Eggshell apex abnormalities in a free-range hen farm with mycoplasma synoviae and infectious bronchitis virus in Rio de Janeiro state, Brazil

Abstract

Eggs, mycoplasm, egg defects, egg abnormality, economic loss.Submitted: June/2013 Approved: March/2014 ABSTRACT A farm with 3,000 free-range hens between 24 and 65 weeks of age was investigated. These hens were separated in small flocks of 400 to 700 birds, presenting 10 to 23% egg production reduction. Twenty serum samples were collected during the period of drop in egg production and three weeks later for the investigation of Mycoplasma synoviae (MS), M. gallisepticum (MG) and Infectious Bronchitis Virus (IBV) antibodies using ELISA. At the time of the second collection, egg production had resumed to normal levels; however, with 10.23% of the eggs showed eggshell abnormalities limited to the apex. Eggshell strength was significantly different between normal and those with eggshell apex abnormalities, but not other egg-quality parameters. ELISA tests showed that MS and IBV titers increased during the evaluated period. MS infection was confirmed by culture and by PCR of tracheal swabs. All samples were negative for MG by ELISA and PCR. Further studies with larger samples to ensure the occurrence of this disease in industrial layer flocks in Brazil are under way.

Eggshell apex abnormalities caused by two different Mycoplasma synoviae genotypes and evaluation of eggshell anomalies by full-field optical coherence tomography

“…This difference could be related to the type of chicken used in the experiment (commercial Bovans Brown layers vs. commercial white layers and white HyLine SPF), or to the genotype of the MS strains. The percentage of abnormal eggs (24.5%) detected in our experimental study was higher than the 10.2% in Brazil and 7.2% in Italy reported previously but similar to the 25% in layers housed on the floor in the Netherlands [2, 3, 23]. Egg production loss in flocks infected with MS over the period of the experiment (10–24.7%) was similar to that seen in flocks in Brazil 10–23% [23].…”

“…The damaging effects of the MS on the hen reproductive organs were evaluated with gross autopsy during the 8-week observation after infection. The mechanism by which MS affects eggshell calcification is not clear although its elucidation has already been attempted by several authors [2, 3, 6, 23, 24]. Many factors can affect the quality of the shell.…”

Dietary L-Glutamine affects Eggshell Quality in the Post-Peak Laying Period

“…The sample size was calculated for a two-tailed Student's t-test with an α of 0.05 and power at 0.8 (Festin, 2018). Available literature data show that for these assumptions sample size of n = 12 has a power of 80% to detect a change of 3.9%, 20% and 8.1% in eggshell Ca, P and Mg content, respectively, a change of 6.4% and 6.8% in the eggshell thickness and weight, respectively, a change of 22% in eggshell cracking force and stiffness (Ahmed et al, 2005;dos Santos et al, 2014;Park et al, 2018;Mori et al, 2020). The normal distribution of the datasets was checked using a Shapiro-Wilk test; the homogeneity of variances was assessed using Levene's test.…”

Avian Viruses that Impact Table Egg Production

“…Recently, Massachusetts (Mass) type IBV was shown to be responsible for repeated outbreaks of shell-less egg syndrome (SES) in Western Canada [ 34 ]. An increase in the anti-IBV antibody titer was detected in non-vaccinated laying flock with a history of eggshell apex abnormalities (EAA) [ 35 ]. A threshold of 6 log2 for the hemagglutination inhibition (HI) anti-IBV antibody titer was shown to be protective against the negative effects on egg production [ 36 ].…”