Control of the ruminal pH depression produced during the concentrate feeding - The possibility of the increase in a saliva secretion by the mechanical stimulus to the ruminal wall

2000 Fiscal Year Final Research Report Summary

• Project/Area Number: 11660273
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Zootechnical science/Grassland science
• Research Institution: Kitasato University
• Principal Investigator: YAMAZAKI Atusi KITASATO UNIVERSITY, SCHOOL OF VETERINARY MEDICINE AND ANIMAL SCIENCES, LECTURER, 獣医畜産学部, 講師 (60200648)
• Project Period (FY): 1999 – 2000
• Keywords: Ruminants / Ruminoreticulum motility / Mechano-receptor / Mechanical stimulation / Rumination / 機械的刺激 / 物理的刺激

Research Abstract

The influence which the mechanical stimulus added into the ruminoreticulum of a ruminant has on the saliva secretion, the ruminoreticulum motility, and the nature of digestion in a rumen during concentrate fed was investigated.
The +Stim conditions which added the mechanical stimulus to the rumen were compared with the control conditions (-Stim).
There was no significant difference in the number of ruminoreticulum contraction per day. However the rate of the rumination to a primary cycle increased significantly on +Stim conditions. Especially, the number of ruminations increased from the midnight to early morning. The amount of saliva secretions per day showed the tendency which increases on +Stim conditions. The increase at the time of a feeding was larger than -Stim conditions on +Stim conditions. The range of fluctuation within a day of a ruminal pH was small on +Stim conditions.
Especially, pH depression rate after feeding start was significantly smaller than -Stim conditions. The total VFA concentration in a rumen became high significantly on +Stim conditions, the rate of the dry-matter digestion in a rumen in +Stim conditions had the low rate of hay digestion, and its rate of concentrate digestion was high. The mechanical stimulus to the rumen given to the ruminant fed in the concentrate stimulated the mechano-receptor in a ruminoreticulum. The rate of a rumination was made to increase although a mechanical stimulus does not change the number of ruminoreticulum movements. Consequently, it was suggested that the increase in the amount of saliva secretions and the stability of pH in the stomach may be caused, and the improvement in the fermentability in a forestomach and the improvement in the rate of digestion may finally be caused.