Relationship between ingestive behavior and ruminal pH using a rumen-dwelling bolus sensors of Nellore cattle receiving different feed additives.

• Grant number: 23/14171-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2023
• End date: November 30, 2025
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Nutrition and Feeding
• Principal Investigator: Rodrigo Silva Goulart
• Grantee: Lázaro Gabriel Lopes Lima
• Host Institution: Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Universidade de São Paulo (USP). Pirassununga , SP, Brazil

Abstract

The objectives of this research will be evaluating the relationship between ingestive behavior and ruminal pH values in Nellore cattle using a rumen-dwelling bolus sensors receiving different levels of a calcined magnesium oxide source. Five ruminally cannulated Nellore steers (390 ± 15 kg of body weight) will be randomly assigned to a 5 x 5 Latin square design with different feed additives and/or levels of magnesium oxide, such as: diet without feed additive; diet with 25 ppm of sodium monensin (as-fed basis); and three diets containing 25 ppm of sodium monensin and magnesium oxide from one of the following levels: 0.25%, 0.50% or 0.75% (as-fed basis). In each experimental period, during the sixth day of data collection, ingestive behavior will be performed for 24 hours to obtain the following variables: feed intake, water intake, rumination time, chewing time and resting time. Rumen pH monitoring daily will be carried out by means of intra-ruminal sensors from the company SmaXtecâ (Sandgasse, Austria, https://smaxtec.com). Based on the data collected, it will be possible to evaluate the relationship between ingestive behavior and ruminal pH values of cattle receiving different levels of calcined magnesium oxide source. The results produced in this project may provide valuable information on the visual relationship between ingestive behavior and ruminal pH measurements via intra-ruminal sensors, with a view to suggesting management and nutritional strategies in commercial feedlots.