# Calf Rearing and Colostrum Management: Best Practices for Health and Growth ## Key Takeaways - **Failure of Passive Transfer (FPT) is the primary risk factor for calf morbidity and mortality**, with calves experiencing FPT being 3-10 times more likely to become sick and 5-10 times more likely to die before weaning. - **Colostrum quality is critical and must be assessed using a Brix refractometer**, with a minimum reading of 22% indicating adequate immunoglobulin G (IgG) concentration (≥50 g/L). - **Optimal colostrum absorption occurs within the first 2-4 hours post-birth**, necessitating feeding within 2 hours and no later than 6 hours, with a target volume of 10% of body weight within the first 12 hours. - **Contamination of colostrum with bacteria, particularly coliforms, significantly impairs IgG absorption and increases disease risk**, emphasizing the need for rigorous hygiene in collection, storage, and feeding equipment. - **Serum total protein testing at 24-48 hours of age is essential to validate colostrum management efficacy**, with a threshold of ≥5.5 g/dL indicating adequate passive transfer. --- Raising healthy calves starts with the first few hours of life. The decisions you make in that narrow window determine whether a calf develops adequate immunity, grows efficiently, and stays healthy through weaning. This guide covers the complete process of calf rearing with a focus on colostrum management, including timing, quality testing, feeding methods, housing, nutrition, and health monitoring. It is written for beef and dairy producers, farm managers, and livestock workers who want practical, field-ready protocols for newborn calf care and beyond. ## At a Glance - **Colostrum timing matters more than anything else.** Feed colostrum within 2 hours of birth and no later than 6 hours. Every hour of delay increases the risk of failure of passive transfer. - **Quality is not optional.** Colostrum should test at 22 percent or higher on a Brix refractometer. Anything below that is inadequate for a newborn calf. - **Volume targets are firm.** Feed 10 percent of the calf's body weight in colostrum within the first 12 hours. A 90 pound calf needs 9 pounds or about 1 gallon. - **Cleanliness is a survival factor.** Contaminated colostrum causes disease even when antibody levels are adequate. Use clean collection equipment and sanitize feeding tubes. - **Test for passive transfer.** A blood test at 24 to 48 hours of age tells you whether your colostrum program is working. - **Colostrum is not milk.** It is a specialized product with antibodies, growth factors, and energy. Treat it accordingly. - **Keep records.** Write down birth time, colostrum source, volume fed, feeding method, and test results for every calf. - **Call your veterinarian** if you see a calf that is weak, depressed, scouring, or refusing to nurse beyond 12 hours. ## Why Colostrum Management Is the Foundation of Calf Health Calves are born with no circulating antibodies. The bovine placenta does not allow maternal antibodies to pass to the fetus during pregnancy. A calf enters the world completely dependent on colostrum for its initial immune protection. This system works well when colostrum is fed correctly, but it fails rapidly when colostrum is delayed, inadequate, or contaminated. The term failure of passive transfer (FPT) describes a calf that has not absorbed enough antibodies from colostrum to achieve protective blood levels. This is the single most important risk factor for calf disease and death in the first weeks of life. Calves with FPT are 3 to 10 times more likely to become sick and 5 to 10 times more likely to die before weaning compared to calves with adequate passive transfer. These numbers come from decades of veterinary research and field observation across many production systems. Beyond immunity, colostrum provides concentrated energy, vitamins, minerals, and growth factors that support the calf's transition from the stable uterine environment to the outside world. Colostrum is rich in fat for energy, protein for tissue building, and immunoglobulins for disease protection. It also contains maternal hormones and signaling molecules that help the digestive tract mature and prepare for digesting milk and eventually solid feed. The window for antibody absorption closes quickly. The calf's intestine is most permeable to antibodies in the first few hours after birth. This permeability declines steadily and is essentially gone by 24 hours of age. Feeding colostrum after 24 hours still provides nutritional value and some local protection in the gut, but it does not produce meaningful blood antibody levels. This is why timing is non-negotiable in colostrum management. ## Understanding Colostrum Composition and Quality Colostrum is the first secretion from the mammary gland after calving. It is not milk. Its composition differs dramatically from mature milk in ways that matter for calf survival. ### Immunoglobulins Immunoglobulins are the antibodies that provide passive immunity. The three main types in bovine colostrum are IgG, IgA, and IgM. Immunoglobulin G is the most abundant and the most important for systemic protection. It makes up about 85 to 90 percent of the total antibodies in colostrum. Immunoglobulin A protects the respiratory and digestive tracts, and IgM provides early broad-spectrum protection. High-quality colostrum contains more than 50 grams of IgG per liter. Very high quality colostrum can contain 100 grams per liter or more. Colostrum that contains less than 50 grams per liter is considered poor quality and should not be fed to newborn calves if better options exist. ### Other Components Colostrum also provides: - Fat for immediate energy, typically 6 to 7 percent - Protein for tissue growth and repair, typically 14 to 16 percent - Lactose for energy - Vitamins A, D, and E in much higher concentrations than milk - Minerals including calcium, phosphorus, and magnesium - Growth factors that stimulate intestinal development - White blood cells that provide additional immune support - Maternal hormones that signal metabolic changes These components support the calf's first critical transition. The energy density of colostrum helps the calf maintain body temperature and blood sugar levels in the first hours after birth. ### Factors That Affect Colostrum Quality Several factors influence the quality of colostrum a cow produces: - **Parity:** First calf heifers produce lower quality colostrum on average than mature cows. Quality generally improves with each lactation up to about the fourth or fifth lactation. - **Breed:** Some breeds produce higher immunoglobulin concentrations than others. Holsteins tend to produce large volumes of moderately concentrated colostrum, while beef breeds often produce smaller volumes of more concentrated colostrum. - **Dry period length:** Cows need a complete dry period of 45 to 60 days to produce high quality colostrum. Short dry periods reduce colostrum quality. - **Vaccination status:** Cows vaccinated against common calf pathogens produce colostrum with higher levels of specific antibodies against those diseases. - **Nutrition:** Cows that are well fed throughout gestation produce better quality colostrum than underfed cows. - **Time from calving:** Colostrum quality declines rapidly after calving. The first milking contains the highest concentration of antibodies. By the second milking, IgG concentration drops by half or more. - **Milking or nursing:** Cows that leak milk before calving produce lower quality colostrum. Calves that nurse slowly may not consume enough colostrum in the critical window. ### How to Assess Colostrum Quality You cannot tell colostrum quality by looking at it. Thick, yellow colostrum is not necessarily high quality. Thin, watery colostrum is not necessarily poor quality. You need to measure it. The most practical field tool is a Brix refractometer. This handheld device measures the sugar concentration in a liquid sample, which correlates well with immunoglobulin concentration in colostrum. You can find digital and analog versions at farm supply stores and through veterinary suppliers. To test colostrum: 1. Collect a small sample from the bucket or bottle you plan to feed. 2. Place a few drops on the prism surface of the refractometer. 3. Close the cover plate and look through the eyepiece. 4. Read the Brix percentage at the boundary line. A Brix reading of 22 percent or higher indicates good quality colostrum with an estimated IgG concentration of 50 grams per liter or more. A reading between 18 and 21 percent indicates moderate quality. A reading below 18 percent indicates poor quality that should not be fed to a newborn calf. If you use a colostrometer instead of a refractometer, the threshold is the same concept but the scale differs. A colostrometer measures specific gravity and is color coded. Green indicates good quality, yellow indicates moderate quality, and red indicates poor quality. Colostrometers are more fragile and temperature sensitive than refractometers. Many operations have switched to refractometers for this reason. ## Timing: The First Hours Are Critical The single most important factor in colostrum management is timing. The calf's ability to absorb antibodies across the intestinal wall declines rapidly from the moment of birth. This process is called gut closure. ### The Absorption Window At birth, the calf's intestine is open to large molecules like antibodies. This allows immunoglobulins to pass directly into the bloodstream. The efficiency of this absorption is highest in the first 2 to 4 hours after birth. By 6 hours, absorption efficiency drops to about 50 percent of the initial rate. By 12 hours, it drops further. By 24 hours, the intestine has essentially closed to antibody absorption. This means that colostrum fed at 12 hours of age provides far less systemic protection than colostrum fed at 2 hours of age, even if the volume and quality are identical. The calf may still benefit nutritionally, but the immune benefit is greatly reduced. ### Recommended Timing Protocol Feed the first colostrum meal within 2 hours of birth. This is the target for every calf, every time. If the calf is strong and can nurse, allow it to nurse the dam for up to 1 hour, but monitor closely to ensure it is actually nursing and not just searching. If the calf does not nurse effectively within 1 to 2 hours, tube feed colostrum immediately. Feed a second colostrum meal 6 to 8 hours after the first meal. This second feeding provides additional antibodies and energy. Some operations feed a third meal at 12 to 16 hours. The exact schedule matters less than the total volume and the timing of the first meal. ### What to Do With Weak or Slow Calves Some calves are slow to stand or nurse. This is common after difficult calvings, in calves born to first calf heifers, and in calves that experienced oxygen deprivation during birth. These calves need intervention, not patience. Waiting 6 to 8 hours for a weak calf to figure out nursing is waiting too long. Tube feeding is the answer for any calf that has not nursed effectively within 1 to 2 hours of birth. Esophageal tube feeding is safe, quick, and ensures the calf receives the full measured volume of colostrum. Every operation that raises calves should have a clean esophageal feeder and staff trained to use it. ## Volume: How Much Colostrum to Feed The volume of colostrum is as important as the timing. Underfeeding is a common cause of failure of passive transfer even when the colostrum quality is good. ### The 10 Percent Rule Feed colostrum at 10 percent of the calf's body weight within the first 12 hours of life. For a typical 90 pound dairy calf, that is 9 pounds of colostrum, which is about 1 gallon or 4 liters. For a 75 pound beef calf, that is 7.5 pounds or about 3.4 liters. Split this total into two feedings. Feed half within 2 hours of birth and the other half 6 to 8 hours later. This approach provides early protection and then tops up antibody levels while the gut is still open. ### Why Volume Matters A calf needs to absorb a minimum of 100 grams of IgG to achieve adequate passive transfer. If colostrum contains 50 grams of IgG per liter, the calf needs to consume at least 2 liters to reach that threshold. But absorption is not 100 percent efficient. Calves typically absorb only 30 to 50 percent of the IgG they consume. This means a calf needs to consume 3 to 4 liters of high quality colostrum to reliably achieve adequate blood antibody levels. Feeding only 2 liters of colostrum is a common mistake. It is easier to feed a smaller volume, especially to a reluctant calf, but it often results in failure of passive transfer. The volume target is not negotiable. ### Adjusting for Calf Size Larger calves need more colostrum than smaller calves. Weigh the calf if possible, or use a weight tape. If you cannot weigh the calf, estimate conservatively and err on the side of feeding more rather than less. Colostrum feeding does not have a meaningful upper limit for a newborn calf. Overfeeding colostrum is rarely a problem. ### Small Breed and Beef Calves Beef calves often nurse naturally and are not routinely tube fed. But the same volume standards apply. If a beef calf is slow to nurse, weak, or the cow has poor udder conformation, intervene with the same 10 percent volume target. Do not assume that natural nursing is always adequate. Observing the calf to confirm it is actually nursing is essential. ## Colostrum Sources and Storage You need a reliable supply of high quality colostrum. There are several options, and the best choice depends on your operation. ### Fresh Colostrum From the Dam This is the gold standard. Fresh colostrum from the calf's own dam provides the most complete protection because it contains antibodies specific to the pathogens on your farm. It is also warm, clean, and readily available. The main limitation is that you cannot control quality. First calf heifers may produce poor quality colostrum. Cows with mastitis produce contaminated colostrum. Cows that leaked before calving may have low antibody levels. ### Fresh Colostrum From Other Cows Colostrum from another cow that calved recently is an excellent option, especially if the dam's colostrum is poor quality or insufficient. Many operations maintain a colostrum bank of frozen colostrum from healthy, mature cows with good quality colostrum. Use only colostrum from cows that: - Have no history of Johne's disease or other chronic infections - Are negative for bovine leukosis virus - Have no mastitis or abnormal udder secretions - Calved normally and had a complete dry period - Produced colostrum that tested at 22 percent Brix or higher ### Frozen Colostrum Frozen colostrum is a practical way to build a reserve supply. Collect good quality colostrum from healthy cows, test it, and freeze it in 1 to 2 quart containers. Label each container with the collection date, cow ID, and Brix reading. Store frozen colostrum at 0 degrees Fahrenheit or colder. It will keep for up to 1 year. Thaw it slowly in warm water at 110 to 120 degrees Fahrenheit. Do not microwave colostrum. Microwaving destroys antibodies and creates hot spots that can burn the calf's esophagus. ### Colostrum Replacers and Supplements Commercial colostrum replacers are available from veterinary and feed suppliers. These products contain dried bovine immunoglobulins and are designed to provide passive immunity when no colostrum is available. Colostrum replacers are not equivalent to fresh colostrum. They contain less IgG per dose, lack the growth factors and white blood cells of natural colostrum, and are more expensive. They are a backup option, not a first choice. Colostrum supplements are different from replacers. Supplements contain some IgG but not enough to provide full passive transfer. They are designed to be fed in addition to natural colostrum, not instead of it. Never use a supplement as a replacement. If you must use a replacer, choose one that delivers at least 100 grams of IgG per feeding and feed the full recommended dose. Follow the manufacturer's mixing instructions exactly. ## Feeding Methods: Nursing, Bottle, and Tube The method you use to deliver colostrum matters for both effectiveness and safety. ### Natural Nursing Natural nursing is the simplest method. The calf nurses the cow and receives colostrum directly. This works well when the cow has good udder conformation, the calf is strong and vigorous, and you can confirm that nursing actually occurred. The problem with natural nursing is that you cannot measure how much colostrum the calf consumed. A calf may appear to nurse but actually consume very little. This is especially common in beef herds where calves are not closely observed in the first hours after birth. If you rely on natural nursing, observe the calf closely. Confirm that it stands, finds the udder, and nurses for several minutes. If there is any doubt, intervene with a bottle or tube feeding. ### Bottle Feeding Bottle feeding works well for calves that have a strong suckle reflex. It allows you to measure the exact volume fed and ensures the calf receives the full dose. Use a clean nipple bottle designed for calves. Hold the bottle at a 45 degree angle so the nipple stays full of colostrum. Do not let the calf suck air. Encourage the calf to nurse by placing the nipple in its mouth and allowing it to suckle at its own pace. Bottle feeding can be slow, especially for a calf that is weak or reluctant. If the calf does not finish the bottle within 15 to 20 minutes, tube feed the remainder. ### Esophageal Tube Feeding Tube feeding is the most reliable method for ensuring a calf receives the full volume of colostrum. It is indicated for: - Weak or depressed calves - Calves that do not have a strong suckle reflex - Calves that refuse to nurse from a bottle - Any calf that needs colostrum quickly and reliably To tube feed: 1. Use a clean esophageal feeder with a soft, flexible tube. 2. Measure the tube from the calf's nose to the point of the shoulder to determine the correct insertion length. 3. Restrain the calf in a standing position with its head in a normal position. 4. Open the calf's mouth and gently guide the tube over the tongue and into the esophagus. 5. Advance the tube slowly until the measured length is reached. The tube should pass down the esophagus, not into the trachea. 6. Confirm placement by feeling for the tube in the esophagus on the left side of the neck. You should feel two structures: the trachea and the esophagus with the tube in it. 7. Attach the bag or syringe and slowly release the colostrum. Allow it to flow by gravity. Do not pump it. 8. Remove the tube quickly but gently after the colostrum is delivered. If the calf coughs, chokes, or shows signs of distress, stop immediately and check tube placement. If you are unsure whether the tube is in the esophagus, remove it and start again. Tube feeding into the lungs is a fatal mistake. Clean the tube thoroughly after each use. Rinse with warm water, wash with soap, and disinfect with a sanitizing solution. A dirty tube can introduce bacteria directly into the calf's digestive system. ## Preventing Contamination Colostrum is food for the calf, but it is also a culture medium for bacteria. Contaminated colostrum is a common cause of calf scours and other diseases. ### Sources of Contamination - Dirty udders and teats - Dirty milking equipment - Unclean feeding tubes and bottles - Dirty hands - Contaminated storage containers - Colostrum that is left at room temperature for too long ### How to Keep Colostrum Clean - Milk the cow cleanly. Wash and dry the udder before collecting colostrum. - Use clean, sanitized collection equipment. - Collect colostrum into a clean bucket or bottle. - Feed colostrum within 1 hour of collection. - Refrigerate colostrum immediately if you cannot feed it within 1 hour. - Discard colostrum that has been at room temperature for more than 2 hours. - Thaw frozen colostrum in warm water, not at room temperature. - Clean and sanitize feeding tubes and bottles after every use. - Wash your hands before handling colostrum and calves. ### The Bacterial Load Problem Even good quality colostrum can be harmful if it carries a high bacterial load. Bacteria compete with antibodies for absorption in the calf's intestine. High bacterial counts reduce antibody absorption and increase the risk of scours. Research and field experience show that colostrum with high bacterial counts is associated with lower IgG absorption and higher disease rates. The target is to keep total bacterial counts below 100,000 colony forming units per milliliter and coliform counts below 10,000 per milliliter. You cannot test for this on most farms, so prevention through cleanliness is essential. ## Monitoring Passive Transfer You cannot see whether a calf has absorbed enough antibodies. You need to test. ### The Blood Test A blood test for serum total protein or IgG concentration is the standard method for evaluating passive transfer. The test is most accurate at 24 to 48 hours of age. Testing before 24 hours may show falsely low values because antibodies are still being absorbed. Testing after 48 hours is less useful because the calf's own immune system begins producing antibodies. To test: 1. Collect a blood sample from the calf using a sterile needle and tube. 2. Centrifuge the sample to separate serum. 3. Measure serum total protein using a refractometer. A serum total protein reading of 5.5 grams per deciliter or higher indicates adequate passive transfer. Readings between 5.0 and 5.4 indicate marginal transfer. Readings below 5.0 indicate failure of passive transfer. ### How to Use the Results Test a sample of calves, not just the ones you are worried about. Testing 10 to 15 calves per group gives you a picture of your colostrum program. If more than 10 to 15 percent of tested calves have inadequate passive transfer, your program needs improvement. Common problems identified by testing: - Colostrum quality is lower than expected - Calves are not nursing enough - First feeding is delayed - Feeding volumes are too low - Colostrum is contaminated - Tube feeding technique is faulty Work with your veterinarian to review results and adjust protocols. Do not ignore the results. Failure of passive transfer is a management problem, and it is correctable. ## Calf Rearing Beyond Colostrum: Housing and Environment Colostrum gets the calf started, but the rearing environment determines whether that good start leads to healthy growth. ### The Calf's Immune System After Colostrum Colostrum provides temporary protection. The antibodies the calf absorbed decline over the first weeks of life. The calf's own immune system gradually takes over, but it is not fully functional for several months. This means calves are vulnerable to disease throughout the preweaning period, especially from about 2 to 6 weeks of age. Good colostrum management reduces the severity of disease challenges, but it does not eliminate the need for a clean, low stress environment. ### Housing Options Calves can be raised in individual hutches, group pens, or on pasture. Each system has advantages and disadvantages. Individual hutches are the most common system for dairy calves. They reduce disease transmission between calves, allow individual feeding and monitoring, and keep calves clean. The downsides are labor requirements and the social isolation of calves. Group pens allow calves to socialize and often reduce labor. They require careful attention to group size, stocking density, and cleanliness. Disease can spread quickly in group housing if management is poor. Pasture rearing is common for beef calves. Calves run with their dams and nurse naturally. This works well when pastures are clean, stocking rates are appropriate, and cows have adequate nutrition. The main challenge is monitoring individual calves. ### The Calf Pen Environment Regardless of housing type, the calf pen must be: - **Clean:** Remove manure and wet bedding daily. Add fresh bedding as needed. - **Dry:** Wet bedding promotes disease and chilling. Calves need a dry place to lie down. - **Draft free but ventilated:** Calves need fresh air but not drafts. Good ventilation removes moisture, ammonia, and pathogens. - **Well drained:** Water pooling in the pen is a disease risk. - **Appropriately sized:** Calves need room to stand, lie down, and move normally. Overcrowding increases stress and disease. ### The Calf Jacket Question In cold weather, calf jackets can help calves maintain body temperature and reduce energy expenditure. They are most useful for calves under 3 weeks of age in temperatures below 50 degrees Fahrenheit. Keep jackets clean and dry. Remove them in warm weather to prevent overheating. ## Nutrition: Feeding the Growing Calf After the colostrum period, the calf's nutrition shifts to milk or milk replacer and eventually to solid feed. ### Milk or Milk Replacer Calves need about 10 to 12 percent of their body weight in milk or milk replacer daily, split into two feedings. This is a starting point. Adjust based on calf condition, growth, and environmental temperature. Whole milk is the gold standard for calf nutrition. It is highly digestible and provides balanced nutrition. The main drawbacks are cost and the risk of disease transmission if milk from sick cows is fed. Milk replacer is a practical alternative. Choose a high quality product with at least 20 percent protein and 20 percent fat. Mix according to the manufacturer's instructions. Use water at the correct temperature. Feed immediately after mixing. ### The Risk of Scours Scours, or calf diarrhea, is the most common disease of preweaned calves. It is caused by multiple pathogens including rotavirus, coronavirus, Cryptosporidium, and E. coli. Scours causes dehydration, electrolyte loss, and acidosis. Severe cases can be fatal. Prevention is the best approach. Good colostrum management, clean housing, and consistent feeding schedules reduce the risk. If a calf develops scours, continue feeding milk and provide oral electrolytes between milk feedings. Dehydrated calves need veterinary care for intravenous fluids. ### Introducing Solid Feed Calves are ruminants in development. They are born with a nonfunctional rumen that develops as they consume solid feed. Introduce calf starter grain within the first week of life. Provide fresh, palatable starter in a clean container. Calves should consume 1 to 2 pounds of starter daily by 4 weeks of age. Fresh water should be available from the first week. Water intake promotes starter consumption and rumen development. ### Weaning Wean calves when they are consuming 2 to 3 pounds of starter daily for 3 consecutive days. This usually occurs at 6 to 8 weeks of age. Weaning based on starter intake rather than age reduces weaning stress and growth setbacks. After weaning, continue feeding starter and gradually introduce forage. Calves should be eating 4 to 5 pounds of starter daily before forage is introduced in significant amounts. ## Common Mistakes in Calf Rearing Many calf rearing problems trace back to a small set of recurring mistakes. Review this list regularly to check your own practices. ### Colostrum Mistakes - **Feeding colostrum too late.** The first feeding must occur within 2 hours of birth. Waiting for the calf to nurse naturally without confirming intake is risky. - **Feeding too little.** One quart is not enough. Feed 10 percent of body weight in the first 12 hours. - **Feeding poor quality colostrum.** Untested colostrum may be inadequate. Test every batch. - **Feeding contaminated colostrum.** Dirty equipment and dirty udders introduce bacteria that cause disease. - **Feeding colostrum from the wrong cows.** Cows with Johne's disease or other chronic infections can pass disease through colostrum. - **Microwaving frozen colostrum.** This destroys antibodies and can burn the calf. - **Using colostrum supplements as replacements.** Supplements do not provide enough antibodies for passive transfer. ### Feeding Mistakes - **Inconsistent feeding times.** Calves thrive on routine. Feed at the same times every day. - **Feeding cold milk.** Milk should be at body temperature, about 100 to 105 degrees Fahrenheit. - **Feeding dirty milk.** Use clean equipment and clean milk from healthy cows. - **Skipping water.** Calves need fresh water from the first week. Water is essential for starter intake and rumen development. - **Weaning too early.** Wean based on starter intake, not age or convenience. ### Management Mistakes - **Ignoring the test results.** If passive transfer testing shows problems, change your protocol. - **Not keeping records.** Without records, you cannot identify problems or track progress. - **Overcrowding calves.** Too many calves in a pen increases disease pressure. - **Poor ventilation.** Stuffy, humid calf barns promote respiratory disease. - **Using the same equipment for sick and healthy calves.** Disinfect everything between calves. ## Decision Thresholds: When to Intervene Knowing when to act is as important as knowing what to do. Use these thresholds to guide your decisions. ### Colostrum Decisions - **Test every batch of colostrum.** If Brix is below 22 percent, do not feed it to a newborn calf. Use a higher quality source. - **If the calf has not nursed within 1 hour of birth,** intervene. Do not wait. - **If the calf is weak or depressed,** tube feed immediately. - **If the dam has mastitis or abnormal udder secretions,** do not use her colostrum. - **If you do not have good quality colostrum available,** use a colostrum replacer that delivers at least 100 grams of IgG per feeding. ### Health Decisions - **If a calf has scours and is still bright and nursing,** provide oral electrolytes and monitor closely. - **If a calf has scours and is depressed, weak, or not nursing,** call your veterinarian. - **If a calf has a fever, coughing, or nasal discharge,** isolate it and call your veterinarian. - **If a calf is bloated, straining, or showing signs of abdominal pain,** call your veterinarian immediately. - **If a calf dies,** request a necropsy to determine the cause. This information is valuable for preventing further losses. ### When to Call Your Veterinarian or Extension Agent Your veterinarian is a partner in calf health, not just a responder to emergencies. Call for: - **Any calf that is not improving within 12 to 24 hours** of supportive care - **Any calf with severe dehydration or weakness** - **Outbreaks of scours or respiratory disease** affecting multiple calves - **Blood testing for passive transfer** if you are not set up to do it yourself - **Necropsies on dead calves** to determine cause of death - **Review of your colostrum and calf rearing protocols** to identify improvement opportunities Your local cooperative extension agent can help with: - **Designing colostrum management protocols** - **Training staff on tube feeding and other techniques** - **Interpreting passive transfer test results** - **Developing recordkeeping systems** - **Planning facilities improvements** ## Recordkeeping and Monitoring You cannot manage what you do not measure. A simple recordkeeping system is essential for calf rearing success. ### What to Record for Each Calf - Calf ID and birth date - Dam ID and parity - Calving ease score - Birth weight - Time from birth to first colostrum feeding - Colostrum source and Brix reading - Volume of colostrum fed at each feeding - Feeding method (nursing, bottle, tube) - Passive transfer test result at 24 to 48 hours - Daily health observations - Treatments administered - Starter intake at weaning - Weaning weight ### How to Use the Records Review records monthly. Look for patterns: - Are calves from certain cows or heifers more likely to have poor passive transfer? - Are calves born at certain times of day getting colostrum later? - Are certain staff members achieving better results than others? - Are disease rates higher in certain pens or seasons? Use these patterns to adjust your protocols. Share the records with your veterinarian during herd health visits. ### Simple Recordkeeping Tools You do not need sophisticated software. A notebook, a whiteboard, or a simple spreadsheet works well. The key is consistency. Record the information at the time it happens, not at the end of the day when details are forgotten. Some operations use calf cards attached to each hutch. These cards travel with the calf and provide a quick reference for anyone working with that animal. ## Seasonal Considerations Calf rearing challenges vary by season. Plan accordingly. ### Winter Calving Cold weather increases the calf's energy needs. The calf must burn energy to stay warm, which reduces energy available for growth and immunity. Calves born in cold weather need: - A dry, draft free environment - Extra bedding - Calf jackets in severe cold - Higher milk or milk replacer intake - Close monitoring for hypothermia Colostrum feeding is especially critical in winter. A chilled calf absorbs antibodies less efficiently. Warm the calf before feeding if it is severely chilled. ### Summer Calving Heat stress affects calves as well as cows. Calves need: - Shade in outdoor pens - Fresh, cool water at all times - Ventilation in indoor housing - Adjusted feeding times to avoid the hottest part of the day Heat stressed calves may drink less milk. Monitor intake closely and adjust as needed. ### Spring and Fall Calving These are often the easiest seasons for calf rearing. Temperatures are moderate, and disease pressure is often lower than in extreme seasons. Use these seasons to establish good routines that carry through the challenging months. ## Biosecurity for Calves Calves are vulnerable to disease introduction from many sources. A simple biosecurity program reduces risk. ### People Anyone who works with calves should wear clean boots and clothing. Provide boot wash stations at the entrance to calf facilities. Do not allow visitors to walk through calf areas without proper precautions. ### Equipment Do not share equipment between sick and healthy calves. Clean and disinfect feeding tubes, bottles, and buckets after every use. Use separate equipment for colostrum collection and feeding. ### Animals Keep calves separated from older animals. Do not allow calves to have contact with cows that have mastitis, diarrhea, or other illnesses. Control rodents, birds, and other wildlife that can carry disease. ### Traffic Limit vehicle traffic through calf areas. Do not allow feed trucks or other vehicles to drive through areas where calves are housed if they have been on other farms. ## Economics of Calf Rearing Good calf rearing is an investment that pays returns. The costs of colostrum management are modest compared to the costs of disease, death, and slowed growth. ### The Cost of Failure A calf that dies before weaning represents a complete loss of the cow's production and the calf's potential. The cost of a dead calf includes: - The value of the calf - The cost of the dam's feed and care - The opportunity cost of the cow's reproductive cycle - The cost of treatment for sick pen mates A calf that survives but has poor passive transfer grows slower, gets sick more often, and may never reach its genetic potential. These losses are harder to measure but are real. ### The Cost of Doing It Right The costs of a good colostrum program include: - Testing equipment (a refractometer costs about 50 to 100 dollars) - Colostrum replacer for emergencies - Feeding tubes and bottles - Time for feeding and monitoring - Recordkeeping supplies These costs are small compared to the value of a healthy calf. A single calf saved from death or severe disease pays for the entire program many times over. ## Troubleshooting Common Problems Use this section to diagnose and correct common calf rearing problems. ### Problem: High Rate of Failure of Passive Transfer Possible causes: - Colostrum quality is below 22 percent Brix - First feeding is delayed beyond 2 hours - Feeding volume is below 10 percent of body weight - Colostrum is contaminated with bacteria - Tube feeding is not delivering the full volume Corrective actions: - Test all colostrum and discard poor quality batches - Review timing protocols and staff training - Increase feeding volume to 10 percent of body weight - Improve udder preparation and equipment cleaning - Verify tube placement and delivery technique ### Problem: High Rate of Scours Possible causes: - Contaminated colostrum or milk - Dirty pens and bedding - Overcrowding - Inconsistent feeding schedules - Poor passive transfer Corrective actions: - Improve cleaning and disinfection of feeding equipment - Increase bedding frequency and pen cleaning - Reduce group size - Standardize feeding times - Review colostrum management and test passive transfer ### Problem: Calves Are Slow to Grow Possible causes: - Underfeeding milk or milk replacer - Poor quality milk replacer - Low starter intake - Chronic disease or parasite burden - Cold stress Corrective actions: - Increase milk or milk replacer volume - Switch to a higher quality milk replacer - Offer fresh, palatable starter daily - Work with your veterinarian to rule out disease - Improve housing and bedding ### Problem: High Calf Mortality Possible causes: - Failure of passive transfer - Severe disease outbreak - Inadequate nutrition - Poor calving management - Environmental stress Corrective actions: - Conduct necropsies on dead calves - Review colostrum management and passive transfer results - Work with your veterinarian to identify disease causes - Review calving management, especially for heifers - Improve housing conditions ## Working With Your Veterinarian and Extension Agent Your veterinarian and extension agent are valuable resources for calf rearing. They can provide: - Herd specific recommendations based on your facilities and goals - Diagnostic testing to identify disease causes - Training for you and your staff - Review of your protocols and records - Help with difficult cases Build a relationship with these professionals before you need them in an emergency. Invite them to your farm for a calf rearing review. Share your records and ask for their input. The investment in their time is repaid in healthier calves and better outcomes. ## Frequently Asked Questions ### How soon after birth should I feed colostrum to a calf? Feed the first colostrum meal within 2 hours of birth. The calf's intestine is most efficient at absorbing antibodies in the first few hours of life. By 6 hours, absorption efficiency drops significantly, and by 24 hours it is essentially gone. Delaying the first feeding is the most common cause of failure of passive transfer. ### How can I tell if colostrum is good quality? Use a Brix refractometer. A reading of 22 percent or higher indicates good quality colostrum with adequate antibody levels. Readings between 18 and 21 percent are moderate, and readings below 18 percent are poor. Do not rely on the appearance of colostrum to judge quality. You cannot tell antibody levels by looking at it. ### What is the right amount of colostrum to feed a newborn calf? Feed 10 percent of the calf's body weight within the first 12 hours. For a 90 pound calf, that is about 1 gallon or 4 liters. Split this into two feedings, with the first half fed within 2 hours of birth and the second half 6 to 8 hours later. Underfeeding is a common mistake that leads to inadequate immunity. ### Can I use milk instead of colostrum for a newborn calf? No. Milk does not contain antibodies. A calf is born with no immune protection of its own. Colostrum provides the antibodies the calf needs to survive. Feeding milk instead of colostrum leaves the calf completely unprotected and at very high risk of disease and death. ### How do I tube feed a calf with colostrum? Measure the tube from the calf's nose to the point of the shoulder. Restrain the calf standing with its head in a normal position. Gently guide the tube over the tongue and into the esophagus. You should feel the tube in the esophagus on the left side of the neck. Attach the bag and allow the colostrum to flow by gravity. Remove the tube quickly after delivery. If the calf coughs or shows distress, stop and check placement. ### How long can I store frozen colostrum? Frozen colostrum stored at 0 degrees Fahrenheit or colder will keep for up to 1 year. Thaw it slowly in warm water at 110 to 120 degrees Fahrenheit. Do not microwave colostrum. Use a clean container and feed promptly after thawing. Label frozen colostrum with the date and quality test result. ### How do I know if my colostrum program is working? Test blood serum total protein at 24 to 48 hours of age. A reading of 5.5 grams per deciliter or higher indicates adequate passive transfer. Test a sample of 10 to 15 calves per group. If more than 10 to 15 percent of calves have inadequate levels, review and improve your colostrum protocol. ### What should I do if a calf develops scours? Continue feeding milk or milk replacer. Provide oral electrolytes between milk feedings. Monitor the calf closely for dehydration and weakness. If the calf becomes depressed, stops nursing, or does not improve within 12 to 24 hours, call your veterinarian. Severe dehydration requires intravenous fluids. ## Related Farming Guides This section will be populated with links to related farming guides covering newborn calf care, dairy herd management, [beef cattle production](/knowledge/animal-farming/beef-cattle/beef-cattle-production-systems-economics-and-sustainability), and related topics. Check back for updates. ## Related Clinical & Scientific Guides * [Animal Welfare Audits: Building a Useful Farm Program](/knowledge/animal-farming/farm-management/animal-welfare-audits-building-a-useful-farm-program) * [Total Mixed Ration (TMR) for Dairy: Mixing and Feeding Management](/knowledge/animal-farming/farm-management/total-mixed-ration-dairy-mixing-feeding) * [Feed Additives for Livestock: Probiotics, Enzymes, and More](/knowledge/animal-farming/farm-management/feed-additives-livestock-probiotics-enzymes) ## References - [USDA Farm Management](https://www.farmers.gov/) - [FAO Farm Management](https://www.fao.org/farmer-field-schools/en/) - [FAO Animal Production and Health](https://www.fao.org/animal-production/en/) - [WOAH (World Organisation for Animal Health)](https://www.woah.org/en/home/) > This article is educational and is not a substitute for veterinary diagnosis, treatment, public-health guidance, or regulatory reporting.