Cowboy Obstetrics: Assisting with calving
Richard Randall, DVM, University of Missouri, Columbia
Approximately 80 percent of all calves lost at birth are anatomically normal. Most of them die because of injuries or suffocation resulting from calving or delayed calving. Knowing when and how to assist (or more importantly, when the situation calls for the timely attention of an experienced veterinarian) can make a big difference in the calf crop from year to year. Reproductive losses, which affect the percent calf crop weaned each year, are very high in the first two weeks of life and are second only to losses due to failure to conceive!
The first step to a successful calving season is recognizing a normal calving. As long as the calf is normally presented, the vast majority of animals will give birth without assistance. Recognizing a normal calving that does not require assistance can be as important as knowing when calving is abnormal and requires assistance.
The most likely animals on the farm to have problems are first calf heifers. Less than 2% of calving difficulties occur in mature cows. Special attention should be given to young heifers, who are also more apt to tire quickly, especially if they are in sub-optimal body condition.
Table 1. Stages of Normal Delivery
Stage and Event Time
Preparatory(2 to 6 hours)
- Calf rotates to upright position
- Uterine contractions begin
- Water sac expelled
Delivery (1 hour or less)
- Cow usually lying down
- Fetus enters birth canal
- Front feet and head protrude first
- Calf delivery complete
Cleaning (2 to 8 hours)
- Button attachments on placenta relax
- Uterine contractions expel membranes
Tips on when and how to assist the cow
- Rule of thumb: Assist after 30 minutes of no progress.
- Cleanliness is a must. Introduction of bacteria by equipment or arms of the person assisting can reduce fertility by delaying return to estrus and lowering conception.
- Wash and disinfect equipment, arms and perineal area (anus and vulva).
- Do NOT use liquid soap as a lubricant. It breaks down the natural lubricant of the cow. Methylcellulose based lube is best. You can also use cooking oil, mineral oil or vaseline.
- Calving area should be 12 square feet minimum, covered, well lit and well bedded.
- Assess the situation by asking these four questions
each time during an assist. Ask and answer in this
order:
- Has the cervix dilated?
- Is the water sac broken?
- Is the calf in the proper position?
Can the calf pass through the pelvis?
- You can tell if the cervix is dilated by sliding your palm along the vaginal wall toward the uterus. You should not feel cervix or any cervical ridges (should be continuous and smooth). Assisting prior to full dilation can damage the cow and injure the calf.
- Once the water sac is broken, it is important to make good progress. First, because there is a loss of lubrication. Second, the calf's impetus to take the first breath is the pressure differential between an all water environment and an all air environment. If the calf has tried to begin breathing, you will see a frothy mouth and nostrils. NEVER try to rupture the sac (unlike in horses and humans where rupturing the sac can increase strength of contractions and speed delivery).
- If the position of the fetus is abnormal, use your best judgement to determine if you can correct the situation or should call the veterinarian. Approximately 5% of calving difficulties result from abnormal presentation, and most need the expertise of a veterinarian to assist.
- Assess the size of the calf relative to the birth canal. Forcing a large calf through a small pelvic opening can result in injury and/or death of the cow and calf. If the head and front feet are still in the birth canal, a veterinarian can still deliver via caesarian.
- Dr. Randle recommends 60-inch chains as opposed to 30-inch chains. Chains should be attached below the dewclaw and above the hooves. Placement is important to avoid injuring the calf.
- Pull alternately on each leg to "walk" the shoulders out. At this point, traction should be applied straight back toward the tailhead. All traction should be applied gradually to prevent damage that will result in later infertility of the cow.
- Once the head and shoulders are free, rotate the calf 90 degrees to aid in passage of the hips. Apply traction downward.
- If the calf becomes "hip locked," the umbilical can be pinched. If delivery is delayed, make sure the calf begins breathing normally and call for professional help.
- All posterior (rear feet first) presentations are an emergency. Delivery must be made quickly and professional assistance is preferred.
Some other tips from Dr. Randle:
It is best for a cow to lay on her left side so that the rumen lays under and not on top of the calf. Always set the cow back up after birth to avoid bloat.
Breach births and/or uterine fatigue are often characterized by a cow that acts like she wants to calve, then stops and grazes for a while, repeating this behavior several times. Call for assistance!
Finally, note that penicillin is not a long-acting treatment. One dose of penicillin only lasts approximately six hours in the bloodstream. Longer acting, broad spectrum antibiotics are available from your veterinarian and should be used with his/her guidance.