| By means of feeding experiment, digestion experiment, slaughter experiment and so on, the optimal levels and effects of multi-enzyme, probiotics, nano-selenium, vitamin E (VE) and their combination on growth performance, nutrient apparent digestibility, diarrhea incidence, immunity and anti-oxidation of weaned Rex Rabbit were researched.In this research, two phase experiments were done. The first phase experiments were made up of 3 independent experiments, which were screening the optimal levels of multi-enzyme, probiotics, nano-selenium and VE.The second phase experiment contained 1 experiment which was combination of multi-enzyme, probiotics, nano-selenium and VE with optimal levels based on the pre-experiments.Experiment 1: Effect of multi-enzyme on growth performance and nutrient apparent digestibility of weaned Rex Rabbit60 weaned Rex Rabbits with age of 35 days were randomly divided into 4 treatments with 3 replicates in each treatment and 5 Rex Rabbits per replicate to study the effect of multi-enzyme level on their growth performances and nutrient availabilities and the optimal level of multi-enzyme. The formal experiment of feeding lasted 60 days and the adjustment period was 5 days. The 4 treatments were control (basal diet), GroupⅠ(basal diet +2g/kg multi-enzyme), GroupⅡ(basal diet +4g/kg multi-enzyme), GroupⅢ(basal diet +6g/kg multi-enzyme) respectively.Results showed that:(1) average daily gains in 3 treatment groups were 10.65%(P<0.05), 14.49%(P <0.01), 12.39%(P <0.01)higher than in control group respectively. Feed conversions in 3 treatment groups were 11.26%(P <0.01), 15.47%(P <0.01), 13.36%(P <0.01)lower than in control group respectively. Diarrhea incidences in 3 treatment groups were 53.31%(P <0.05), 70.79%(P <0.01), 62.55%(P <0.01)lower than in control group respectively.(2)Nutrient apparent digestibility in 3 treatment groups was all higher than in control group. Nutrient availabilities of crude protein in 3 treatment groups were 11.86%(P >0.05), 22.73%(P <0.05), 18.10%(P <0.05)higher than in control group respectively. Nutrient availabilities of crude fiber in 3 treatment groups were 14.53%(P <0.05), 23.00%(P <0.01), 22.15%(P <0.01)higher than in control group respectively and the 4g/kg level was better. The nutrient apparent digestibility of crude fat in 3 treatment groups were 3.5%(P >0.05), 8.68%(P <0.05), 9.36%(P <0.05)higher than in control group respectively. Nutrient availabilities of dry matter, crude ash, Ca and P in treatment groups were higher than in control group but the differences were not significant(P >0.05).So we concluded that 4g/kg level was better than other levels.Experiment 2 : Effect of probiotics on growth performance, nutrient apparent digestibility and diarrhea incidence of weaned Rex Rabbit60 weaned Rex Rabbits with age of 35 days were randomly divided into 4 treatments with 3 replicates in each treatment and 5 Rex Rabbits per replicate to study the effect of multi-enzyme level on their growth performances, diarrhea incidences and nutrient availabilities and the optimal level of probiotics. The formal experiment of feeding lasted 60 days and the adjustment period was 5 days.The 4 treatments were control ( basal diet ), GroupⅠ(basal diet +0.25g/kg probiotics), GroupⅡ(basal diet +0.5g/kg probiotics), GroupⅢ(basal diet +0.75g/kg probiotics) respectively.Results showed that:(1) As the level of probiotics increased, the daily gains reduced and feed conversions raised in treatment groups. The effect in groupⅠwas the best in which average daily gain improved by 9.69%(P<0.05)and feed conversion reduced by 7.63%(P<0.05)compared to control group respectively.(2) With the level of probiotics increasing, percentages of half-evisceration and evisceration in treatment groups decreased, and the groupⅠwas optimal in which percentages of half-evisceration and evisceration improved by 1.66%(P>0.05) and 2.48%(P<0.05) compared to control group respectively.(3) With the level of probiotics increasing, nutrient apparent digestibility in treatment groups decreased and groupⅠwas optimal in which nutrient apparent digestibility were higher than in control group obviously(P>0.05 or P<0.05).(4) The spleen index and thymus index in treatment groups were not significant compared to control group but had the tendency of increasing. The spleen index and thymus index in groupⅠwere the highest and improved by 0.82%(P>0.05) and 2.67%(P>0.05)compared to control group respectively.(5) Slaughter performances in treatment groups were not significan(tP>0.05) compared to control group, but had tendency of rising.(6) The diarrhea incidences in treatment groups were 54.55%(P<0.05), 42.42%(P>0.05), 12.12%(P>0.05)obviously lower than in control group.Based on above results, it was concluded that probiotics can improve average daily gain and nutrient apparent digestibility and reduced diarrhea incidences of weaned Rex Rabbit. The optimal level of probiotics was 0.25g/kg. Experiment 3: Effect of nano-selenium and VE on growth performance, immunity and anti-oxidation of weaned Rex Rabbit105 weaned Rex Rabbits with age of 35 days were randomly divided into 7 treatments with 3 replicates in each treatment and 5 Rex Rabbits per replicate to study the effect of nano-selenium and VE level on their growth performances, nutrient availabilities and immunity and the optimal level of nano-selenium and VE. The formal experiment of feeding lasted 60 days and the adjustment period was 5 days. The 7 treatments were control (basal diet), GroupⅠ(basal diet +0.3mg/kg nano-selenium), GroupⅡ(basal diet +0.5mg/kg nano-selenium), GroupⅢ(basal diet +0.7mg/kg nano-selenium), GroupⅣ(basal diet +0.3mg/kg nano-selenium +80mg/kg VE), GroupⅤ(basal diet +0.5mg/kg nano-selenium +80mg/kg VE), GroupⅥ(basal diet +0.7mg/kg nano-selenium +80mg/kg VE)respectively.The results showed that:(1) Compared to control group, the addition of nano-selenium and /or VE can improve average daily gain and reduced feed conversion significantly or extremely significantly(P<0.05 or P<0.01). The effect of groupⅤwas optimal, but the differences between treatment groups were not significant(P>0.05).(2) The immunity organ index in treatment groups were improved obvious compared to control group. The immunity organ index in groupⅤwas the highest and in which spleen index and thymus index raised by 23.90%(P<0.01), 18.70%(P<0.01)respectively compared to control group.(3) The nutrient apparent digestibility in treatment groups was all higher than in control group and was relative higher in 0.5mg/kg level of nano-selenium. Addition of VE can improve nutrient apparent digestibility to a certain degree.(4) IgG, IgM and IgA in serum in treatment group were higher than in control group and the differences between treatment groups were not significant. GroupⅤwas optimal and IgG, IgM and IgA in serum improved by 28.57%(P<0.01), 15.95%(P<0.01)and 30.65%(P<0.05) respectively compared to control group.(5) GSH-Px and SOD in serum in treatment groups improved largely as the level of nano-selenium rose up and were significant or extremely significant (P<0.05 or P<0.01) compared to control group. In VE added treatment group, GSH-Px and SOD have tendency of improving compared to treatment group with the same level of nano-selenium but no VE added. MDA in serum in treatment groups decreased as the level of nano-selenium rose up, and were significant compared to control group(P<0.01).(6) Selenium contents in tissues in treatment groups were improved as the level of nano-selenium rose up and were significant or extremely significant (P<0.05 or P<0.01) compared to control group. In VE added treatment group, selenium content have tendency of improving compared to treatment group with the same level of nano-selenium but no VE added. The four tissues according to selenium content from high to low were kidney, liver, serum and muscle successively.(7) Diarrhea incidences in treatment groups decreased (P>0.05 or P<0.05) compared to control group and the differences between treatment groups were not significant.It is concluded that nano-selenium or combination of nano-selenium with VE had effect of improving weaned Rex Rabbit growth performance, nutrient apparent digestibility, immunity and anti-oxidation, and reducing diarrhea incidence. The optimal level and scheme were 0.5mg/kg nano-selenium +80mg/kg VEExperiment 4: Effect of multi-enzyme, probiotics, nano-selenium and VE combination on growth performance, diarrhea incidence and immunity of weaned Rex Rabbit45 weaned Rex Rabbits with age of 35 days were randomly divided into 3 treatments with 3 replicates in each treatment and 5 Rex Rabbits per replicate to study the effect of combination of multi-enzyme, probiotics, nano-selenium and VE on their growth performances, nutrient availabilities, immunity and diarrhea incidence. The formal experiment of feeding lasted 60 days and the adjustment period was 5 days.The 3 treatments were control (basal diet), GroupⅠ(basal diet + 4g/kg muti-enzyme + 0.25g/kg probiotics), GroupⅡ(basal diet + 4g/kg muti-enzyme + 0.25g/kg probiotics + 0.5mg/kg nano-selenium + 80mg/kg VE)respectively.Results show that:(1) Average daily gain in treatment groups improved 8.55%(P<0.01)and 10.97%(P<0.01) respectively compared to control group, and feed conversions in treatment groups decreased 8.93%(P<0.01) and 11.34%(P<0.01)respectively compared to control group.(2) Percentages of half-evisceration and evisceration in treatment groups improved compared to control group but the difference between treatment groups and control group were not significant(P>0.05).(3) Nutrient apparent digestibility in treatment groups improved significantly or extremely significantly (P<0.05 or P<0.01)compared to control group and nutrient apparent digestibility in GroupⅡwere the highest.(4) The spleen index and thymus index in treatment groups were 2.66%(P>0.05),10.24%(P<0.05) and 1.80%(P<0.01), 12.35%(P<0.01)higher than in control group respectively.(5) Total protein and albumen in serum in treatment groups were 1.16%(P>0.05), 5.41%(P<0.05)and 3.06%(P>0.05), 7.64%(P>0.05)higher than in control group respectively. Serum urea nitrogen in treatment groups were 5.04%(P>0.05) and 9.34%(P>0.05)lower than in control group respectively. IgG, IgM and IgA in serum in GroupⅠwere close with which in control group. IgG, IgM and IgA in serum in GroupⅡimproved significantly or extremely significantly(P<0.05 or P<0.01) compared to control group.(6) GSH-Px, SOD and MDA in serum in GroupⅠwere close with which in control group. GSH-Px and SOD in serum in GroupⅡimproved extremely significantly (P<0.01), and MDA in serum in GroupⅡdecreased extremely significantly(P<0.01) compared to control group.(7) Diarrhea incidences in treatment groups decreased 54.00%(P<0.05) and 56.00%(P<0.05)compared to control group respectively. The difference of diarrhea incidences between treatment groups was not significant(P>0.05).It is concluded that combination of 4g/kg multi-enzyme, 0.25g/kg probiotics, 0.5mg/kg nano-selenium and 80mg/kg VE can improve weaned Rex Rabbit production performance, nutrient apparent digestibility, immunity and reduce diarrhea incidence obviously. |
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