Digesta flow and mineral absorption in lambs before and after weaning

Abstract

Four young lambs fitted with cannulas at the pylorus and at the ileo-caecal junction were used to study the effects of weaning on digesta flow and mineral absorption. Prior to weaning when milk alone was fed the small intestine was the major site for dry matter disappearance and for the absorption of Ca, P, Na and K. Both the small and the large intestine were, however, important sites for Mg absorption at this time.After weaning, when the lambs were fed a concentrate diet, at least two-thirds of the digested dry matter disappeared within the reticulo-rumen. The small intestine, however, still remained the major site for the absorption of Ca, P, Na and K. Most Mg absorption, in contrast, now occurred anterior to the pylorus and it would appear that the move from hindgut to foregut as a site for Mg absorption was directly associated with the introduction of dry feed and the development of fermentative digestion within the reticulo-rumen.Both before and after weaning the faeces was the major route for the excretion of Ca surplus to requirement and the faeces also became increasingly important as a pathway for P and Mg excretion once dry feed was given. The urine, in contrast, was consistently the major pathway for the excretion of Na and K.

Absorption by sheep of calcium, phosphorus and magnesium from a poultry litter supplemented diet

“…The major role of the small intestine in P and Ca absorption, and that of the stomach in Mg absorption, has been demonstrated and confirmed in many studies with sheep (Ben-Ghedalia et al 1975;Tomas & Potter, 1976;Dillon & Scott, 1979). The data of the present study show that the absorption sites of Ca, P and Mg in sheep fod a PL-supplemented diet are the same as those found with conventional sources of the elements.…”

Influence of different calcium supplies and a single vitamin D injection on vitamin D receptor and calbindin D9k immunoreactivities in the gastrointestinal tract of goat kids

“…It can be concluded that the RU is a main site for active Ca transport mechanisms in growing goat kids. Previous studies described Ca net absorption before the DD in single-and multi-fistulated ruminants ( Pfeffer et al, 1970;Dillon and Scott, 1979;Wylie et al, 1985). Höller et al (1988) and Schröder et al (1997Schröder et al ( , 1998) also observed active Ca transport mechanisms in caprine and ovine rumen by Ussing chamber technique.…”

“…It is not known, how the ruminal Ca absorption influences Ca homoestasis (Martens, 2005). Different studies showed different results on the permeability of Ca across ruminal epithelium (Pfeffer et al, 1970;Dillon and Scott, 1979;Schröder et al, 1995;2001).…”

FLUX OF CALCIUM ACROSS THE SHEEP RUMEN WALL IN VIVO AND IN VITRO

“…In balance experiments with sheep cannulated in the proximal duodenum or supplied with fistulae in the abomasum and fed between 2 and 18 g calcium/day, Ca2+ movement through the pre-duodenal part of the gastrointestinal tract was measured by several authors. Ca2+ net secretion into the tract in the range between 0.15 and 1-44 g/day was found by Pfeffer, Thompson & Armstrong (1970), Ben-Ghedalia, Tagari, Zamwel & Bondi (1975), Greene, Webb & Fontenot (1983) and Wylie, Fontenot & Greene (1985), Ca2+ net absorption from the upper part of the tract of between 0 5 and 4-3 g/day was observed by Grace, Ulyatt & MacRae (1974), Leibholz (1974), Dillon & Scott (1979), Breves (1985) and Grings & Males (1987), whereas no Ca2+ net movement across the walls of this region was detected by Pfeffer (1968) and Sklan & Hurwitz (1985). It should be noted, however, that all balance data cited above included endogenous Ca2+ inflow with saliva which should amount to 0 2-0 3 g/day (Rosenhagen, 1985) and also some addition of Ca2l with gastric juice.…”