Normal calving in the Highland cow is simple and easy, but despite the reputation of the breed for ease in calving, small calves, and excellent mothering, problems can, and do arise.
Gestation in the Highland is going to usually run about 280-285 days from the breeding date. If you are lucky enough to catch the cow in heat and see her bred, that date should be recorded, as it can aid in predicting when the cow will actually calve. Bear in mind that some individuals will carry their calves for considerable shorter, or considerably longer periods of time, and still be healthy and normal. Known gestation lengths of 270 to 292 days have been reported on the same farm. The bigger risk will be in those cows that carry their calves for the longer time period. Calves add 1 to 2 pounds of weight per day during the last 2 weeks of pregnancy, so that longer gestation periods result in larger calves. Carried to the extreme, this can lead to oversized calves for the cow. The cow is not the only contributing factor to gestation length. The bull also can contribute genetics for either shorter or longer gestation lengths. Thus, some bulls will routinely produce larger calves than the norm in many of the cows to which they are bred, while others will produce smaller calves because of a shorter gestation length. Large calves do not, in and of themselves, cause any problems unless they are too large for their dam, however heavy birth weights do account for most of the problems related to calving difficulty caused by calf effects. Birth weights are affected by the breed of the sire, individual bull within a breed, sex of the calf (bull calves tend to gestate for a longer period,) the age of the cow (calf size increases with the age of the cow) and nutrition of the cow. Sometimes the shape of the calf may have an effect on calving problems. (Large shoulders or hips may be two critical areas, and help explain why even normal lighter weights in bull calves may still be associated with dystocia.
The cow herself can contribute to calving problems not only through her contribution to calf size, but to her maturity. First calf heifers are generally smaller in size than mature cows, and their pelvic area increases in size as the cow approaches maturity. Calving difficulty is more likely to be seen in 2 and 3 year cows with a smaller pelvic area. This pelvic area will increase as the cow ages, and difficulty calving as a heifer does not necessarily indicate a lifetime of calving problems.
Pelvic area also varies by individual, so there will be members of a breed that in fact do have smaller pelvic areas than the average. Measurements of pelvic area can be used to make culling decisions, but only when compared between similar aged animals.
Calf position at birth needs to be normal; and about 5% of calves will be in an abnormal position. If you are unlucky enough to have one of these calves, it will be a problem and assistance must be given to the cow in order to save her and hopefully the calf as well.
Helping yourself find the cow that is due to calve:
1. Move cows due to calve to a special calving pasture. The pasture should be easily seen from a road, lane or house, and should provide good footing for a newborn calf. Slippery, muddy conditions may prevent the calf from getting to its feet and delay colostrum consumption. If the calf thrashes around in slick mud, it makes that much more work for the cow in cleaning off the calf. All that highland hair is a liability to the newborn calf until it is dry.
2. Fence cows out of woods and timber, but leave windbreaks.
3 .Have some area available that is a special calving assistance pen or barn.
4 .Keep all calving equipment in a clean plastic container with a cover, that can be easily moved to a truck or calving area.
5. Train your spouse, children and neighbors, if necessary, to look for signs of labor. Check cows in early afternoon.
6. Count cows at feeding time and check for missing cows.
7. Get a calving video and watch it. Know when and how to assist in labor.
8. Never leave a cow that has started labor to go to bed or work. Cows is active labor should be observed every hour.
Impending parturition has several indicators. Udder development is one of the earliest signs of impending parturition, but it is not reliable to predict actually timing of calving. Heifers can show enlargement of the udder as early as 4 months of pregnancy. Cows generally don’t show enlargement until considerably closer to calving, many times in the neighborhood of 2-3 weeks prior. Still other cows may bag up literally days prior to calving.
The most accurate signs indicating close onset of labor is the changes occurring in the pelvic ligaments. The croup ligaments and muscles sink, the caudal border of the sacro-sciatic ligament between the tailbones and the pin bones becomes less cordlike and tight, and more flaccid and relaxed. As a result, the tailhead will become slightly raised and the entire area around the tailhead and vulva will be soft and flabby. Calving will usually commence within 24-48 hours.
Normal calving can be divided into 3 general stages.
Stage 1 Preparation for calving takes approximately 2-6 hours, although this can vary considerably between breeds and individuals within the breed. During pregnancy, the calf has been on its back. Just prior to labor, the calf rotates to an upright position with its head and front legs pointed toward the birth canal. This position provides the least resistance during birth. Cows and heifers will often appear nervous and wander away from the main cow herd during this stage. Often they can be seen lying down and getting back up often. They are obviously uncomfortable. The sac comprising the chorioallantois breaks as it presses against the cervix and forces its complete dilation. The uterus begins contractions.
At this point Stage 2 Delivery starts. This usually will take 1-2 hours, sometimes longer in a heifer. The amnionic water sac pushes through the cervix and the fetus enters the birth canal, usually with the cow lying down, although occasionally a cow may stand during delivery. Often the animal will lie on its side and will be visibly straining. This water sac may appear at the vulva as a distended translucent membrane. The two forelegs (actually the hooves) should be the first thing you will see of the calf itself. Many times the feet will appear and disappear several time during the early part of delivery. Once the feet have made their appearance at the vulva of the cow, definite progress should be noted within 30 minutes, or the cow should be checked. The head should be resting between the legs just inside the vulva at this point. When the nose is exposed at the opening of the vulva, the cow will commence maximal straining to pass the shoulders and chest through the pelvis. Once the head is clear of the vulva, the cow may rest for several minutes before she begins maximal contractions again. At this point complete expulsion of the calf is rapid. Once the hips pass through he pelvis of the cow, the umbilical cord will break and respiration generally begins. Once the calf’s nose is outside the vulva, it can start respiration, although its ability to inflate the lungs are limited by the confines of the vaginal walls. Occasionally the hips and legs will remain inside the birth canal until the calf or the cow moves. Delivery generally occurs within 1 hour or less in mature cows. First calf heifers can take 1-2 hours for normal delivery. Assistance is warranted if any labor goes beyond 2-3 hours.
Stage 3 of parturition is the passing of the placenta (afterbirth.) This usually occurs within 2 to 8 hours. The button attachments (cotyledons) that attach the placenta to the uterus relax and then uterine contractions expel the placenta. If the placenta is retained past 24 hours, consultation with a veterinarian is indicated. Often, no treatment is necessary, however any cow that is sick, off feed or running a fever should be examined by a veterinarian. Artificial induction of labor may also be associated with a retained placenta. If your herd suffers from high rates of retained placenta, the diet ration should be checked for protein and energy values. Likewise, some mineral deficiencies, such as selenium, can contribute to the abnormally long retention of the afterbirth.