Influence de la cinétique d'évacuation gastrique de l'aliment sur l'insulinémie chez le veau préruminant

Abstract

Summary. Effect of gastric emptying on plasma insulin in the preruminant calf.The aim of this work was to clarify the possible role of blood metabolites (glucose, aminoacids, triglycerides) in the regulation of postprandial blood insulin in the preruminant calf. The animals used were 6 male Friesian bull calves with an average weight of 80 kg. They were divided into groups I and li. During the first experimental period (A), group I received a control diet that contained skim-milk powder as the only protein source, whereas group 11 received an experimental diet containing fish protein concentrate as the main protein source. During the second experimental period (B), the diets were switched.It was previously shown that the rate of fat and amino acid absorption increased when milk proteins in such milk substitutes were replaced by hydrolyzed fish proteins (Guilloteau et al., 1975).The results showed that during any experimental period in the control group, there was a decrease in the postprandial blood free amino nitrogen. Blood triglycerides exhibited a small increase at 0.5 h after the meal but a large decrease at 1-4.5 h. The meal also resulted in a very large increase in blood glucose with maximal values occurring at 1-4.5 h. Blood insulin showed a large increment at 0.5 h then increased slowly, peaking at 2-3 h. The postprandial increase in blood insulin was less during the first experimental period than during the second one.In calves fed the fish diet, blood free amino nitrogen and blood triglycerides showed a large postprandial increase. Blood glucose exhibited a smaller postprandial increment than in the controls and began to decrease at half an hour. In contrast, the trend of changes in blood insulin was the same as in the controls (i.e. a maximum at 3 h occurring after a large increase at 0.5 h). There were no significant differences in blood insulin between the two experimental periods. It was lower in the calves fed the fish diet than in the controls during the first experimental period ; during the second period, it was similar in both groups. From these observations, it may be inferred that, as compared to the control diet, the fish diet resulted in a decrease in glucose stimulation of postprandial insulin secretion ; in contrast, the effect of aminoacids and lipids may be increased.Le remplacement des protéines du lait par des protéines de poisson dans l'aliment d'allaitement distribué au veau préruminant entraîne une accélération de l'évacuation gastrique des lipides, des protéines et parfois du lactose (Guilloteau

The incorporation of solubilized wheat proteins in milk replacers for veal calves: effects on growth performance and muscle oxidative capacity

“…In that same period, the contribution of lipids (TG and NEFA) to the energy supply to muscleappeared here to increase in the first postprandial hours. The use of non-clotting milk replacers also improves insulin sensitivity [25]. In the present experiment, there were suggestions (lower insulinemia and glycemia) that animals fed the non clotting diets showed a less pronounced increase in insulin resistance with age (for a review [26]) than the C calves.…”

“…The use of non-clotting diets was also shown to enhance the postprandial amino acid supply, muscle protein synthesis rate [25] thereby possibly increasing the energy demand by peripheral tissues. Thus with the SWP containing diets, a quantitative increase in the utilization of energy-yielding nutrients is expected in the postprandial period itself.…”

Digestibility, blood levels of nutrients and skin responses of calves fed soyabean and lupin proteins

“…Thus despite the high contents of lipids reaching the duodenum, the circulating level of triglycerides remained unchanged or decreased with the control diet. This has been explained to be due to increased pancreatic secretion of insulin (Grizard et al, 1982). The drastic postprandial increase in plasma concentrations of triglycerides when the 2 legume diets were fed indicates an increased gastric emptying rate for lipids due to the lack of coagulation.…”

Contrôle hormonal du métabolisme hépatique chez les ruminants

“…Ils apportent enfin à des centres cérébraux sensibles, un message sur l'état du métabolisme périphérique (Woods et al, 1981 ;Le Magnen, 1984). Le (Grizard, Patureau-Mirand et Pion, 1976 ;Grizard et al, 1982 Trenkle, 1971 ;0,6-2,3, Grizard et Szczygiel, 1983) la chèvre (0,6-1, ou les bovins (0,3-4, Geay et Grizard, 1986 ;Hart, Bines et Morand, 1980). Ils sont aussi semblables à ceux rapportés chez des espèces monogastriques comme le chien ou le singe (Kanazawa, Kuzuya et Ide, 1968 ;lshiwata, Hetenyl et Vranic, 1969 ;Rubenstein et al, 1972 ;lshida et al, 1983 (Geay et Grizard, 1986).…”