Water vapor conductance: a technique using eggshell fragments and relations with other parameters of eggshell

Abstract

-The objective of this study was to evaluate a technique for quantifying eggshell conductance using shell fragments from hatched eggs. Additional objectives were to calculate the correlation between eggshell conductance, porosity, and thickness and correlate these parameters with incubation data. The study design was fully randomized in a 3 × 3 factorial scheme (three egg regions -large end, equator, and narrow end -and three ages of broiler breeders -29, 35, and 59 weeks). A total of 216 eggs were used, with 24 repetitions for each treatment. Neither conductance nor shell thickness showed any interaction with egg region. Breeder age influenced eggshell conductance, such that it was greatest in eggshells from 59-week breeders (0.323 mg day −1 torr −1 ), while for 29-week and 35-week breeders, the conductance values found were 0.285 and 0.270 mg day −1 torr −1 , respectively. The eggshell thickness was similar in eggs from 29 and 35-week breeders and these were greater than the thickness of eggshells from 59-week breeders. Correlations between mean eggshell conductance and chick body weight and yolk free chick body weight were found significant. There were no correlations between mean eggshell thickness and any of the data evaluated. There were positive correlations between mean eggshell porosity and egg weight loss up to the time of transfer, chick weight, and yolk free body weight. The technique of using eggshell fragments can be used for measuring eggshell conductance. Eggshell porosity is the characteristic that best correlates with incubation parameters.Key Words: fertile eggs, porosity, shell conductance, shell thickness Revista Brasileira de Zootecnia

Data mining as a hatchery process evaluation tool

“…The higher relative air humidity in the incubator for BB is related to the larger egg size and greater eggshell pore number, losing more water during embryo development changing the incubation environment (Boleli et al, 2016;Araújo et al, 2017). The presence of this variable in the construction of rules is consistent since many incubation problems arise from changes in the variables of the physical incubation environment.…”

Results of hatching and rearing broiler chickens in different incubation systems

“…The egg weight loss was 12.06% for SS and 11.76% for MS, both within the expected normal range of 11.00–13.00% ( Boerjan, 2011 ). According to Araújo et al. (2017) , controlling egg weight loss during incubation optimizes incubation results.…”

“…In turn, eggshell quality is directly influenced by the age of broiler breeders. Older broiler breeders produce thinner and more porous eggshells, which provides greater conductance, thus increasing gas exchange between eggs and the external environment and, consequently a higher rate of weight loss during incubation ( Araújo et al., 2017 ). Because the ages of broiler breeders of the 2 treatments in each incubation trial were similar, the difference in egg weight loss was due to the better control of RH inside the SS machine, with higher water loss likely being due to increased embryonic metabolism in the MS.…”

Effects of breeder age on embryonic development, hatching results, chick quality, and growing performance of the slow-growing genotype

“…The use of nutrients present in eggs is fundamental to greater development of embryos ( Yang et al., 2020 ), and embryos from older breeders tend to make better use of the nutrients present in the egg ( Araújo et al., 2016 ). The higher conductance of eggshells of older breeders, which allows greater oxygen entry, may have favored beta-oxidation of the yolk sac and, consequently, the use of the nutritional contribution of the egg yolk ( Araújo et al., 2017 ). This greater embryonic metabolism may explain the lower yolk sac weight and the greater development of embryos from older breeders.…”

“…Changes occur in the constituents of eggs as breeders age, which can affect the embryonic mortality rate and, consequently, hatching percentage ( Peebles et al., 2001 ). Industrial breeders produce, at the beginning of the laying process, eggs with thick shells, fewer pores, and dense albumen, characteristics that reduce moisture loss and gas exchange, which can compromise embryonic development in the early stages and reduce subsequent hatching rates ( Araújo et al., 2017 ). On the other hand, industrial broiler chicks hatch in a time span of 480 to 510 h ( Araújo et al., 2016 ).…”