Calving season is a critical time for beef producers. The events have a direct effect upon the number of live, healthy calves at birth and the ability of the dam to raise the calf. Calving management is also related to lifetime calf performance and rebreeding efficiency in the cow herd.
Management decisions really begin with bull selection and must be done well in advance of the breeding season. For example, selection decisions regarding the use of calving ease bulls or selection to produce replacement heifers requires thorough planning.
Final preparation for calving should begin several months ahead of the actual calving season. Even though the genetic hand we will play has already been dealt, there's still time to monitor the nutritional development of heifers and make certain our cows calve in satisfactory body condition.
This is also a time to prepare for other challenges that can have devastating effects at calving. Important factors that are related to a successful birth and a productive cow/calf pair include:
- The duration of normal labor.
- How and when problems are handled.
- How soon the calf receives colostrum.
- How the pair "mother-up."
Duration Of Normal Labor Labor at calving is divided into three stages. The first is characterized by uneasiness (seeking a quiet place away from the herd) and an elevated tail. The second stage is actual dilation of the cervix and starts with serious hard straining, lying down and delivery of the calf. The third stage is delivery of the placenta or "afterbirth."
First-stage labor is often a clue that we need to closely observe the dam. Second-stage labor in first-calf heifers that exhibit a normal birth (the calf's front feet and head first) often require about two hours of serious labor.
This doesn't have to be continuous, but the heifer should be observed closely to assure progress. In older cows, serious labor is generally shorter, lasting one-half to one hour.
If reasonable progress stops, assistance is indicated. This assumption is based on the fact that the beginning of serious labor is known. If we check heifers approximately every two to three hours, we can be reasonably certain. If we check them every six to eight hours or even less, the rules should probably change.
Any heifer acting abnormally for several hours should be examined for a possible malpresentation or oversized calf. Examination is not detrimental if it is performed in a quiet, sanitary manner.
Mild to moderate traction is rarely detrimental and often results in a more favorable, less stressful outcome. Leaving heifers alone when the calf's front feet and nose are clearly visible for a prolonged time adds stress, reduces calf vigor and has been associated with decreased fertility at rebreeding in first-calf heifers.
Mild to moderate traction can be defined as two adults pulling a calf together with typical obstetrical chains and handles. If a calf puller/fetal extractor is utilized, traction should not exceed 500-700 lbs. pull. Depending on the size of dam and calf, this is only slightly more pull than two adults can apply with chains and handles (400-600 lbs.).
Calf pullers can exceed 2,000 lbs. of pull and must be used with extreme caution. It should be applied intermittently during abdominal press to avoid injury or death to the calf and damage to the birth canal.
If progress during assistance isn't obvious, it's time to think of an alternative method of delivery. When a Caesarean section is necessary, the decision is best made when the outcome results in a live, vigorous calf and a healthy normal dam.
Colostrum Intake Important If a calf is assisted, it should receive colostrum immediately after delivery. Many calf deaths and disease problems are related to inadequate and/or delayed colostral intake.
Administration immediately following birth reduces the interval of time the newborn calf is highly susceptible to invasion by pathogenic organisms. It also optimizes the amount of disease fighting protein (immunoglobulin) that the calf absorbs.
There are a variety of thumb rules for how much colostrum to administer. These include:
- Feed 10% of the calf's body weight (3.2L in a 70-lb. calf),
- 20-25 ml/lb. of calf body weight (1.6L in a 70-lb. calf) or
- Feed 2L within first 12 hours of life.
"Mothering-Up" The Pair Following assistance of delivery, the pair should always be kept together quietly in a small pen until the calf is observed to suckle and the dam actively claims the calf.
Under ideal circumstances, 24 hours of penning up a pair is best before turning them out. Longer may be necessary if the calf is slow or the dam fails to claim the calf.
Failure to assist in calving at the correct time, excessive traction, failure to administer colostrum immediately and failure to properly mother up the cow/calf pair can carry serious consequences. Such conditions often result in increased calf disease, death loss, reduced performance and delayed rebreeding.