Effects of a Blend of Glycerol Esters of Short- and Medium-Chain Fatty Acids and Saponins on Growth and Fecal Detection of Selected Enteric Pathogens in Preweaned Calves: A Pilot Study

Enteric pathogens can impair health and growth during the preweaning period, while non-antibiotic feed additives may support gastrointestinal resilience. This pilot study evaluated a liquid blend of glycerol esters of organic and fatty acids and saponins in 20 Holstein calves assigned at birth to control group or additive groups (n = 10 per group). Calves were housed and fed individually. From the fourth milk feeding to weaning at 60 d of age, additive calves received 2.5 mL of the product/L of whole milk immediately before feeding (15 mL/calf per day), whereas control calves received the same milk without the additive. Body weight was recorded on days 1, 30, and 60; starter disappearance and the presence or absence of diarrhea were recorded daily. Fecal samples collected at 1, 2, 3, 4, 6, and 8 weeks of age were examined for selected protozoa and bacteria. Overall average daily gain (0.910 vs. 0.841 kg/d; p = 0.194) and cumulative starter disappearance (16.016 vs. 11.087 kg/calf; p = 0.228) were not statistically different between treated and control calves. Diarrhea was detected for 6.6 days per calf in the control group and for 7.6 days per calf in the additive group (p = 0.401). Cryptosporidium spp. scores were higher in treated calves at weeks 1 and 6 (p = 0.039 and p = 0.041, respectively), providing no evidence of inhibition. Giardia spp. detection was lower in treated calves at week 2 (p = 0.041). Campylobacter coli detection was lower at week 2 (p = 0.019) and showed a suggestive reduction at week 6 (p = 0.088). Klebsiella pneumoniae was detected only in controls at weeks 2, 3, and 6, whereas Clostridium perfringens showed no consistent treatment response. These exploratory findings do not establish efficacy, but support larger, appropriately powered studies using longitudinal models and quantitative pathogen measurements.