Effects of a combination of hinokitiol (β‐thujaplicin) and an organic acid mixture on ruminal fermentation in heifers fed a high‐grain diet

• Published in: Animal science journal Vol. 83; no. 1; pp. 36 - 42
• Main Authors: ISHII, Junichiro, OMURA, Hiroshi, MITSUI, Tadao, EGUCHI, Norichika, UENO, Takashi, GOTO, Hisaya, ITO, Hiroshi
• Format: Journal Article
• Language: English
• Published: Melbourne, Australia Blackwell Publishing Asia 2012; Blackwell Publishing Ltd
• Subjects: alfalfa meal; Animal Feed; Animal populations; Animal sciences; Animals; Anti-Infective Agents - pharmacology; Antibacterial activity; antibacterial properties; bacteria; barley; Bloat; Cattle; citrate; citrates; Citric acid; Citric Acid - pharmacology; Diet; Diets; Digestion - drug effects; Digestive system; Drug Resistance, Bacterial; Edible Grain; Feeding; feedlot bloat; Feeds; Female; Fermentation; Fermentation - drug effects; froth; Gram-negative bacteria; Gram-positive bacteria; heifers; hinokitiol; Hordeum vulgare; Megasphaera - drug effects; Megasphaera elsdenii; minimum inhibitory concentration; Monoterpenes - pharmacology; organic acids; Protozoa; Rumen - microbiology; Rumen - physiology; rumen fermentation; Salts; soybean meal; Soybeans; Streptococcus bovis; Streptococcus bovis - drug effects; Thujopsis dolabrata; Tropolone - analogs & derivatives; Tropolone - pharmacology; Volatile fatty acids
• ISSN: 1344-3941; 1740-0929
• DOI: 10.1111/j.1740-0929.2011.00915.x

This study evaluated the effects of hinokitiol (a natural antibacterial compound extracted from Thujopsis dolabrata var. hondai) and an organic acid mixture (citrate content 50%) on ruminal fermentation. Antibacterial properties were examined by measuring minimal inhibitory concentration. Hinokitiol at 1.56 µg/mL or an organic acid mixture at 1600 µg/mL inhibited Streptococcus bovis growth. The combination of 0.78 µg/mL hinokitiol and 200 µg/mL of an organic acid mixture also inhibited S. bovis growth. Both hinokitiol and the hinokitiol and an organic acid mixture combination showed strong antibacterial properties on Gram‐positive bacteria such as S. bovis, but relatively weak antibacterial activities on Gram‐negative bacteria such as Megasphaera elsdenii. Three ruminally cannulated heifers were fed a bloat‐producing diet containing barley, pelleted alfalfa meal, soybean meal and salt without long‐cut roughage to investigate the ruminal characteristics in vivo. Feeding to heifers a bloat‐producing diet containing 7.8 mg/kg hinokitiol and 0.2% of an organic acid mixture significantly decreased the increase in stable ingesta volume. Hinokitiol or an organic acid mixture did not affect ruminal volatile fatty acids, protozoa and bacteria. These results suggest that a combination of hinokitiol and an organic acid mixture might reduce frothy bloat in cattle fed high‐grain diets.