Session: Ruminant Nutrition I: Feed Additives

295 - Effects of Live Yeast and Ruminal Environment on Beef Cattle Diet Digestibility: An in vitro Approach

Thursday, July 15, 2021

9:15 AM – 9:30 AM EST

Location: Kentucky International Convention Center (KICC), L005/009

Author(s)

Kaliu G. Scaranto Silva

Student Intern
Texas Tech University
IDALOU, Texas
JO

Jhones Onorino Sarturi, n/a

Associate Professor
Texas Tech University
Lubbock, Texas
DH

Darren D. Henry, n/a

Assistant Professor
Texas Tech University
Lubbock, Texas
Kk

Kip karges

Texas Tech University
Lubbock, Texas
JH

Jordan K. Hinds, n/a

Undergraduate
Texas Tech University
Lubbock, Texas

Presenting Author(s)

Kaue Tonelli Nardi

Masters Student
Texas Tech University
Lubbock, Texas

PDF Slides and Audio

Author(s)

IG

Igor Gomes Fávero

Student Intern
Texas Tech University
Lubbock, Texas
YS

Yasmin Saes

Texas Tech University
Lu, Texas
CR

Camron J. Rush

Undergraduate Student
Texas Tech University
Lubbock, Texas

The effects of live yeast (Saccharomyces cerevisiae) and ruminal environment on in vitro true digestibility of dry matter, organic matter, and fiber components were evaluated. Ruminally-cannulated beef steers (n = 4; BW = 520 ± 30 kg) were used in a cross-over design to serve as donors of ruminal content. In vitro substrates (6 grower and 6 finisher diets) and individual ingredients (steam-flaked corn, wet corn gluten feed, and old-world bluestem hay) were dehydrated (55^o C), ground (1 mm), and incubated using a 2 × 2 factorial arrangement of treatments: a) the presence or not of yeast (8×10⁹ CFU/animal-daily adjusted to a 70 L ruminal content volume), and b) two ruminal inoculums collected from donors fed a grower (50:50) or a finisher (92:08) diet (concentrate:forage). Four incubation batches (experimental unit) were performed, in which the initial two batches were performed followed by another two after animals switched diets and were adapted again during 21d. A Daisy in vitro incubation system was used, and samples incubated for 48h (39°C). The GLIMMIX procedure of SAS was used for the statistical analysis. No 3-way interactions (P ≥ 0.71) or 2-way interactions with substrate were observed (P ≥ 0.25). The in vitro true digestibility of DM, OM, NDF, and hemicellulose increased when yeast was added to the incubator containing a 50:50 ruminal content (Rumen × Yeast; P ≤ 0.02). The ADF digestibility increased (P = 0.02) with yeast addition regardless of ruminal content type (50:50 or 92:08). As expected, finisher substrate diets were more (P < 0.01) digestible than grower diets. The combination of live yeast and a specific ruminal environment seemed to be more important than substrate type, in which live yeast improved in vitro digestion within a 50:50 ruminal inoculum more evidently.