Ruminal degradation of corn silage, corn plant fractions, and TMR with different contents of undigested neutral detergent fiber

• Grant number: 24/06379-6
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Effective date (Start): August 15, 2024
• Effective date (End): August 14, 2025
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Nutrition and Feeding
• Principal Investigator: Francisco Palma Rennó
• Grantee: Nathália Trevisan Scognamiglio Grigoletto
• Supervisor: Luiz Felipe Ferraretto
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Research place: University of Wisconsin-Madison (UW-Madison), United States
• Associated to the scholarship: 23/03872-0 - Omasal flow and ruminal kinetics in dairy cows fed diets with different levels of insoluble indigestible Neutral Detergent Fiber (iNDF), BP.DR

Abstract

The aim of this study is to evaluate neutral detergent fiber digestibility (NDFD) using the in situ and in vitro methodologies for corn silage with different cutting heights, corn plant fractions, and experimental diets, as well as compare the uNDF in situ 288 h and in vitro 240 h for the same samples. The hypothesis of this experiment is that the NDFD is proportionally and negatively associated with uNDF content of feed samples. Treatment sequences with increasing levels of uNDF (9.0, 9.7, 10.4, and 11.1% diet DM). Dietary uNDF was manipulated using corn silage (CS) made from plants harvested at 2 heights from the ground level [40 cm (CS40) and 65 cm (CS65)]. Diets were fed as TMR with 48:52 forage to concentrate ratio. CS was the sole forage source. The forage proportion of diets with 9.0, 9.7, 10.4, and 11.1% uNDF comprised 100, 66.6, 33.3, and 0% of CS65, respectively, while the remainder consisted of CS40. Corn silage uNDF content was measured by incubating feed samples in the rumen of 2 cows for 288 h. The in situ and in vitro degradability procedures will be performed at the Department of Animal & Dairy Science at the University of Wisconsin, Madison, WI, USA, under supervision of Dr. Ferraretto.