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

ABSTRACT 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.

摘要 本研究旨在评估饲养系统对三种兼用型鸡基因型的生产性能、蛋品质及孵化性状的影响。本研究总计选取180只家禽，涵盖3个基因型各48只青年母鸡与12只青年公鸡，于产蛋阶段（27~46周龄）开展性能评估。为此，从18个处理区组中随机选取144只青年母鸡与36只青年公鸡，转入种鸡笼，按每1只公鸡搭配4只母鸡的比例进行分组，试验采用完全随机区组设计（Completely Randomized Complete Block Design，RCBD）。本次试验对比了3个基因型：纯系裸颈鸡（Naked Neck，缩写NN）、两个杂交组合——洛岛红×裸颈鸡（Rhode Island Red × Naked Neck，RIR×NN=RNN）与黑奥品顿×裸颈鸡（Black Australorp × Naked Neck，BAL×NN=BNN）。在第26周与第46周，集约化饲养系统组与BNN基因型母鸡的体重均更高（p<0.0001）。集约化饲养系统组与BNN基因型母鸡的产蛋量更高（p<0.0001）。采用集约化饲养的母鸡所产鸡蛋单重与总蛋重更高（p<0.0001）；RNN与BNN基因型母鸡所产鸡蛋单重更大（p<0.0001），而BNN基因型母鸡的总蛋重更高（p<0.0001）。RNN与BNN基因型母鸡所产鸡蛋的蛋形指数（初始阶段，p=0.0002）、蛋表面积（初始阶段p<0.0001；终末阶段p<0.0001）、蛋体积（初始阶段p<0.0001；终末阶段p<0.0001）及哈氏单位（Haugh unit，初始阶段p=0.0002；终末阶段p<0.0001）均显著更高。试验结束时（46周龄），RNN与BNN基因型鸡蛋的蛋黄指数（yolk index）更高（p=0.0004），RNN基因型鸡蛋的蛋壳厚度更大（p<0.0001）。散养系统组与RNN基因型的孵化率（hatchability）更高（p<0.0001）。散养系统组及RNN、BNN基因型的受精率（fertility rate）最高（p<0.0001），无精蛋率（infertile egg rate）最低（p<0.0001）。散养系统组的死胚率（dead-in-shell rate）最低（p=0.0456）。综上，散养与半集约化饲养系统对家禽的生产性能、蛋品质及孵化性状均有显著影响；就基因型而言，RNN与BNN杂交母鸡的表现优于NN纯系母鸡。