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ARS Home » Midwest Area » Lexington, Kentucky » Forage-animal Production Research » Research » Publications at this Location » Publication #348253
Title: Effect of starch source in pelleted concentrates on fecal bacteria in prepartum and postpartum mares

Author
item PYLES, MORGAN - University Of Kentucky
item FOWLER, ASHLEY - University Of Kentucky
item BILL, VERONICA - University Of Kentucky
item CRUM, ANDREA - University Of Kentucky
item HAYES, SUSAN - University Of Kentucky
item HARLOW, BRITTANY - Orise Fellow
item Flythe, Michael
item LAWRENCE, LAURIE - University Of Kentucky

Submitted to: Journal of Equine Veterinary Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/8/2018
Publication Date: 11/13/2018
Citation: Pyles, M.B., Fowler, A.L., Bill, V.T., Crum, A.D., Hayes, S.H., Harlow, B.E., Flythe, M.D., Lawrence, L.M. 2018. Effect of starch source in pelleted concentrates on fecal bacteria in prepartum and postpartum mares. Journal of Equine Veterinary Science. 72:31-36. https://doi.org/10.1016/j.jevs.2018.10.014.
DOI: https://doi.org/10.1016/j.jevs.2018.10.014

Interpretive Summary: The diet of mature horses contains forages that are high in structural carbohydrates (i.e. fiber), but horses lack the enzymes to break down these structural carbohydrates. Therefore, horses rely on the microbial community of the gastrointestinal tract (bacteria and other microorganisms) to digest structural carbohydrates and produce nutrients that can be absorbed and utilized as energy by the horse. Previous work by our group and others indicates that foals are born without bacteria in the gastrointestinal tract, but they are rapidly colonized after birth. Little is known of the factors influencing the the process of microbial colonization. In this experiment, we looked at the effects of maternal diet during and after pregnancy on foal colonization. The mares received either a corn- or oat-based pelleted feed. Diet did not change the total numbers of either starch or cellulose (a fiber) utilizing bacteria. However, there were more of a particular genus of bacteria in the foals of the mares on the oat-based diet in the first 4 days of life. The genus, Lactobacillus, is a well known group of bacteria that are generally considered beneficial. The impact of this work is that we now know the bacteria in a foal's gut can be changed by how its dam is fed. Foals can suffer from a variety of gastrointestinal problems, including diarrhea and colic, and the causes of these problems are often unclear. More research is needed to understand foal gastrointestinal health, and that research should include impacts of the mare diet.

Technical Abstract: Adult horses depend on the microbial community in the hindgut to digest fiber and produce short chain fatty acids that are utilized for energy. Colonization of the foal gastrointestinal tract is essential to develop this symbiosis. However, factors affecting colonization are not well understood. The objectives were to evaluate the age-related changes and effects of maternal diet on select fecal bacterial groups in foals from 1 d to 28 d of age. Thoroughbred foals (n=20) were from dams fed forage and one of two concentrates: an oat-based (OB) or corn and wheat middlings-based (CWB) pelleted concentrate. The foals had access to assigned concentrates along with a mixed hay and cool season grass pasture. Fecal samples were collected from foals at 1 d (14-36 h), 4 d, 14 d, and 28 d after birth. Fecal samples were enumerated in enriching and selective media. Enumerations were performed for Lactobacillus spp., amylolytic bacteria, and cellulolytic bacteria. Enumeration data were log transformed then analyzed with mixed model ANOVA (SAS 9.3) to test the main effects of maternal diet (OB or CWB), time of sample, and interaction between maternal diet and time. Cellulolytic bacteria first appeared in foal feces between 4 d and 14 d of age and increased with age (P < 0.05). Amylolytics and lactobacilli were abundant at 1 d then increased with age (P < 0.05). There was an interaction between maternal diet and time for Lactobacillus spp. with OB foals having more lactobacilli than CWB at 1 d and 4 d (P < 0.05); however, there were no differences observed at 14 d (P > 0.05). Maternal diet did not influence amylolytic or cellulolytic bacteria (P > 0.05). These results indicate that colonization of the hindgut is a sequential process beginning early in the foal’s life and maternal diet may influence some bacteria in foals.