Relevance of nutritional metabolites to modulate the gastrointestinal microbiota in calves
The successful rearing of calves requires quality colostrum, cleanliness of their environment, their comfort, well-balanced rations, adequate dry matter intake, and consistency. Colostrum failure can be due to several reasons including, but not limited to, colostrum contamination, poor quality colostrum, improper storage and/or thawing of colostrum, not enough colostrum, colostrum not offered within the first 6 hours after birth, and heat stress. Any combination of these factors can lead to failure of passive transfer, which, in turn, can cause poor performance, poor feed efficiency, and poor health.
Rapid development of the rumen in a calf is a key to transitioning it from a monogastric to a ruminant. Establishment of bacteria in the rumen allows for production of volatile fatty acids, specifically propionate and butyrate, which promote the growth of rumen papillae increasing the absorptive ability of the tissue. The primary driver in rumen development is the intake of fermentable carbohydrates in a calf starter. Increasing the dry matter intake of the calf involves proper management, such as, providing calf starter that is fresh, dry, palatable, and with minimal fines. In addition, clean water should be available to calves at all times.
The use of Saccharomyces cerevisiae fermentation products (SCFP) has been shown to increase dry matter intake, growth, and rumen papillae size in calves (Lesmeister et al., 2004). Calf health, measured as improvements in calves exhibiting fever, diarrhea, and lower mortality, occurred when treated with SCFP as compared to a control (Magalhaes, 2008). Recently, in a study conducted at Iowa State University’s College of Veterinary Medicine, calves that were challenged with salmonella enterica serotype Typhimurium strain SL1344 were assigned to one of two treatments, an untreated control and a treatment group which contained SCFP in the milk replacer and calf starter. SCFP-treated calves had decreased rectal temperatures, decreased diarrhea scores, and increased papillae development (P<0.05) as compared to the control calves (Brewer et al., 2014). In addition, SCFP-treated calves had decreased fecal shedding of salmonella and decreased salmonella ileal colonization (P<0.05) as compared to the control calves (Brewer et al., 2014).
Along with proper management of the colostrum, appropriate care and feeding of calves, the use of Saccharomyces cerevisiae fermentation products can improve starter dry matter intake, rumen development, average dairy gain, and calf health.