Periódicos Brasileiros em Medicina Veterinária e Zootecnia

Productive Performance, Egg Characteristics and Hatching Traits of Three Chicken Genotypes under Free-Range, Semi-Intensive, and Intensive Housing Systems

Ahmad, SMahmud, AHussain, JJaved, K

The present study aimed at evaluating the effect of housing system on the live performance, egg quality, and hatching traits of three dual-purpose chicken genotypes. In total, 180 birds, comprising 48 pullets and 12 cockerels from each of three genotypes, were evaluated during the production phase (27-46 weeks). For this, 144 pullets and 36 cockerels were randomly picked from 18 treatment block groups were shifted to breeding coops, allotting 4 pullets to one cockerel. A completely randomized complete block design (RCBD) was employed. Three genotypes, purebred Naked Neck (NN) and two crosses Rhode Island Red × Naked Neck (RIR × NN = RNN) and Black Australorp × Naked Neck (BAL × NN = BNN), were compared. Intensive system (p 0.0001) and BNN hens (p 0.0001) were heavier on week 26 and 46. Higher egg production (p 0.0001) was obtained in the intensive system and in BNN hens (p 0.0001). Hens maintained in the intensive systems produced heavier eggs and higher egg mass (p 0.0001), and RNN and BNN hens laid heavier eggs (p 0.0001) while higher egg mass (p 0.0001) was found in BNN hens. Higher egg shape index (initial, p=0.0002), egg surface area (initial, p 0.0001; final, p 0.0001), egg volume (initial, p 0.0001; final, p 0.0001) and Haugh unit score (initial, p=0.0002; final, p= 0.0001) were obtained in RNN and BNN hens. At the end of the experiment (46 weeks), higher yolk index (p=0.0004) was found in RNN and BNN eggs, and thicker eggshells (p 0.0001) in RNN eggs. Higher egg hatchability was obtained in the free-range system (p 0.0001) and in the RNN genotype (p 0.0001). The highest fertility rates were detected in the free-range system (p 0.0001), and in the RNN and BNN genotypes (p 0.0001). The lowest infertile egg rates were observed in the free-range system (p 0.0001) and in RNN and BNN genotypes (p 0.0001). The lowest dead-in-shell rate was calculated for the free-range system (p=0.0456). In conclusion, free-range and semi-intensive system largely influence productive performance, egg quality and hatching traits. Regarding genotypes, RNN and BNN crossbred hens perform better than NN purebreds.(AU)

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