PSIV-A-6 - Effects of a yeast cell wall additive on the growth performance and fecal Eimeria load of finishing lambs

Abstract: Yeast-based additives have been shown to alter the rumen environment and exhibit immunomodulatory properties that can lead to enhancements in health status and subsequent performance. The objectives of this study were to evaluate the impacts of supplementing a yeast cell wall additive (Safwallâ, Phileo by Lesaffre, Milwaukee, WI) on finishing lamb growth performance and fecal Eimeria load. A total of 44 Polypay lambs were used in a 35-day experiment at the Kansas State University Sheep and Meat Goat Center. On d 0, a fresh fecal sample was collected from each lamb and submitted to the Kansas State University Veterinary Diagnostic Lab to determine a baseline Eimeria count via quantitative fecal float. Lambs were then randomly assigned to either a control diet or diet supplemented with 1.5 g Safwallâ. Diets were fed for 35-d and contained no coccidiostat. Lambs had ad libitum access to both feed and water for the duration of the experiment. A basal lamb finisher diet was manufactured as a control diet and Safwallâ was hand-mixed into rations daily to make the treatment diet. Lambs and feeders were individually weighed weekly to track dry matter intake (DMI) and changes in body weight (BW). Data were analyzed using the GLIMMIX procedure of SAS (v.9.4, SAS Inst., Cary, NC) with an alpha set at (P < 0.05). From d 0 to 7 there was no evidence of a difference (P = 0.19) in DMI between treatment groups; however, during the second week of the study (d 7 to 14) lambs fed the control diet had significantly greater (P = 0.02) DMI compared to those fed a diet supplemented with yeast cell wall. There was no evidence of differences in DMI between treatments for the remainder of the study (P > 0.05). Likewise, BW did not differ significantly (P > 0.05) between treatments on d 0 or by d 35. There was no evidence that fecal Eimeria load differed significantly (P > 0.05) on d 0 or 21; however, on d 35, lambs fed the control diet had a lower Eimeria load compared to those fed a diet with yeast cell wall, but neither group had biologically relevant levels of Eimeria present in the feces. In summary, feeding a diet containing a yeast cell wall additive did not alter finishing lamb growth performance. While lambs fed the control diet had lower fecal Eimeria at the end of the study, there was a reduction in this parameter across both treatments. Further research should be conducted with younger animals with a known Eimeria challenge.