Six tests for the detection of West Nile virus (WNV) antibodies in the serum of experimentally infected chickens were compared. The tests included the hemagglutination-inhibition test (HIT), immunoglobulin M (IgM)-capture enzyme-linked immunosorbent assay (ELISA) with WNV-infected mouse brain antigen, immunoglobulin G (IgG) indirect ELISA with tickborne encephalitis viral antigen, the microtitre virus neutralization test, the standard plaque reduction neutralization test (PRNT), and the microtitre PRNT (micro-PRNT). Thirty adult chickens, intravenously and intramuscularly inoculated with 107 plaque-forming units (PFU) of WNV strain Egypt 101, were bled and given a booster of 107 PFU at 7, 15, and 21 d postinoculation; the final blood collection was on day 28. Although the micro-PRNT is capable of detecting the highest antibody titres during both early and late infection, because of the technical complexity and time requirements of this test a combination of IgM and IgG ELISAs is recommended for serologic screening. Serum samples that give positive results in the ELISAs can then be tested by the micro-PRNT to determine the specificity of antibodies to WNV.

The innate immune system is a critical component directing the overall response of the immune system early in the inflammatory process. Evaluation of the innate immune system could offer a screening method for the selection of breeding stock from commercial chicken operations to improve flock health and prevent the loss of genes crucial to disease resistance. Three commercial broiler chicken lines (designated Lines A, B and C) were profiled for efficiency of their innate immunologic response. Oxidative burst and bactericidal functions of heterophils and monocytes, as well as heterophil degranulation, were analyzed. The birds were tested 1, 4, 8 and 15 days post-hatch. Individual lines differed in their ability to perform innate immunological responses during the first 15 days post-hatch. Although bactericidal capabilities were similar, oxidative burst responses by monocytes were low in comparison to that generated by heterophils. The fact that monocytes are not particularly adept at producing an oxidative burst at this age suggests that this is not a major avenue of innate defense by monocytes. Heterophil oxidative burst response was stronger in Line C than Line A during the first four days post-hatch. Line B showed no difference from Line C in heterophil oxidative burst response at 1 d, but produced a stronger response than Line C on 4 and 8 d post-hatch. Degranulation by heterophils showed significant differences in responses of Lines A and C depending on the day post-hatch, and stronger response in Line C vs Line B in the first four days post hatch. The first week post-hatch is an important time as chicks are particularly susceptible to infection as neonates. Mortality data of the commercial lines indicates that Line A is the most susceptible to demise, followed by Line C and then Line B. These results suggest that oxidative burst production efficiency is an important defensive function to monitor for immunoprofiling.

Proliferative enteropathy is an important enteric disease caused by Lawsonia intracellularis. A wide range of host species can be infected by the same bacterium, yet the clinico-pathologic features among these hosts remains almost identical. The disease has been recognized regularly among ratites, but not in other avian families, such as galliforms, even though these suffer uncharacterized enteric conditions. Fresh ileum-colon contents were obtained from 228, 3- to 8-week-old chickens with enteric disease, kept at 14 large commercial farms in the southern USA. DNA was extracted from each sample and subjected to polymerase chain reactions (PCR) with primers specific to eubacterial DNA, L. intracellularis, and Bilophila wadsworthia. All chicken samples were positive for eubacterial DNA, 29 chickens (13%) were positive for B. wadsworthia DNA, and none were positive for L. intracellularis DNA. Given the ubiquitous nature of L. intracellularis, we consider it likely that some avian families do not carry the necessary mechanism for L. intracellularis viability. Bilophila wadsworthia appears to be a consistent member of the colonic flora of some host animals. Neither bacterium appears to be associated with malabsorption syndromes in chickens.

A study was conducted to determine the effect of different nutrients i.e. metabolizable energy (ME) and crude protein (CP) content of ration on the egg production and egg weight of rural layers. For the purpose six different experimental rations containing 2700, 2900 kcal/kg ME and 14, 16, 18 percent CP were offered to the birds. The results indicated that egg number increased with proportional adversely affected as the CP of the ration was increased weight of the layers was proportionally increased with ration at constant ME level, while increase in ME level egg weight. increase in ME, while it was at constant ME level. The egg increase in CP content of the did not significantly affect the egg weight.

In this study five samples each of serum glucose, serum cholesterol and uric acid contents were measured in Fayoumi, Rhode Island Red, Parent desi, desi Fl and desi F2 strains of chickens. Cholesterol contents were found to be lowest in desi F2 chickens whereas in other strains there was least significant difference, which can be attributed to reduced lipogenic activity in desi F2 generation. When five samples each of meat from two locations i.e. breast and thigh was subjected to proximate analysis it was found that there was no difference (P greater than 0.05) in crude protein, crude fat, total ash and moisture contents regardless of sex and strains. Dry matter contents differed (P less than 0.05) in breast meat and found to be lowest in Parent desi stocks.

This study was conducted to examine growth performance of black, dark brown and light brown varieties of Desi Generation-1 chickens obtained from selected Desi parents (originally procured from rural areas of Mianwali and Bhakkar districts) maintained at Poultry Research Institute, Rawalpindi. A total number of 900 day-old Desi chicks 300 each of black, dark brown and light brown varieties were divided into 3 separate groups and further sub-divided into 3 equal replicates. The experimental chicks were maintained on littered floor in 9 separate pens under optimal managemental conditions for a period of 12 weeks. They were fed ad libitum a balanced chick starter ration (from day- old to 8 weeks) and a grower mash (from 9 to 12 weeks). The birds had free access to clean and fresh drinking water. The results showed non- significant difference in growth rate, feed intake and feed conversion efficiency (feed/kg gain), whereas, significantly (P less than 0.05) lower mortality rate was recorded in Desi light brown chicks in comparison to other two varieties. The better growth performance in different varieties of Desi chicks observed during the present study than reported in earlier findings could be due to effect of genetic improvement through selection breeding carried out in the parent Desi flock.

This study was conducted to examine the present productive potentials of field Desi chickens housed under deep litter system. For this purpose a detailed survey was conducted in rural areas of Punjab Province (Pakistan) to know availability of true specimens of Desi birds. After the survey a total number of 1329 adult Desi birds were selected from different villages of Mianwali and Bhakkar districts. The birds were housed at Govt. Poultry Farm, Mianwali for initial acclimatization for 6 to 8 weeks and subjected then to prophylactic vaccination and then they were shifted to Breeding and Incubation Division of Poultry Research Institute, Rawalpindi. A total number of 450 Desi birds (150 each of black, dark brown and light brown varieties) were randomly selected and were sub-divided into 3 groups of equal size. They were maintained on littered floor in 9 separate pens under optimal managemental conditions for a period of 42 weeks. The results indicated that black, dark brown and light brown groups of Desi chickens produced 1.93, 1.96 and 2.17 dozen eggs (0.0459, 0.0467 and 0.0516 dozen eggs per week) with intake of 29.75, 29.29 and 29.64 kg feed, respectively. The results showed similar performance in egg production and feed intake of different groups of Desi chickens. A similar pattern in egg weight, egg mass and FCR (feed/kg eggs) was observed, however, FCR in light brown Desi (13.68) was found to be significantly (P less than 0.01) better than that of Desi black (15.42) birds. The results further showed depression in production potential of field Desi chickens in comparison to previous production data recorded in the earlier period.

In this study ELISA was standardized for detecting antibodies against Hydropericardium Syndrome Virus. Factors like Antigen, Conjugate and incubation time were studied. Standardization was carried out by checker board titration method. Optimum incubation time for colour development was found to be 15 minutes while 50 mug/ml of antigen gave better results than 100 mug/ml. The conjugate dilution of 1:500 was observed to give satisfactory results as determined by regression analysis. Cut off value was determined by adding 2SDs and 3SDs in the mean optical density (OD) values of negative serum samples. It was found that mean OD+2SD (0.0684) resulted in better diagnostic sensitivity) and diagnostic specificity than mean OD+3SDs (0.0741).

This study was conducted to examine comparative productive performance of different varieties of Desi chickens identified from group of Desi flock procured from rural field conditions of Mianwali and Bhakkar districts of Punjab province (Pakistan). A total of five varieties of Desi chickens viz., dark brown, medium brown, light brown, black and mixed colour were identified on the basis of their plumage colour and uniformity of body characters. Four hundred and eighty birds (96 of each variety) were selected for further study. The birds of each variety were randomly divided into 3 equal replicates. They were maintained in 15 separate pens on deep litter system under optimal managemental conditions and were fed a balanced layers ration ad-libitum. The birds were provided 16 hours light per day. The experiment was conducted for 8 weeks. The results indicated that varieties differed significantly in egg production, feed conversion efficiency and egg mass, whereas, no difference was observed in feed intake and egg weight between them. Based on the findings of this study, it appeared that different varieties of Desi chickens identified and selected during the course of this study on phenotypic basis differed in their productive potential on the basis of better productive potentials in terms of egg yield, FCR and egg mass, dark brown, and black varieties of Desi chickens could be used to carry out further selective breeding work to study possibility of improving their productive potentials.