Egg specific gravity in improvement of hatchability in laying hens

Abstract

The aim of the study was to assess the suitability of egg specific gravity (ESG) as an accompanying trait in estimation of the birds' breeding value for hatchability. The study involved 3 generations of performance recorded laying hens Rhode Island White (RIW) and Rhode Island Red (RIR). The breeding merit for number of chicks hatched from eggs laid (NCH) was estimated with three different model variants which differed with regard to the information accounted for: 1. all the standard information plus post factum hatchability record and ESG, 2. no post factum hatchability data on the last generation but ESG present, and 3. no hatchability data on last generation nor ESG. In both lines a high positive correlation between the egg specific gravity and hatchability was observed (0.47 to 0.66). In RIR, when ESG was included in the left-hand-side, a significantly higher concordance of birds' NCH breeding value ranking between 2. and 1. than between 3. and 1. were observed.

A 2-D imaging-assisted geometrical transformation method for non-destructive evaluation of the volume and surface area of avian eggs

“…All the above can lead to a remarkable breakthrough in various related areas including research of egg quality traits and their impact on incubation, poultry breeding, storage conditions, etc., as well as development of industrial applications such as automated egg sorting. For instance, the egg density (sometimes referred to in the egg-related papers as specific gravity) is still one of the basic parameters that can predict egg freshness (e.g., Usturoi et al, 2014;Mezemir et al, 2017), shell thickness (e.g., Nordstrom and Ousterhout, 1982;Sooncharenying and Edwards, 1989), shell strength (e.g., Ahmad et al, 1976;Hamilton et al, 1979;Voisey et al, 1979), hatchability (e.g., Bennett, 1992;Rozempolska-Rucińska et al, 2011), and some variables of its interior (Narushin, 1997c). Taking into account that the egg density is physically determined as the ratio of egg weight and its volume (e.g., Paganelli et al, 1974), these both parameters should be obtained in a fast, accurate and noninvasive manner as we demonstrated in this study.…”

Eggshell Qualities as Indicative of Eggshell Strength for Layer Selection

“…Although the use of egg specific gravity for the genetic improvement of eggshell quality is sometimes controversial, the additive variability of egg specific gravity accounts for ca. 20%-45% of the total trait variability (Nirasawa et al, 1998;Ledur et al, 2003;Begli et al, 2010;Rozempolska-Rucińska et al, 2011), thereby making it a predictor candidate in effective selection for eggshell quality. The objections against the use of egg specific gravity as a trait that defines eggshell quality in a broad sense are mainly related to the fact that the reliability of this measurement largely depends on environmental factors, e.g., the duration of egg storage or the lag of measurement time (Voisey and Hamilton, 1977;Sloan et al, 2000).…”

Comparative analysis of physical, morphological, and mechanical characteristics of eggs from three pheasant subspecies

“…Significantly lower specific gravity of pheasant eggs in the range 0.93 to 0.94 g/cm 3 was reported by Kirikci et al (2004) . According to Rozempolska-Rucinska et al (2011) , the egg specific gravity is a trait that broadly characterizes the quality of eggs that are used in hatching. The egg specific gravity indirectly defines the shape of an egg, resistance, and structure of the shell, that is, traits that are essential for a normal hatching process.…”