The effect of different feeds, including those containing soya-bean products, on the passage of digesta from the abomasum of the preruminant calf

Abstract

I. The effects of various factors on rates of flow and composition of digesta leaving the abomasum of preruminant calves were studied. The possible relation of some of these effects to the development of serum antibodies to certain dietary constituents has also been examined. Two situations were distinguished : (a) unsensitized responses, shown by calves receiving milk protein or soya-bean products for the first one or two occasions; (b) sensitized responses, shown by calves receiving certain soya-bean products, after a number of these feeds had been given.2. For unsensitized calves, the rate of flow of total digesta from the abomasum was greater in the first few hours after a feed consisting of a mineral solution was given, than after cow's milk was given. This difference was apparently due to differences in the composition of digesta entering the duodenum. Total digesta flows after giving synthetic milk feeds, prepared from different protein sources, were similar to those after cow's milk was given.3. For sensitized calves, rates of flow of total digesta from the abomasum were greatly affected by the nature of the protein source used in the diet. Soya-bean flour (heated or unheated) generally caused inhibition of flow for some hours after feeding; a soya-bean protein isolate (isoelectric) had a similar but smaller effect, but a soya-bean concentrate (prepared by alcohol extraction of a soya-bean flour) and milk protein had little or no effect. The inhibition, believed to be a sign of more general disorders, appeared to be caused by a factor entering the duodenum which induced a change in the way in which the calf responded, probably as the result of a gastrointestinal allergy. 4.Calves given soya-bean flour or a soya-bean protein isolate (isoelectric) in their diets for several weeks, showed respectively high and low titres of serum antibodies to an antigen prepared from soya-bean flour. Calves given alcohol-extracted soya-bean concentrate had no similar antibodies.5. In addition to variations in total digesta flow, dietary nitrogen compounds were held up in the abomasum to different extents after different feeds. After a whole-milk feed or a synthetic feed prepared from casein, a slow, steady release of N occurred over at least 9 h. N hold-up after giving soya-bean-containing feeds was slight for the soya-bean flour, but extremely marked for the soya-bean protein isolate (isoelectric). The latter hold-up was followed after several hours by a rapid outflow of N from the abomasum.The movement of digesta from the abomasum of a calf given a feed of cow's milk is a slow, well-controlled process (Ash, 1964; Mylrea, 1966a). The rate of flow of digesta is most rapid immediately after this type of feed and decreases progressively with time, although a considerable flow continues for many hours and remains appreciable even after an 18 h fast. With increasing time the digesta contain greater proportions of materials of endogenous origin, but certain dietary constituents continue to be found for many hours. This applies ...

Effect of Age on the Exocrine Pancreatic Secretion of the Preruminant Milk-fed Goat

“…The secretory pattern after the ingestion of milk, as measured by the flow rate and the electrolyte concentrations, seems to indicate the presence in these animals of a continuous abomasal emptying and a consistently acid pH in the proximal duodenum. Experiments performed by Toullec et al (1971) and Smith and Sissons (1975) in calves, as well as those carried out by Hernandez-Clua et al (1988) in goat kids, evidence a continuous emptying of milk that lasts until the end of the 8 hours experimental period. Such emptying reaches maximum values during the first three postprandial hours.…”

Effects of processing methods for soybean meal used in milk replacers on intestinal xylose uptake and serum antibody to soybean antigen when fed to calves of various ages

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Susceptibility of Proteins Used in Calf Milk Replacers to Hydrolysis by Various Proteolytic Enzymes

“…J. Anim. into the small intestine (Hill et al 1970 (Smith and Sissons 1975 .--{ \'u*-r:€tsXttbbs * R:: e 9q"1.1"? \ !q I !"?…”