USE OF NARASIN TO REDUCE LESIONS AND IMPROVE THE DEVELOPMENT OF THE RUMINAL AND CECAL EPITHELIUM OF CONFINED NELORE CATTLE.

• Grant number: 23/11698-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2023
• End date: October 31, 2025
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Nutrition and Feeding
• Principal Investigator: Danilo Domingues Millen
• Grantee: Giovanna Lombardi de Oliveira Araújo
• 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 the effects of increasing levels of Narasin in feedlot diets on the morfometrics and incidence of rumen and cecum lesions of Nellore cattle. The study will last 112 days, in which 128 18-month-old, Nellore yearling bulls will be randomly allocated to 32 pens (n = 4 per pen). The animals will go through a step-up protocol, which means that three adaptation diets containing 75%, 79%, and 83% of concentrate will be provided. The transition from the adaptation diet to the finishing diet will be as follows: 5 days of adaptation 1 (75% concentrate), 4 days of adaptation 2 (79% concentrate), and 5 days of adaptation 3 (83% concentrate). The finishing diet will consist of 87% concentrate ingredients and the treatments will be divided as follows: 1) 0 ppm of Narasin (control); 2) 13 ppm of Narasin; 3) 20 ppm of Narasin; and 4) 27 ppm of Narasin (Zimprova"; Elanco Saúde Animal, São Paulo, SP). At the end of the study, all animals will be slaughtered, and the ruminal and cecal compartments will be evaluated for incidences of lesions. Similarly, fragments of approximately 1cm2 of each compartment will be collected for microscopic morphometric measurements, such as height, area, and keratin thickness of the rumen papillae, and crypt depth and number of Goblet cells in the cecum. The data will be analyzed by PROC MIXED of (SAS).