Every cow-calf operation contains several basic components without which it cannot survive. First, the producer has to get the females bred. Second, the bred females have to carry the unborn calf to term. Third, she has to calve with a minimum of stress to the cow and to the calf. Finally, she need to raise that calf to weaning. While all of these are vital to operational success and are equal in importance, the calving period seems to be the most stressful for all concerned, the cow AND the producer.
We know, fortunately, that most calves are born alive and unassisted. We also know that those that require assistance create some of the greatest headaches on the farm. This is especially true on ranches that purchase or retain and calve out heifers. Some current data indicates that an estimate 16 to 18 percent of all heifers calved require some type of assistance with the calving process. That can be compared to about three to four percent of cows which may require assistance.
Another point to consider is that in a normal year, calf losses during calving typically range from 6 to 8 percent. In a 100 head cow-calf operation, this would result in an estimate loss of approximately $3,000 in revenues. This does not include the additional health and vet related expenses that might be incurred with these calf losses or associated complications.
The following text will examine some factors which must be considered both before and during calving for cows and heifers.
The Precalving Period
Management during the last third of pregnancy is very critical, especially for the growing heifer and developing calf. The producer must keep in mind that the heifer must continue to grow structurally and gain body weight during this 90-day period. The weight of the fetus and fetal fluids and membranes will increase about .90 lb per day. Therefore, the heifer needs to gain about 1 to 1.5 lbs per day to sustain her growth and that of the fetus. However, a heifer should not gain excessive weight and become fat as this may increase the likelihood of calving difficulty since a significant amount of this fat may be deposited in and around the reproductive organs.
If the heifer is on a deficient nutritional level, she will draw nutrients from her body tissues to provide for the developing calf. The calf may lack vigor or energy at birth and need help nursing. These heifers may be short of colostrums, which is a component of the first milk given by the female that passes on crucial antibodies to the calf that helps build the calf's immune system. In extreme cases, the calf may be born dead or die shortly after birth. Milk production will usually be decreased, which will reduce growth rate and weaning weight of the calf. Also, the heifer will tend to rebreed late or may fail to rebreed. All this said, it is obvious that producers cannot afford to compromise the nutritional plane of bred heifers.
Some producers feel that reducing energy and/or protein intake prior to calving will reduce calf birth weights and, subsequently, calving difficulty and calf losses. Research does not agree with this. Restricting feed to heifers may reduce calf birth weights, but does not reduce calving difficulty. It may also decrease the percent of cows cycling and conceiving during the breeding season and it may reduce the weaning weight of the calves. Therefore, the practice of reducing feed to heifers in average or thin condition prior to calving is not advisable. However, feeding excess protein or energy to heifers should also be avoided.
Nutrient requirements for bred heifers are given in Table I. These requirements and rations do not include extra energy needed during extremely cold, windy or wet weather. Provide cattle with all the roughage they will consume during severe cold periods.
How to Determine if a Heifer or Cow Requires Assistance
In many situations it can be difficult to determine if or when to help a female in the calving process. The following steps can provide some clarification.
1. A COW OR HEIFER IS HAVING DIFFICULTY WHEN:
• the cow actively strains for 40 to 60 minutes with no progress
• 90 minutes have passed since the waterbag first appeared
• feet and legs emerge with the surface of the hooves pointing up
• only the head or tail (bad sign) emerges
• a cow has demonstrated greater than 5-6 hours of anxiety, e.g. walking about, tail extended, apparently looking for something
2. TO EXAMINE A COW HAVING DIFFICULTY:
• restrain the cow either in a chute or in a safe and secure manner
• clean all manure away from around rectum and vulva. Washing is preferable to reduce contamination.
• Use the plastic obstetrical sleeves with lubricant to improve sanitary conditions and reduce irritation of the vulva and birth canal.
• Explore the problem a normally positioned calf will have both the front feed and head positioned as shown in Figure 1.
|Figure 1. Normal Positioning of Unborn Calf
3. PULL CALF IF:
• Two front legs and a nose OR two hind legs and the tail head can be guided into the bony part of the birth canal
4. IF THE CALF IS INCORRECTLY POSITIONED:
• Gently position the legs and head correctly. Gently push the calf back a little way to get some working room. Do not push against the cow's contractions - work with her, not against her. Cover the teeth and feet with your hand as you move them to reduce injury to the cow.
• NOTE: If the position is too difficult to correct in 20 minutes, or two strong people cannot pull the calf - call your veterinarian.
• Attach loops of soft nylon rope or surgical chain to the legs. By convention, place a loop above the fetlock joint as well as a half hitch below. A loop may also be placed around the head - over the poll behind the ears and under the mouth. NEVER attach a loop to the lower jaw.
• Pull back and down on the ropes for a head-first calf, straight back for a tail-first calf. Pull alternately on either leg to angle the shoulders through the pelvis. Two strong people (pulling force of 250lbs. max.) should be able to pull a calf into the birth canal.
• Use calf pullers with caution. Remember to release tension periodically. Allow cow to push calf out.
5. WHEN TO CALL THE VETERINARIAN FOR A CAESARIAN SECTION:
If the calf is too large. This can be measured by the following:
• If the front feet fill the pelvic opening and you can't get your hand beside them
• If with gentle pulling, you cannot get the head and feet into the pelvis at the same time; two people using body weight only (e.g. 250 lbs.)
• If the heifer/cow has been actively straining for 30-40 minutes and hasn't been able to push the head and feet (or the tail head if coming backwards) into the bony part of the birth canal
A) If there are other complications, like:
• Incomplete opening of soft tissues of the birth canal (incomplete dilation of the cervix)
• twisted uterus
• misshapen pelvis
The Most Common Post-Calving Complications
In addition to problems a producer may see before and during calving, the post calving period can also produce a variety of problems. These include:
1) Prolapsed Uterus
If the cow is straining badly and the uterus is very loose and soft, she may push the uterus out through the birth canal, inside-out. What you will see is a large solid mass of tissue with 2-3 inch long "buttons" on the surface where the membranes were attached. In these situations do the following:
• Restrain the cow; the uterus is less likely to be damaged and is easier to be replaced in cows that are down
• If there is a delay, cover the uterus with a wet towel or blanket to keep moist and protect from elements. Depending on the situation it may need to be washed off with warm water.
• Keep other animals, including cows, away; they may eat or damage the uterus
• Call your veterinarian
2) Retained Placenta
Normally the afterbirth will come away by 24 hours. There is no concern unless the cow is sick; example, with a high temperature and "off feed." In these cases you will need to provide:
• daily antibiotic injections as directed by your veterinarian; if there is no response in three days, call your veterinarian who may need to remove the retained placenta manually.
Calving is a critical time in your cattle operation. With close observation, planning and preparation calving can go smoothly and create only minimal stress for the producer and cow herd alike.
Dr. Steve Blezinger is a management and nutritional consultant with an office in Sulphur Springs, Texas. He can be reached at P. O. Box 653 Sulphur Springs, TX 75483, by phone at (903) 885-7992 or by e-mail at firstname.lastname@example.org.