Oviposition and egg quality traits of dwarf and naked neck layers

Abstract

Oviposition and egg quality traits were studied in dwarf and naked neck layers in Maputo (Mozambique) during a 28-d period at 35 weeks of age. Birds were caged individually in a laying house with natural light and ventilation. Average daylight length during the study was 11.2 hr and minimum and maximum temperature was 19.6 °C and 30.1 °C, respectively. The main results show that the sex-linked dwarfing gene (dw) increased the mean interval and time of oviposition, and reduced the sequence length and rate of lay. A bimodal distribution of oviposition intervals was observed in the dwarf population. No meaningful effect of the naked neck (Na) gene could be seen on oviposition traits. The dw gene also reduced the egg and components weight as well as the height of the albumen. The Na gene was associated with increased yolk weight and reduced albumen height.

The effect of oviposition time and genotype on egg quality characteristics in egg type hens

“…The number of eggs laid at each collection time was influenced by genotype (Table 1), which coincides with findings of Lillpers and Wilhelmson (1993), Garces and Casey (2003) or Lewis et al (2004), who described differences in the mean oviposition time according to genotype. Plymouth Rock hens laid more eggs early in the morning (until 6:00) whereas in Blue strain and F1 genotypes the time of oviposition at 6:00 and 10:00 was similar.…”

“…Lillpers and Wilhelmson (1993) stated that in three different selection lines (line selected for egg number, line selected for egg mass and line selected for feed consumption) the mean oviposition time was different and affected egg weight. Garces and Casey (2003) studied the effect of oviposition time in dwarf and naked neck laying hens. There was no effect of naked neck gene on oviposition time but the gene was associated with increased yolk weight and reduced albumen height.…”

The effect of genotype, housing system and egg collection time on egg quality in egg type hens

“…A linear relationship between eggshell weight and shell strength with egg collection time corresponds to the results of Novo et al (1997), Pavlovski et al (2000) and Tůmová et al (2007). Deviations in eggshell weight in response to the time of oviposition and genotype were previously described by Lillpers and Wilhelmson (1993), Garces and Casey (2003) and Tůmová et al (2007).…”

“…The number of eggs recorded at each collection time was influenced by the genotype, with each hybrid having a particular laying pattern, which is in agreement with Lillpers and Wilhelmson (1993), Lewis et al (2001), Garces and Casey (2003) or Tůmová et al (2007). ISA Brown, the hybrid which reached the highest egg production, laid eggs mainly early in the morning whereas Hisex Brown with smaller eggs than ISA Brown produced the majority of eggs before the 10:00 h collection.…”

“…In spite of the fact that Schmidt et al (1997) stated that selection for egg production had no significant effect on the oviposition interval, Lewis et al (1995) (Lillpers and Wilhelmson, 1993;Garces and Casey, 2003;Tůmová et al, 2007). In recent years in Europe there has been a significant trend to develop and use alternative housing systems rather than cages.…”