Effects of psyllium in milk replacers for neonatal dairy calves
Psyllium has been shown to exert beneficial effects on intestinal health and function in several non-ruminant species. The effects of psyllium inclusion in milk replacers for neonatal dairy calves have been minimally researched. The purpose of my research was to determine the impact of psyllium inclusion in milk replacer on feed intake, water intake, growth, illness, digesta viscosity, rate of passage, nutrient digestibilities, blood components, VFA concentrations and microbial populations throughout the gastrointestinal tract, size and scale of gastrointestinal tissues, ion transport measures, and histomorphological development in the gastrointestinal tract in neonatal dairy calves. Male Holstein calves, less than 36 h of age, were purchased for this trial. Calves were blocked by pairs and randomly assigned within pair to one of two dietary treatments. Treatments consisted of milk replacers (reconstituted to 12.5% DM and fed at a rate of 12% of BW) formulated to contain 22% protein and 20% fat either with (PSY) or without (CON) a 1.1% inclusion of psyllium. Pairs of calves were harvested at wk 1, 2, 3, and 4 for analysis. Feed intake (DM, protein, and metabolizable energy), water intake, growth, and illness did not differ between treatments. Digesta viscosity was increased in the abomasal and colon digesta for the PSY treatment. In addition, DM content of digesta from the proximal colon, distal colon, and feces was decreased for the PSY treatment. Apparent digestibility of DM was greater for the CON treatment. The predominant effect of psyllium inclusion in the milk replacer on VFA concentrations was in the lower gastrointestinal tract as indicated by the higher total VFA concentrations in the jejunum, proximal colon, and distal colon. Greater lower gut fermentation is logical because psyllium is a fiber that can be fermented by intestinal bacteria. Effects of inclusion of psyllium on bacterial counts were minimal. Size and scale of the gastrointestinal tract were impacted by psyllium predominantly in the lower gastrointestinal tract. Calves fed PSY had heavier duodenums, more duodenal tissue per kilogram BW, increased duodenal wet weight, increased jejunal mass per unit of BW, denser jejunal tissue, and greater jejunal tissue density per unit of BW. Length of the jejunum per unit of calf BW was increased for the CON calves. In the ileum, the PSY calves had denser tissue. Colon wet weight, as well as dense colon tissue per unit of calf BW was increased for the PSY calves. The increase in size and scale of the gastrointestinal tract could be of benefit to the neonatal dairy calf from a standpoint of potentially greater absorptive capacities of the tissue and greater tissue resistance to disease intrusion into the bloodstream. The inclusion of a fermentable fiber could also potentially “set-up” the gastrointestinal tract to allow more rapid growth once calf starter ingestion begins. In isolated segments of gastrointestinal tissues, inclusion of psyllium in the diet significantly affected the change in short circuit current induced by addition of 10 mM glucose. Glucose transport was greater in rumen, ileum, and colon from CON calves compared with calves fed PSY . These data could potentially indicate that psyllium inclusion slowed the rate of glucose absorption in the rumen, ileum, and colon. Psyllium inclusion in milk replacer resulted in physiological changes consistent with improved performance and health. The effects of psyllium inclusion on growth and health should be determined in large numbers of calves under field conditions.
University of Illinois - Urbana-Champaign
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University of Illinois at Urbana-Champaign