more often the cause is rough handling from the human assisting her. Special care must be taken when using obstetric chains, fetotomy wire, or a fetal extractor because these instruments are frequently associated with damage to the birth canal. Lubrication is also necessary when assisting laboring cows because they will often use up all of their uterine secretions, especially in the case of prolonged labor.2

    Management of these problems should be supervised by a veterinarian. In the case of major lacerations, surgical repair may be needed. If shock is a concern, fluid therapy and corticosteroids should be provided as well as blood transfusions when there is excessive hemorrhage.2 Oxytocin is recommended to shrink the uterus and to help control bleeding. Uterine antibiotic boluses can also be administered, along with systemic antibiotics to help control infection; however, administration of anti­biotic boluses is considered controversial for several reasons. First, most boluses are dispersed so slowly that they fall onto the ground with the uterine fluids or placenta before they can be beneficial. A second consideration is that when these anti­biotics are dispersed in the uterus, they are ab­sorbed and result in meat residues.

    Grass Tetany

    Similar to milk fever, grass tetany occurs in lactating cows, but rather than losing calcium, they lose magnesium in the milk. Unlike milk fever, this is a dietary condition caused by grazing in lush spring pastures, which often are deficient in magnesium and contain excessive potassium. Overfertilization of pastures with potassium can also predispose cows to this condition.a Acute cases are characterized by "cows that are grazing normally, and suddenly throw up their heads, bellow, gallop in a blind frenzy, fall, and exhibit severe paddling convulsions."10

    Cows with grass tetany often become aggressive and try to head butt. They are afebrile and, in less severe cases, walk with a stiff gait and are obviously uncomfortable. Many cows simply exhibit weakness and recumbency and often are found dead in the pasture with signs of convulsions before death.10 Because signs of grass tetany can be confused with those of rabies, care should be taken when dealing with an animal exhibiting neurologic signs.

    Immediate treatment should consist of intravenous magnesium and calcium administered slowly over 20 minutes. Because of the cardiotoxic effects of calcium, the heart rate should be monitored.10 Grass tetany treatment, however, is not always effective, and some cows may not respond.10

    Feeding is the most economic way to provide the supplemental magnesium needed during times of deficiency and is the best form of prevention. A commonly recommended mineral mix includes 25% magnesium oxide, 25% dicalcium"phosphorus, 25% trace mineralized salt, and 25% ground corn.1,2,10,a

    Uterine Prolapse

    Uterine prolapse (i.e., expulsion of the uterus through the vulva to the outside of the body) occurs soon after the calf has been delivered.2 It is seen more commonly in older animals or animals that have experienced difficulty calving or other injury to the birth canal. Although calving causes the uterine attachments to relax, some animals are predisposed to poor uterine attachment to the abdominal cavity. Malnutrition and poor body condition as well as poor uterine tone after calving are also thought to bring on this condition.2

    A prolapsed uterus is an emergent condition, so treatment should be started immediately. The uterus should be kept clean and moist until the veterinarian is ready to replace it, and epidural anesthesia must be used. It is important that the uterine horns are in the correct position and are fully everted and not torsed. If this is not done correctly, the cow may continue straining, and re-prolapse may occur. Systemic antibiotics can be prescribed to prevent infection, and the veterinarian may often utilize the Buhner method as well.2,10,a

    A cow that has experienced uterine prolapse will not necessarily experience this condition again; therefore, culling may not be necessary. However, complications such as laceration, infection, or freezing of the uterus could render the cow infertile, which is why timely treatment is necessary.2,10,a

    Obturator Paralysis

    Also known as downer cow syndrome, obturator paralysis occurs in cows that experience swelling of the birth canal because of tissue trauma during a difficult delivery. The swelling can damage the obturator nerve in the pelvis, causing the cow's legs to "split" and preventing normal leg function. The condition can also stem from a calf being pulled straight out rather than out and down, the calf being in the birth canal too long, or the cow slipping and "splitting out."2,10

    Nursing care and prevention of further injury are the most practical methods to manage this condition. To prevent the hips from becoming dislocated, it is important to tie the back legs together to stop them from spreading. Care should be taken to prevent rope burns on the hocks, fetlocks, and udder. The cow should be removed from concrete flooring and placed in a dry pen with a dirt floor covered in clean, dry straw to help prevent slipping and mastitis. Because decubital ulcers can develop on recumbent animals, especially if they remain in soiled areas, sand can also be a useful bedding material. Sand aids in removing urine by allowing it to flow away from the animal; it also helps keep feces clumped together for easy removal.10

    Recumbent animals should be lifted at least twice daily for 15 to 20 minutes to help prevent muscle and nerve damage, decubital ulcers, and bloat. Hoisting should be done with well-padded hip clamps (which are not to be left on longer than 10 minutes) and a wide, nylon belly band, which aids in reducing pressure applied by the hip clamps. To help speed recovery and allow for independent movement and exercise, a sternal band or a four-wheeled cart (livestock wheelchair) can be used.10

    Many aspects should be considered in the prevention of obturator paralysis. Calcium and phosphorus levels should be evaluated and adjusted to adequate amounts before calving to prevent skeletal weakness. Maternity lots or stalls should be provided that have good footing to prevent slippage, but pasture is best.a Cows should also be monitored before, during, and after calving to help reduce the incidence of this condition and to facilitate timely treatment.10 The easiest and most effective way to prevent this condition, however, is to reduce the dystocia rate.a

    Conclusion

    Calving problems lead to lost revenue in the beef industry. The responsibility of client education often falls on the shoulders of veterinary technicians. Technicians should be knowledgeable about these conditions, including signs and treatment as well as economic ways to prevent them. Sharing this knowledge with the cow"calf producer will help ensure a profitable herding operation.

    1. Lemanager R: Class notes from ANSC 441, West Lafayette, IN, Purdue University, Spring 2002.

    2. Cuneo SP, Card CS, Bicknell EJ: Injuries and diseases of beef cattle associated with calving. Beef Cattle Handbook, BCH-3125. Accessed June 2005 at www.iowabeefcenter.org.

    3. Deutscher GH: Pelvic Measurements for Reducing Calving Difficulty. Accessed May 2005 at www.ianr.unl.edu.

    4. Anderson P: Minimizing Calving Difficulty in Beef Cattle. Accessed May 2005 at www.extension.umn.edu.

    5. Faries FC: Assisting Difficult Calving, L-5242. Accessed May 2005 at http://agpublication.tamu.edu.

    6. Duetscher GH, Hudson DB: Assisting the Beef Cow at Calving Time. Accessed May 2005 at www.ianr.unl.edu.

    7. Dargatz D, Grant A, Mortimer R: Calving and calving management of beef cows and heifers on cow-calf operations in the United States." Theriogenology 61:997"1007, 2004.

    8. How to Save More Calves at Calving. Beef Today/Elanco Animal Health Video, Greenfield, IN, 1994.

    9. Calving difficulty in beef cattle, a review. C-705, Manhattan, KS, 1989.

    10. Kahn CM (ed): Merck Veterinary Manual, ed 8. Whitehouse Station, NJ, 1998.

    aHilton M: Personal communication, West Lafayette, IN, Purdue University, spring 2002.

    References »

    NEXT: Case Report: An Unexpected Finding in a "Clinic Cat"

    didyouknow

    Did you know... Chronic alveolitis/osteitis is seen in older cats and presents as a supereruption of the maxillary canines with thickening of the alveolar bone or bulging.Read More

    These Care Guides are written to help your clients understand common conditions. They are formatted to print and give to your clients for their information.

    Stay on top of all our latest content — sign up for the Vetlearn newsletters.
    • More
    Subscribe