Egg physical quality and hatchability in captive African Ostrich (Struthio camelus camelus, Linnaeus 1758) reared in Benin: effect of season and relationships

Abstract

The current study carried out on 33 ostriches of 7 years old aimed to determine egg quality and hatchability in relation with season. It appears that egg weight was of 1370 g in rainy season to 1200 g in dry season (p<0.05). The eggs collected during rainy season were longer (150 mm vs 148 mm) and wider (125.12 vs 123.93 mm) than those of dry season (p<0.05). The long circumference (42.05 vs 41.38 cm) was more important in rainy season than the value recorded in dry season. Nevertheless, the short circumference (39.4 to 38.9 cm), egg specific gravity (1.03 to 1.13 g/cm3), egg shape index (83.5 to 83.86%) and egg yolk weights (411 to 445 g) weren’t affected by season (p>0.05). However, the higher egg volume (1197.42 vs 1157.84 cm3) and albumen weight (668 vs 539 g) were obtained in rainy season (p<0.05), while the shell thickness (2 vs 2.2 mm), the shell weight (248 vs 250 g) and shell percentage (18.4 vs 21.4%) were greater in dry season than in rainy season (p<0.05). The fertility rate (51 vs 57%), hatchability, ratio chick weight/egg weight (73 vs 68%) and incubation time (41 vs 42 days) were higher in dry season than in rainy season (p<0.05). The hatching rate was negatively and weakly associated to egg weight, egg breadth and short perimeter (-0.5 ≤ r ≤ -0.42; p<0.05) but positively and weakly correlated with egg length (r=0.44; p<0.05). Egg selection based on physical quality traits can improve hatching rate in ostriches.