By Dayna Locitzer, DVM, Columbia Veterinary Services, Hudson, NY
I like to say that it is important to treat your heifer calves like they are princesses because they will become queens. They will become the heart of your farm and the principal drivers of farm income. While it can be complicated to hone in your systems for raising healthy heifers, there are key concepts to guide each stage of heifer development from birth to weaning. The stages that are important to differentiate are: the first 24 hours of life, under two weeks old, two weeks to pre-weaning, and weaning. Each of these periods have unique characteristics that require special attention that, if you are aware of, you can tailor your infrastructure to accommodate.
The first 24 hours after birth may be the most important period of a calf’s life. This is when their body is most porous, which serves a vital function but also poses a high risk. When a calf is first born, it is the only time that their intestinal tract will absorb large particles. This is because they must absorb antibodies from colostrum which provide them with an immune system before they are able to build their own. As the hours go by, the calf’s gut becomes less porous. Knowledge of this feature of a calf’s gastrointestinal tract is important for two reasons. First, it is imperative that calves get colostrum as soon as possible. A good rule of thumb is 4 L of colostrum within 4 hours of life. If they do not receive colostrum in the appropriate time frame, their immune system will have no protection against outside pathogens.
The second reason is because not only can colostrum be absorbed, but bacteria and viruses can as well. This puts the calf at risk of contracting severe disease at an early age. In fact, if the calf swallows something other than colostrum, the gut will start to close up faster as a protection mechanism. This means it is vital to keep the maternity pen clean in order to prevent the calf from getting a mouthful of manure instead of colostrum. Keeping the maternity pen clean is also important because the umbilical cord is also very porous and is an efficient avenue for bacteria to get into the bloodstream in those first 24 hours. Calf navels should be dipped with a strong iodine solution at least every 8 hours for the first 24 hours to help prevent bacterial infection and sepsis via the umbilical cord.
Ok, they have made it past day one, now what? While day one might be the most important, they are still considered neonates until two weeks old and there are critical things to keep in mind during that time. During their first two weeks, calves should get increasingly more milk as they grow. Calves should be getting AT LEAST 10% of their body weight in milk every day. Neonates are particularly susceptible to certain diseases, including pneumonia and diarrhea. Providing young calves with more milk has been proven to help combat disease pressure better than any antibiotic.
While you are building up calves’ immune systems by feeding adequate quantities of high-quality milk, it is vital that you minimize their exposure to pathogens. This means providing your calves with a clean place to live and ample ventilation. Make sure to regularly clean out their pens and provide them with fresh bedding. Do your best to make sure the pathogens that may be present from the previous calf in that pen don’t contaminate the environment of the new calf. After a calf is weaned, the pen she was in should be deep-cleaned and allowed time to rest before the next calf moves in. If you are group housing calves, consider raising groups in an “all-in, all-out” manner rather than continually adding and removing calves from a pen.
Ventilation is important to consider in both the summer and winter. Summer is easy: windows and walls can be opened, calves can be outside, and fans can be blowing. In the winter months, make sure to have systems in place for adequate ventilation. Stagnant air holds pathogens and particulate matter that can not only irritate a calf’s respiratory tract but also infect her with disease. If you don’t have indoor calf housing with adequate ventilation, set up calf hutches outside and use calf blankets. Calves can tolerate cold better than they can tolerate stagnant air.
Once calves have passed the neonate stage, they are a little more hardy. This is a time when their immune system starts to work on its own and they are more resilient. This time of their life should be focused on growing; they should be growing 1-2 lbs per day. In order for them to accomplish this, they need to be fed adequate milk. By two weeks of age, calves should be getting a gallon of milk twice daily. Jersey calves will need a little less, and large Holstein calves will need more. In the wintertime, when calves need to expend more energy to keep warm, you could increase their milk by adding a 3rd feeding in a day.
Calves will also need calf grain, high-quality hay, and free-choice access to clean water. The hay provided should have roughage with a balance of green leafy material. Roughage is a crucial element because it will help with rumen development. As calves get older they will start to get more energy from grains and forages and will be less dependent on milk. So the supplemental feed you provide them becomes crucial.
As they approach weaning, their milk can be reduced and grain increased, both gradually. At weaning, calves should be eating 3-5 lbs of a calf-specific grain daily. It is important to recognize that whole milk is about 28% fat and 25% protein (% dry matter). As calves’ milk intake is reduced, they must be provided with high-quality forages and grains to make up for the reduction in the high fat and protein milk of their previous ration. Calf grains usually have 20% protein, likely much higher than your dairy grain. These age specific grains also have targeted vitamin and mineral content geared towards that life stage. Providing a high plane of nutrition is vital in order to meet growth demands.
Weaning age is dependent on your farm’s system. Conventionally, calves can be successfully weaned onto a diet of grain and hay at about two months old. If their diet is more heavily reliant on forages, like on organic farms, it might be helpful to delay weaning to three months. If you are raising your calves as certified grass-fed, they should not be weaned before four months old. Pre-weaned calves are not ruminating yet. This means that, unlike adult cows, they are not able to convert forages into energy and will require more direct energy inputs. The rumen fully develops between four and six months old. If calves are weaned and not provided with grain, they need to be able to efficiently convert forages into energy. This means a grass-fed calf or a calf fed minimal grain should be weaned later to give their rumen a chance to develop more fully.
The principles of raising healthy calves are the same as most other animals: provide them with a clean and comfortable place to live and nutritious, age-appropriate food. These principles will provide you with good guidelines for preventative care in order to stave off disease. Raising heifers is an investment in the future of your farm. Improving your systems might cost money, but it will pay you back with healthy cows. As the saying goes, happy cows make more milk, and I would add healthy calves make happy cows.
Dr. Dayna Locitzer has over 10 years of experience working with pasture-based dairies in the Northeast. She worked on organic dairy farms in the Hudson Valley of New York for six years before starting vet school. After veterinary school, Dr. Locitzer spent four years in the Brattleboro, Vermont area serving the small dairies in that region. She recently moved back to the Hudson Valley to join Columbia Veterinary Services in Hudson, NY where she works exclusively as a farm animal veterinarian.
Posted: to Organic Production on Sun, Nov 3, 2024
Updated: Thu, Nov 7, 2024
