Effects Of Probiotic Additives And Breeding Density On Growth Performance Of Fattening Pigs

In recent years,with the implementation of anti-resistance and anti-resistance policies,the space for antibiotics as feed additives will become narrower,so R&D of high-efficiency,pollution-free and residue-free green feed additives has become a hot spot in animal husbandry research.Meanwhile,in the context of reducing the use of antibiotics,livestock and poultry-welfare farming has also received more and more attention from the industry,and the appropriate feeding density of animals has also become an important issue for farms,and the proper feeding density of animals has also become an important issue of concern to farms.This study mainly used additives such as berberine and probiotics to replace antibiotics in fattening pig feed,and explored the effects of both on the growth performance of fattening pigs,and analyze the welfare indicators and growth performance of fattening pigs under different feeding densities,which aims to find a suitable density suitable for the healthy growth of fattening pigs.The research content is divided into three aspects:(1)to explore the possibility of compatibility of the two and the antibacterial effect after compatibility by conducting an experiment on compatibility and antibacterial effect of berberine and lactic acid bacteria;(2)to explore the possibility of being an alternative to antibiotics through conducting an experiment on probiotics additives and composite additives of probiotics and berberine on the growth effect of fattening pigs;(3)to explore the suitable feeding density of fattening pigs by conducting a comparative experiment on growth speed and behavior dynamics of fattening pigs under different feeding densities.The primary testing result of this thesis are shown below:(1)Adding different concentrations of berberine to the culture solution of lactic acid bacteria,there is no significant difference in the pH value and the number of live bacteria of lactic acid bacteria,indicating that the two can be used in combination.The mixed culture solution of berberine and lactic acid bacteria all produced bacteriostatic rings in the pathogenic E.coli medium,indicating that the combination of berberine and lactic acid bacteria has a bacteriostatic effect,of which 0.02%berberine and lactic acid bacteria mixed culture group the largest diameter,the best antibacterial effect.(2)Adding different proportions of probiotics,berberine group and antibiotic group,the average daily weight gain has improved,but there is no significant difference(P>0.05),the F/G and diarrhea rate there was no significant difference in other aspects(P>0.05);compared with the control group,the average daily weight gain of the experimental group was improved,of which the groups 4,6 and 7 were significantly better than the control group(P<0.05),the F/G and diarrhea rate decreased significantly.In terms of crude protein and crude fat digestibility,the experimental group was significantly higher than the control group(P<0.05).In terms of calcium and phosphorus digestibility,the experimental group as a whole was better than the control group,of which P10+B02 group(probiotics 0.10%+berberine0.02%)works best.The results of economic benefit analysis show that adding probiotics or probiotic berberine compound additives,the gross profit is higher than the control group and antibiotic group,of which the seventh group(probiotics 0.10%+berberine 0.02%)generated the highest profit.(3)In terms of rest time,the high-density group(0.8m~2/head)was significantly lower than the low-density group(1.6m~2/head)(P<0.01);in terms of drinking behavior,the drinking time of pigs with the increase in density was extremely significant The upward trend(P<0.01);in terms of game interaction,the medium-density group(1.2m~2/head)is significantly higher than the high-and low-density groups(P<0.01);the high-density group is significantly higher in terms of fighting time with each other In the low-density group(P<0.01);in terms of total body surface scars,it increased with the increase of feeding density,the high-density group was significantly higher than the medium and low-density group(P<0.05),the medium and low-density group no significant difference(P>0.05);in terms of body surface manure coverage,the high-density group was significantly higher than the medium and low-density group(P<0.01);in terms of body surface temperature,with the increase in feeding density,body surface temperature It showed an upward trend,in which the high-density group was significantly higher than the medium and low-density group on the 5th day after mixing(P<0.05);in terms of growth performance,the average daily gain and average daily feed intake between different density groups were not significantly different.However,the high-density group is obviously higher than the medium and low of the group(P<0.01).In summary,(1)Berberine at different concentrations has a significant inhibitory effect on lactic acid bacteria,and the combination of 0.02%concentration of berberine and lactic acid bacteria has the best effect on the inhibition of pathogenic bacteria(E.coli).(2)The use of probiotics or their combination with berberine can replace antibiotics,which can promote the growth performance and nutrient digestibility of fattening pigs,which can ultimately improve the economic benefits of breeding enterprises.(3)The medium-density group(1.2m~2/head)and low-density group(1.6m~2/head)showed better welfare,and the high-density group(0.8m~2/head)had poorer welfare;in terms of growth performance,the high-density group had a higher weight-to-weight ratio It is significantly higher than other density groups,and there is no significant difference between the middle and low density groups.Combining various factors,1.2m~2/head should be the best density choice for raising fattening pigs.