Submitted to: Journal of Animal Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/9/2009
Publication Date: 3/17/2010
Citation: Eicher, S.D., Wesley, I.V., Sharma, V.K., Johnson, T.R. 2010. Yeast Cell-Wall Products Containing Beta-Glucan plus Ascorbic Acid affect Neonatal Bos-Taurus Calf Leukocytes and Growth after a Transport Stressor. Journal of Animal Science. 88(3):1195-1203. Interpretive Summary: Objectives of this study were 1) to determine if a yeast cell-wall extracts containing beta-glucan plus vitamin C improved neonatal calves’ innate immunity and ability to cope with transportation and 2) to compare two yeast cell-wall extracts to determine the effect of the beta-glucan component. One yeast cell-wall product was less purified (2 % beta-glucan) and the other highly purified (70% beta-glucan). After calves were transported, they were fed milk replacer supplemented with their treatments. Body weights were not different among calves, but intake at wk 4 was less for the less purified product than for calves given no supplements. Feed efficiency (feed required for gain) was improved for the less purified product and tended to be improved for the highly processed product at wk 4. Calves fed the beta-glucan products had more days that E. coli O157:H7 was found in their feces than the unsupplemented control calves. White blood cell counts were least for the highly purified beta-glucan compared with the less purified product, but the lymphocytes were only different than the control at d 3 and 10. Phagocytosis and oxidative burst (showing ability of neutrophils to ingest and kill pathogens) was least for calves fed the highly purified supplement compared to control calves on d 28. Both beta-glucan products were beneficial for feed efficiency by wk 4, showing that feed efficiency was probably an effect of the beta-glucan in both products. Mechanisms for modulation of health and immunity may be different, but we can not determine if it is a concentration effect or an effect of the composition of the extract for the two supplements from this research. This research established that the yeast cell-wall extracts modulate immunity and intestinal microbiology of young calves.
Technical Abstract: Objectives of this study were to ascertain if a yeast cell-wall derivative (1.8 % ß-glucan) plus ascorbyl-2 polyphosphate improved neonatal calves’ innate immunity and ability to cope with transportation stressors and to compare the yeast cell-wall derivative with a more purified ß-glucan (70% ß-glucan) from yeast. Treatments were: 1) 113 g of a 1.8 % beta'-glucan derivative of yeast cell-walls EnergyPlus (Natural Chem Group, LLC, Houston, TX) plus a 250 mg of L-ascorbic acid phosphate, Stay-C (DSM Nutritional Products, Parsippany, NJ), EP; 2) 150 mg of a purified ß-glucan fraction from yeast cell-walls, approximately 70% beta-glucan (BioThera, Eagan, MN), plus L-ascorbic acid phosphate, Stay-C (DSM Nutritional Products, Parsippany, NJ), BG; or 3) an unsupplemented control, CNT. Calves (n = 39) were transported for 4 h, then treatments were fed in milk replacer to calves in outdoor hutches. Weekly, dry feed intake and BW were determined and fecal samples collected for Salmonella and E. coli O157:H7 PCR analysis. Jugular blood was collected pre- and d 0, 3, 7, 10, 14, 21, and 28 post-transport. Body weights were not different among calves, but intake at wk 4 was less (P < 0.05) for EP than for CNT. Feed efficiency (gain / kg dry grain) was improved for EP (P < 0.05) and tended to be improved for BG (P < 0.10). However, feed efficiency that included milk replacer dry matter was only improved (P < 0.05) for BG at wk 4. Calves positive for E. coli O157:h7 were greatest (P < 0.05) for EP on d 7 compared to the other 2 treatments. Hematocrit percentages and leukocyte numbers were least (P < 0.05) for BG. Granulocytes counts were less (P < 0.05) for BG fed calves than EP calves on d 21 as were peripheral blood mononuclear cells on d 10, 21, and 28. Differences in neutrophil function were only detected on d 28. Percentage of neutrophils positive for high CD18 expression tended to be greater (P < 0.05) in the EP calves than for those of the BG fed or CNT and phagocytosis and oxidative burst was least (P < 0.05) in BG calves compared to CNT calves on d 28. The high concentration (70%) of ß-glucan was beneficial for feed efficiency by wk 4, showing that improved feed efficiency is probably an effect of ß-glucan. Mechanisms for modulation of health and immunity may be different, but we can not determine if it is a concentration effect or an effect of the composition of the extract for the two supplements from this research. This research established that the yeast cell-wall extracts modulate immunity and intestinal microbiology of young calves.