Effects of corn grain hybrid on digestibility and ruminal metabolism of Holstein and Angus cattle

• Grant number: 17/08952-1
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Start date: June 23, 2017
• End date: November 15, 2017
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Nutrition and Feeding
• Principal Investigator: Danilo Domingues Millen
• Grantee: Ana Carolina Janssen Pinto
• Supervisor: Tara Louise Felix
• Host Institution: Faculdade de Ciências Agrárias e Tecnológicas. Universidade Estadual Paulista (UNESP). Campus de Dracena. Dracena , SP, Brazil
• Institution abroad: Pennsylvania State University, United States
• Associated to the scholarship: 16/04262-8 - Adaptation to high-energy diets of cannulated nellore cattle previously submitted to either nutritional restriction or intake of concentrate feedstuffs on rumen fermentation patters and microorganisms profile, BP.MS

Abstract

The objectives of this study are to evaluate the in situ and in vitro degradability and the total tract digestibility and ruminal metabolism of light weight corn hybrids, steam-flaked corn and yellow dent#2 corn (common corn) in ruminal cannulated Holstein and Angus beef steers. The study will be conducted at Pennsylvania State University, United States of America. For this proposal 2 trials will be conducted. For trial 1, it will be used 12 cannulated beef steers (6 Holsteins x 6 Angus) in a completed randomized design with 2 x 3 factorial arrangement of treatments. The treatments will be involving Holstein and Angus steers fed different corn hybrids, such as light weight, steam-flaked corn and yellow dent#2 corn. Ankom bags will be inserted in the rumen and withdrawn at 3, 6, 9, 12 and 24 hours post feeding to determine the degradation over time. Samples will be analyzed for starch. An in vitro technique, where an Ankom Daisy II equipment will be utilized, will use a similar sampling and analytical structure, so that correlations among the results may be compared for future references. For trial 2, 12 cannulated steer calves (6 Angus x 6 Holstein) will be used in a replicated 3 x 3 Latin Square, where each breed will be allocated in one square. The treatments will be as follows: 1) light weight corn (hybrid), 2) steam-flaked corn, and 3) yellow dent #2. The study will last 60 days and it will involve 3 periods of 20 days: 14 days for diet adaptation and 6 days to collect data and samples. For the total tract digestibility (starch) will be collected fecal samples during 5 consecutive days, and the pH and short-chain fatty acid production will be collected before the morning feeding and at 3 and 6 hour post-feeding on day 20 of each period.