Effects of vagotomy, atropine, hexamethonium and adrenaline on the destination in the stomach of liquids sucked by milk‐fed lambs and calves

Abstract

SUMMARY1. The normal passage to the abomasum of liquid sucked by lambs and calves was confirmed in radiographic studies to be changed to passage of liquid to the reticulum and rumen after cervical or abdominal vagotomy.2. The effects of hexamethonium (8-10 mg kg-1 i.v.) were similar to those of vagotomy.3. Atropine (200-800,g kg-' i.v.) had either no detectable effect on the destination in the stomach of liquid sucked by lambs or caused a partial failure of the reticular groove mechanism.4. Fluid sucked by lambs passed wholly to the abomasum after adrenaline (5-40 #ug kg-' i.v.).5. Atropine and adrenaline caused a greater dysfunction of the reticular groove mechanisms in calves than in lambs.6. Contraction of the reticular groove was observed via rumen fistulae in three lambs. Eversion of the caudal oesophagus into the reticulum which occurred when saliva was swallowed into the reticulum and rumen was not observed when liquids were sucked from a bottle.7. The continued passage to the abomasum of sucked liquid in atropinized lambs has been taken as an indication of the importance of caudal oesophageal reactions, tonic activity of the reticular groove and the atropine-resistant vagally induced opening of the reticulo-omasal orifice in the reticular groove mechanism.

Consequences of failure of the reticular groove reflex in veal calves fed milk replacer

“…The reticular groove reflex has been studied intensively in the past (7,12,13,14,16,20,21). Most of these studies were done in lambs, and in almost all cases the animals were allowed to suck a rubber nipple attached to a bottle or a bucket.…”

The Effects of Vagotomy on the Abomasum in Calves: Radiography and Protein Gene Product 9.5 Immunohistochemistry.

“…Although a vagal nervous dysfunction has been suggested as a possible cause of abomasal disorders [16], vagal nerve injury in the abomasal wall is still uncertain. The distribution of vagal nerve endings in the sheep stomach has been reported after short-term vagotomy [15], however, the long-term effects of vagotomy on the mural innervation of the ruminant stomach have not been described.Radiographic studies of the abomasum of lambs and calves before and after vagotomy were mostly undertaken during motility [17] and abomasal emptying [1]. The former was a short-term investigation while the latter maintained the calf after vagotomy by cannulation feeding into the abomasum.…”

“…Radiographic studies of the abomasum of lambs and calves before and after vagotomy were mostly undertaken during motility [17] and abomasal emptying [1]. The former was a short-term investigation while the latter maintained the calf after vagotomy by cannulation feeding into the abomasum.…”

Plasma cholecystokinin concentrations in 3-day-old lambs: effect of the duration of fasting preceding a sucking bout

“…In both experiments, however, postprandial levels of CCK rose back to pre-fasting concentrations and never above. This postprandial increase most likely reflects the stimulatory effect of milk on the endocrine cells as digesta passes through the duodenum within minutes after feeding has ended (Newhook and Titchen, 1974 (Guilloteau et al, 1994). The absence of a substantial increase in CCK induced by feeding when lambs were fasted for 1-2 h could be ascribed to the high basal concentrations of CCK that are present during the neonatal period.…”