Dr. Gebreyohannes BerhaneDr. Wondmeneh EsatuAbiyu Tadele2023-12-172023-12-172023http://etd.aau.edu.et/handle/123456789/1059This study consisted of two independent experiments carried out in Southwest region, Ethiopia. In the first experiment the effect of genotype on fertility and hatchability, growth performance, and carcass traits were assessed from the naked-neck, normal-feathered, and Tetra H chicken genotypes. For this study, a total of 135 day-old chicks, with 45 chicks from each genotype, were divided into 9 replicates (15 chicks per replicate) in a completely randomized design. The chicks were fed the same commercial starter, grower, and layer ration for 40 weeks. Data collection for growth, fertility, hatchability, morphometric, and carcass traits took place during the first 18 weeks of age, while the reproductive and productive performances and egg quality traits were evaluated between weeks 20 and 40. Statistical analysis using SAS software and one-way analysis of variance were employed to analyze the data. In the second experiment, the effect of genotype and addition of phytolacca dodecandra (Endod) up to 2g/kg on growth performance, carcass traits, blood profiles, and breast meat quality were evaluated during 18 weeks of age. In this experiment, a total of 360 unsexed chicks were assigned into nine groups with 40 chicks in each group, and each group was replicated four times with 10 chicks in each replicate. The study employed a 3 × 3 factorial design, consisting of three genotypes and three diets, namely standard commercial ration/control (C), phytolacca dodecandra 1g/kg (C+1), and phytolacca dodecandra 2g/kg (C+2). The data were analyzed using the general linear model in R, a two-way analysis of variance (ANOVA) was conducted. The Tukey standard range test was used to compare means, with a significance level of (P < 0.05). The results showed that daily feed intake, daily weight gain, and final body weight of the Tetra H genotype were significantly higher (P < 0.05) than the naked-neck and normal-feathered. The feed conversion ratio of the Tetra H genotype (3.76) was significantly lower (P < 0.05) than the naked-neck (5.6) and normal-feathered (6.1) genotypes, indicating the Tetra H was better in feed conversion efficiency. The Tetra H genotype had significantly higher body length, chest width, keel bone length and carcass traits such as carcass weight, breast, drumstick, and thigh muscle than the naked-neck and normal-feathered genotypes. The reproductive and productive performance traits indicate that the Tetra H hen exhibited significantly superior body weight, feed consumption, hen-housed egg production, egg mass, and a lower (better) feed conversion ratio compared to the other genotypes. The egg quality traits indicated the Tetra H genotype demonstrated better characteristics except for yolk width and color. In the second experiment, the results showed that diet and genotype*diet interactions significantly influenced performance parameters, with the 1g/kg Endod supplementation demonstrating better results compared to the other. Genotype also affected dressing percentage and various carcass components, with the naked-neck * Tetra H cross showing higher values. Supplementation improved dressing percentage and breast muscle compared to the control. Blood parameters were significantly influenced by genotype, diet, and their interaction. It increased protein levels and reduced cholesterol and triglyceride levels in the blood. Incorporating 1g/kg of phytolacca dodecandra (Endod) into the diet improved protein content and reduced fat content in the breast muscles. Thus, these findings contribute to the advancement of more efficient breeding programs for these chicken genotypes by providing valuable insights into their performance and egg quality. The study concluded that the Tetra H genotype is ideal for meat production due to its superior growth performance, body size, carcass traits, and feed conversion efficiency. The indigenous genotypes exhibited better fertility, hatchability, and livability. Adding up to 2g/kg phytolacca dodecandra (Endod) to chicken feed can enhance performance, carcass traits, blood profiles, and breast meat protein levels. Further investigations are recommended to confirm cross-breeding and adaptation of those genotypes in various agroecologies. Assessing Endod effects on various chicken genotypes, optimum dosage, and duration, evaluating consumer health and economic efficiency, and exploring underlying mechanisms are recommended.enBlood profilesBody weight gainBreast meatEgg massFeed conversion ratioPhytolacca dodecandraProximate compositionsReproductive performancesComparative studies on performance and carcass traits of Naked Neck, Normal-Feathered, Tetra-H Chicken genotypes, and their crossbreeds in Southwest EthiopiaThesis