Effect of Compound Sulfadiazine Suspension on Growth Performance of Broiler in Clinical Efficacy Trial

Compound Sulfadiazine suspension is used mainly to prevent and cure E. coli, Salmonella infection of chicken in veterinary clinical application. Effect of compound Sulfadiazine suspension on growth performance of broiler in clinical efficacy trial was studied in the study. One hundred eighty 15-day-old broilers were divided randomly into six groups, blank control group, negative control group, Trisulmixos gavage group, Trisulmixos drinking group, Sufuning gavage group and Sufuning drinking group, respectively. There were three repeating treatments in each group and ten broilers in each treatment. Results showed that compound Sulfadiazine suspension can promote the feed conversion rate of broiler when curing E. coli, Salmonella infection of chicken. Both from the perspective of efficacy and from the perspective of growth performance, giving drug by gavage were more effective than giving by drinking. When two products of Compound Sulfadiazine suspension were compared, the indicators of Sufuning were a little better Trisulmixos.


INTRODUCTION
Sulfadiazine (SD), a sulfa antibiotic with broad antibacterial spectrum, was used to cure the infections of Gram-positive bacteria, Gram-negative bacteria and many prokaryotes.Trimethoprim (TMP) is an antibacterial synergist and its antibacterial spectrum is broad and is stronger in effectiveness than SD (Chretin et al., 2007;Kongsaengdao et al., 2008;Agunos et al., 2012).Compound preparation composed by SD and TMP has excellent antibacterial effect, even kill bacteria.The compound preparation can not only enhance efficacy and shorten treatment, but also decrease the production of resistant strains (Mathlouthi et al., 2012;Skjot-Rasmussen et al., 2013).Compound Sulfadiazine suspension was maken up of SD and TMP in the ratio of 4:1 and was used to prevent and cure E. coli, Salmonella infection of broiler in veterinary clinical (Ghosh et al., 2012;Salim et al., 2013).Enterprises and researchers in the world paid much attention to the research and development of compound Sulfadiazine suspension (Ali and Zahran, 2010;Ajay and Kaushik, 2011;Chaudhari and Lee, 2013;Giombelli et al., 2013) and several products of compound Sulfadiazine suspension were produced by different enterprises.However most researchers focused on the efficacy of the compound preparation and seldom researchers paid attention to effect of compound Sulfadiazine suspension on growth performance of broiler in clinical efficacy trial.In this study, Trisulmixos, a kind of compound Sulfadiazine suspension product produced by French Vic pharmaceutical group and Sufuning, another kind of compound Sulfadiazine suspension product produced by Qingdao KDN Animal Pharmaceutical Co. were selected as drug candidate to cure bacteria infection.By different methods of giving drug, effect of compound Sulfadiazine suspension on growth performance of broiler in clinical efficacy trial was studied.Newcastle disease using LaSota vaccine by intranasalling.When these broilers grew till 15 day old, they can be used in this experiment.

Methods: Preparation of bacterial liquid used in experiment:
Firstly, we inoculated Escherichia coli and Salmonella bacteria on LB agar and MacConkey agar.After these bacteria were cultivated at 37°C about 24 h, some typical colonies were chosen to inoculate on 100 mL Broth medium.Then, they were cultivated in desktop bath oscillator at 37°C for 6 to 8 h.After that, 0.1 mL bacteria liquid was 10-fold diluted gradiently by nutrient broth.Then part of the bacteria liquid being diluted was coated on a normal flat medium.Finally, Colony Forming Units (CFU) were counted at 37°C after the bacteria was cultivated for 24 h.The ratio of E. coli and Salmonella in the liquid was 3:1.
Pre-experiment for screening dosage: Forty ten-dayold broilers were divided randomly into four groups.Each group were injected bacteria liquid in different dilution factor, that is, 1, 1×10 -1 , 1×10 -2 , 1×10 -3 , respectively.One ml corresponding bacteria liquid was injected into broilers in corresponding group through pectoral.Then, observe the broilers for 5 days and count the number of dead chickens so as to gain LD 50 using Karber method.At last, suitable dosage strength can be obtained.
Clinical cure experiment: One hundred and eighty healthy fifteen-day-old broilers were divided randomly into six groups after being weighed individually.Every group contained three repeat treatments and each treatment contained ten broilers.The broilers in blank control group were fed normally and not injected bacteria liquid.And every broiler in other groups was injected, respectively 1 mL bacteria liquid through pectoral.After typical clinical symptoms appeared, the other treatment processes of the six groups were shown in Table 1.The chickens were observed twice every day and the number of the sick and the number of the dead in every group was counted.We weighed the dead broilers one by one.And then the dead broilers were dissected in order to observe pathological changes.After observation period, the broilers still living were weighed individually.Finally, cure rate, average day gain and feed conversion ratio of every group were obtained.

Evaluation indicators of efficacy:
The indicators of efficacy involved in this experiment, including morbidity rates, mortality rates, effective rate and cure rate, were consistent with that in reference (Zhihui et al., 2009).

Evaluation indicators of growth performance: Average Day Gain (ADG):
The broilers were weighed one by one at 14 and 24 day old, respectively, obtaining ADG 14 and ADG 24 , respectively.Then average day gain can be calculated:

Clinical symptoms and necropsy lesions:
The broilers in later five groups were injected 1 mL bacteria with dosage strength of 5.6×10 7 CFU/mL.After that, many typical clinical symptoms appeared, such as lassitude, loose feathers, severe diarrhea.All dead broilers were dissected to observe visceral.It smelled stench while they were dissected.And there were perihepatitis or pericarditis on their hearts and livers in different extents, shown as Fig. 1.
Experiment results on growth performance: On the one hand, the broilers of negative control group were all sick and the mortality rate of this group was 23.3% after being infected by bacteria liquid.On the other hand, there was no dead or sick broiler in blank control group.These results showed that the injection of bacteria liquid can infected successfully these broilers with E. coli and Salmonella.The cure rates of later four groups were shown in Fig. 2. The cure rates of Sufuning gavage group and Trisulmixos gavage group were higher than other two groups, which meant that when drug was given, the method of gavage was better than the method of drinking.The method of gavage was The average day gains of different groups were shown in Fig. 3.The ADG of blank control group was the highest and the ADG of negative control group was lowest, which indicated that the infection of E. coli and Salmonella can influence the growth of broiler greatly.From the ADGs of the four-administered groups, it can be seen that the effect of giving-drug method on growth Fig. 4: The feed conversion rates of different groups of broiler was lower in Sufuning gavage group and Trisulmixos gavage group than in Sufuning drinking group and Trisulmixos drinking group.And the ADG of Sufuning gavage group was a little higher than that of Trisulmixos gavage group.All above-mentioned indicated that giving drug by gavage affected less on the broiler growth than drinking.This trend was similar to the trend of cure rate in these groups.
The feed conversion rates of different groups were shown in Fig. 4. From the experimental results, it can be seen that the feed intakes of different groups were similar, whereas the difference of FCR was huge and the trend of FCR was Inverse to the ADG.The FCRs of administered groups were lower than that of blank control group and higher than that of negative control group.These results indicated that infection of E. coli and Salmonella affected a little on the broiler feeding process, but affected much on digestion and absorption function of broiler.The infection inhibited in vivo nutrient conversion of broilers.However, compound sulfadiazine suspension can change this condition and improve the FCR of broiler.

CONCLUSION
Through observing the growth performance of broiler in efficacy trial, it was concluded that compound sulfadiazine suspension can effectively cure the infection of E. coli and Salmonella for broilers and can reduce FCR and decrease the loss of infection.Moreover, the efficacy and growth performance of compound sulfadiazine suspension given by gavag was better than given by drinking.When two products of Compound Sulfadiazine suspension were compared, the indicators of Sufuning were a little better Trisulmixos.This study provided scientific basis and trial data for rational use of compound sulfadiazine suspension and provided important references for the cure of E. coli and Salmonella in the course of broiler breeding.However, the action mechanism of compound sulfadiazine against E. coli and salmonella and the mechanism of compound sulfadiazine promoting growth still need to be further study.

Fig. 1 :
Fig. 1: Photograph of heart and liver of boiler after being infected by bacteria

Table 1 :
The treatment processes of the six groups