Detection of Toxoplasma gondii in chicken and soil of chicken farms in Nanjing region,China

Background:Soil is increasingly recognized as an important source in the transmission of Toxoplasma gondii(T.gondii).The aim of this study was to investigate the presence of T.gondii in the soil and to grasp the relationships between the contamination of soil and chicken infections.Methods:PCR method based on T.gondii-conserved gene internal transcribed spacer 1(ITS-1)as target gene and ELISA method(sGRA8-ELISA)using the recombinant protein of shortened GRA8 gene of T.gondii as antigen were developed and applied.From April 2013 to March 2014,a total of 700 soil samples were collected at various sites located in thirty farms categorized as free range farm and scale farm in Nanjing,Jiangsu,China,in different seasons.Additionally,a total of 350 sera of chickens were collected from free range farms to determine the presence of antibodies against T.gondii using sGRA8-ELISA.Results:The serological results showed that,antibodies were found in 194 of 250(67.14%)samples from farms with T.gondii positive in soil and 41 of 100 samples from farms with T.gondii negative in soil(41.00%)(P<0.01).The PCR detection of soil samples showed that,7(2.0%)of 350 samples collected from feeding zone in free range farms were found positive of T.gondii,whereas no sample was positive in scale farms.In the seasonal detections,T.gondii was found in 6(3.33%)samples collected in autumn and 1(0.56%)collected in winter.Conclusions:The results indicated that the contamination of T.gondii in soil in the free range farms was higher than that in the scale farms and seroprevalence of T.gondii in chickens in the farm with soil contamination was higher than that with no soil contamination.The soil contamination might be an effective indicator of T.gondii infection in chickens.

Comparative Analysis of Slaughter Performance and Meat Flavor Traits of Quality Chicken under Cage Rearing and Free-range Farming Conditions

[Objective]The paper was to compare the slaughter performance and meat flavor of quality chicken under cage rearing and free-range farming conditions.[Method]A total of 4001-day-old cocks,S07 line cultivated by Sichuan Dahen Poultry Breeding Co.,Ltd.(bred for 4 succes-sive generations),were kept in cages until the end of 5 weeks of age,which were then divided into cage rearing and free-range farming groups.All cocks were fed with the same diet,and slaughter tests and meat quality analysis were carried out at the end of 10 and 22 weeks of age,respectively.[Result]The live weight,carcass weight and abdominal fat percentage in cage rearing group were significantly higher than those in free-range farming group(P<0.01),and the percentage of half-eviscerated yield and percentage of eviscerated yield in cage rearing group were significantly higher than those in free-range farming group(P<0.05),but there were no significant differences in dressing percentage,percentage of leg muscle and per-centage of breast muscle.The intramuscular fat(IMF)content and muscle fiber density of chicken in cage rearing group were significantly higher than those in free-range farming group(P<0.01),but there was no significant difference in inosinic acid(IMP)content.The content of IMF and IMF increased with the increase of feeding age,but the deposition rate of intramuscular fat was higher than that of IMF in late feeding period.[Conclusion]The study will provide reliable guidance for production and market consumption of high quality chicken.