Resumo

DELGADILLO-RUIZ, Lucía et al. Ruminal bacteria and protozoa present in sheep supplemented with probiotics identified by counting and PCR endpoint. Abanico vet [online]. 2022, vol.12, 104.  Epub 31-Out-2022. ISSN 2448-6132.  https://doi.org/10.21929/abavet2022.6.

Some microbial cultures, mainly the use of probiotics, have been used in ruminant nutrition, generating a positive effect by solving imbalances due to dietary changes in the rumen. The objective was to identify and evaluate bacteria and ruminal protozoa present in sheep supplemented with biopreparation of microorganisms (PNC) vs commercial probiotic REVET® (PCRE) at different concentrations by Neubauer chamber count and PCR endpoint. Twenty-one Katahdin and Dorper cross sheep of 3 months of 18-25 kg were used, they were supplemented with PNC and PCRE, at different concentrations: PNC 100%, 66%, 33%, control, PCRE 100%, 66%, 33%. The ruminal liquid was obtained through a probe, the ruminal microorganisms were counted in a Neubauer chamber every six hours. Genomic DNA extraction using the Ultra Clean Microbial DNA kit, DNA quantification was performed in a spectrophotometer, and PCR reactions were performed with oligonucleotides synthesized by Invitrogen®. Statistical analysis was through the GENMODE procedure for counting bacteria and protozoa. The highest amount of protozoa was at 24 hours in PNC at 100%, followed by PNC 33% at 18 hours, for commercial probiotic PCRE at 66% at 12 hours. Regarding bacteria, they showed statistically equal values. Genomic DNA quantification was greater than 25 ng/µL. The inhibitory effect of the probiotic on Fibrobacter succinogenes at a concentration of 100% was demonstrated. Total bacteria were not affected by probiotic supplementation. Therefore, it is concluded that the non-commercial probiotic can be an alternative to supplement the diet of growing sheep, observing an increase in bacteria and protozoa. Likewise, probiotics are an additive that can be used successfully since they did not modify the population of total bacteria in the rumen.

Palavras-chave : sheep; ruminal fermentation; bacteria; protozoan; PCR.