Studies on Cecal Morphalogy, Development and Methane Production in White Roman Geese

• Main Authors: Yieng-How Chen, 陳盈豪
• Other Authors: Jenn-Chung Hsu
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/78764407068432883887

博士 === 國立中興大學 === 畜產學系 === 91 === This study involved 5 experiments to investigate fine structure and development model of cecum, the importance of cecum, and to establish caecum content methane production model, and the effect of dietary fiber levels on volatile fatly acid （VFA）production in cecum of goslings. In experiment 1, The objective of this study was to investigate the villus distribution in the ceca of domestic geese based on the fine structure. The ceca of White Roman geese, 14-week old, were sampled and specimens were detected under photomicroscope and scanning electron microscope （SEM）. The results indicated that the villi existed at the proximal cecum. The morphologies of these villi showed finger-like, peak-like or tongue-like shapes. The heights of the villi decreased far from the proximal caecum. No villi were found in the middle and distal cecum. It was obvious that the proximal segment was the main portion for absorbing food nutrients in the ceca. The surface of the middle cecum exhibited parallel ridges with no villi. There were band plicae circular shapes found in the middle cecum under scanning electron microsopy. In experiment 2, this study was conducted to determine the development of hindgut in goslings during early age. Thirty-six 1-day-old White Roman goslings were used. The lengths and weights of caecum as well as colon and rectum were measured and the hindgut specimens were detected under lightmicroscopy from 0 to 4 wks old. The results indicated that the lengths of ceca, colon and rectum in goslings increased as age increased（P<0.05）. The relative length of ceca（ceca/intestine）increased as age increased, whereas the relative length of colon and rectum（colon and rectum/ intestine）decreased as age increased. The weights of ceca, colon and rectum, and body from 0 to 4 wks of age increased 32.6, 10.7, and 17.7 fold, respectively. The villus height, villus line, villus area, crypt depth, and muscle layer of cecum as well as colon and rectum in goslings increased as age increased（P<0.05）and those increased 2.86, 1.79, 3.52, 9 and 5.16 fold in cecum, respectively at 4 wks of age compared to those at 0 wk of age. However, those increased were 3.42, 1.78, 3.22, 5.87 and 2.39 fold in colon and rectum, respectively at 4 wks of age compared to those at 0 wk of age. There were linear relationships between morphology parameters and age in caecum as well as colon and rectum. The villus height, villus line, villus area, crypt depth, and muscle layer of colon and rectum were larger than those of caecum in gosling during 0 to 4 weeks of age（P<0.05）. In experiment 3, the purpose of this study was to investigate the effects of caecectomy on intestinal characteristics, body weight gain and enteric gas production in goslings. This study included two trials. In trialⅠ, forty eight 2-wk-old female White Roman goslings with similar body weight were randomly divided into four treatments: sham（SHAM）, left side cecum removed（LSCR）, right side cecum removed（RSCR） and both ceca removed（CECECTOMY）. In trial Ⅱ, twelve 5-wk-old male White Roman goslings with similar body weight were randomly divided into two treatments: SHAM and CECECTOMY. At the end of trial Ⅰ, goslings were sacrificed to determine their gut length and weight . At 7 and 9 wks of age in trial Ⅱ, two birds from each treatment were put into one respiratory chamber as a measurement unit. The gas accumulated in the chamber was collected and analyzed for measuring methane and nitrous oxide production. In trial Ⅰ, results indicated that there were no significant differences in body weight gain among the treatments in the entire experimental period. However, the SHAM goslings had a higher average daily gain than cecetomised birds from 2 to 3 wks of age. Cecectomy did not significantly affect relative weight (g/100g BW) of gizzard, small intestine, rectum and colon weight (P>0.05); however, the relative lengths of the colon and rectum did increase (P<0.05). The remaining cecum did not show compensatory growth in both LSCR and RSCR treatments. There were the highest serum total chlosterol and the lowest uric acid concentration of goslings in caectomised birds (P<0.05). In experiment 2, results indicated that the SHAM goslings had higher average daily gain than the cecectomy group from 5 to 7 wks of age (p<0.05). However, there was no significant difference from 7 to 9 wks of age (p>0.05). The average enteric methane production from the SHAM goslings was significantly higher than that from the CECECTOMY birds (40.82 vs. 3.68 mg/ bird/day or 17.61 vs. 1.68 mg/kg BW/day；P<0.05). The enteric nitrous oxide production in goslings was very low and not significantly different between the two treatments (p>0.05). In experiment 4, Three trials were conducted to determine the methane production rate of cecum content, and the conversion of methane from formic acid and acetate in caeca of goslings. In trial Ⅰ, twenty-four 1-day-old female White Roman goslings were fed low (basal diet, 0 % rice hull) or high dietary fiber (8 % rice hull) diet for a 4-wk experimental period. cecum contents of goslings were sampled to measure the methane production. Twelve 4-wk-old White Roman goslings were used in trial Ⅱ and Ⅲ, respectivity. Goslings were fed commercial diet and allocated to control (injected the ceca with saline) and experimental groups ( injected the ceca with formate in trial Ⅱ and acetate in trial Ⅲ). After drug was injected into cecum of goslings, two birds from each treatment were put into a respiratory chamber as a measure unit for 3 hours, and repeated 3 times. Results indicated that the methane production was 14-20 µg/ g cecal content/hr in goslings and it was affected by microbial fermentation. Compared with the control group, the methane production increased 8.6 fold in cecum injected with formate (0.86 vs 0.10 mg/kg BW/day; P<0.05). However, there was not significant difference between acetate injection and control treatments (P>0.05). The present study suggests a possibility that acetate might be not a precursor of methane in caeca of goslings. In experiment 5, three trials were conducted to determine the effect of time and pH value on methane production in cecum content of goslings. In trialⅠ, One gram of caecum content from 14-week-old White Roman goslings was put into serum bottle and anaerobically incubation at 38 ℃ for 0, 0.3, 1, 2, 3, and 4 hours. In trial Ⅱ, the pH values of incubation buffer solution were adjusted to 2.4, 5.4. 6, 6.5 and 8.8 with chloride hydrogen. The sampling cecum content and incubation method was the same as trialⅠ. In trial Ⅲ, formic acid were added into incubation buffer solution and the pH were adjusted to 5.4. 6, 6.3 6.5, 7.1, 7.5 and 8.3. In trial Ⅱ and trial Ⅲ, the caecum content were incubated for 3 hours and then the production of methane was measured. Results indicated that the methane production rate increased with incubation time increased and the methane production rate was the highest（P<0.05）at 0.3-1 hour, however, after 2-hour incubation, the methane production rate decreased with incubation time increased（P<0.05）. In trial Ⅱ, the methane production of caecum content decreased significantly（P<0.05）when pH value of incubation buffer solution decreased from 6.0 to 5.4. In trial Ⅲ, the methane producton of caecum content had a tendency（P>0.05）to decrease when pH value of incubation buffer solution decreased from 6.0 to 5.4. ( KeyWords: Goslings, Cecum, Morphology, Development, Methane.)