1. Introduction Results Objective References Conclusion Materials and Methods Seasonal Newcastle disease antibody titre in village chickens of Mbeere District, Eastern Province, Kenya PRESENTED AT THE 3 RD RUFORUM BIENNIAL CONFERENCE ON 24 TH TO 28 TH SEPTEMBER 2012 IN ENTEBBE, UGANDA DAVID C KEMBOI DEPARTMENT OF VETERINARY PATHOLOGY, MICROBIOLOGY AND PARASITOLOGY UNIVERSITY OF NAIROBI  To determine Newcastle disease antibody titres in village chickens in Mbeere District during dry and wet seasons as an indicator of NDV endemicity. Acknowledgment Free-range poultry keeping: Most common type of poultry production system in Kenya. Diseases are the main constraint to poultry production, especially Newcastle disease. Newcastle disease: characterized by variation in morbidity and mortality, hemorrhage in gizzard and proventriculus.  ND virus (NDV) is present in healthy village chicken and hens that survive outbreaks have antibodies titres  Njagi et al.(2010) did a study in Mbeere district and found that chicken had antibody titers through out the year, indicating ND virus endemicity.  The aim of the study was to establish the current status of NDV antibody titers as an indicator of endemicity. Map 1: The study was carried in Mbeere district, Eastern Province, Kenya. Wet season: Long rain (March-June), Short rains (October to December) Dry period (January to early March, August -December) Some of the 48 apparently healthy chickens purchased from purposively selected farms  Forty eight apparently healthy chickens were purchased from purposively selected farms (24 birds each in dry and wet season). The least statistically allowed number was used due to animal welfare concerns.  Wet season was in November while the dry season was in March  The chicks were less than 2 months old; growers were between 2 to 8 months; and adults, above 8 months of age. Wet season (7 chicks, 8 growers and 9 adults), Dry season (9 chicks, 8 growers and 7 adults)  All birds were labelled and transported in cages to Kabete, University of Nairobi campus for sampling Collected sera were tested for NDV specific antibody by hemagglutination inhibition (HI) test (OIE, 2000). Blood was collected for collection of serum  Overall 100% and 95.8% of the birds in the wet season and dry season respectively had specific antibody titers against NDV (>1:8)  Overall, there was a statistically significant higher (P<0.05) titer during the wet season (GMT 65.85) (Table 1) compared to the dry season (GMT 31.08) (Table 2).  In the wet season, titers ranging from 1:16 (2 4 ) to 1:256 (2 8 ) (Fig 1) while in the dry season the titer ranging from 1:4 (2 2 ) to 1:128 (2 7 )  Chicks and adult birds had a statistically significant higher titer (P<0.05) in the wet than dry season. For growers, the titers were higher in the dry season, but the difference was not statistically significant. Based on the findings it can be concluded that:  In all seasons birds had high titers, the antibodies waned off during the dry season  The results are comparable to those of Njagi et al (2010)  The presence of antibodies in the chicken indicate endemicity of ND virus in Mbeere district :  The authors would like to thank RUFORUM for their sponsorship and funding of the project. The University of Nairobi for providing the work space and facilities. J.K. Kibe, Mary Mutune and Richard Otieno for their technical assistance, the farmers of Mbeere for their corporation.  Njagi, L.W., Nyaga, P.N., Mbuthia, P.G., Bebora, L.C., Michieka, J.N., and Minga, U.M. (2010). A retrospective study of factors associated with Newcastle disease outbreaks in village indigenous chickens. Bulletin of Animal Health and Production in Africa, 58(1). http://ajol.info/index.php/bahpa  OIE (Office International des Epizooties) (2000) Newcastle disease. In: Manual of standards for diagnostic tests and vaccines, 4 th edition. OIE, Paris. Pp. 221 – 232. Recommendations  Vaccination is recommended during the start of dry season to maintain high levels of antibodies and prevent outbreaks. Titer Age Samp le size 1:21:41:81:161:321:64 1:1281:256 GMT Chicks7---1-41170.66 Growers8---124-153.82 Adults9----153-74.65 TO TA L 2400023134265.85 Titer Age Sample size 1:21:41:81:161:321:641:1281:256GMT Chicks9-11241--20.16 Growers8---2-33-58.69 Adults7--22-21-26.25 TO AL 240136464-31.08 Key GMT= Geometric mean titer calculates as: Where G= Geometric mean, n= Number of variables, X= values of the variable Fig 1 Microtiter plate showing some of haemmaglutination inhibition test result Table 1:Newcastle disease virus antibody titers in the wet season Table 2:Newcastle disease virus antibody titers in the dry season