ABSTRACT Clinical manifestation of the disease caused by the chicken anaemia virus (CAV) occurs when chicken chicks are vertically contaminated or before the second week of life. CAV control is based on the vaccination of broiler breeders in order to promote progeny protection through maternal antibodies. This work aims to evaluate, under field conditions, the antibody title in commercial broiler breeders at 28, 48, and 68 weeks of age, the rate of transference to the progeny, as well as the duration of antibodies in the progeny up to 21 days of age. Thus, a total of 92 sera samples from 93,000 broiler breeders vaccinated with a live vaccine for CAV at 14 weeks of age and 366 sera samples from their respective progeny were analyzed using ELISA. Breeders’ antibody title for CAV ranged between 5051 and 8660, and these titles may provide sufficient protection for their progeny. On average, 63% of the maternal antibodies were transferred to the progeny and lasted up to the second week of chick’s life. It is possible to conclude that the vaccine and the vaccination procedure used by this company for breeders against CAV seems to be effective in inducing high antibody levels in the breeders and transfering protective maternal antibodies to the progeny.

A study on the occurrence of epididymal lithiasis (EL) in Gallus gallus domesticus of different breeds and from different geographical regions of Brazil was carried out. Forty breeding roosters were collected in the states Santa Catarina, São Paulo, Minas Gerais, Espírito Santo and Goiás, representing two specific pathogen free Leghorn lines (SPF), one commercial Leghorn layer breeder (Hy-Line) line, two commercial broiler breeder lines (Ross and Cobb), and two backyard chicken flocks. In commercial poultry breeders, EL was observed mainly after 55 weeks of age, and lithus resulted in lower fertility caused by inadequate maturation of spermatozoa and testicular atrophy, which evolved to more severe testicular dysfunction at 100 weeks of age. One hundred percent of the sampled roosters of the evaluated SPF lines presented epididymal lithiasis, which was also observed in all commercial genetic lines. The analysis of EL occurrence revealed no differences among regions and breeds: all regions and genetic lines presented epididymal calculi and the occurrence seemed higher in the more intensively-reared chickens. As for the backyard roosters, 50% presented calculi. Considering the occurrence of EL in the SPF flocks, its primary association with infectious bronchitis virus (IBV) infection was discarded, despite its contribution to fertility loss.

Campylobacter was investigated in cecal droppings, feces, and cloacal swabs of 22 flocks of 3 to 5 week-old broilers. Risk factors and the likelihood of the presence of this agent in these flocks were determined. Management practices, such as cleaning and disinfection, feeding, drinkers, and litter treatments, were assessed. Results were evaluated using Odds Ratio (OR) test, and their significance was tested by Fisher's test (p<0.05). A Campylobacter prevalence of 81.8% was found in the broiler flocks (18/22), and within positive flocks, it varied between 85 and 100%. Campylobacter incidence among sample types was homogenous, being 81.8% in cecal droppings, 80.9% in feces, and 80.4% in cloacal swabs (230). Flocks fed by automatic feeding systems presented higher incidence of Campylobacter as compared to those fed by tube feeders. Litter was reused in 63.6% of the farm, and, despite the lack of statistical significance, there was higher likelihood of Campylobacter incidence when litter was reused. Foot bath was not used in 45.5% of the flocks, whereas the use of foot bath associated to deficient lime management increased the number of positive flocks, although with no statiscal significance. The evaluated parameters were not significantly associated with Campylobacter colonization in the assessed broiler flocks.