Role of caeca in the nitrogen nutrition of the chicken fed on a moderate protein diet or a low rotein diet plus urea

Abstract

1. A study was carried out to investigate whether the back-flow of urine into the caeca benefits the nitrogen economy of adult cockerels fed on a diet containing 100 g protein/kg and when dietary urea is absorbed, excreted into urine and utilised. 2. No significant effects of colostomy on nitrogen utilisation were observed in chickens fed on 100 g/kg protein diet, whereas colostomy was highly effective in decreasing it in chickens on a diet containing 50 g protein/kg plus urea (P < 0.05). 3. Nitrogen utilisation in conventional birds was significantly less when a diet of moderate protein content was fed than when a low protein diet plus urea was fed, but the opposite effect was seen with colostomised birds (P < 0.05). 4. Colostomy increased urea excretion (nitrogen/kg body weight/day) from 4 to 9 mg in chickens fed on the moderate protein diet, but greatly, from 45 to 182 mg, in those fed on the low protein diet plus urea (P < 0.05). 5. Blood urea concentration increased by about 20 mg per 100 ml in 3 h, a value which was maintained up to 6 h but which returned to the prefeeding concentration at 24 h; both control and colostomised chickens on the low protein diet plus urea responded similarly. 6. After feeding urea, half the daily excretion of urea was observed to occur within 6 and 9 h, respectively, in control and colostomised chickens.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of Ligation of Ceca on Nitrogen Utilization and Nitrogen Excretion in Chickens Fed a Moderate Protein Diet or a Moderate Protein Diet plus Urea.

“…Dietary urea is suggested to be utilized in chickens fed on a low protein diet by entering the ceca by way of urine which back-flows from the cloaca to the ceca and being hydrolyzed in the ceca by micro-organisms (KARASAWA, 1989;KARASAWA and MAEDA, 1994). The increase in urea excretion and the decrease in ammonia excretion by cecal lgation in the present study at least support the suggestion that dietary urea enters the ceca along with urine and is hydrolyzed there in chickens.…”

“…These results are aimilar to previous findings with chickens fed a 5% protein diet or a 5% protein diet plus urea . Blood urea concentration was remarkably increased by feeding of urea as reported previously in chickens fed a low protein diet (KARASAWA and MAEDA, 1994). This accumulation of urea in the blood suggests an absorption of deitary urea in the intact form from the small intestine in chickens fed a moderate protein diet, because the essential initiator of the urea cycle, carbamyl phosphate synthetase, is absent in the fowl (TAMIR and RATNER, 1963).…”

“…It is also shown that colostomy reduces nitrogen balance in chickens fed a low protein diet or a low protein diet plus urea, but does not cause such a reduction in those fed a moderate protein diet (KARASAWA and MAEDA, 1994), suggesting that nitrogen recovery by way of ceca depends on the adequacy of dietary protein supply. It is possible, therefore, that the response of nitrogen balance to cecal ligation in chickens Received Aug. 7, 1995 All correspondence should be addressed to: Yutaka Karasawa, Ph.…”

Effects of Dietary Methionine or Arginine Levels on the Urinary Creatinine Excretion in Broiler Chicks

“…Therefore, creatinine in excreta was considered to be derived from urine. However, Karasawa and Maeda (1994) cannot be discussed whether intestinal bacteria in caecum influence the urinary creatinine or not. Chamruspollert et al (2002a) demonstrated that breast muscle creatine was affected by dietary arginine levels in broiler chicks.…”

Effect of colostomy on the occurrence of dietary [15N]urea in intestinal contents, blood, urine and tissues in chickens fed a low protein diet plus urea

“…The involvement of the caeca in the utilisation of dietary urea was also supported by the observation that urine was prevented from entering the caeca by colostomy and that such surgical modification had resulted in a considerable increase in urea excretion, almost accounting for all of the increase in total nitrogen excretion from colostomised birds (Karasawa, 1989;Karasawa and Maeda, 1994). However, in these previous studies, where the urea had been fed with a low protein diet, the value desired for nitrogen utilisation represented the combined utilisation of urea nitrogen and protein nitrogen, because the proportion of excretory nitrogenous compounds derived from dietary urea was not determined.…”