Counting and determination of the population of ciliate protozoars of bovine rumen kept under different levels of pasture intensification

• Grant number: 20/13979-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2021
• End date: February 28, 2022
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Production
• Principal Investigator: Ives Cláudio da Silva Bueno
• Grantee: Rafaella Zuliani Spalato
• Host Institution: Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Universidade de São Paulo (USP). Pirassununga , SP, Brazil
• Associated research grant: 17/20084-5 - Strategic practices for mitigating greenhouse gas emissions in grassland systems of the Brazilian Southeast, AP.PFPMCG.TEM

Abstract

The present work aims to quantify and classify the protozoan populations in the rumen of Nellore steers, submitted to different levels of pasture intensification and, accordingly, to evaluate the levels that have the greatest potential to minimize the emission of greenhouse gases in the systems of animal production. The animals will be randomized under the procedures: 1) degraded pasture (PD); 2) dryland pasture with moderate stocking rate (TLM); 3) dry land pastures with high stocking rate (TAL); 4) livestock-forest system with a moderate stocking rate (IPF); 5) irrigated pasture with high stocking rate (IAL).For a total count and identification of protozoa, samples of rumen content will be collected in eight Nellore cattle, with permanent and moist cannulas, and will be collected before feeding, 3, 6, 9 and 12 hours after morning feeding. The samples will be fixed, colored, diluted and later, arranged in the Neubauer chamber. This will be coupled to an optical microscope and thus, the total and differential counting will be performed. The ciliated protozoa will be classified as morphological characteristics of the genera Isotricha, Dasytricha, Entodinium, Epidinium, Ophryoscolex and subfamily Diplodiniinae.