A 3 to 4 week feed restriction of about 20% to 25% of the free intake is widely applied in rabbit breeding systems to reduce post-weaning digestive disorders. However, a short intensive feed restriction is described in few studies and can be beneficial for growing rabbits due to a longer re-alimentation period. The aim of this study was to evaluate the effect of ad libitum (AL) and two restriction levels of feeding (50 and 65 g/rabbit per day) applied for 1 week on performance, gastrointestinal morphology and physiological parameters during the restriction and during the re-alimentation period. Rabbits were divided into three experimental groups: AL rabbits were fed AL, R1 rabbits were restricted from 42 to 49 days of age and received 50 g daily (29% of AL) and R2 rabbits were restricted at the same age and were fed 65 g of feed daily (37% of AL). In the 1(st) week after weaning and in the weeks after restriction, all the groups were fed AL. During the restriction period, daily weight gain (DWG) in R1 significantly dropped to 11% (experiment 1) and 5% (experiment 2) compared with rabbits in the AL group, although they were fed 29% of AL, whereas in the R2 group it decreased to 20% (experiment 1) and 10% (experiment 2). In the week following feed restriction, DWG in the restricted groups increased (P<0.001) to 166% and 148% in R1 and to 128% and 145% in R2. Restricted rabbits in both the experiments reached up to 90% to 93% of the final live weight (70 days) of the AL group. Over the entire experimental period, feed restriction significantly decreased feed intake to 85% to 88% of the AL group; however, the feed conversion ratio was lower (P<0.05) only in experiment 1 (-6% in R1 and -4% in R2). Digestibilities of CP and fat were not significantly higher during the restriction period and during the 1(st) week of re-alimentation compared with the AL group. Significant interactions between feeding regime and age revealed the shortest large intestine in the AL group at 49 days of age and the longest at 70 days in the AL and R1 groups. Small intestinal villi were significantly higher and the crypts were significantly deeper in the restricted groups. It could be concluded that short intensive feed restriction increased digestible area in the small and large intestines, including the height of villi and depth of crypts, which might be involved in the compensatory growth and defence mechanism.

• Klíčová slova
• feed consumption, feed restriction, gastrointestinal tract, growth, rabbit,
• MeSH
• časové faktory MeSH
• dieta veterinární   MeSH
• hmotnostní přírůstek MeSH
• králíci růst a vývoj   fyziologie   MeSH
• odstavení MeSH
• potravinová deprivace fyziologie   MeSH
• tělesná hmotnost MeSH
• trávení * MeSH
• trávicí systém růst a vývoj   MeSH
• zvířata MeSH
• Check Tag
• králíci růst a vývoj   fyziologie   MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Data are summarized about digestion and absorption of carbohydrates, lipids and proteins during mammalian perinatal development including human fetuses. Corresponding with the high fat intake in suckling rats, absorption of triglycerides was found to be approximately 2-3 times higher in suckling than in adult rats. Carnitine contents of the small intestinal mucosa of rats decrease postnatally, reaching adult levels at the time of weaning. Other studies suggested that gluconeogenesis may occur in the small intestine in the neonatal period. The intestinal mucosa of infant rats produces ketones; it was suggested that ketone production is to a large extent due to a breakdown of long-chain fatty acids. Studies dealing with the development of colonic sodium transport in rats are described. Other studies on the developing colon showed that the proximal colon resembles ileum during the early postnatal period. Developmental changes of the "specialization" of intestinal segments are reviewed. In all studies attention is given to the maturative effects of hormones of the adrenal cortex and thyroid gland (88 references).

• MeSH
• dospělí MeSH
• krysa rodu Rattus MeSH
• lidé MeSH
• trávicí systém - fyziologické jevy MeSH
• trávicí systém embryologie   růst a vývoj   MeSH
• zvířata MeSH
• Check Tag
• dospělí MeSH
• krysa rodu Rattus MeSH
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Using mounting casein and wheat gluten protein values (0-40%) in the animals' diet, the optimum and minimum physiological daily doses were determined in 49-day-old growing rats from changes in their body water, body nitrogen and protein intake. The optimum physiological doses were identical with the peak of linearity of the given parameters, which coincided with a 15% casein protein and a 20% gluten protein concentration in the diet. This was also confirmed by the maximum body amino acid values, which were found in animals given a 15% casein or 20% gluten protein diet. It was further confirmed by the finding of significantly elevated alanine aminotransferase and aspartate aminotransferase activity in the liver of animals with a higher intake of the above protein sources. The minimum physiological dose of the given protein was determined from the equations of the regression curves in the presence of zero changes in the body nitrogen or body water content. The optimum physiological daily doses of casein and wheat gluten protein were 3.25 g and 4.05 g respectively. The minimum physiological daily doses of casein protein were 268 mg (from body nitrogen changes) and 371 mg (from body water changes) and the minimum physiological daily doses of gluten protein were 892 mg (from body nitrogen changes) and 1,000 mg (from body water changes). The above indicators demonstrate, in the presence of higher and high dietary concentrations, that an intake of the given proteins over and above the optimum physiological daily dose is at the very least uneconomical (gluten), if not harmful (casein), making this a highly topical problem for further study.

• MeSH
• alanintransaminasa metabolismus   MeSH
• aminokyseliny analýza   MeSH
• aspartátaminotransferasy metabolismus   MeSH
• dietní proteiny * MeSH
• dusík analýza   MeSH
• gluteny * MeSH
• inbrední kmeny potkanů MeSH
• játra enzymologie   růst a vývoj   MeSH
• kaseiny * MeSH
• krysa rodu Rattus MeSH
• stárnutí MeSH
• tělesná hmotnost MeSH
• tělesná voda analýza   MeSH
• trávicí systém růst a vývoj   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Názvy látek
• alanintransaminasa MeSH
• aminokyseliny MeSH
• aspartátaminotransferasy MeSH
• dietní proteiny * MeSH
• dusík MeSH
• gluteny * MeSH
• kaseiny * MeSH

• MeSH
• dýchací soustava růst a vývoj   MeSH
• kojenec MeSH
• lidé MeSH
• nervový systém růst a vývoj   MeSH
• novorozenec MeSH
• růst * MeSH
• trávicí systém růst a vývoj   MeSH
• vývoj dítěte * MeSH
• výzkum * MeSH
• Check Tag
• kojenec MeSH
• lidé MeSH
• novorozenec MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH
• Geografické názvy
• Československo MeSH

• MeSH
• krysa rodu Rattus MeSH
• ledviny růst a vývoj   MeSH
• odstavení * MeSH
• slezina růst a vývoj   MeSH
• trávicí systém růst a vývoj   MeSH
• velikost orgánu MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH