The Effects Of Different Probiotics On Growth Function In The Rongchang Weaning Piglets

Probiotics are potential substitutes of the common antibiotics. In a broad sense, probiotics included antibacterial peptide, lactic acid bacteria, zinc methionine, mannan oligosaccharides and so on. This study explored the effect of antibacterial peptide, zinc methionine, mannan oligosaccharides and lactic acid bacteria on the growth function and blood characters of Rongchang weaning piglets. The synergistic effects of antibacterial peptide/zinc methionine and mannan oligosaccharides/lactic acid bacteria were also estimated. The effects of different additives was evaluated as substitutes of antibiotics.Antibacterial test in vitro: 0.2g/ml antibacterial peptide solution, 0.2g/ml Zn solution, 0.2g/ml mannan oligosaccharides solution, lactic acid bacteria culture solution and the different mixed solution of above four substance were prepared to determine their antibacterial activity on Escherichia coli and salmonella. Diameter of inhibition zone were recorded.Weaning piglets feeding test and blood collection: Rongchang male piglets (28 days of age, initial weight had no significant difference) were used. All piglets were randomly allotted to eight diets including the control group, the antibiotic group with 100mg Oxytetracycline(OTC)/kg diet, the antibacterial peptide(AP) group with 10mg AP/kg diet, the Zn-Methionine(Zn-Met) group with 1200mg Zn-Met (equal to 200mg Zn2+/kg diet)/kg diet, the Zn+AP group with 10mg AP and 1200mg Zn-Met/kg diet, the Mannan Oligosaccharides (MOS)group with 2000mg MOS/kg diet, the Lactic Acid Bacteria (LAB) group with 1000mg LAB/kg diet, the MOS/LAB group containing 2000mg MOS and 1000mg LAB/kg diet, respectively, in a 4-week feeding experiment. Each of these groups consisted of 6 piglets. All piglets were given ad libitum access to feed and water. The feed intake and diarrhea status were recorded everyday. On 6th, 7th, 8th and 9th week of age of piglets, the blood was collected and routine blood indexes were determined.The results showed:(1) The AP solution, Zn solution and LAB culture solution had antibacterial activity on Escherichia coli and salmonella, except the MOS solution. Antibacterial activity of Zn showed evident dose-effect relationship. The different mixed solution had no antagonistic action. (2) The average daily gain(ADG) of piglets fed with MOS was significantly higher than that of the control and LAB(P<0.05), but had no significance with other groups(P>0.05). The average daily feed intake(ADFI) didn't show significant difference among all groups(P>0.05). The feed/gain(F/G) of MOS group reduced compared with the control(P<0.05). The diarrhea index(DI) of OTC, AP, Zn-Met and LAB group was significantly lower than that of the control(P<0.05). DI of AP, Zn-Met and LAB group were significantly decreased than the MOS group(P<0.05), and DI of LAB group was significantly lower than AP, Zn-Met and OTC group(P<0.05). So it can be concluded that MOS can improve the growth of piglets, and LAB has the best effect on improving the diarrhea status of piglets.(3) Compared with the control, on 9th week of age, the red blood cell count(RBC) of AP group was increased significantly(P<0.05); on 8th week of age, the HDL content of AP, Zn-Met and LAB group was significantly higher than that of the control(P<0.05); the IgG contents of AP group (on 9th week of age), Zn-Met group(on 6th week of age ), LAB group(on 6th ,9th week of age) were increased than the control(P<0.05); the SOD activity of AP group(on 6th ,7th, 8th, 9th week of age), Zn-Met group(on 6th, 7th, 9th week of age), MOS group(on 9th week of age) and LAB group(on 7th, 8th, 9th week of age) were significantly increased than the control(P<0.05); the serum Zn content of Zn-Met group was significantly higher than the control(P<0.05). So the above four additives were showed different effect on oxygen transportation function, immunity, anti-oxidizing ability and zinc nutrition of weaned piglets.(4) On 6th week of age, The associated appalication of MOS and LAB could increase the serum total protein(TP) synergistically. On 6th, 7th, 8th week of age, the associated appalication of AP and Zn-Met had antagonistic action on increasing SOD activity(P<0.05).(5) In this study, the determination of routine blood indexes indicated that dietary supplementation of AP, Zn-Met, MOS and LAB was safe to Rongchang piglets.(6) According to the results of (1), (2), (3), the growth promoting effects of different additives were not related to the antibacterial activity in vitro, respectively.(7) The growth functions and physiological functions of Rongchang weaning piglets were obviously different compared with that of other populations. So it is necessary to formulate a more appropriate proposal for the breeding of Rongchang weaning piglets.