Normally, she takes care of the birth process. Here’s why it’s important to help when there’s trouble
Birth represents an abrupt change for the beef calf from one environment to another. One of the shortest periods in the life of the bovine, it is also the most hazardous, marking the end of gestation and the start of independent life. Calf death loss increases toward the end of gestation partly because of the dangers of birth, specifically trauma or anoxia as a result of a difficult or prolonged birth.
The common term for a difficult birth is dystocia and is the major cause of death of the newborn calf. It is also important to understand that dystocia and/or prolonged birth affects the vitality and health of the newborn calf. The calf may be born alive but doomed by unrecognized damage. This can be explained by understanding the effects of anoxia and trauma.
Anoxia is a lack of oxygen and it is a common occurrence. Most calves are born with some degree of anoxia but are able to compensate and survive. Severe anoxia can occur as a result of dystocia. When the critical oxygen supply is cut off, tissue damage occurs because anoxia causes acid to accumulate in the blood. When the blood pH falls below 6.6, the heart ceases beating.
Birth trauma describes the mechanical damage incurred during birth and adds to anoxia with the resulting hemorrhage in the brain or spinal cord. Trauma may also cause fractured ribs, ruptured livers, hemorrhaging in the joints and blood in the muscles. Trauma during birth compresses the calf. The newborn calf is already anoxic and unable to breathe due to the birth trauma--the trauma causes further anoxia and a continuation of the build up of acid in the blood, resulting in death shortly after birth.
The damage caused by trauma and anoxia is often latent and contributes to illness or death following birth, according to USDA’s Cow-Calf Health and Productivity Audit. The report revealed that the average mortality estimated from birth to weaning was 8% to 10% of all calves delivered, and 70% of those losses occur by 3 days of age. Here are the leading causes:
Therefore it is clear that the key to reducing calf death loss is to prevent dystocia and to recognize when the birthing process is prolonged or difficult and provide timely assistance.
Generalizations about when to intervene and provide assistance are of little value. Experience is necessary for making sound decisions in this matter. A case of dystocia caused by a constricted vulva requires immediate assistance and should be easy to identify.
If a fetus is presented breech or with the head turned, intense labor may never be observed. Assistance is necessary and the herdsman must pay attention to the behavior of each individual animal.
In most cases, initial assistance during parturition should be limited to regular observations of the female from a distance. Unnecessary excitement brought on by an anxious attendant often causes reduced labor efforts by the cow or heifer, causing a prolonged birth.
The result is often a stillbirth. Hard and fast rules are difficult to establish but in general when a cow has been in labor four hours without progress, an examination is warranted.
Wisdom in management of beef cattle at calving time to decrease the damage caused by dystocia is based on the following basic points. First, the attendant must be patient enough to let nature take its course and second they must be able to recognize when assistance is needed. They must apply common sense to all efforts of assistance. Every attendant should take time to observe the normal birthing process. This training will provide the experience and common sense required to successfully assist Mother Nature at calving time.
For most beef-cow herds the single most important means of increasing income is increasing the number of calves weaned and sold in relation to the number of cows in the operation. Timely assistance to detect and correct dystocia in the beef cow herd is an important step in achieving that goal.
When an animal approaches the time for giving birth, the rancher may observe several changes in its behavior and physical appearance. However, he should remember that each individual animal and each consecutive parturition may be different. Caution should be given to predicting time of arrival based upon behavioral or physical symptoms.
Animals that are approaching parturition often segregate themselves from other animals. They may go off feed and be found standing alone or walking fencelines. These animals may appear to be restless by lying down and rising again. A heifer may show signs of discomfort by kicking at her abdomen and twitching her tail. Occasionally animals show no behavioral signs until just prior to giving birth.
As the animal approaches parturition, several physical signs may be observed. Relaxation of the pelvic ligaments indicated by a raised tail head and sunken croup usually occurs 24 to 48 hours prior to parturition. In addition, the vulva may become swollen 2 to 6 times its normal size. The udder may become enlarged and tight. Occasionally the udder becomes so enlarged that it interferes with walking in high producing cows. Colostrum may leak from the teats due to distention of the udder. A whitish stringy type of mucus discharge is usually visible just prior to parturition.
The first stage of parturition is labor. While labor is a continuous process, three stages of progression can be identified. These stages are arbitrary but fairly well defined. Each animal may vary in symptoms and consistency in labor. The stages of labor are: (1) the stage of cervical dilation, (2) fetal expulsion, and (3) expulsion of fetal membranes. When three stages are slow to develop or fail to progress normally, dystocia is considered to be occurring.
This stage is characterized by relaxation of the cervix and muscles in and around the reproductive tract. Stage 1 begins when muscles in the uterus start to contract and ends when the cervix is dilated and fetal parts begin entering the birth canal. This stage normally occurs for 1 to 4 hours. However, if this stage exceeds 6 hours, dystocia may be a concern. Heifers may take longer for any stage of labor. This stage is marked by restlessness, anorexia (off feed), arched back stance, raised tail, occasional straining and irregular ruminating. Pulse and respiratory rates may increase.
This stage is characterized by uterine contractions, breaking of the allantoic sac and expulsion of the fetus. At the beginning of Stage 2, contractions occur about every 3 to 5 minutes. Almost all animals will lie down during this stage. However, during the early part of Stage 2, the cow may be standing. Once the second stage begins, the abdominal contractions develop with gradually increasing frequency and intensity until birth has occurred. The time for this second stage of birth in the cow is from ½ to 5 hours.
This stage is characterized by expulsion of the fetal membranes usually within a few hours after birth and the beginning of involution of the uterus. Complete involution of the uterus will take up to a month to occur. Contractions in the uterus continue for about 48 hours after birth of the calf. These contractions help expel fetal membranes, reduce the size of the uterus and prevent hemorrhage. Retained placenta occurs when the fetal membranes are not expelled. During Stage 3 the animal will usually arise and begin attending to the calf. The afterbirth should be removed from the area to prevent the animal from eating it and possibly choking.
Reprinted with permission from BEEF TODAY/APRIL 1998.
Written by Bill Kvasnicka, Ben Bruce and Ron Torell