The mechanism of accumulation of abomasal gas in cows with abomasal displecement

2005 Fiscal Year Final Research Report Summary

• Project/Area Number: 16580260
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Clinical veterinary science
• Research Institution: Obihiro University of Agriculture and Veterinary Medicine
• Principal Investigator: YAMADA Haruo Obihiro University, Agriculture and Veterinary Medicine, Professor, 畜産学部, 教授 (20003113)
• Co-Investigator(Kenkyū-buntansha): KITAMURA Nobuo Obihiro University, Agriculture and Veterinary Medicine, Professor, 畜産学部, 教授 (70142792) ; SASAKI Naoki Obihiro University, Agriculture and Veterinary Medicine, Associate Professor, 畜産学部, 助教授 (00360975) ; TAKAHASI Jun-ich Obihiro University, Agriculture and Veterinary Medicine, Professor, 畜産学部, 教授 (20111198)
• Project Period (FY): 2004 – 2005
• Keywords: dairy cattle / abomasal displacement / abomasal gas / plasma NO concentration / NOS nerve / tunica muscularis nerve / vagoiomized calf

Research Abstract

To clarify an etiological factors of abomasal gas in bovine abomasal displacement (AD), components of ruminal and abomasal gas in cows with abomasal desplacenennt, plasma nitric oxide (NO) concentration in cows with and without AD, the distribution of nerves containing immunoreactivity for PGP 9.5,VIP,MENK,TH,NOS,GAL in abomasal wall with and without AD, and the distribution of nerves containing immunoreactivity for PGP 9.5,VIP,MENK,TH,NOS,GAL in the reticulorumen and abomasums of vagotomized calves were investigated.
Plasma NO concentration in cows with AD (23.5±9.0μmol/L) was significantly higher than that without AD (10.3±7.2μmol/L). In cows without AD,VAT,SP,MEN-immunoreactive cell were high density dispersed on the outer muscle layer in the tunica muscularis.
On the other hand, in cows with AD, the density of all immunoreactive cells decreased significantlly in comparison with those of cows without AD. Generally, these immunoreactive nerves in the corpus, proximal and distal areas of the pyloric region were more influenced than those in the cardiac region. In the vagotomized calves, the milk first entered the rumimoreticulum and then the abomasums. Tonus of abomasums was detected just after vagotomy, and atony with dilatation of the abomasums was detected 4 and 7 days after vagotomy in radiograms. The nerve distribution particularly decreased significantly in the proximal and distal areas of the ruminoreticulum, the corpus region 4 days after vagotomy.
Present study indicates that the decreasing frequency of intramural nerve from the vagus nerve in tunica muscularis could be one of the etiological factors of abomasal gas in bovine abomasal displacement.