egg-white and Avian-Leukosis

The efficacy of the albumen test for infectious avian leukosis virus (ALV) was examined in detecting congenitally transmitting hens. Seventy-three White Leghorn non-viremic hens with antibody to ALV were used. Eleven of the hens shed infectious ALV into their egg albumen, whereas only 7 of the 11 ALV-positive hens shed ALV antigens. The egg albumen test for infectious ALV was shown to be more effective in detecting the congenitally transmitting hens than that for ALV antigens. Then, twenty of the 62 hens which shed no infectious ALV into the albumen were studied for transmission of ALV to their embryos and for discharging ALV into the oviduct and vagina. Six of the 50 embryos from 4 hens were found to be infected with ALV but all of the 227 embryos from remaining 16 hens were free from the infection. Discharge of the virus into the oviduct and vagina was found both in the 4 transmitting hens and in 6 of the 16 non-transmitting hens. These results suggest that the hens discharging ALV into the oviduct, even though they do not shed ALV into egg albumen, may transmit the virus sporadically to their embryos.

Topics: Animals; Antibodies, Viral; Antigens, Viral; Avian Leukosis; Avian Leukosis Virus; Chick Embryo; Chickens; Egg White; Enzyme-Linked Immunosorbent Assay; Female; Oviducts; Vagina

1. Shedding of group-specific antigen of avian leukosis virus (ALV) into egg albumen was determined in three Australorp lines: AS line that had been selected primarily for short oviposition interval, ASS line that had been derived from the AS line and developed as a commercial dam line for egg laying, and AC line that had been kept as a randombred control. 2. The proportion of shedders was 13.1 to 16.7% in the AS line in 1984-88, 16.3% in the ASS line in 1984 (before culling of the shedders), and 6.1% and 6.6% in the AC line in 1984 and 1988, respectively. 3. In the AS line, shedders were 1.8% lower in rate of lay to 300 d of age, 1.3 g lower in average egg weight at 34 weeks of age, 5.6% lower in hatchability of fertile eggs and 0.24 h shorter in oviposition interval than non-shedders. In the ASS line (1984 only), the differences between shedders and non-shedders were in the same direction, but in magnitude greater for rate of lay and smaller for oviposition interval. 4. The shedders were favoured by the artificial selection because of their shorter oviposition interval and this appeared to be responsible for the higher levels of ALV shedding in the selection lines.

Topics: Animals; Antigens, Viral; Avian Leukosis; Avian Leukosis Virus; Breeding; Chickens; Egg White; Female; Oviposition

A total of 72 White Leghorn grandparent hens was examined by ELISA for avian leukosis virus (ALV), ALV antigens and anti-ALV antibodies to identify and characterize the hens transmitting ALV to their embryos (transmitters) by using fertilized eggs. These hens were divided into 3 groups as no antibody and non-viremic (NANV) (49 hens), antibody-positive and non-viremic (APNV) (21 hens) and no antibody and viremic (NAV) (2 hens) by testing the sera for the presence of ALV and anti-ALV antibody. Egg albumen and embryos were tested for the presence of ALV and ALV antigens. As a result, no ALV was detected in both albumen and embryos in the NANV group. On the other hand, all albumen samples collected repeatedly from 3 hens of the APNV group and 2 hens of the NAV group contained infectious ALV, although the infectivity differed with the individual. Also, these 5 hens produced infected embryos at varying frequencies. However, on AP hen which shed neither ALV nor ALV antigens into the albumen produced an infected embryo at a lower rate. These results indicate that testing for infectious ALV in albumen from a newly laid egg per hen is effective to identify the transmitters to some extent. When virus titers in each of 8 tissue samples from the 6 transmitting hens were determined, the highest virus titers were found in washing from the ampulla of the oviducts in most of the shedders, suggesting that embryo infection is closely correlated with ALV produced at the oviduct, but not with ALV transferred from the other parts of the body.

Topics: Animals; Antibodies, Viral; Antigens, Viral; Avian Leukosis; Avian Leukosis Virus; Chick Embryo; Chickens; Egg White; Enzyme-Linked Immunosorbent Assay; Female; Male; Oviducts; Viremia

Seventy-two female broiler breeders produced 500 pedigreed chicks that were classified as infected or free of avian leukosis virus (ALV) by assay for ALV in their meconia. The albumen of one egg produced by each dam was assayed for group-specific (gs) antigen by the complement fixation (CF) test and enzyme-linked immunosorbent assay (ELISA). Cloacal swabs of dams were assayed for gs antigen by ELISA. Assays on albumens differentiated between transmitting and nontransmitting dams slightly better than swabs. The ELISA was more sensitive than the CF test on albumens, but more nontransmitting dams were positive by ELISA. The ELISA and virus assay on the same samples of swabs and meconia were highly correlated.

Topics: Animals; Antigens, Viral; Avian Leukosis; Avian Leukosis Virus; Chickens; Cloaca; Complement Fixation Tests; Egg White; Enzyme-Linked Immunosorbent Assay; Female; Immunoenzyme Techniques; Meconium; Poultry Diseases