Purified lipopolysaccharides (LPS) from 16 serotypes of Pasteurella multocida were complexed with Aspergillus fumigatus ribosomes. The complexes were used as inocula to prepare antisera, in chickens, for somatic antigen typing by the gel diffusion precipitin test (GDPT). Antisera made against 15 of 16 LPS reacted with their respective specific heat-stable antigens in the GDPT and homologous LPS in the passive hemagglutination test. Antisera could not be made against serotype 15 LPS. Correlation was not observed between intensity of the precipitin reaction in the GDPT and titer to homologous LPS in the passive hemagglutination test. Most antisera cross-related with other heat-stable antigens of other serotypes in the GDPT. Many of these cross-reactions were eliminated by dilution. Cross-reactions that occurred in the GDPT with antisera made against LPS of serotypes 2, 5, 7 and 8 could not be eliminated by dilution.

The relative myocardial irritant properties of halothane, isoflurane, and pentobarbital were evaluated in chickens. Sixteen adult male broiler chickens were randomly assigned to 1 of 3 groups: group-1 chickens were anesthetized with pentobarbital (30 mg/kg, IV), group-2 chickens were anesthetized with halothane (end tidal halothane 1.2%), and group-3 chickens were anesthetized with isoflurane (end tidal isoflurane 2.1%). Birds in any 2 of the 3 treatment groups were tested on any 1 day. Local anesthesia was induced, and blood pressure, heart rate, ECG, and blood gas variables were measured before general anesthesia was induced. Positive-pressure ventilation with an inspired O2 fraction > 0.95 was adjusted to result in an end tidal CO2 concentration that reflected a PaCO2 similar to that obtained prior to anesthesia and ventilation. All measurements were repeated. The threshold for ventricular fibrillation in response to electrical stimulation of the heart was then determined for all birds. Effects of anesthesia on hemodynamic and blood gas variables were similar in all 3 groups. Compared with halothane or pentobarbital, isoflurane anesthesia resulted in a significantly (P < 0.05) lower threshold for electrical fibrillation of the heart.

To analyze and identify selected risk factors for infectious bronchitis virus (IBV) infection in the growing and laying period of laying-hen flocks, a longitudinal field study was conducted with 27 commercial flocks reared in three provinces of Korea during the period from May 2003 to April 2004. Using monitored data for IBV infection status among study flocks we computed the multivariate odds ratios (ORs) and their corresponding confidence intervals (CIs), and population attributable risks (PARs). Multivariate logistic regression showed significant risk increments for: continuous entry of chick (OR=1.9, 95% CI, 0.7-69.1) and operation years of the layer house greater than or equal to 5 years (OR=3.2, 95%CI, 1.6-389.9).

The effect of vacuum packaging on microbiological quality of roasted chicken. Roasted chicken were subjected to two different type of packaging treatment i.e. aerobic packaging with low density polyethylene bags (con) and vacuum packaging using barrier bags (VP.). Microbiological analyses were done on 0th, 5th, 10th, 15th and 20th day at refrigeration temperature (4±1oC). Studies revealed that microbial counts in terms of total plate count, proteolytic count and yeast and mold count increased significantly (P0.05) with the advancement of storage period and were significantly higher (P0.05) for aerobically packaged product throughout the observation period however, yeast and mould count observed only on 10th, 15th and 20th day of observation period. Lactic acid bacterial counts of vacuum packaged product were significantly higher as compared to aerobically packaged sample.

Survivability of Listeria monocytogenes in clay loam soil was examined at 30° C for a period of 35 days. The microorganism inoculated in soil steadily declined from 3.5 × 10 6 g -1 to 3.9 × 10 4 g -1 (P = 0.05) on 35 th days. Destruction of normal soil microflora by heat treatment resulted in marginal rise in 3.3 × 10 6 g -1 of L. monocytogenes to 4.2 × 10 6 g -1 during the first 7 days, followed by steady decline to 5.6 × 10 4 g -1 on 35 th days. Heat treated soil inoculated with lower concentration of L. monocytogenes (3.6 × 10 4 g -1 ) supported sharp rise in its population to 4.8 × 10 6 g -1 (P=0.05) during the first weak which gradually declined, but remained higher (6.1 × 10 4 g -1 ) than the initial load even on 35 th days. In non-sterile soil, the rise was less appreciable but L. monocytogenes maintained its levels (10 4 g -1 ) during the experimental period. Survivability of the microorganisms was also observed in the soil with added chicken manure, cattle manure or sheep/goat manure.

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.

Test vaccines comprised of inactivated water-in-oil emulsions containing various antigen levels were prepared using a non-pathogenic H5N1 avian influenza (AI) virus, A/duck/Hokkaido/Vac-1/04 (H5N1). The potencies of these test vaccines were evaluated by two experiments. In the first experiment, the triangular relationship among the antigen levels of test vaccines, the hemagglutination inhibition (HI) antibody response, and the protective effect against challenge with a highly pathogenic avian influenza (HPAI) virus, A/chicken/Yamaguchi/7/04 (H5N1), was confirmed. Then lasting immunity of chickens after a single-shot vaccination was confirmed in the second experiment. As a result, complete protection after the challenge was observed in chickens immunized by test vaccines with an antigen level of 160 HA units/dose or higher. Thus, it was ascertained that the minimum antigen level in the AI vaccine was 160 HA units/dose, and the minimum HI antibody titer that could protect chickens from HPAI virus infection-related death was considered to be 1:16. Dose-dependent HI antibody responses were observed in chickens after the vaccination. Thus, 640 HA units/dose were thought to be similar to the optimal antigen level. Alternatively, the HI antibody titers of chickens, injected with the vaccine containing 640 HA units/dose, were maintained at 1:181 or higher for 100 weeks after the single-shot vaccination.