Evaluation of corn gluten meal and fermented corn gluten meal supplementation on growth and physiological responses in Holstein dairy calves

This study evaluated the effects of incorporating corn gluten meal (CGM) and fermented corn gluten meal (FCGM) into calf starter diets on growth performance, nutrient utilization, ruminal fermentation, feeding behavior, and blood metabolites in pre-weaned Holstein calves. Thirty calves were randomly assigned to three dietary treatments: control (CON, 100% calf starter), CGM (5% inclusion, replacing an equal proportion of starter on a DM basis), and FCGM (5% inclusion, DM basis). Outcomes were monitored from day 3 to day 60 of life. Data were analyzed using mixed-model ANOVA to assess diet and time effects. Calves fed CON exhibited the highest dry matter and crude protein intake; however, calves receiving CGM and FCGM showed improved feed conversion ratios with comparable average daily gains, indicating enhanced efficiency, particularly in the FCGM group. Relative to CON, FCGM increased apparent total-tract dry matter (DM) digestibility. Ruminal fermentation profiles were modulated, with an increased acetate:propionate ratio in FCGM-fed calves. Plasma metabolite patterns were consistent with improved nitrogen utilization in the FCGM group. Feeding behavior was largely unaffected by diet. Collectively, a 5% inclusion of FCGM in the starter improved growth efficiency and aspects of rumen function over days 3–60 of life, without compromising intake, supporting FCGM as a viable early-life nutritional strategy. • Fermented corn gluten meal (5%) improved feed efficiency in Holstein calves • Fermented corn gluten meal-fed calves matched control daily gain despite lower protein intake • Fermented corn gluten meal increased acetate:propionate ratio and isobutyrate in rumen fermentation • Both fermented and not fermented corn gluten meal reduced blood urea nitrogen, indicating better N utilization