Impact of ergot alkaloids on rumen motility: Time required to impact motility

• Grant number: 16/08867-1
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: August 08, 2016
• End date: August 07, 2017
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Nutrition and Feeding
• Principal Investigator: Flávio Dutra de Resende
• Grantee: Cleisy Ferreira Do Nascimento
• Supervisor: David L. Harmon
• Host Institution: Agência Paulista de Tecnologia dos Agronegócios (APTA). Secretaria de Agricultura e Abastecimento (São Paulo - Estado). São Paulo , SP, Brazil
• Institution abroad: University of Kentucky (UK), United States
• Associated to the scholarship: 15/07046-1 - Use of Aspergillus oryzae alpha amylase in feedlot diets for Nellore, BP.DR

Abstract

The objective of this study is to determine the amount of time necessary for rumen motility to be affected by ruminal dosing of endophyte-infected tall fescue seed for growing steers feed once daily. Eight ruminally-cannulated Holstein steers will be paired by weight in a randomized complete block design (RBD). Within each block, one steer will be assigned to each treatment: endophyte-free (E-; "KY 32"; 0 mg ergovaline + ergovalinine / kg DM) or endophyte-infected (E+; "KY 31) tall fescue seed treatment. A dosage level of 20 µg ergovaline + ergovalinine/kg BW will be administered to E+ steers. To keep total weight of seed constant for all steers, a combination of E+ and E- seed may be administered to some steers. Animals will be pair-fed alfalfa cubes (% composition on a DM basis: CP = 16.8; ADF = 33.5; NDF = 43.1; NEm = 5.09 MJ/kg) once daily at 0800 h to the quantity the E+ steer consumed the previous day. Steers will be housed indoors at the University of Kentucky C. Oran Little Research Center in Woodford County at 22°C in individual 3 m x 3 m stalls. Ad libitum access to water will be provided. A wireless telemetry system will be used to monitor real-time pressure changes in the rumen. Over the first 21 d of ruminal seed dosing, a 16-h data collection period will begin after feeding each day (0800 h). Water intake will be recorded using water flow meters immediately after feeding. The rhythmic analyzer will be used simultaneously wile data is being collected to analyze the raw rumen pressure data, identify ruminal contractions, and to calculate the following parameters for each contraction: baseline pressure, peak pressure, amplitude, frequency, time to peak (TTP), relaxation time (RT), and area under the curve. Blood samples will be collected from the jugular vein immediately before feeding for determination of serum prolactin concentrations. Additionally, rumen contents will be emptied manually through the cannula, mixed, and weighed. Values for baseline pressure, peak pressure, amplitude, frequency, TTP, RT, duration, and area under the curve for each animal will be averaged over the 16 h period every day using the Proc Means procedure of SAS. Motility variables will be analyzed as an RBD with repeated measures for the effects of seed, day, and your interaction. All other variables will be measured as an RBD for seed effects. It is expected to end of test identify the time and dosage ergot alkaloids necessary to affect the motility of the rumen.