Comparative Study Of Fiber Characteristics Of Different Particle Sizes Rice Husk And Corn Cobs, And Digestion And Utilization By Geese

In this study, the experimental materials were different particle sizes of rice husk and corn cobs, and adult Yangzhou geese were chosen as the experimental animals. The purpose of this study was to address the effects of different processing methods on fiber components and structure of rice husk and corn cobs, the effects of feeding different particle sizes of rice husk and corn cobs on digestion organs, the structure of digestive tract and intestinal histology, flow rates and mean retention time(RMT) of solid chyme as well as the utilization of fiber component, calcium and phosphorus, and so on. Moreover, we explored effects of particle sizes fiber on geese utilizing dietary fiber. The experiment was divided into four parts. Experiment one:effects of different fiber processing methods on fiber component and structure of different particle sizes of rice husk and corn cobs. The results showed as follows:Different particle sizes of rice husk and corn cobs were processed by methods including digestion of geese, as well as 1.5% NaOH,1.0% H2SO4,2.0% H2SO4, and these plus microwave heating. We determined the fiber composition of the processed rice husk and corn cobs and analyzed structure of that to evaluate their fiber properties. The result showed as folowed:The different fiber processing methods decreased percentage of hemicellulose of rice husk and corn cobs to some extent. The percentage of fiber component in rice husk or corn cobs was reduced through geese digestion. Effects of geese digestion on fiber component were larger than other processing methods inclouding acid and alkali treanments, and so on. The change of crystallization index and crystallinity of rice husk and corn cobs processed tended to be consistent. Moreover, the degree of crytallinity of rice husk and corn cobs was reduced after geese digestion. The decreases in degree of crytallinity of whole rice husk was larger than that of crushed rice husk, and that of crushed rice husk was larger than that of fine corn cobs. Experiment two:effects of different particle sizes of rice husk and corn cobs on production performance, intestinal physiology and digestive tract.Sixty of 35-week-old Yangzhou geese were randomly divided into 4 groups with 15 geese. Geese in groups were respectively fed on whole rice husk, crushed rice husk, crushed rice husk and fine com cobs for 21d. The test was conducted to test the effects of different particle sizes of rice husk and corn cobs on digestion organs, serum boiochemical index, physiological and biochemical indexes in the gut,and so on. The results showed as follows:1. The groups of geese fed with whole rice husk displayed a significantly increased serum glutamic-oxaloacetic transaminase (P<0.05). Total serum cholesterol and high density lipoprotein were significantly reduced in the adult geese fed with fine com cobs compared to those fed with coarse corn cobs (P<0.05).2. Whole rice husk feeding significantly improved liver weight and its relative weight of adult geese (P<0.01). Feeding whole rice husk significantly increased the weight and thickness of gizzard (P<0.05) and its relative weight (P<0.01). Whole rice husk diet significantly reduced relative length of total intestinal tract and duodenum (P<0.05). Feeding coarse com cobs significantly increased the absolute and relative weights of gizzard (P<0.01) and the relative length of jejunum (P<0.05), but that significantly reduced the relative weight of ileum weight (P<0.05). The group of geese fed with whole rice husk exhibited a significant increase in the pH value of duodenum (P<0.01), while particle size of corn cobs had no significant effect on the pH value (P>0.05). Feeding whole rice husk significantly decreased the wall thickness of jejunum (P<0.05). Coarse com cobs increased villous height of jejunum,decreased crypt depth of jejunum. The crypt depth of ileum was significantly reduced but the wall thickness of jejunum (P<0.05) was significantly increased (P<0.05) in the group of geese fed with coarse com cobs.3. Coarse com cobs feeding significantly increased body weight gain(P<0.05). There were no significant differences in body weight gain between groups of geese fed with whole rice husk and the crushed rice husk (P>0.05). There were no significant differences in slaughter performance between the groups of geese fed with whole rice husk and crushed rice husk as well as between coarse and fine com cobs (P>0.05). Experiment three:effects of different particle sizes of rice husk and corn cobs on flow rate and retention time (RTM) of solid chyme of gastrointestinal gract in geese.Sixty adult Yangzhou geese were used in this experiment. The flow rate and retention time (RTM) of solid chyme were determined with Cr-marked fiber to illustrate the digestive kinetics of different particle sizes of rice husk and corn cobs in goose gastrointestinal tract. The results showed as follows:Feeding whole rice husk significantly promoted the flow of solid chyme in ileum (P<0.01) and significant decreased the retention time of solid chyme in ileum (P<0.01). The flow rate of solid chyme in duodenum was increased in the group of geese fed with coarse com cobs. Experiment four:effects of different particle sizes of rice husk and corn cobs on the utilization of fiber component, calcium and phosphorus in geese.A total of 12 adult Yangzhou geese were divided into 2 groups with 6 each. Digestion trial was carried out by means of collection full excrements analysis method. After 24-h-fasting, each group of geese were force-fed with one type of diet. All excretion of each group was collected in 24h after force feeding with plates. The test was divided two times. There was a 11-day recovery period between treatments. Geese were forced with half of homozygous diet. The results showed as follows:The utilization of ADF and cellulose was significantly improved in the group of geese fed with whole rice husk,and the efficiency of utilization in this group was 24.33%(P<0.05), 23.95%(P<0.05) higher than that in the group of geese fed with crushed rice husk, respectively. However, the particle size of corn cobs had no significant effect on the utilization of dietary fiber (T>0.05). Moreover, feeding whole rice husk significantly decreased the utilization of phosphorus (P<0.01), but did not significantly change the utilization efficiency of calcium (P>0.05).Coarse corn cobs was significantly reduced the utilization of calcium (P<0.05) phosphorus (P<0.01), and the utilization efficiency was 26.92%,54.94% lower than that for fine corn cobs, respectively.In summary, the degree of crytallinity of different particle size of rice husk and corn cobs was decreased in the acidic environment of gastrointestinal tract, and these feeding materials became loose with increased number of pores to allow for more interactions with microbes and enzymes. Different particle sizes of rice husk and corn cobs affected digestion organs, gastrointestinal tract, serum biochemistry index, flow rates and mean retention time(RMT) of solid chyme as well as the utilization of fiber component, calcium and phosphorus in adult geese. Feeding whole rice husk and coarse corn cobs stimulated gastrointestinal tract, enlarged gizzard, promoted intestinal peristalsis, thus might lead to improvement in digestion system, utilization of dietary fiber, and feed conversion in adult geese. In one word, particle sizes affected utilizing fiber for geese, and using of whole rice husk and coarse corn cobs may result in better production in adult goose.