How successful a milking herd is in the future begins with the health of calves being born today. By providing proper nutrition and management, a calf’s gut microbiome and immune system can get off to a good start and help production, performance, and ultimately a dairy’s bottom line.
Quality nutrition and proactive management are vital from day one. Establishing a healthy gut microbiome from birth can have a lasting impact on a calf’s life. Providing high-quality colostrum is critical as it helps develop a calf’s microbiome and is an essential part in keeping them healthy. At birth, a calf’s microbiome is immature. Colostrum helps develop it, protecting the gut lining and helping shape the immune system. A good starting point for evaluating the effectiveness of the colostrum program is measuring serum total proteins in the blood of calves. Improved passive transfer results in healthier calves. However, according to the 2007 National Animal Health Monitoring System survey, approximately 19% of dairy heifer calves in the US had failure of passive transfer. To provide successful passive transfer of immunity, feed high quality colostrum promptly after birth – within 1-2 hours – and minimize bacterial contamination of colostrum by proper udder preparation, collecting colostrum in a clean container, and following other sanitation best practices. Colostrum management is the single most important management factor in determining calf health and survival.
Why establishing a healthy microbiome is critical.
The rumen and intestine microbiomes contribute to most of a dairy animal’s functions. They play a key role in the digestion of nutrients, education of the immune system, function of gut epithelium, and setting up a proper gut environment. Members of the gut microbiome also produce a range of metabolites that impact the function of distant organs such as the lungs, liver, udder, and reproductive system. Therefore, establishing proper rumen and intestine microbiomes early in life, and supporting their populations throughout different stages of life, is pivotal for the long-term health and production efficiency of dairy calves and cows.
What factors affect establishment of the gut microbiome?
Microbial colonization of the rumen and intestines starts during and after birth. Microbes from the vaginal tract and cow environment are among the first colonizers followed by those introduced by colostrum, milk, and liquid or solid feed. Among these, colostrum and milk microbiota perhaps play a more important role in intestinal microbiome development than that of the rumen. During the first several weeks of a calf’s life, microbiomes of the rumen and hindgut are changing quickly from one composition to the next. The first group of colonizers change the gut environment in a way that promotes the growth of a certain group of secondary colonizers, and so on. Their adequate abundance maximizes calf growth and immune efficiency and promotes robustness and resilience of the microbiome against stressors and infectious agents.
How can we impact microbiome development?
Calf nutrition and management strategies can play a critical role in setting up the proper rumen and intestine microbiomes for life. These strategies start with timely feeding of colostrum. Research at University of Alberta showed that delaying first colostrum feeding by 12 hours tends to decrease Bifidobacterium spp. and Lactobacillus spp., compared to calves fed colostrum immediately after birth. Other strategies during the pre-weaning stage, such as feeding liquid calf diets fortified with probiotics and postbiotics, can improve proper colonization of the calf microbiome, help prevent microbial imbalance, and reduce incidence of infectious diseases.
Low rumen pH at weaning accompanied by an imbalance of rumen and intestine microbiomes can compromise epithelial barrier function and result in leaky gut. As a result, a weaning strategy that includes postbiotic supplementation can provide influential members of microbial community a competitive edge over opportunistic and pathogenic microorganisms. This prevents excessive growth of those species and helps maintain the diversity and balance of the rumen and intestinal microbial communities. The outcome is a controlled fermentation and improved rumen and hindgut environment. All together, these strategies can minimize weaning-associated feed intake depression, improve calf growth, and reduce susceptibility of calves to infectious diseases within and outside of the gut.
Sufficient nutrition and management early in life not only improve performance, health, and the wellbeing of young calves, and can also allow them to express their genetic potential for milk production and longevity. We need to recognize these effects and capitalize on them through our animal management and feeding practices. Through genetic selection in our breeding programs, we might achieve 150-300 lbs. of milk production improvement per lactation. Striving for continued genetic improvement is important, but it’s key to remember that, as managers, we can have a significantly greater impact on lifetime performance.
Lifetime performance is influenced by early life development. Dairy producers can manipulate the early life of a calf through nutrition. Ensuring a productive cow in the future will depend on feeding and managing the calf of today.