Journal of Applied and Industrial Sciences, 2014, 2 (5): 213-218, ISSN: 2328-4595 (PRINT), ISSN: 2328-4609 (ONLINE) Research Article 213 Abstract— This study was designed to estimate the prevalence of bovine brucellosis and to investigate the effect of lactation phase on the prevalence of bovine brucellosis in Khartoum state. Milk and blood samples were collected simultaneously from 338 milking cows at different lactation phases from the three provinces of Khartoum State(Khartoum, Omdurman and Khartoum Bahri) using stratified random samples, During January -April 2013. Samples were examined for antibodies to Brucella using the Milk Ring Test (MRT) and Milk Elisa (M Elisa) for the milk samples and the Rose Bengal Plate Test (RBPT) and the Serum Elisa (S Elisa) for the serum. The overall prevalence of bovine brucellosis within the milking cows was 38.2% and 40.8% for the milk samples using MRT and M Ekisa respectively and 32 % and 38.8% of the serum samples were positive to the RBPT and S Elisa, respectively. The highest prevalence rate value was in Bahri, (47.2%) then Khartoum province (45.3%), then Omdurman province (9%). The prevalence value reported for Omdurman was significantly higher compared to the other two provinces at (P< 0.01). In the early lactating cows, 41.5% of milking cows were positive compared to 31.6% and 47.5% in mid and late lactating cows in M Elisa, respectively .The difference among lactation phases was insignificant (P<0.05). The odd ratio in early lactation was 1.7 (OR=1.7: 0.6 - 3.1 at C.I. 95%) and the odds in late lactating cows was 1.9 (OR= 1.9: (1 – 3.2 at 95% C.I.). There was a significant association between the M Elisa and the MRT (0.004 P<0.05) with 74% of the samples positive in both tests along with 0.46 kappa statistic value and 76% over all agreement. The association between the RBPT and S Elisa was significant (0.00 P<0.05) along with 0.64 kappa value, 76% positive samples in both tests and 82% overall agreement between the two tests Index Terms — Sudan, Bovine Brucellosis. MRT, ELISA, RBPT I. INTRODUCTION rucellosis is an endemic disease in most areas of the world, including Mediterranean Europe, Northern and Sub-Saharan Africa, Middle East, South East Asia and many South American countries [1]. It is considered to be a serious problem in at least 86 countries [1]. Brucellosis is considered as one of the major zoonosis transmitted by direct contact within animals and/or their secretions, or by consuming milk and dairy products [2]. Much of the developing countries is still in the early stages of attempting to control the disease [3-4].The disease is associated with significant morbidity rate that can lead to increase rate of spontaneous abortion and infertility in livestock [5]. [6] reported that the disease is a major bacterial zoonosis that poses a barrier to trade of animals and animal products and can seriously impair socioeconomic development of livestock owners. It causes great economic loss to livestock industries because it induces delayed oeustrus, increased calving interval, birth of weak calves, infectious abortion, infertility and subsequent culling. Furthermore, interruption of lactation may lead to a reduction in milk yield [7]. It is predominantly a disease of sexually mature animals and characteristically associated with abortion at the first gestation [8]. [9] stated that the disease is very likely to occur via the oral route. This is attributed to licking aborted foetuses and the genital discharge of aborting cows. Exposure to Brucella organisms in vitro [10] or when calves born to healthy dams are fed on colostrum or milk from infected dams [11] were also evident. Infection with Brucella in a herd occurs when infected animals that are not yet diagnosed introduced into it. [12- 13].The main factor for the spread of brucellosis are cows those aborting in stables and farm yards. It has been reported that cows infected with brucella are three to four times more likely to abort than unexposed cows [14-15].While the disease is usually asymptomatic in non-pregnant female cows, pregnant adult females infected with Brucella abortus develop placentitis, which normally causes abortion between the fifth and ninth month of pregnancy. There is also a heavy shedding of bacteria through the placenta, fetal fluids and vaginal exudates in infected animals that did not abort [16]. When cows contract the infection, they commonly abort during their next pregnancy and 80% of them abort only this once [17].While in most cases subsequent pregnancies will come to term with no apparent signs, or with the birth of weak calves, infected cows suffer repeated uterine and mammary infections, with microorganisms evident in birth products and milk [17]. Such cows will continue shedding large numbers of brucellae at delivery that will go on to become sources of infection for other animals [12 and18]. Serological tests are economical and reliable tools of diagnosis as there is a good correlation between isolation of Brucella and positive tests performed with sera and milk. When tests for detecting Brucella antibodies in milk and serum are considered, the principal methods for detecting infected herds and for diagnosing brucellosis in individual animals are the serological tests which are mainly used for diagnosis of brucellosis [19]. Application of Different Serological Tests for the Detection of the Prevalence of Bovine Brucellosis in Lactating Cows in Khartoum State, Sudan Adil M.A. Salman¹, Elniema A. Mustafa² , Amona M. Hamid³ and Lmyaa Mohammed Hassan 4 ¹Bahri University, College of Veterinary Medicine, Department of Preventive Medicine and Veterinary Public Health ² University of Bahri, College of Veterinary Medicine,. E.mail: elniema.mustafa@hotmail.com ³Bahri University, College of Graduate Studies, Department of Preventive Medicine and Veterinary Public Health, (MVM). 4 BVM, Vet. Officer, Ministry of Agriculture and Animal Resources, Veterinary Teaching Hospital , Alkadaro. (Received: June 09, 2014; Accepted: September 29, 2014) B *Correspondent author E. mail: Adilsal400@gmail .com