Eggshell quality and calcium utilization in feed of hens in repeated laying cycles

Abstract

Hens of the laying hybrid Shaver Starcross 288 were used in two consequential experiments. The first experiment (for 10 months) was conducted on hens at the age from 18 to 60 weeks (1<sup>st</sup> cycle; <i>n</i> = 50) and moulted hens after 10 months laying from 70 to 110 weeks of age (2<sup>nd</sup> cycle; <i>n</i> = 50). For the second experiment (for 8 months) in the 1<sup>st</sup> cycle 18 weeks old hens were bought (<i>n</i> = 60) and hens from the first experiment after moulting were used in the 2<sup>nd</sup> and 3<sup>rd</sup> cycle (<i>n</i> = 32 and <i>n</i> = 28). During the experiments eggshell qualitative parameters and calcium utilisation (%) were determined. The results indicate that the percentage of eggshell decreased with the increasing number of cycles. The significant correlation of the eggshell proportion and the age of hens was higher in long, advanced cycles (<i>P</i> < 0.05). The shell strength in both experiments decreased slightly in relation to the age of hens and repeated laying cycles. The shell deformation had an opposite trend to the shell strength, i.e. it increased with the increasing laying. The average shell thickness showed a decrease in the repeated laying cycles, more significant in shorter cycles (<i>P</i> < 0.01). The specific shell gravity maintained balanced values both in cycles and by the age of hens. The shell density in all cycles in both experiments showed a decreasing tendency in relation to the age of hens. In dietary calcium utilization for the shell formation a significant decrease was recorded in the second cycles after moulting (<i>P</i> < 0.05).

Interaction between oviposition time, age, and environmental temperature and egg quality traits in laying hens and broiler breeders

“…However, there was a significant interaction (P ≤ 0.050) between temperature and age -higher shell percentage was measured in old birds at 20°C (11.7%) but the lowest also in old hens but at 28°C (10.8%). Specific gravity was higher (P ≤ 0.001) in laying hens, and decreased (P ≤ 0.029) with age, which differed from the results of Arpášová et al (2010) where no relationship between specific gravity and age was found. Specific gravity was also reduced (P ≤ 0.007) by temperature, which was frequently reported in the past, e.g.…”

Evaluation of Calcium Carbonate Content in Eggshells of Avian, Turtle, Snail, and Ostrich Using Chemical Analysis and Scanning Electron Microscopy

“…The dynamics of changes in the eggshell properties in hens are related to physiological processes of mineral metabolism before, during, and after molting. During the pre-laying period, young hens create reserves of mineral substances especially calcium, which is stored in bones and other tissues [14]. However, during the laying period, the Ca reserves in medullar bones reduce, and an insufficient intake of Ca through the feed, the eggshell quality deteriorates, the incidence of nonstandard and broken eggs increased, and also shell-less eggs can be laid [14].…”

“…During the pre-laying period, young hens create reserves of mineral substances especially calcium, which is stored in bones and other tissues [14]. However, during the laying period, the Ca reserves in medullar bones reduce, and an insufficient intake of Ca through the feed, the eggshell quality deteriorates, the incidence of nonstandard and broken eggs increased, and also shell-less eggs can be laid [14]. Moreover, it is worth mentioning that dark-colored eggshells contain a higher percentage of CaCO 3 when compared to white-colored eggshells and this may be due erence in hens' diet [15], indicating that brown egg has a higher strength than a white one.…”

Effect of asam kandis (Garcinia cowa Roxb) extract in drinking water on egg quality of Japanese quail (Coturnix coturnix japonica)

“…According to Adil et al (2010), organic acids are able to increase the digestibility of calcium, phosphorus, magnesium, zinc, and proteins. The availability of calcium is the main factor that determines the eggshell quality because calcium mineral is the major component of the eggshell (Arpášová et al, 2010;Shwetha et al, 2018). Asam kandis contains hydroxy citric acid (Onakpoya et al, 2011) that might be able to enhance calcium absorption and decrease calcium excretion by acid-base balance mechanism in the gastrointestinal tract.…”