Neonatal Calf Health Issues
By R. G. Helman, DVM, MA, PhD and Jessie Monday, DVM, MS
With over 800,000 tests run annually, TVMDL encounters many challenging cases. Our case study series will highlight these interesting cases to increase awareness among veterinary and diagnostic communities.
This winter, the Texas A&M Veterinary Medical Diagnostic Laboratory (TVMD)L has seen a number of submissions in newborn calves described as “weak”, “dummy”, “maladjusted”, and “poor doer”. Most commonly, these animals are born alive but lack normal vigor and die within the first week of life. Postmortem exam and ancillary diagnostic testing has shown vitamin and trace mineral deficiencies in many of these calves including vitamin A, selenium, and copper deficiencies.
Nutrient deficiencies in newborn calves are a reflection of maternal health status and nutrition. Cows that go into pregnancy in poorer body condition with less than optimal nutrition are simply not able to supply the developing calf with the necessary levels of nutrients to prepare for life outside of the uterus. Some cows may even have stillborn calves due to inadequate or unbalanced dam nutrition during late gestation.
Approximately 80% of fetal growth occurs in the last 2 months of gestation. The dam needs adequate protein, energy, minerals and vitamins during this time to maintain her health, provide for this accelerated fetal development, and allow the calf to store reserves that will allow it to adapt to neonatal life, stand, and nurse. Cold weather will increase the cow’s need for adequate nutrition even more. Heifers are more prone to producing weak or maladjusted calves if they do not receive enough nutritional support in late gestation.
Problems with nutrient deficiencies can vary from poor musculoskeletal development, decreased immune competence, decreased vigor, decreased thermal heat production, increased time to standing and weakness. Calves born from cows that did not have adequate protein and energy in late gestation will not have the brown fat stores needed to support the calf until adequate colostrum and milk are ingested. Such calves do not nurse as well as healthy calves and there is evidence that such affected “weak” calves have less that optimal digestion resulting in poor assimilation of maternal nutrients and antibodies in the critical early days of life. As a result, calves so affected have an increased susceptibility to a variety of diseases (pneumonia, enteric disorders, joint and naval infections) as well as being less able to withstand the stresses associated with severe weather. Evaluation of the nutritional status in an animal or feed is routinely performed at TVMDL. In the deceased animal, fresh chilled liver is the preferred sample for trace mineral and vitamin analysis. In living animals, liver biopsy or serum are the samples of choice for trace minerals and vitamins. Serum can be sent on groups of 10 animals for metabolic profiling to investigate protein deficiencies and energy malnutrition. The ruminant energy profile can be used to investigate negative energy balance in individual animals.
Of course, there may be another underlying health problem such as in utero infection with BVD, leptospirosis, or other pathogens. Infectious causes of weak neonatal calves can be evaluated via selected testing to include one or more of the following tests routinely performed at TVMDL – bacterial culture, serology, PCR, virus isolation, and histopathology.
Neonatal calf health issues can be complex and besides infectious disease or nutritional problems, may involve deficiencies in herd management. For this reason, please take advantage of TVMDL’s Veterinary Services for consultation on disease and management related conditions. In the area of livestock, Dr. Guy Sheppard at the College Station laboratory and Dr. Jessie Monday at the Amarillo laboratory are available to discuss these issues and provide feedback on your disease or nutritional problem and the best program for diagnostic confirmation. Please call 1.888.646.5623 for the College Station lab or 1.888.646.5624 for the Amarillo lab.
For more information on TVMDL’s services or test offerings, visit tvmdl.tamu.edu.