What determines hatchling weight: breeder age or incubated egg weight?

Abstract

Two experiments were carried out to determine which factor influences weight at hatch of broiler chicks: breeder age or incubated egg weight. In Experiment 1, 2340 eggs produced by 29-and 55-weekold Ross ® broiler breeders were incubated. The eggs selected for incubation weighed one standard deviation below and above average egg weight. In Experiment 2, 2160 eggs weighing 62 g produced by breeders of both ages were incubated. In both experiments, 50 additional eggs within the weight interval determined for each breeder age were weighed, broken, and their components were separated and weighed. At hatch, hatchlings were sexed and weighed, determining the average initial weight of the progeny of each breeder age. Data were analyzed using the Analyst program of SAS ® software package. In Experiment 1, the weight difference between eggs produced by young and mature breeders was 10.92 g, and the component that mostly influenced this difference was the yolk (7.51 g heavier in mature breeders, compared with 4.23 g difference in albumen and 0.8 g in eggshell weights). Hatchling weight difference was 9.4 g higher in eggs from mature breeders. In Experiment 2, egg weight difference was only 0.74 g, but yolk weight was 4.59 g higher in the eggs of mature breeders. The results obtained in the present study indicate that hatchling weight is influenced by egg weight, and not by breeder age. INTRODUCTIONA chicken egg generally consists of 58.5% albumen, 31% yolk, and 10.5% shell, but this composition varies according to genetic strain and breeder age (Vieira & Moran, 1999).Chick weight at hatch is directly related to egg weight, corresponding to 62 to 76% of egg weight. This correlation between increases after the 11th day of incubation and may remain the same during the entire rearing period (Wilson, 1991).Breeder age strongly influences egg weight, as well as egg quality and composition. Young breeders tend to produce lighter eggs, and consequently, lighter day-old chicks (Dalanezi et al., 2004); however, egg with the same weight can be produced by breeders of different ages as well breeders of the same age can produce eggs with different weights. Some studies showed that chick weight is independent of breeder age and it is only influenced by egg weight (Pinchasov, 1991).Egg weight increases with breeder age due to the increase in yolk size, whereas the variation in the weight of the eggs produced by breeders of the same age results from an increase in albumen proportion (Lima et al., 2001). It must be mentioned that eggs with the same weight, independently of breeder age, produce day-old chicks with the same weight and quality. Mail Adress

Comparison of Three Temperatures for the Hatching Phase in the Artificial Incubation of Red-legged Partridge (Alectoris rufa) Eggs

“…As confirmed by the positive correlation among the chick weight at hatching and the initial egg weight, the hatchling weight differences observed between treatments were due to the differences in initial egg weight, as the eggs incubated at 37.4ºC were lighter than eggs of the other experimental batches. This agrees with Traldi et al (2011), who demonstrated in broilers that hatchling weight is influenced by egg weight. Our results do not agree, however, with those of Gómez-de-Travecedo et al (2014c), who did not found hatchling weight differences when lowering the incubation temperature from 37.8 to 37.5ºC between days 18 and 22 of incubation in red-legged partridges.…”

Efficacy of three sealing methods on hatchability of microcracked eggs from broiler breeder hens

“…These results appear to be reflected in CW. Traldi et al (2011) explained that CW is highly influenced by egg weight. Our findings are in close agreement with Narahari et al (2000), who applied different eggshell treatments (synthetic adhesive resin, cellophane or insulation tape) to cracked eggs.…”

Regression models for estimating chick hatchling weight from some egg geometry traits

“…The highest coefficients of determination in both lines were those of simple linear models which used egg weight as predictor -0.606 for line L and 0.671 for line К, е.g 61-67 % of hatchlings' weight depended on egg weight (model 1). According to Tserveni-Gousi and Yannakopoulos (1990) 70m% of variation in the weight of pheasant chicks was attributable to egg weight which was a better predictor than shape index and shell deformity. Tahir et al (2011) and Ramaphala and Mbajiorgu (2013) also predicted the hatching weight of chickens but reported higher coefficients of determination R 2 , 0.856 and 0.995 respectively, while Olutunmogun et al 2017reported a much lower value (R 2 =0.15) than our data.…”

“…In comparison with these geometry traits, egg weight was more important for hatchling's weight Sahin et al, 2009), with specific effect of the line and breed. Numerous studies have shown that egg weight had a substantial influence on the weight of day-old chickens (Mitrović et al, 2011;Traldi et al, 2011;Mukhtar et al, 2013;Ng'ambi et al, 2013;Mbajiorgu and Ramaphala, 2014;Iqbal et al, 2016;.…”