Date of Graduation


Document Type


Degree Name

Bachelor of Science in Agricultural, Food and Life Sciences

Degree Level



Animal Science


Coffey, Ken

Committee Member/Reader

Rosenkrans, Charles

Committee Member/Second Reader

Philipp, Dirk


Feed costs account for up to 70% of total production costs making it vital that livestock producers maximize feed efficiency in a cost-effective manner (Bach, 2012). Producers often utilize feed additives to optimize nutrient absorption and increase productivity (McGrath et al., 2018). This study was conducted to determine the effects of an enzyme supplement containing Aspergillus niger and Aspergillus oryzae on dry matter (DM), organic matter (OM), neutral detergent fiber (NDF) and acid detergent fiber (ADF) intake and digestibility by lambs fed ad libitum diets of either alfalfa or bermudagrass hay. The study was set up in a 2 2 factorial treatment arrangement in which 20 lambs were weighted, stratified by weight, then randomly assigned to one of the four treatments: 1) alfalfa hay plus enzyme, 2) alfalfa hay with no enzyme, 3) bermudagrass hay plus enzyme, and 4) bermudagrass hay with no enzyme. Intake or digestibility of DM, OM, NDF, or ADF were not affected (P 0.42) by enzyme supplementation. Intake of DM and OM and digestibility of DM were greater (P < 0.05) from lambs offered alfalfa than from those offered bermudagrass, resulting in greater (P < 0.05) digestible DM and OM intake by lambs offered alfalfa hay. Intake of NDF or ADF was not different (P ≥ 0.21) between forages, but NDF and ADF digestibility was greater in lambs fed alfalfa diets (P < 0.01). Ruminal pH was greater in lambs offered enzyme (P < 0.05). The enzyme had no effect on total or individual ruminal VFA concentrations (P 0.10), but total ruminal VFA concentrations were higher, and acetate concentrations were lower in lambs offered alfalfa (P < 0.05). Forage by time interactions were observed for all individual ruminal VFA concentrations with the exception of acetate (P < 0.05). Therefore, the Aspergillus enzyme blend increased ruminal pH but had no effects on intake or digestibility of alfalfa or bermudagrass hay.


Enzyme supplement, Fiber digestion, Ruminant