| Summary: | 碩士 === 國立嘉義大學 === 動物科學系研究所 === 94 === The purpose of this study was to investigate the effects of dietary supplementation with nilegrass on growth performance, digestive tract development and protease activity in White Roman geese. This study includes two trials. In trial 1, total of 240 one day old White Roman goslings divided randomly into 4 groups through sex and body weight, each group has three replicate. In experimental period 2-5 weeks old, geese were fed 4 treatment diets that contained 3, 6, 9 and 12% fiber. In experimental period 6-9 weeks, birds were fed 4 treatment diets that contained 4, 8, 12 and 16% fiber. Nilegrass were the chief fiber resource of feed. In trial 2, 180 one day old White Roman goslings divided randomly into 3 groups through sex and body weight, each group has three replicate. The experimental period 2-5 week included three groups: (1)control group which was contained 3% crude fiber in diet, (2)Nilegrass hay group which was used nilegrass hay to adjust dietary fiber to 6%, (3)Nilegrass group which was used nilegrass to adjust dietary fiber to 6%. In experimental period 6-9 week old, (1)control group which was contained 4% crude fiber in diet, (2)Nilegrass hay group which was used nilegrass hay to adjust dietary fiber to 8%, (3)Nilegrass group which was used nilegrass to adjust dietary fiber to 8%. The experimental birds were adopted floor raise. There are 20% crude protein and 2900 kacl/kg metabolisable energy of 2-5 week old period diet, and 15% crude protein, 2900 kcal/kg metabolisable energy of 6-9 week old period diet, respectively. Feed and water were supplied ad libitum.
The trial 1 results indicate that the 6% fiber level of 2-5 week old period and 4% fiber level of 6-9 week old period has greatest feed intake and average daily gain (P<0.05). The weight and length of digestive organ of geese were increase as follow the dietary fiber levels increased on 5 and 9 weeks old (P<0.05). The activity of pepsin in the mucosa of proventriculus was decreased by higher dietary fiber level (P<0.05). The 6% fiber level in 5 week stage and the 8% fiber level in 9 week stage, the activity of trypsin and chymotrpsin of small intestine had the highest than other groups (P<0.05). The 6% fiber level group has the highest trypsin activity of pancreas at 5 week (P<0.05). The specific activity of trypsin and chymotrypsin in pancreas were significantly increased in 8% fiber level group (P<0.05). The geese has greatest villi growth abilities when dietary contained 12% fiber level (P<0.05), villi growth abilities were became slowly when dietary fiber over 12%. The duodenum of geese has wider and bigger villi which shape were plate-like and leaf-like at 9 weeks old. The size of jejunum villi were became bigger when dietary contained higher fiber level. However, the size of jejunum villi were decreased when dietary contained over 8 % fiber. The villus of jejunum was tongue-like shape on 4 and 8% treatment groups, and thin tongue-like shape or finger-like shape on 16% treatment groups. The villus of ileum has thin stick-like shape of 4 to 12% treatment groups, and has thick, short, bigger and column-like shape on 16% group. The caecum mucosa has wave-like shape, ruga of the mucosa surface were increased when dietary contained higher fiber. In short chain fatty acid composition, when the dietary fiber was increased, the concentration of acetic acid was decreased, and the concentration of propionic acid and butyric acid were increased. In the blood trails, the concentration of blood glucose was significantly increased and the concentration of amylase, cholesterol and triglyceride was opposite results (P<0.05).
The results of trial 2 indicated that the birds has the greatest feed intake and average daily gain when geese fed nilegrass (P<0.05). The weight of caecum was increased significantly on nilegrass hay than the other groups at 5 and 9 weeks old (P<0.05). Dietary supplementation of nilegrass has longer intestine length on 5 weeks old than other treatment group (P<0.05). When the dietary with nilegrass at 9 weeks old, the length of small intestine and caecum were longer than other groups (P<0.05). The nilegrass hay and nilegrass group has the lowest pepsin activities in the mucosa of proventriculus, the activities of trypsin and chymoytypsin in the small intestine and pancreas were significantly higher than control group (P<0.05). The ability of development in intestine villi were greatest in nilegrass hay group, lesser in nilegrass group and poor in control group. The appearance of duodenum villi were tongues-like shape and leaf-like shape. The villi of duodenum were dense and showed various shape in nilegrass hay group, and the villi of duodenum in nilegrass group were longer and had thin sparse tip. However, the villi of jejunum and ileum were thin, dense and has finger-like shape. The villi of jejunum and ileum had thin and short tip. The villi of caecum were display wave-like shape. The flods of villi surface were clearly in nilegrass and nilegrass hay group. In short chain fatty acid composition, the molar percentage of acetic acid were significantly lower in nilegrass hay and nilegrass group than control group (P<0.05), the molar percentage of propionic acid and butyric acid were significantly higher than control group (P<0.05). The concentration of amylase, cholesterol, triglycerol, and total lipid were decreased significantly in nilegrass hay or nilegrass group (P<0.05).
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