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Contamination of poultry carcasses by fecal or ingested material is a major problem in the processing of poultry products. It was determined that the automatic equipment used to process uncontaminated carcasses could be used to clean and reprocess contaminated carcasses and significantly reduce the manual labor required to reprocess these carcasses. The potential for cross-contamination of the automatic viscera removal equipment was tested by microbiological evaluation, and it was determined that cross-contamination by this equipment was not a problem.

Inactivated Newcastle disease virus (NDV) and infectious bursal disease virus (IBDV) were incorporated into water-in-oil emulsion vaccines alone or as a bivalent vaccine. Twenty-week-old broiler breeder chickens that had received previous live virus vaccination with NDV and IBDV were injected intramuscularly with the monovalent or bivalent vaccine. The antibody titers to either the monovalent vaccine or bivalent vaccine increased rapidly and then remained at high levels for the duration of the 40-week trial. There were no practical differences in amplitude or duration of the antibody response to either antigen used alone compared to that of the bivalent combination. Progeny hatched from the vaccinated breeders possessed maternal antibody levels at one day of age comparable to those of the hens at the time the eggs were laid. The maternal antibody titers declined at a steady rate until they reached negligibly detectable levels at approximately 3 weeks of age. This trend held true without regard to the initial antibody titer.

Inactivated Newcastle disease (NDV), infectious bursal disease (IBDV), and viral arthritis/tenosynovitis (VA) viruses were incorporated into water-in-oil emulsion vaccines, either alone, in bivalent combinations, or in a trivalent vaccine. Twenty-week-old broiler breeder chickens that had received previous live virus vaccination with NDV, IBDV, and VA were injected intramuscularly with the monovalent, bivalent, or trivalent vaccines. The antibody titers to the antigens contained in the monovalent, bivalent, or trivalent vaccines increased rapidly and peaked 4 to 8 weeks postvaccination. The titers declined during the next 3 months and increased to levels equal to or higher than the initial peak values. The titers remained high through 10 months postvaccination. Progeny hatched at intervals throughout the 40-week trial possessed detectable antibody titers to the appropriate antigens incorporated into the breeder vaccine through 21 days of age.

One-day-old chicks used in this study were from breeder flocks vaccinated with live (B1 and LaSota) or inactivated oil emulsion Newcastle disease (ND) vaccine. Chicks were vaccinated against ND by various procedures. The vaccination response was evaluated by hemagglutination-inhibition antibody titers and by challenge. Chicks from breeder flocks vaccinated with live virus vaccine had a geometric mean hemagglutination-inhibition antibody titer (GMT) for Newcastle of 7 (low maternal antibody titer) at 1 day of age, whereas those chickens derived from breeder flocks vaccinated with inactivated oil emulsion ND vaccine had a GMT of 84 (high maternal antibody titer). One-day-old chicks injected with live B1 vaccine were not immunized against ND regardless of breeder flock source. However, chickens with low maternal antibody titers were effectively immunized against ND when injected at 1 day of age with an inactivated or inactivated plus live ND vaccine. Chicks with high maternal antibody titers were not effectively protected when vaccinated with inactivated vaccine at 1 day of age; however, these chicks were protected when injected with a combined live and inactivated ND vaccine. Chicks from both breeder flocks were effectively immunized against ND when injected at 1 day of age with a live or inactivated ND vaccine and revaccinated by aerosol at 21 days of age with live B1 ND vaccine. Even though they were protected against ND, there appears to have been an interference phenomenon in chicks derived from breeder flocks vaccinated with the live ND vaccine. Beak-O-Vac vaccinated chickens were not effectively protected against ND when compared with chicks vaccinated by aerosol at 1 day of age. Water vaccination at 7, 14, or 21 days of age was as effective as aerosol vaccination when administered to chicks with low maternal antibody titers. However, water vaccination was not as effective as aerosol vaccination when administered to chicks with high maternal antibody titers.

Inactivated Newcastle disease (NDV), infectious bursal disease (IBDV), and viral arthritis/tenosynovitis (VA) viruses were incorporated into water-in-oil emulsion vaccines either alone, in bivalent combinations, or in a trivalent vaccine. Twenty-week-old broiler breeder chickens with no previous exposure to NDV, IBDV, or VA live virus vaccines were injected intramuscularly with the monovalent, bivalent, or trivalent vaccines. The antibody responses to NDV in all three vaccines were poor, and NDV-hemagglutination-inhibition (HI) geometric mean titers (GMTs) never rose above 20 during the 40-week trial. The antibody response to IBDV showed a strong primary response 4 weeks after vaccination, but IBD-VN geometric mean titers declined steadily to less than 100 by 4 months after vaccination. The antibody GMTs to IBDV continued to decline for the remainder of the trial. The antibody response to VA virus was biphasic, with peak VA-virus neutralization (VN) geometric mean titers occurring at 3 months and 6 months postvaccination. The amplitude of the response to the monovalent, bivalent, and trivalent vaccines was inversely proportional to the number of antigens incorporated into each vaccine. Maternal antibody titers in the progeny against each of the three antigens reflected those of the parents. In no case were maternal antibody titers detectable beyond 14 days of age.

Chickens vaccinated with a live Newcastle disease (ND) vaccine and subsequently revaccinated with an inactivated oil emulsion ND vaccine had higher and more persistent hemagglutination-inhibition (HI) antibody titers than birds vaccinated with live ND vaccine. The geometric mean HI antibody titers of flocks vaccinated with the inactivated ND vaccine ranged from 121 to 172, whereas the titers of flocks vaccinated every 90 days with a live ND vaccine ranged from 18 to 54. Breeder flocks revaccinated with live LaSota ND vaccine had lower egg production than the flocks vaccinated with inactivated vaccine. The average egg production per hen for the 40-week laying cycle was 174 and 170 eggs per hen for hens in the two houses vaccinated with the inactivated vaccine. Hens vaccinated with the live virus vaccine averaged 167 and 164 eggs per hen. The increase in egg production would more than offset the additional cost of the oil emulsion ND vaccine as well as the cost of injecting each individual bird at 18 weeks of age. Between 8 and 32 weeks after onset of egg production, geometric mean maternal antibody titers in 1-day-old chickens derived from breeders vaccinated with live ND vaccine ranged from 7 to 24, whereas, chicks from breeders vaccinated with the inactivated oil emulsion vaccine had maternal antibody titers that ranged from 64 to 89.