Nature de l'aliment, finesse de mouture et données anatomo-fonctionnelles du tube digestif proximal du lapin

Abstract

Summary. Diet type, grinding size and anatomo-functional characteristics of the proximal digestive tract in rabbits.Two diets containing either dehydrated lucerne (40 %) or dehydrated beet pulp (50 %) both being coarsely (4 mm) of finely (1 mm) ground before pelleting, were fed to 120 rabbits after weaning. Feed intake and weight gain were estimated.After 79 days, 11 rabbits in each group were slaughtered between 14.00 and 17.00 h. The parameters measured were stomach and ileal weights, dry matter, fibre and nitrogen contents, volatile fatty acid concentrations. Gastric emptying and intestinal transit time were estimated in each group.Rabbits fed the beet pulp diet had a better feed conversion ratio associated with a higher solid matter gastric retention and also a longer jejuno-ileal transit time.Finely ground diet further increased the transit time, particularly in the ileon, which was also associated with a higher concentration of fermentation by-products.Introduction.

Replacement of digestible fibre by starch in the diet of the growing rabbit. I. Effects on digestion, rate of passage and retention of nutrients

“…Compared to low digestible fibres (such as cellulose), pectins (for instance provided by beet pulp) are supposed to slow down the digestive transit in monogastric animals [22,37]. In the rabbit, this effect has been mentioned for the liquid phase between the mouth and ileum [2]. Our results indicated on the contrary, a shorter caecal retention time (either for solid or liquid phase) when the level of pectins and hemicelluloses increased.…”

Effect of different feed grinding fineness on the performances and digestive efficiency of growing rabbits

“…Alicata et al [1] and Diaz Arca et al [7] did not find any improvement of these parameters using feeds with a finer particle size. In other trials, feeds with smaller particles than those currently used were able to improve feed/gain ratio [3,13] or induce a better growth in the first breeding period [6]. On the contrary, diets with very small particles sizes (∅ < 0.25 mm) induced a significant reduction of growth rate [15].…”

“…De même, la composition chimique des classes granulométriques a été différente. En particulier, la fraction la plus grossière des aliments (∅ > 1 mm) contenait 40,9 % de NDF pour le lot F et 27,7 % pour le lot G ; la fraction la plus fine (∅ < 0,25 mm) au contraire contenait 42 % de NDF pour le lot G et 32,5 % pour le lot F. Ces différences n'ont toutefois pas eu d'influence significative sur les performances de croissance (GMQ : 32 g) et l'indice de consommation alimentaire (3,6), ni sur les données d'abattage (rendement de carcasse : 62 %), le poids du caecum plein, le contenu caecal et le nombre de coliformes de celui-ci. Le pH du caecum s'est révélé semblable pour tous les lapins (5,84, 5,93 et 5,96 pour les lots G, F et C, respectivement) ainsi que la composition chimique du contenu caecal.…”

“…The results from different trials support a close relationship between diet particle size and digesta transit rate [8,9,13]. On the contrary, they do not univocally outline the effects on the performances and digestibility of dietary components [1,3,7,15].…”

Nutrition of the rabbit

“…Increasing the dietary fibre contents from 220 to 400 g kg -1 decreased the total mean retention time by 12 h (an 11 h reduction in the ileo-rectal mean retention time) (Gidenne, 1994). Particle size can also modify the rate of passage, with longer times being obtained using diets with smaller particle size (Laplace and Lebas, 1977;Auvergne et al, 1987).…”