Performance and microbiota of the digestive tract of Nellore calves supplemented with fungi isolated from bovine rumen

Abstract

Background and Aim: In tropical semiarid regions, supplementation with fungi could contribute to rumen modulation, promoting greater production of fibrolytic enzymes and degradation of forage. The objective of this study was to analyze the effect of supplementation with fungi, isolated from the bovine rumen, on the performance and microbiota of the digestive tract of Nellore calves. Materials and Methods: The experiment was conducted in randomized blocks evaluating eight Nellore calves that were daily supplemented with isolates of Aspergillus terreus and Trichoderma longibrachiatum, along with eight calves that were not supplemented. After 55 days, the animals were weighed, and samples of rumen fluid and feces were collected for analysis. The characteristics that showed normal distribution were subjected to analysis of variance and compared using Tukey's test. Whereas, the variables that did not show normal distribution were subjected to the Kruskal–Wallis test, and the frequencies of the bacterial and fungal genera were compared using the Chi-square test. Results: Supplementation with fungi promoted the reduction in ruminal pH (p<0.05). However, the final live weight; average daily weight gain; total weight gain; rumen protozoa; and the count of Enterobacteriaceae, mycelial fungi, and yeasts of ruminal fluid and feces were not influenced by supplementation (p>0.05). Moreover, the protozoa Eodinium spp. was identified only in supplemented calves (p<0.05). Conclusion: Supplementation with the fungi presented the potential for use as possible additives because it did not alter the physiological parameters of the facultative anaerobic microbiota composition in the rumen and feces. In addition, it favored the presence of the ciliate genus Eodinium. However, further studies should be performed to better define suitable dosages for supplementation.

Fermentation parameters in the rumen of goats supplemented with polyphenol oxidase derived from Gliricidia sepium leaves under in vitro conditions

“…Buetschlia is classified as a holotricha protozoa and is commonly found in the rumen of domestic and wild ruminants (Patel and Ambalam 2018;Firkins et al 2020). Buetschilia was the most identified genus of ruminal ciliates in Nellore calves that were raised in tropical pastures during the dry season without feed supplementation (Duarte et al 2018;dos Santos et al 2021).…”