This study aimed at evaluating the effect of dietary calcium levels and the replacement of calcium sources with different particle size compositions on the performance and egg quality of brown layers in their second egg production cycle. A randomized block experimental design was applied with 12 treatments in a 3x4 factorial arrangement: three calcium levels (2.6, 3.2, 3.8 %) and four combinati...

Hosts of avian brood parasites often vary in their response to parasitized clutches: they may eject one or several eggs, desert the nest, or accept all the eggs. Focusing on hosts exposed to single-egg parasitism by an evicting brood parasite, we construct an optimality model that includes all these behavioral options and use it to explore variation in rejection behavior. We particularly consid...

A total number of 330 native Libyan chicken eggs were collected from smallholders over different areas of south Libya to determine and classify some quantitative and qualitative traits in Libyan native fowls. The quantitative traits studied in the current trial were fertility and hatchability percent, egg weight, eggshell characteristics (weight, thickness, area), chicks weight and body measure...

Haplodiploid species display extraordinary sex ratios. However, a differential investment in male and female offspring might also be achieved by a differential provisioning of eggs, as observed in birds and lizards. We investigated this hypothesis in the haplodiploid spider mite Tetranychus urticae, which displays highly female-biased sex ratios. We show that egg size significantly determines n...

This study was conducted to investigate the effects of garlic powder on the performance, egg traits, egg cholesterol and serum parameters of laying Japanese quails. One hundred and twenty 10-weeks-old quails were allocated to four dietary treatments. Quails were caged individually and fed diets supplemented with 0 (control), 1, 2, 4% garlic powder for 12 weeks. There were significant (P < 0.05)...

The spermathecae and egg morphology of Stenozygum coloratum (Klug, 1845) were examined with light scanning electron microscopy, their external was characterized in detail (egg chorion surface, operculum, aero-micropylar processes, spermatheca morphology). Eggs barrel-shaped; operculum round the hatching line can be easily distinguished photograph. batches usually consist 12 eggs. Because thick ...

A total 2400 hatching eggs were obtained from Japanese quails breeders ranged from 100 to 150 days of age used to analyze the effect of shell color on fertility, hatchability, embryonic mortality and malposition as well as internal and external egg quality. Results revealed that shell color had significant effect on fertility and scientific hatchability while it doesn't affect commercial hatcha...

Hatching studies with Heterodera glycines typically have been conducted with a mixture of egg-mass and encysted eggs. Laboratory research was conducted to compare hatching of H. glycines eggs from external egg masses with that of eggs extracted from within females and cysts (encysted eggs). Egg-mass eggs were collected by soaking infected soybean roots in 0.5% sodium hypochlorite, and encysted ...

This study aimed to identify putative quantitative trait loci (QTL) that significantly affect internal parasite resistance in a backcross sheep population. A Romney x Merino backcross (to Merino) flock was challenged in 3 separate infections with Trichostrongylus colubriformis (primary and secondary) and Haemonchus contortus (tertiary). Haematological parameters were measured and faecal worm eg...

The prevalence of keel bone damage as well as external egg parameters of 2 pure lines divergently selected for high (H) and low (L) bone strength were investigated in 2 aviary systems under commercial conditions. A standard LSL hybrid was used as a reference group. Birds were kept mixed per genetic line (77 hens of the H and L line and 201 or 206 hens of the LSL line, respectively, per pen) in ...