Breed dependent influences on relative size of intestinal tract as well as composition of its chyme in rabbits
Wolf, P.; Zumbrock, B.; Kamphues, J.
Zuchtungskunde 82(2): 165-175
While in laboratories and in meat production primarily larger breeds of rabbits are used smaller ones (e.g. dwarf rabbits) are predominantly kept as pets. At the same time, data on nutrition physiology and digestive capacity generally gathered for larger rabbit breeds are sometimes indiscriminately applied to dwarf rabbits. However, in feeding studies on digestibility in different rabbits breeds (smaller and greater ones) dwarf rabbits showed a higher digestibility rate than New Zealand White or Belgian Giants. Therefore, this study was conducted to illustrate physiological parameters in the intestinal tract and possible breed-related peculiarities. The experiment was carried out with 5 adult female rabbits each of the breeds Belgian Giant (BG; circle divide BW 7.27 +/- 0.18 kg), New Zealand White (NZ; circle divide BW 4.36 +/- 0.60 kg), and Dwarf rabbit (DR; circle divide BW 1.82 +/- 0.30 kg), that were fed a pelleted complete diet on the basis of green meal. After an adaptation of 10 days the rabbits fasted about 24 hours. On the next day they get 1 g diet per 100 g BW. Chyme of distinct individual compartments (stomach, duodenum, caecum, proximal/distal colon, rectum) was analysed 6 h ppr. using standard analyses methods (nutrients, pH, NH(3), FFA, lipopolysaccharides). Particle sizes in chyme and faeces were determined via wet sieve analysis. It can be concluded, that dwarf rabbits are more similar to New Zeeland white than to German Giants. In dwarfs as well as in New Zealand white a higher chewing activity of the offered diets could be observed, measured by the proportion of the particle sizes in chyme and faeces. A higher proportion of finely ground particles, that was microbially degraded after a reflux into the caecum, led in a higher extent to caecotrophia and therefore to a higher digestibility of nutrients in dwarfs and new zeeland white compared to German Giants. All in all it could not be decided if a faster passage rate of the chyme from the gastric via duodenum into the caecum - as it could be observed in the dwarfs - led to higher digestibility rates by a longer rentention time and a higher hydrolysis of the feed in the caecum.