Effect of supplementing bacterial probiotics on microbial protein synthesis, blood indices and rumen ciliate protozoa population of lactating crossbred cattle in Nepal

In recent times, the dairy industry in Nepal has been recognized as a burgeoning agro-industry, successfully meeting the domestic demand for fluid milk. Nevertheless, further efforts are necessary to achieve self-sufficiency in dairy products. To enhance milk production, alongside breed improvement and health management initiatives, nutritional interventions have been identified as crucial. In this context, a study was conducted in Rampur, Chitwan, focusing on the supplementation of diverse strains of bacterial probiotics in lactating crossbred cattle to evaluate their effects on microbial protein synthesis, animal health assessed through blood indices, and changes in rumen fauna. The findings of the study revealed that the inclusion of bacterial probiotics resulted in notable improvements in the overall excretion of purine derivatives. Specifically, the individual excretion of allantoin, xanthine, and hypoxanthine significantly increased (p<0.01) in the group supplemented with Lactobacillus acidophilus, while uric acid levels remained unchanged. Consequently, microbial nitrogen supply and absorption also showed a significant increase within the same group. However, blood hematological and biochemical parameters remained unaffected across all treatment groups. Moreover, the supplementation did not induce any notable changes in the individual or overall population of rumen ciliate protozoa. The study underscores that the use of L. acidophilus can enhance the overall protein economy of the rumen, thus potentially reducing production costs by substituting expensive sources of dietary protein for lactating crossbred dairy cows.