For most of us, calving season is just around the corner. In the craziness of this time period, don't forget the importance of colostrum for the future performance of calves. This is a busy time as producers continue to feed, fix fence, manage the crazy winter weather and grind away at their winter to-do lists. In the midst of all this, sometimes simply getting a calf born alive is a huge success! Adequate colostrum intake within the first 24 hours of life can play a huge role in future health and performance of calves.
The definition of colostrum is the first milk extracted from the mammary gland within 24 hours of birth. During the first day of life, the gut of the baby calf can absorb a unique set of immunoglobulins or large proteins that provide passive transfer of immunity from the cow. The clock starts ticking at birth as the absorptive capacity of these proteins is reduced over time. The gut of a baby calf will have 66% absorptive capacity to these proteins 6 hours after birth, 50% at 12 hours and intestinal closure is finalized 24 hours post birth. In reality, most absorption occurs within 12 hours of birth solidifying the importance of a strong lively calf that is motivated to nurse.
The passive transfer of maternal antibodies through the colostrum will provide a calf with exclusive immunity to diseases that may be encountered later in life. In fact, research from the USDA Experiment Station in Clay Center, Nebraska demonstrated that colostrum may be the key to lifelong health in calves. In this particular study, blood samples were obtained from 263 calves 24 hours after birth to determine colostrum intake reflected by passive transfer of maternal antibodies. Growth performance and health were monitored on these calves through weaning and into the feeding period.
Data from this study established that calves with inadequate maternal antibodies were 6.4 times more likely to be sick in the first 28 days of life as compared to calves that received adequate colostrum. In fact, the risk of death before weaning was 5.4 times greater in calves with poor transfer of immunity. In addition, inadequate colostrum reduced expected weaning weights by 35 pounds and the risk of being sick at the feedlot tripled. This study is a great illustration that passive transfer of immunity is a very important factor of calf health and performance before weaning and into the feeding period.
So, what can be done to improve colostrum intake and chances of a healthy calf crop? Many factors of immune transfer are impacted by the cow. Genetics of the cow may influence the quality and quantity of colostrum that is produced. However, tangible factors of cow age, body condition, and udder structure can be more easily addressed by the producer. Mature cows will produce more colostrum compared to a first calf heifer and additional protection may be provided in these older cows due to their exposure to disease and vaccinations. As one would expect, cows in lower body condition and poor health will produced lower quality colostrum for their calves. Udder shape and size can also prevent sufficient colostrum intake. Large teats or a pendulous bag can prevent a new calf from locating the teat and nursing in a timely manner.
Stress is also a crucial player in the timing of colostrum consumption and many factors of stress can cause calves to be sluggish at birth. Long and difficult deliveries, inclement weather, and separation from the cow can hinder intake. In these situations, stress can reduce the absorptive capacity of the intestinal wall even if high quality colostrum is available.
In the event that a calf may not have received adequate colostrum, consider having frozen or replacement colostrum on hand. Keep a tube and bottle in your calving kit for the situation when calling a vet or making a trip to town is not possible. Always thaw frozen colostrum slowly and read label directions on colostrum supplements. Sources recommend providing 5-6% of the calf's body weight in colostrum within the first 6 hours and follow with another feeding at 12 hours. Consult your veterinarian for colostrum guidance and assistance choosing the best supplemental colostrum product.