Effects Of Dietary Fiber And Copper On Production Performance And Cecal Microflora Of Finishing Pigs

Dietary fiber(DF)has a main role in optimizing the intestinal micro flora,improving intestinal health,and the growth performance of pigs.Besides,there are complex physical and chemical properties of dietary fiber.As well,dietary fiber has an effect on the bioavailability of trace elements such as copper and iron these are importance for the growth and development of the animal.Furthermore,dietary fiber level and copper supplementation has effect on nutrient digestion,utilization of diets and intestinal microflora of pig.The experiment adopted a 2×2two-factor factorial experimental design and selected 24(castrated boars Junmu No.1)with similar body weight(76 kg ± 1.5 kg).They were randomly divided into 4 groups: LN group,LA group,HN group and HA group,each group was set into 6 replicates,and each replicate was one pig.Four groups of diets: The LN group: the total dietary fiber level was 22%,and the copper concentration was 25 mg/kg.The LA group: the total dietary fiber level was 22%,and the copper concentration was 45 mg/kg.The HN group: the total dietary fiber level was 28%,and the copper concentration was 25 mg/kg.The HA group: the total dietary fiber level was 28%,and the copper concentration was 45 mg/kg.Pre-feeding for 7 days,and after 56 days of formal feeding,all finishing pigs slaughtered and sampled,and tested.1.Effects of dietary fiber and copper on the Production performance of finishing pigsThe results showed: 1)In terms of growth performance: Compared with the total dietary fiber level of 22%,the total dietary fiber level of 28% significantly increased the final weight of finishing pigs,the average daily gain(ADG)and reduced the feed-to-weight ratio(F/G)(P<0.05).Besides,the final weight and ADG of the HN group and the HA group were significantly higher than that of the LN group(P<0.05);the F/G of the HA group was significantly lower than that of the LN group and the LA group(P<0.05).2)Blood biochemistry: Compared with the total dietary fiber level of 22%,the total dietary fiber level of 28% significantly increased the total protein concentration of finishing pigs(P=0.04).Furthermore,the blood glucose concentration of the HA group was significantly lower than that of the LN group(P<0.05).Besides,the total protein concentration of the HA group was significantly higher than that of the LN group and the LA group(P<0.05).3)In terms of nutrient digestibility: Compared with the total dietary fiber level of 22%,the total dietary fibre level of 28% significantly improved the digestibility of dry matter(DM),crude protein(CP),crude fiber(CF)and Natural detergent fiber(NDF)(P<0.05).Compared with the copper concentration of 25 mg/kg,the copper concentration of 45 mg/kg significantly improved the digestibility of DM(P=0.05)and there was a tendency to increase the digestibility of CF(P=0.07).As well,the digestibility of DM,CP,CF,and NDF in the HA group was significantly higher than that in the LA group and the LN group(P<0.05).Besides,the digestibility of DM,CP,and CF in the HN group was significantly higher than the LN group(P<0.05);the CP digestibility in the LA group significantly higher than the LN group(P<0.05).4)Carcass traits and meat quality: Compared with the total dietary fiber level of 22% and the total dietary fibre level of 28% reduced the backfat thickness of finishing pigs(P=0.05).As well,it significantly increased in the eye muscle area(P=0.03).Besides,there is a tendency to increase the oblique length of the carcass(P=0.06),a* value(P=0.09),and the drip loss tends to decrease(P=0.08).The carcass oblique length and a* value of the HA group were significantly higher than that of the LN group(P<0.05).On the other hand,the eye muscle area of the HA group was significantly lower than that of the LN group(P<0.05).2.Effects of dietary fiber and copper on the cecal microflora of finishing pigs1)Blood copper and cecal chyme copper: Compared with the total dietary fibre level of22%,the total dietary fiber level of 28% significantly reduced the cecal chyme copper concentration(P=0.01).As well,there was a tendency to reduce the plasma copper concentration(P=0.08).Compared with the copper concentration of 25 mg/kg,the copper concentration of 45 mg/kg,led to significantly increased plasma copper concentration and the cecal chyme copper concentration(P<0.05).On the other hand,the plasma copper concentration in the LA group was significantly higher than that in the LN group and the HN group(P<0.05);the cecal chyme copper concentration in the LA group was significantly higher than the other groups(P<0.05);the cecal chyme copper concentration in the HN group was significantly lower than the other groups(P<0.05).2)cecal chyme cellulose activity: Compared with the total dietary fiber level of 22%,the total dietary fiber level of 28% significantly increased the cecal carboxymethyl cellulose activity(CMC)and β-glucosidase activity(β-glu)(P<0.05).Furthermore,Compared with the copper concentration of 25 mg/kg,the copper concentration of 45 mg/kg significantly increased the CMC of the cecum(P=0.02).As well,The CMC and β-glu in the HA group were significantly higher than the other groups(P<0.05).3)volatile fatty acids in the cecal: Compared with the total dietary fiber level of 22%,the total dietary fiber level of 28% significantly increased the cecal acetic acid,propionic acid,and total acid concentrations(P<0.05).As well,compared with the copper concentration of 25mg/kg,the copper concentration of 45 mg/kg has a tendency to increase the total acid concentration(P=0.09).In addition,the concentration of acetic acid in the HA and HN groups was significantly higher than that in the LN group(P<0.05).Besides,the propionic acid in the LN group was significantly lower than the other groups(P<0.05).Furthermore,the total acid concentration in the HA and HN groups was significantly higher than the LA and LN groups(P<0.05).4)The cecal microbes: Compared with the total dietary fiber level of 22%,the total dietary fiber level of 28% significantly improved the α diversity index(P<0.05).Compared with the copper concentration of 25 mg/kg,the copper concentration of 45 mg/kg significantly reduced the α diversity index(P<0.05).As well,dietary fiber and copper had a significant interaction effect on the α diversity index(P<0.05).The α diversity index of the LA group was significantly lower than the other groups(P<0.05).On the other hand,for Bacteroidetes,the LA group has the highest ratio,the HN group has the lowest ratio,the LN group and HA group has the similar ratios.Besides,for the beneficial bacteria Lactobacillus,the LA group has the highest ratio,the LN group has the lowest ratio.At the same time,for the cellofermentation bacteria Prevotella＿9,the LA group has the highest proportion,and the HA group>HN group>LN group.At the end,adding 28% dietary fiber and 45mg/kg copper concientration in the growing and finishing feeding period of pigs,promoted the proliferation of beneficial microorganisms in cecum and optimize the microflora structure.As well,improved the digestion of dietary fiber and the performance of finishing pigs.