The Cow-Calf Manager:
Extra Attention at Calving-- It's so Important
Livestock Update, February 2000
John Hall, Extension Animal Scientist, Beef, Virginia Tech
Calving season is upon us! The weather in early January was an unexpected gift for winter calving herds, but late January was a different story. No matter when you calve, it's still important to pay extra attention to cows at calving time. Most of you have probably heard us say the rule of seeing cows at least twice a day and heifers four times a day during calving. Why is it so important to see cattle that often?
Labor is over sooner than you think
Labor and delivery usually lasts less than 8 hours. Labor is divided into three stages with all three stages only lasting 6-12 hours. Cows and heifers can attempt to calve and fail in the time it takes us to perform our off farm job or other tasks around the farm. Tasks like planting and harvest often occupy 10-12 hours of the day. Understanding the stages of labor will help you in making decisions on assisting during delivery. Table 1 details the three stages of labor.
The first stage of labor we'll call the Preparation stage. During this stage contractions begin, but they are mild and spaced fairly far apart. The contractions become more coordinated and stronger as the first stage progresses. The primary purpose of the first stage is to force the calf and fetal membranes toward the birth canal and dilate the cervix. Cows and heifers will often appear nervous and isolate themselves from the rest of the cowherd during this stage. These expectant dams can often be observed lying down and getting up often. They are obviously uncomfortable. The preparation stage ends with the emergence (and sometimes breaking) of the fetal membranes or "water bag". This stage will last 2 to 6 hours.
The second stage of labor is Delivery or "hard labor." During this stage contractions are strong and coordinated. The fetal membranes and then the calf are forced into the cervix or birth canal. During this stage cows and heifers will often lie on their side and will be visibly straining. Calves are born with the dam either lying or standing. Normal presentation is the front feet first with the head between the knees and shoulders. Any other presentation is a signal that assistance is needed. It is not unusual for the feet to appear and disappear several times during the early part of delivery. However, definite progress towards delivery should be made within 1/2 hour from appearance of the feet or cows should be checked. The second stage ends with the delivery of the calf. Normally this stage should last 1 to 2 hours in heifers and 1/2 to 1.5 hours in cows. If the second stage lasts longer than 2-3 hours cows should be checked.
The final stage of labor is cleaning or passing of the after birth. The continued contractions of the uterus expel the remaining fetal membranes. The third stage of labor lasts 1 to 8 hours. Cows not cleaning within 12 hours of birth of the calf are considered to have retained placenta. Cows with retained placenta should be treated with antibiotics as suggested by your veterinarian.
Table 1. Stages of Calving
|Stage and time||Events|
(2 to 6 hours)
|1.Calf rotates to upright position.|
2.Uterine contractions begin.
3.Water sac expelled
(1 hour or less)
|1.Cow usually tying down.
2.Fetus enters birth canal. |
3.Front feet and head protrude first.
4.Calf delivery completed.
(2 to 8 hours)
|1.caruncle-cotyledon (button) attachments relax. |
2.Uterine contractions expel membranes.
Total impact of calving difficulty greater than imagined
Incidence of calving problems. In most herds that choose moderate to low birth weight EPD bulls for their cows, calving problems (dystocia) run about 1 to 5 %. However, in first-calf heifers, dystocia runs 5 to 20% even in herds that use low birth weight EPD bulls. Incidence of dystocia in herds that don't pay attention to birth weight EPD's of sires can run as high as 50 to 75%. That's why heifers need extra observation. In addition, heifers don't necessarily give as good an indication that they are beginning the calving process.
Calves that experience calving difficulty are less healthy. Delays during delivery cause calves to be more susceptible to illness or death shortly after birth. Researchers from Nebraska and Colorado indicated that mortality is increased by 15 to 30% in calves that experience calving difficulty. In addition, calves will take longer to get up and nurse if they experience a difficult birth.
Calves need to nurse within 4 hours of birth. In order for calves to absorb antibodies from colostrum, they need to nurse within 12 hours of birth. However, research from Colorado State demonstrated that calves that nurse within 4 hours of birth have higher antibody levels and a lower incidence of scours and respiratory disease. In addition, calves that get sick early in life have lower weaning weights and decreased performance in the feedlot. So calves need to be checked to insure they have nursed.
Cows and heifers that experience calving difficulty will be delayed in rebreeding. Two studies with 220 cows in Montana examined the effects of assisting cows at the first sign of calving problems with letting cows struggle before assisting. In these studies, calf growth rate was not effected by duration of labor. However, cows and heifers, that were assisted early, bred back earlier (Table 2.). In addition, overall pregnancy rates were decreased by 13-14 % percent by allowing cows to struggle.
Table 2. Effects of duration of labor on subsequent reproduction and calf growth
|Duration of Labor||No. Cows||Services per conception||Pregnancy rate||Calf gain Birth to weaning|
|Short||117||1.15||91.4 %||1.68 lbs/day|
|Prolonged||103||1.24||77.7 %||1.75 lbs/day|
Hints for easier calving checks and calving assistance