Nutritional protocols to increase marbling in carcasses of Nellore cattle finished in feedlot

• Grant number: 19/24747-4
• Support type: Research Grants - Research Partnership for Technological Innovation - PITE
• Duration: March 01, 2021 - February 29, 2024
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Nutrition and Feeding
• Principal researcher: Danilo Domingues Millen
• Grantee: Danilo Domingues Millen
• Home Institution: Faculdade de Ciências Agrárias e Tecnológicas. Universidade Estadual Paulista (UNESP). Campus de Dracena. Dracena , SP, Brazil
• Company: Maiz Indústria e Comercio de Produtos Agropecuários Ltda
• CNAE: Criação de bovinos ; Atividades de apoio à pecuária ; Pesquisa e desenvolvimento experimental em ciências físicas e naturais
• CNAE: Criação de bovinos ; Atividades de apoio à pecuária ; Pesquisa e desenvolvimento experimental em ciências físicas e naturais
• City: ArarasDracena
• Assoc. researchers: Bradley Joseph Johnson ; Bruno Ieda Cappellozza ; Felipe Azevedo Ribeiro ; Sérgio Bertelli Pflanzer Júnior

Abstract

The objective of this project is to evaluate different nutritional protocols including high-moisture corn, rumen-protected fat, zinc and organic chromium in the diets of feedlot Nellore cattle, ranked by estimated progeny difference (EPD) as high and low marbling, on adipogenesis of intramuscular and subcutaneous tissues, meat quality, performance and rumen and cecum morphometrics. In this project, two studies will be proposed: for study 1, it will be used 132 18-mo-old Nellore bulls (380 kg), which will be blocked by EPD and by initial body weight. Twelve bulls will be slaughtered at day 0 of the study (two per block) for carcass baseline measurements. Therefore, this study will be carried out with 120 Nellore bulls, which will be randomly allocated into 30 pens (n=4 per pen) according to the blocking criteria just described in a 2 × 2 + 1 factorial arrangement of treatments: T1) Finely-ground corn; T2) High-moisture corn; T3) Finely-ground corn + rumen-protected fat; T4) High-moisture corn + rumen-protected fat; T5) High-moisture corn + rumen-protected fat + Zn and Cr. The finishing diets will contain 84% concentrate and 25 ppm of sodium monensin. This study will last 112 days and performance variables will be evaluated, such as: average daily gain, feed efficiency, hot carcass weight, and adipogenesis on intramuscular and subcutaneous tissues, besides meat quality (fatty acid profile and tenderness) and ruminal bacterial communities. For the study 2, five 30-mo-old Nellore steers (550 kg), cannulated in the rumen, will be allocated in individual pens in a 5 x 5 Latin square design. Each period will last 28 days with a 10-d washout interval between periods. The treatments employed to this study will be the same described for the study 1, and variables related to ruminal fermentation pattern, nutrient degradability and ruminal bacterial communities will be evaluated. (AU)