| (College of Animal Science and Technology, Yangzhou University,225009) The effects of dietary fiber levels on the production performance, slaughter performance,、the apparent faecal digestibility of dietary nutriment, luminal morphology, meat quality and express of gene related meat quality in finishing Huai pig were studied. Sixty finishing Huai pigs with the body weight of about50kg were selected and equally divided into four treatments and each treatment had three replicates with five pigs in each replicate. The percent of dietary fiber of four treatments were5.50%(control group),7.00%(experimental group1),8.50%(experimental group2) and10.00%(experimental group3), respectively. The feeding trial lasted87days, and experimental diets and water were available ad libitum during the entire experimental period. Our study is composed of the following four parts.Experiment1:Effects of dietary fiber levels on the production performance and slaughter performance in finishing Huai pigAt the beginning and the last day of experiment, pigs were fasted for12h and weighted. Pen feed consumption was recorded everyday during the test. The average daily gain, the average daily feed intake and the ratios of feed/gain of the four groups were calculated respectively. After the feeding experiment,4pigs closest to the average BW of the group were removed to be fasted for24h and slaughtered. The rate of carcass weight and the rate of leaf fat weight were computed. The area of loin eye, the length of carcass, the ratios of leg weight/hit weight and average back fat thickness from the right side of each carcass were measured. The proportion of carcass lean weight, carcass fat weight, skin weight and bone weight to carcass weight were calculated respectively. Before slaughter, blood samples were collected to analysis serum biochemical parameters.The results showed that compared with the control group, average daily gain of group2and3were significantly (P<0.05) decreased and the average daily feed intake of the three experimental groups were significantly (P<0.05) decreased. Average back fat thickness of group2was significantly (P<0.05) higher than the control group. The other slaughter performance of all the4groups showed no significant (P>0.05) difference. Serum LDL-cholesterol was significantly (P<0.05) higher with the group3than the control group.Experiment2:Effects of dietary fiber levels on the utilization rate of dietary nutriment in finishing Huai pigApparent faecal digestibility was tested via the method of acid insoluble ash (AIA). The sample of colon from midpoints segment were obtained and processed. The sample was embedded in paraffin and intestinal morphology was observed. The study was show that during the early finishing period (the beginning25d of the formal feeding experiment), apparent faecal digestibility of dry material, crude fiber and crude fat ether extract of the three treatment groups were significant (P<0.05) lower than the control group. Apparent faecal digestibility of crude protein of group2and3were significantly (P<0.05) lower than the control group at the same stage. Compared with the control group, apparent faecal digestibility of the dietary nutriment were significantly (P<0.05)decreased and the apparent faecal digestibility of dietary nutriment of group land3were significantly (P<0.05) lower than group2during the last finishing period (the last25d of the formal feeding experiment).The ratio of length of the large intestine/length of body of group2was significantly (P<0.05) higher than the other groups. The crypt depth of colon of three treatment groups significant (P<0.05) increased. However, no difference (P>0.05) in the ratio of weight of digestive organs/live weight and the ratio of length of small intestine/length of body were observed.Experiment3:Effects of dietary fiber levels on the meat quality in pork of finishing Huai pigThe sample of Longissimus dorsi muscle was collected and the muscle colour, the ratios of expressible moisture, Warner-Bratzler shear force, intramuscular fat and insinic acid concentrations were determined. The results showed that compared with the control group, the ratio of expressible moisture of group2was significantly (P<0.05) increased and Warner-Bratzler shear force of group1,2and3were significantly (P<0.05) decreased. pH45min, meet colour and intramuscular fat of the four groups had no significant difference (P>0.05). Compared with the control group, the content of crude protein of longissimus of group2and3were significantly (P<0.05) increased and the insinic acid of group1was significantly (P<0.05) decreased. Compared with the control group, the content of C18:3n3of longissimus of treatment groups significantly (P<0.05) decreased and the content of C20:1n9of subcutaneous fat of the group1and2were significantly (P<0.05) increased.Experiment4:Effects of dietary fiber levels on the express of gene related meat quality in finishing Huai pigTissue samples were collected from longissimus dorsi muscle and subcutaneous fat and the sample total RNA was isolated. The impact of dietary fiber levels on Leptin, FAS and UCP3mRNA abundance were studied by the method of RT-PCR. The date suggested that there was no significant (P>0.05) differences in Leptin mRNA abundance of longissimus or subcutaneous fat. Compared with the control group, FAS mRNA abundance was significantly (P<0.05) reduced in longissimus of three treatment groups. UCP3mRNA abundance of group3was significantly (P<0.05) decreased compared with the other three groups in subcutaneous fat. |
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