Yield Performance, Laying Behaviour Traits and Egg Quality of Purebred and Hybrid Hens Reared under Outdoor Conditions

Abstract

This study compared the yield performance, laying behavioural traits and egg quality of purebred and hybrid hens (from 28 until 44 weeks of age, considering four periods) reared under outdoor conditions. The four genotypes were reared on the same trial station, on four areas (one genotype/area), and under the same environmental conditions from hatching until the end of the trial. Italian dual-purpose purebred (Ermellinata di Rovigo—ER and Robusta maculata—RM) and hybrid (Hy-Line Brown—HB and Hy-Line White 36—HW) hens (flock size: 70 birds/genotype) were allowed outdoors (4 m2/bird, good pasture during the growing period and poor pasture throughout the laying period, according to the season) and indoors (0.20 m2/bird, five birds/individual nest) and fed commercial feed. Significant (p < 0.01) differences among genotypes were found. The hybrids showed a higher laying rate and hen-day edible egg mass, and a lower body weight than the purebreds. Broken and out-of-nest egg% were higher in RM and HW than ER and HB, respectively. Double-yolk egg% was higher in hybrids than in purebreds. The eggshell colour varied among brown eggshell ER, RM, and HB. The ER showed the lowest shape index. With aging, the yolk to albumen ratio linearly increased in all groups, eggshell% changed in ER, HW, RM (cubic) and in HB (linear). The purebreds showed meat spots% higher than blood spots; HW showed the lowest total inclusion%. In conclusion, according to an egg scoring evaluation (egg weight = medium-large size, yolk to albumen ratio = 0.5, total inclusions = none), HW showed a higher quality than HB and RM, and ER was intermediate. The RM hens showed the highest% of defective eggs, especially for overcrowding at nest, HB showed the lowest. Under outdoor conditions the laying behaviour of the purebred hens and the nest management are important factors for the saleable egg rate.

Laying hen biodiversity: a study on the effect of age on the yield performance and quality of eggs produced by two Italian purebred hens

“…The egg inclusions detected in these breeds are higher than those reported for hybrid strains, which have been selected for this trait. In a previous trial carried out on ER and Robusta Maculata hens (Rizzi, 2020), the blood and meat spots were similar to those of this study. Eggs laid by other breeds showed egg inclusions similar or higher to those of this trial (Lordelo et al, 2020).…”

“…A comparison with other trials is only possible for some traits, because it is difficult for others due to different environmental conditions during rearing and storaging of the eggs. At the beginning of egg production, the yolk:albumen ratio was similar to those of hybrid eggs (Philippe et al, 2020, Rizzi, 2020, where yolk is less than 50% albumen weight, but with age the ratio increased. Eggs laid by other Italian and Portuguese hen breeds showed higher yolk percentages and lower albumen percentages than those of this trial (Di Rosa et al, 2020, Lordelo et al, 2020.…”

“…Previous studies on local laying hen breeds have been carried out in many countries (González Ariza et al, 2019a,b, Lordelo et al, 2020 and some indications exist for the Italian breeds (Rizzi & Chiericato, 2010, Rizzi & Marangon, 2012, Di Rosa et al, 2020, Rizzi, 2020. In order to increase the knowledge of the productive performance and egg quality of local laying hen breeds, a trial was carried out to study the effect of genotype and age on yield performance and egg quality of two Italian purebreds, at 36 and 50 weeks of age.…”

Albumen Quality of Fresh and Stored Table Eggs: Hen Genotype as a Further Chance for Consumer Choice

“…An important trait for the egg quality is the weight: the four genotypes produced eggs classifiable into different size classes, according to the EC regulation [ 26 ]: the ER and RM eggs were small size (<53 g) until 39 and 35 weeks of age, respectively, and then medium size (53–63 g); the hybrid eggs were medium size at all the ages. For the HB and HW hens, egg weights of large size (>73 g) were observed at 39 and 43 weeks of age, and at 9.3% and 5.2% of the daily production, respectively [ 19 ].…”

“…A previous work compared the egg chemical composition and sensory profile of eggs laid by hybrid and purebred hens; it reported that the albumen height and HU of fresh and stored eggs were similar among hybrids and Italian breed Robusta maculata, whereas the stored eggs of Italian breed Ermellinata di Rovigo showed lower HU [ 18 ]. A recent work on the aforementioned genotypes studied hen’s behaviour at laying and the effect of age on the quality of fresh eggs throughout the laying cycle [ 19 ].…”