Animal Sciences
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ANIMAL SCIENCES Animal Health Animal Health Better health of food animals is one of the major contributing factor towards productivity, in terms of their growth, reproduction and production capabilities. The Animal Health Research Group at the Animal Sciences Institute, NARC is focusing on studying the pathogenesis and epidemiology of emerging and newly introduced animal diseases in this country, which has national, regional or international significance. During the report year most of research focus of this group has been towards studying pathogenesis and pathogen characterization in case of FMD, tick infestation, and selected zoonotic diseases. This program is also hub for activities related to the department of Animal Genomics and Biotechnology under the degree awarding institution of PIASA at NARC. Studies on Foot and Mouth Disease Virus Pakistan is endowed with a large livestock population. The national herd (2010-11) consists of 35.6 m cattle, 31.7 m buffaloes, 28.1 m sheep, 61.5 m goats and 1.0 m camels. Productivity of livestock in Pakistan is generally low. One of the main reasons of low productivity is frequent occurrence of infectious diseases particularly FMD. FMD was reported in animals in pre-partition India and disease has been seen since independence in Pakistan. The disease was usually seen as a mild febrile infection with mild lesions in cattle and buffaloes with a seasonal pattern (usually wheat harvest time or change of weather) up to early 1970s. Now the disease is endemic and wide spread in Pakistan and occurs throughout the year. FMD is currently the most common infectious disease of livestock in the country. Studies were carried out focusing on viral persistence in buffaloes and cattle. In this regard, 45 farms were identified in ICT area having more than 20 animals. Experiment was initiated in 30 farms, where randomly selected 10 animals from each farm were ear tagged for identification purposes and blood was collected besides collecting probing samples and oral swabs. Sero-conversion against non-structural FMDV proteins revealed 77.66% positive animals. The oro-phageal-fluid was collected using probing cub recently introduced in Pakistan and oral swabs were collected for virus isolation on BHK-21/LFBK cell lines and detection of persistant infection by rRT-PCR. These samples are being collected at monthly interval and analysis is ongoing. Polyvalent Vaccine Matching Studies were started at Livestock Research Station, NARC. In this regard, 13 NSP negative animals were vaccinated against FMD using Merial vaccine in two groups. In another trial 11 NSP negative animals were vaccinated with Arriah vaccine. Post vaccination sera were collected and at day 0,7,14,21,28, 60 and 90. All the sera were analyzed using LPBE, NSP-ELISA and SNT. All the animals remained NSP negative throughout the study and titration was carried out using LPBE. Serum neutralization studies with field isolates are planned. Slaughter house based studies were conducted for the detection of FMD infection in animals at ICT and Rawalpindi. Interestingly, 28% animals were found NSP positive and among them viruses were recovered from 27.3% animals. Sero-conversion against non structural proteins of FMDV was observed in 31.85% sheep and 17.27% goat. The overall sero- conversion was 20.38% ANNUAL REPORT 2011-12 131 Animal Health Use of Probang cup Sample in probang cup Blood collection Identification of Tick Species Infesting Large Ruminants at LRS, NARC The study was carried out to determine the prevalence of tick infestation in large ruminants maintained at Livestock Research Station (LRS), National Agricultural Research Centre Islamabad (NARC). Monthly examination of animals for tick infestation at LRS from August 2010 up to October 2011 has been carried out. A total of 90animals (30 Cattle and 60Buffaloes) were screened out for the presence of ticks on monthly basis. Of these, only 27 Cattle were found infested with different species of ticks & none of buffaloes were found infested with any type of tick. Monthly wise Prevalence Rate of Ticks is as follows: Oct, 2010 (36.66 %), Nov, (0 %), Dec, (19.35 %), Jan, 2011 (9.09 %), Feb, (0 %), March, (0 %), April(3.70 %), May( 3.70%), June(3.85 %), July(0 %), August (0%), and Sep, 2011( 12.12 %). The prevalence of ticks in Cattle was high in October (36.66 %) followed by December (19.35 %), January (9.09 %) and April (3.70 %). All ticks were recovered from crossbred and Achai breed of cattle. After collection, permanent mounts of ticks were made for their identification. Ticks were identified on the basis of their morphological features. Hyalomma antolicum spp. was found to be the most abundant tick infesting the Achai breed of cattle. Studies on PPR Virus In continuation of the research activities being carried out on PPR virus at NARC, recently first part of a new study has been completed to ascertain the carrier potential of small ruminants in the persistence and transmission of PPR virus in at selected places in the country. The research focus in this project has been transmission pattern of PPR virus under field conditions, quantification of risk factors and monitoring of changes in virulence of PPR virus circulating in small ruminant population. The information thus generated is expected to help in bridging the epidemiological gaps in existing base line data regarding the occurrence of PPR in Pakistan. Initially, the project area has been selected and registration of affected farmers has been carried out. An awareness workshop involving all the stake holders has been completed. For the purpose of virus isolation and typing, cell culture based procedures along with setting up of Real Time PCR have been accomplished. 132 ANNUAL REPORT 2011-12 Animal Health Bacterial Diseases of Livestock (Brucellosis and Haemorrhagic septicaemia) Brucellosis, also known as Malta fever or undulant fever, in humans and Bang's disease in cattle, is among the oldest and one of the most common bacterial zoonoses with annual reporting of human cases to the tune of 500,000 worldwide. The serological surveys of different location in the country suggested its prevalence of 15% in general livestock population. Some studies carried out so far indicated significant role of cell mediated immune response against the Brucella vaccine in buffalo-calves. Some studies related to disease epidemiology, diagnosis and control of Brucella melitensis infection in small ruminants has been recently initiated in this regards. A live aerosol vaccine of heterotrophic Pasteurella multocida B:3,4 was prepared and tested under field condition. This vaccine was found to be 80-90% effective in challenge protection studies besides conferring immunity for one year. Animal Biotechnology (NIGAB Component) The following research activities were undertaken: · Genetic analysis of genes controlling growth, milk production and disease resistance etc. in important Pakistani sheep, goat, buffalo and cattle breeds · Genetic analysis of inherited disorders in cattle · Teaching and research supervision of PIASA post graduate students. Salient Outcomes Polymorphism of the QTLs affecting live weight gain in two Pakistani sheep and one goat breed was studied. Also polymorphism in genes affecting milk fat contents in Pakistani buffalo and cattle breeds was studied. The results of these studies showed that the polymorphism in QTLs affects growth and milk production in these breeds. Similarly, polymorphisms in prolactin as well as leptin genes were investigated. Results of these studies will lead us to apply these research tools for marker assisted selection in animals, which will result in devising cross-breeding strategies to improve the local breeds of livestock more effectively. ANNUAL REPORT 2011-12 133 National Reference Laboratory National Reference Laboratory for Poultry Diseases Avian health issues have attained high significance due to increase in the commercial poultry farming activities in the country. With the occurrence of disease outbreaks of highly infectious avian diseases, sometime having zoonotic potential, enhanced diagnostic capacity at national level is desperately needed. Although various diagnostic kits, reagents, drugs and vaccines are being imported for the control of various poultry diseases, however, these drugs and vaccines are less effective against local strains of these poultry pathogens. Keeping the above in view the National Reference Lab for Poultry Diseases (NRLPD) has been functional at the Animal Sciences Institute of NARC since 2004. The NRLPD is equipped with the latest state of the art equipments and possesses highly qualified & trained manpower along with the presence of strong national and international collaborations in the field of avian disease research. Avian Disease Diagnosis and Control One of the major activities of NRLPD during 2011 has been development and standardization of effective molecular diagnostic procedures that result in devising effective poultry disease control strategies. The detailed work done in this regard is given below: · During 2011, different types of 45500 clinical samples from all over the country were analyzed for diagnosis of various avian pathogens. In this regard about 273 isolates of different poultry pathogens including AAV, AIV-H9N2, NDV, IBV, APV, Salmonella and E.coli were isolated and preserved in the national repository of NRLPD. · Two new Avian Influenza isolates of types H3N1 and H4N6 were also recovered during the routine surveillance of commercial and domestic poultry