By Cassie Yost
While the new COVID-19 wreaks havoc across the globe, we are being introduced to the concept of “social distancing.” We are encouraged to stay at least 6 feet away from others, practice good hygiene, isolate sick patients, and utilize14-day self-quarantines if exposure has occurred. To farmers and producers across the country, these are not new concepts. These practices, along with many others are daily occurrences on dairy farms. These precautions are followed for the safety of farmers, employees, the animals, and the surrounding community as part of biosecurity protocols that are practiced daily. So while the rest of the world may be learning of the importance of such actions, realize that these extensive measures are also what dairy farmers comply with on a daily basis for the success of their farms and operations as well as the safety of the products they are producing and you, the consumer.
Separating calves from their mothers at birth is a farming practice that is sometimes questioned and criticized. However, this separation is not only beneficial for the dam, but the calf also. Let’s focus on the mother, the dam. Detailed records are kept on every cow on a dairy farm, and date of insemination, is one of them. Each cow is checked by the veterinarian to confirm if she is pregnant or not. From date of insemination, a cow’s gestation cycle is similar to that of a human, approximately 9 months. Famers must keep record of this to know when to separate the cow from the milking herd and let her rest for the last 2 months of her pregnancy. This practice, known as dry-off, means the cow is no longer producing milk and she can devote all of her nutrients and energy to her calf and also reviving her own mammary system. At this point, the dam is separated from the rest of the herd and grouped with other pregnant cows that are in a similar stage of gestation. This is done for a number of reasons, including protecting the cow and her developing calf, providing a diet specifically created to meet her nutritional needs, limiting stress on the cow, and allowing farmers to watch her closely when calving is imminent.
Once a cow has freshened, or given birth, both cow and calf are removed from the freshening pen so they can receive specialized care. The dam is closely monitored for any post-partum complications and will be milked individually to collect the colostrum that will be fed to her calf, a practice that is vital to the health and immunity of the newborn. Unlike in humans, a cow’s antibodies cannot cross the placenta to her developing calf. Therefore, all calves are born with no immunity of their own, making them very vulnerable to disease. Cows pass immunity to calves through colostrum, a type of milk produced at calving that is rich in antibodies and nutrients. Calves must receive 4 quarts of good quality colostrum in the first few hours of life to achieve passive transfer of immunity, meaning the immune status of their mother. When calves are left with the dam to suckle on their own, farmers cannot be sure how much colostrum, if any is being consumed. This will have detrimental impacts on the health of the calf. The cow may also suffer mastitis complications if her newly supplied milk flow is not adequately milked out. Once a newly freshened cow has gone through a few milkings where her milk is withheld from the milk that is sold to consumers and fed to calves, she is then returned to the milking herd.
While the mother is transitioning back to her daily routine, her calf is moved into an individual pen, a sort of social distancing for that calf. Because of the low level of immunity, calves are kept separate from each other to avoid any cross-contamination of diseases and viruses; sound familiar to the current headlines? Calves can be closely monitored, fed a specific diet, watched for sickness, and cared for on an individual basis. If a calf receives good quality colostrum, she will have a peak of immune response that will protect her until her own natural immune response starts to develop, around 3 weeks of age. The following graph illustrates the immune level of a calf if she has received adequate colostrum early in life.
(Chart source: Penn State)
As illustrated in the chart, a calf experiences a very critical or high-risk period in her immune function where her passive immunity is diminishing, and her own active immunity is developing in her system. Because the calves are isolated from their herd mates and their dams, this time period can be properly managed with the right nutrition, adequate bedding, proper ventilation, and vaccines recommended from a veterinarian. Proper management and care are what sets a calf up for her future health and productivity in any herd.
As a calf gets older, she is gradually weaned off of milk and is ready to move onto the next stage of her socialization process. She will be moved out of her individual pen and grouped into a small group setting with other calves her age. Think of this stage as a kindergarten student attending school for the first time, and all of the sickness that can come along with it. Just like little kids, these newly grouped calves will be exposed to anything that their herdmates may have been harboring. Like COVID-19, if calves have been introduced to a virus, their symptoms will start to appear within a few days. As with viruses, exposure can be occurring without visible signs of infection, a calf that may be newly infected, can be passing it to her herdmates unknown to the farmers caring for them. Farmers can minimize these risks to their animals by following proper vaccination schedules, management practices, and biosecurity plans on their farms. Funny how all of this sounds very familiar lately!
Socialization of calves can be a smooth process if managed properly. Problems are also minimized when farmers have a closed herd. However, there are occasions where farms buy calves, heifers, or older cows from other farms or auction barns. When farms purchase outside animals, they have no idea what diseases or viruses may come with that animal. Therefore, those animals need to be isolated from the rest of the herd and quarantined for a specific amount of time, usually 14 days. They must be housed where they cannot come into contact with other animals either through direct contact of through airborne contamination. Animals can spread diseases and viruses through their saliva and other bodily secretions. They must not share water sources or eat from common areas where the disease can be spread. It is also important for the farmers and employees that are working with the quarantined animals to also practice good hygiene. They sanitize boots and clothes to avoid disease transfer to healthy animals and work with sick or quarantined animals last. Farmers assume that quarantined animals MAY be sick and take every precaution to avoid spreading it to the rest of the herd. Crazy how this is what is being preached to us everyday thorough the media!
None of this information is to belittle the current status of COVID-19. This is a serious situation in which we all must practice extra care and follow the current recommendations. However, when this has calmed down and the world around us resumes its normal routine, let us not forget the farmers who continue to implement these precautions each and every day. They maintain these routines for their own personal safety, the safety of their animals and farms, and for the consumer so that you are provided with the safest and highest quality product possible.
Source : psu.edu