Session: Ruminant Nutrition IV: Dairy and Fermentation

323 - Effect of an Acidogenic Diet with Phytogenic Supplementation on in Situ Degradability of Corn and Wheat Grain, and Grass Silage in Dairy Cows

Friday, July 16, 2021

3:45 PM – 4:00 PM EST

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

Presenting Author(s)

Raul Rivera-Chacon, MS

PhD student
University of Veterinary Medicine Vienna, Christian Doppler Laboratory for Innovative Gut Health Concepts of Livestock, Institute of Animal Nutrition and Functional Plant Compounds, Austria
Vienna, Wien

PDF Slides and Audio

Author(s)

Sara Ricci

PhD student
University of Veterinary Medicine Vienna, Christian Doppler Laboratory for Innovative Gut Health Concepts of Livestock, Institute of Animal Nutrition and Functional Plant Compounds, Austria
Venna, Wien
NR

Nicole Reisinger

Project Manager
BIOMIN Research Center
Tulln, Niederosterreich
QZ

Qendrim Zebeli

Professor
University of Veterinary Medicine Vienna, Christian Doppler Laboratory for Innovative Gut Health Concepts of Livestock, Institute of Animal Nutrition and Functional Plant Compounds, Austria
Vienna, Wien
Ezequias Castillo-Lopez

Research Associate
University of Veterinary Medicine Vienna, Christian Doppler Laboratory for Innovative Gut Health Concepts of Livestock, Institute of Animal Nutrition and Functional Plant Compounds, Austria
Vienna, Wien

Modern dairy production systems require larger inputs of energy in diets to increase milk yield. Therefore, dairy cows are at risk of experiencing subacute ruminal acidosis (SARA). The objective of this study was to evaluate grains and forage rumen degradability in cows fed different diets supplemented with a phytogenic (PHY) feed additive. The experiment was conducted with nine rumen-cannulated non-lactating Holstein cows blocked in two groups of four and five animals, and were part of a cross-over design. This study consisted in 2 runs separated by a 12-week washout period, in which cows grazed on pasture. Each experimental run had one week of forage (F) feeding, one week of transition to a high grain (HG) diet, and four weeks of HG (65:35 concentrate to forage ratio in dry matter basis). Cows were supplemented with PHY (a blend of menthol and thymol) or a control carrier (CON) from week F. Corn and wheat grain were ground through a 4 mm screen, while grass silage was ground through a 6 mm screen. Sampling for in situ degradability was performed in F and in week four of HG diet. Data were analyzed with SAS with week of feeding and supplementation as fixed effects and cow as random effect. Corn and wheat 24-h dry matter (DM) and organic matter (OM) degradability increased during HG diet compared with F (P < 0.05), grass silage DM and OM 48-h degradability was reduced by HG diet compared to F (P < 0.01). Additionally, wheat grain 24-h OM degradability was higher for PHY compared to CON under F and HG diet conditions (P = 0.05). Overall, diet composition and SARA conditions can influence grains and fiber degradability in the rumen.