In-vitro Evaluation of Three Conservation Methods of Probiotics from 42-day-old Tropical Calves

Aims: The conservation of probiotics is of great importance due to the microorganism’s viability; therefore, their properties and benefits depend on it. In this work, it was studied three methods of conservation; refrigeration, cryopreservation, and lyophilization of two probiotics isolated from the rumen of 42 day-old calves, previously evaluated: Animal 1-day 42 (A1D42) and Animal 3-day 42 A3D42. Place and Duration of Study: Laboratorio de Rumiología y Metabolismo Nutricional, Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, between August 2020 and September 2021. Methodology: It was evaluated the viability of the probiotics after of 0, 30, 60 and 90 days of refrigeration, cryopreservation, and lyophilization as preservation methods. The effect of the lyophilized probiotic A1D42 on the digestibility in vitro, such as its effect on the volatile fatty acids (VFAs) production was also determined. Results: Cryopreserved and lyophilization methods had better performance about the viability in both probiotics. A1D42 lyophilized maintained its viability (67%) until 60 days and after 90 days it was affected significantly. Despite the fact that VFA production in vitro did not increase with probiotic addiction, A1D42 significantly increased in vitro digestibility by up to 66%. The results demonstrated that lyophilization is the best method of conservation of probiotic production due to it preserves vial cells, as well as the properties and effects of the probiotic. Conclusion: Therefore, lyophilized A1D42 probiotic can be used as an additive in calf diets, which could improve their digestibility, and, therefore, their weight gain, which could have a positive impact on animal production, in addition to the health benefits.