Adaptation to non-forage feedlot diets for Nellore cattle.

• Grant number: 25/09684-7
• Support Opportunities: Scholarships in Brazil - Master
• Start date: July 01, 2025
• End date: June 30, 2026
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Nutrition and Feeding
• Principal Investigator: Danilo Domingues Millen
• Grantee: Rodrigo José de Oliveira
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil
• Associated research grant: 24/07544-0 - Adaptation to high-energy diets in non-conventional production systems for beef cattle., AP.R

Abstract

This study aims to evaluate different nutritional protocols to adapt confined Nellore cattle to the finishing diet without the inclusion of roughage sources. The central idea is to test different adaptation length that allow cattle to adapt to all-concentrate-no-roughage diets, under the hypothesis that feedlot Nellore cattle need 21 days, seven days more than the minimum conventionally proposed, to adapt to finishing diets without any roughage inclusion. It is expected that implementing adaptation protocols to finishing diets without roughage can lead to a significant reduction in the logistics of intensive beef production systems, without impacting animal performance. It will be used 144 Nellore bulls, with an initial body weight of approximately 380 kg. The experimental design will be a randomized blocks, in which the animals will be blocked by initial body weight, and will be housed in colective pens (4 animals per pen) according to the following adaptation protocols: 1) [Control] Adaptation in 14 days by conventional step-up protocol to finishing diet containing corn silage; 2) [14-day restriction] Adaptation in 14 days by restriction protocol to the finishing diet without roughage; and 3) [Restriction 21 days] Adaptation in 21 days by restriction protocol to the finishing diet without roughage. Performance parameters, carcass characteristics, ingestive behavior, rumen and cecum morphometry, in addition to the bacterial and protozoa communities present in the ruminal fluid will be evaluated. The data will be analyzed using PROC MIXED from SAS (2003), with the Tukey test used to compare means. (AU)