Motility Patterns of the Cecum of the Horse

Gas handling in the caecum of the horse

“…The unexpected and surprising observation was that the caecal gas cap baseline pressure was almost always below atmospheric pressure in the hay-fed pony. A similar degree of negativity (-4 to -10 cmH20) was found using air-filled flaccid balloons in a fistulated horse by Howell & Cupps (1949). The possible significance of these values for the efficiency of fermentation appears to have been overlooked by subsequent workers.…”

“…A variety of caecal motility patterns was observed. To a large extent these are described elsewhere in the literature (Howell & Cupps, 1949;Dyce et al 1976; Ross et al 1986Ross et al , 1989. The combination of electromanometry and endoscopy confirmed previous interpretations of work using pressure profiles and the EMG technique.…”

“…Such unwanted preparations would create an unphysiological microenvironment and make quantitative measurements of caecal fermentation open to question either because of a failure of anaerobiosis or altered intra-caecal gas pressure. For example, during their early attempts, Howell & Cupps (1949) reported fluid losses from a fistula of as much as 450-900 ml min-' .…”

“…Investigations of the motility of the caecum of the horse (Howell & Cupps, 1949;Dyce & Hartman, 1973;Ruckebusch & Vigroux, 1974;Dyce, Hartman & Aalfs, 1976;Sellers, Lowe, Renando & Drost, 1982b;Ross, Martin & Donawick, 1985) have demonstrated a range of motility patterns which include local to-and-fro haustral movements and mass contractions directed in propulsive (aboral) and retropulsive (oral) directions. Some of these patterns are independent of the rest of the large intestines (Ross et al 1985;Ross, Rutkowski & Cullen, 1989) and others are part of a co-ordinated process of propulsion into the right ventral colon (RVC), the so-called 'important progressive pattern' (Ross et al 1985(Ross et al , 1989.…”

“…The caecal base appears to behave as two separate functional units with caudal and cranial compartments (Dyce & Hartman, 1973;Dyce et al 1976) separated by an incomplete transverse plical and haustral barrier which may deflect ileal chyme into the caecal body and apex (Sellers et al 1982b). Ingested food arrives at a caecal fistula within 90 min (Howell & Cupps, 1949) and both fluid and particulate material are rapidly emptied from the caecum (Argenzio, Lowe, Pickard & Stevens, 1974). Caecal motility may have a regulatory role in determining caecal volume and caecal-colonic passage time (Vigroux, Candau & Ruckebusch, 1975).…”