MORPHOMETRY AND RUMINAL HISTOLOGY OF NELORE CATTLE SUBJECTED TO DIFFERENT ADAPTATION PROTOCOLS TO INTENSIVE FINISHING DIETS ON PASTURE

• Grant number: 24/16316-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2024
• End date: October 31, 2025
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Nutrition and Feeding
• Principal Investigator: Danilo Domingues Millen
• Grantee: Maria Eduarda Magalhães Lopes
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil

Abstract

This project aims to evaluate different adaptation protocols for intensive pasture finishing diets (IPT) on the ruminal characteristics of Nellore cattle. The experiment will be carried out at the Beef Cattle Department of UNESP, Jaboticabal campus. Twenty-eight intact male Nellore animals with an initial weight of approximately 400 kg will be randomly distributed in 4 paddocks of Urochloa brizantha cv. Marandu (n = 7 per paddock). The animals will be fed using a Calan Gates System to control the feed intake and blocked by the paddock and by body weight (BW) if necessary. Each animal will be randomly assigned to receive one of three treatments: T1 - adaptation in 21 days, with an initial offer of concentrate at 0.5% of BW and equal daily increments until reaching 2.0% of BW at the end of the adaptation; T2 - adaptation in 14 days, with initial offer of concentrate at 0.5% of BW and equal daily increments until reaching 2.0% of BW at the end of adaptation and; T3 - adaptation in 14 days, with initial offer of concentrate at 1.0% of BW and equal daily increments until reaching 2.0% of BW at the end of adaptation. Each treatment will have 9 or 10 replicates. The study will last 127 days, with 112 days of experiment and 15 days to adapt the animals to Calan Gates. After slaughter, after 112 days of study, samples of the ruminal epithelium will be collected, in which characteristics such as absorptive surface area and number of papillae per cm2 of the ruminal wall will be evaluated, as well as height, area, and keratin thickness of the papillae, and incidence of lesions in the rumen. The data will be analyzed by PROC MIXED of SAS.