Comparison of three lines of broiler breeders differing in ascites susceptibility or growth rate. 1. Relationship between acoustic resonance data and embryonic or hatching parameters

Abstract

Ascites is a prevalent cardiovascular disease among modern broilers with negative impacts on production and animal welfare. The peak of mortality due to ascites occurs at the end of the growing period, but the etiology of this problem may start during embryonic development. A few recent reports have demonstrated that the signs of ascites susceptibility are manifested during the late stages of incubation. In the current study, we used a nondestructive method based on egg acoustic resonance parameters [resonant frequency (RF) and damping] to establish a relationship between embryo physiological events during early development in broiler eggs and susceptibility to ascites. The hatching eggs of 3 broiler lines differing in ascites susceptibility were used for this study: ascites-resistant dam line (DAR), ascites-sensitive dam line (DAS), and ascites-sensitive sire line (SASL). These lines were selected on the basis of fast growth, high breast meat yield, and ascites induction at low temperatures such that the order of ascites susceptibility in terms of mortality was SASL >> DAS > DAR. Eggs were incubated under standard conditions in forced-draft incubators. We measured egg weights at setting, albumen pH, Haugh units (HU) at setting, and embryo weights at d 11 and 18, at internal pipping (IP), and at hatch. The durations of IP, external pipping (EP), and hatching were also determined. At 2 hourly periods during incubation, egg RF and damping were also measured. There were differences in egg weights between DAR and SASL vs. DAS, but albumen HU, albumen pH, and the ratio of yolk weight to egg weight were similar. There were differences in RF, damping, embryonic growth rates, and hatching events. Changes in resonant frequency and damping, which certainly suggest eggshell differences among lines, were not totally related to variations in physiological events during early and late embryonic development. A comparison between DAR and DAS, between DAS and SASL, or DAR and SASL indicates that sensitivity to ascites and selection for rapid growth rate in ascites-sensitive lines have different effects on embryonic parameters. We concluded that the sensitivity of broiler breeders to ascites does not influence egg internal quality, but the occurrence of ascites sensitivity in broilers could not be reliably predicted by early in ovo acoustic resonance parameters and hatching events.

Ascites Syndrome in Broiler Chickens - A Physiological Syndrome Affected by Red Blood Cell

“…There is evidence that the primary cause of AS is manifested in the prenatal or very early postnatal phases, when the cardiovascular system is being developed and is starting to function [188][189][190]. Measurements of such a manifestation, especially at the embryonic stage, necessitate sacrificing the investigated individuals, rendering it impossible to later determine, under AIC, if these individuals were susceptible or resistant to AS.…”

Evaluation of cardiac status, ascites related factors and growth performance of five commercial strains of broiler chickens

“…These improvements over the past two decades have reduced the age of slaughter of broiler chickens from 70 days to less fewer than 40 days (Olanrewaju et al, 2014). The shortening of the breeding period and the feed conversion ratio (FCR) improvement of broiler chickens along with choosing to increase the average of the productive traits has caused adverse effects on the various aspects of the physiology of these birds and has led to the occurrence of metabolic diseases (Tona et al, 2005). The causes of these adverse effects are the increase in body volume without parallel changes in the internal organs, cardiovascular and skeletal system to support of rapid growth and very large body size (Zerehdaran et al, 2005).…”

“…Mortality due to ascites in the broiler chickens was estimated about 5 to 8% of all over the world, which can be reached in heavy weight breeders between 20 and 30% (Baghbanzadeh & Decuypere, 2008). Among noninfectious mortality of broiler chicks, about 50% is caused by ascites (Tona et al, 2005).…”

Desarrollo cardiaco embrionario en broilers en relación con enfriamiento y altitud

“…Existen evidencias de que la susceptibilidad del pollo de engorda a la ascitis está relacionada con factores predisponentes originados durante el desarrollo embrionario, como la hipoxia (Maxwell et al, 1987;Odom et al, 1991;Tona et al, 2005) y la tasa metabólica acelerada que tiene el embrión (Hoer, 1988). La hipoxia embrionaria es un factor predisponente al desarrollo de la hipertensión pulmonar cró-nica adaptativa, condición común en pollos ascíticos, provocando estrés cardiaco antes o durante el nacimiento (Arce et al, 1987;Odom, 1993).…”