A conclusive study was conducted for preparation and evaluation of combinedinactivated entero-4 vaccine containing bovine rotavirus (BRV), bovine coronavirus(BCV), E. coli K99 and toxoid of C. perfringens type "C". Laboratory and field evaluations were conducted on laboratory animals, calves and late pregnant cows with monitoring the active and passive antibodies in vaccinated cows and their offspring respectively. Laboratory evaluation proved purity, safety and high efficacy of the vaccine without interference between different vaccine ingredients. Field evaluation gave satisfactory results when pregnant cows vaccinated at late stage of pregnancy with high neutralizing antibody titers against BRV, BCV and C. perfringens as well as high E. coli agglutinating titers. Maternal immunity passively protected offspring during the critical period of age and remained protected till the end of sampling time (30th day post parturition).

Fowl cholera is a contagious bacterial disease of poultry caused by Pasteurella multocida and has a significant economic importance worldwide. Fowl cholera prevention depends mainly on vaccination using live and inactivated vaccines, but they have many limitations. The present study aimed to prepare fowl cholera chicken embryo derived inactivated bacterin and to evaluate it by experimental infection and molecular evaluation. Fowl cholera chicken embryo derived inactivated bacterin prepared by in-vivo growing of Pasteurella multocida serotype 3 (P-1059) on chicken embryonating eggs, then inactivated by formalin (0.3%) and adjuvant added and then quality control parameters tested. The prepared bacterin was evaluated by experimental challenge with homologues and heterologous serotypes of Pasteurella multocida serotypes in comparison with commercial inactivated multivalent vaccine. Molecular evaluation of prepared bacterin was carried out using SDS-PAGE for in-vivo and in-vitro grown Pasteurella multocida serotypes. Results revealed that the prepared fowl cholera chicken embryo derived inactivated bacterin was free from bacterial and fungal contaminations and safe for use. Fowl cholera chicken embryo derived inactivated bacterin provided high protection rates with low mortalities against experimental infections with homologues and heterologous serotypes of Pasteurella multocida. Results of SDS-PAGE revealed that in-vivo grown Pasteurella multocida serotypes showed expression of additional specific bands (35kDa, 39kDa). It was suggested that 39kDa is a dominant structural protein in Pasteurella multocida grown in-vivo and play a role in antigenic cross protection among its serotypes. In conclusion, Fowl cholera chicken embryo derived inactivated bacterin is effective against infections of homologous and heterologous Pasteurella multocida serotypes.

From Aug 1985 through July 1986, 720 meat turkey flocks on 160 California premises were monitored and outbreaks of fowl cholera (Pasteurella multocida) were investigated. Data from 43 outbreak (case) flocks were compared with data from 43 nonoutbreak (control) flocks. Outbreak flocks, compared with control flocks, were more likely to be located on premises with higher maximal bird capacity and history of fowl cholera outbreaks. The overall impression was that flocks in larger, newer, more intensively managed premises were at greater risk of fowl cholera outbreaks than were other flocks.