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Seven experimental trials were conducted to develop and use novel techniques to examine the relationships between pre- and post-hatch physiological parameters in the progeny of young broiler breeders. Trials 1, 2 and 3 together examined the safer and effective use of transponders to determine embryonated egg air cell temperature (Temb) as an estimation of broiler embryo temperature during incubation, and to subsequently calculate eggshell water vapor conductance (GH2O), specific GH2O (gH2O) and GH2O constants (KH2O) in modern broiler strains. Trials 4 and 5 together examined the relationships of early, middle and late post-hatch growth quality parameters and tissue nutritional profiles of broilers with the corresponding Temb, GH2O, gH2O and KH2O. Furthermore, Trials 6 and 7 together examined the changes in nutritional profiles and histological structures of the broiler embryonic pipping muscle between 15 and 19 days of incubation. Based on the results from Trials 1, 2 and 3, it was concluded that transponders may be effectively implanted in the embryonated egg air cells with minimal invasion to the broiler embryo to efficiently determine Temb, and to subsequently calculate GH2O, gH2O and KH2O of modern broiler strain eggs during incubation. The results from Trials 4 and 5 also suggested that within physiological limits, an increased gH2O results in increased embryo metabolism, which subsequently increases growth and yolk sac absorption in the corresponding broiler chicks through 3 days post-hatch. Moreover, it was also observed that a higher gH2O was negatively associated with chick hydration status on day 28 post-hatch; although such effects were not observed through day 48 of the post-hatch grow out period. It was concluded that the effects of gH2O on post-hatch broiler physiology may be more pronounced during early and middle post-hatch periods and may subside as the chick reaches marketing age. Furthermore, the results from Trials 6 and 7 indicated that changes in the nutritional profiles of the pipping muscle occur in accordance with corresponding changes in liver metabolism, and that these together with associated morphological changes in the pipping muscle, as observed through histological techniques may be critical for the broiler embryo’s preparation for hatch.

In this study, the effects of individual and combinatorial electrolyte solution comprised of carbohydrate, salt, and a stimulant injected into broiler hatching eggs on subsequent late term embryogenesis and post hatch performance up to D 10 were evaluated in separate trials. The effects of solution concentration and volume on embryo body weight and yolk reserves were likewise considered, and limited posthatch growth, body weight, and yolk sac effects of a compound electrolyte solution were evaluated. The individual and combinatorial effects of injected solutions were examined in an effort to yield the maximum physiological growth effects on embryogenesis from the metabolic pathways in which these compounds are involved. Limited effects on embryo and post hatch mortality were found. However, both post hatch yolk reserves and liver weights were affected by in ovo injection. These effects could be key in increasing bird weight by processing day.

The study objectives of this thesis were to evaluate the effects of delayed feeding and specific aspects of the Programmed Nutrition (PN) feeding strategy (Alltech, Inc.) on growth performance, carcass characteristics, and skeletal characteristics of commercial broiler chicks through market age, as well as investigate the effects of breed and the PN feeding strategy on early growth and development. When commercial broiler chicks were fed reduced nutrient diets, delayed feeding decreased early growth performance and carcass yield (P<0.05), whereas post-hatch PN conditioning for 72 hours improved early growth performance and alleviated the negative effects of delayed feeding on carcass yield (P<0.05). Through market age, delayed feeding improved Gain: Feed (P<0.05), while PN had the opposite effect. Interactive effects and main effects of delayed feeding and PN were observed for tissue mineral concentration (P<0.05). PN lowered bone ash % (P<0.05) and increased meat oxidation of broiler chicks during storage (P<0.05). PN also had negative effects on early growth performance and bone breaking strength (P<0.05) of various meat-type breeds, but especially for non-commercial, moderate-growing or fast-growing breeds. In conclusion, PN may be suitable for commercial broiler chicks that experience delayed feeding and are fed reduced nutrient diets.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2017-10-16T10:47:22Z No. of bitstreams: 2 Tese - Poliana Carneiro Martins - 2017.pdf: 2303821 bytes, checksum: 3e74a5fc40c60b212e0c79f9270d5b43 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-10-16T10:47:41Z (GMT) No. of bitstreams: 2 Tese - Poliana Carneiro Martins - 2017.pdf: 2303821 bytes, checksum: 3e74a5fc40c60b212e0c79f9270d5b43 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-10-16T10:47:41Z (GMT). No. of bitstreams: 2 Tese - Poliana Carneiro Martins - 2017.pdf: 2303821 bytes, checksum: 3e74a5fc40c60b212e0c79f9270d5b43 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-09-26 / Two experiments were carried on to evaluate the effects of the inclusion of conjugated linoleic acid (CLA) on the diets of breeders and broilers, and the alterations caused by post-hatch fasting. In the first experiment, two commercial flocks of breeders aged 58 weeks old were used, and one of them was supplemented for 26 days with 0.025% CLA. At the end of the supplementation, a completely randomized design was applied, composed by two treatments (0 and 0.025% CLA), to evaluate the physical quality and composition of the eggs. Subsequently, 270 eggs per treatment were distributed in two hatcheries, in a randomized block design, determined according to the hatchery used. The incubation parameters were evaluated and the fatty acid profile of the feed, yolk and yolk sac were determined. After hatching, post-hatching diets (0 or 0.025% CLA) were provided for 12 hours, and 320 chicks were housed in a completely randomized design, in a 2x2 scheme (maternal CLA x post-hatching CLA), totalizing four treatments and eight replicates of 10 birds each. The organs relative weight, intestinal development and humoral and cellular immunity were evaluated in embryos, newly hatched chicks, 12 hours after hatching, and at seven days old, as the pre-starter performance. The inclusion of CLA in the diet was able to alter the physical and bromatological characteristics of the eggs and yolk sacs of the progeny from supplemented breeders, also changing the fatty acid profile, but without causing embryonic mortality. The intestine was also influenced by CLA, both macroscopically and histologically. The CLA offered to the breeders influenced the intestinal development of the chicks from the embryonic phase and continued to exert effect after hatching, associated with the progeny supplementation. Breeder supplementation led to a better pre-starter performance of the progeny. In the second experiment, 320 male and female chicks were distributed in a completely randomized design, in a 2x2 factorial scheme, considering post-hatch fasting (access to water for 12 hours; access to water and food for 12 hours) and post-hatch diet (0; 0.025% CLA). The birds were vaccinated at 15 days old against Newcastle disease virus. The metabolizability of diets from four to seven days old, intestinal and organs development, and cellular and humoral immunity were evaluated weekly up to 35 days old. Post-hatch fasting affected performance, and CLA was not able to minimize the negative effects of fasting. However, birds were able to recover up to 35 days old. Post-hatch fasting decreased the immune response of birds. In both assays, CLA generally positively influenced humoral and cellular immunity. Among the evaluated organs, the liver was the main one to have its relative weight altered due to the use of CLA. Supplementing only progeny did not provide as much benefit as compared to supplementation of the breeder or both. The obtained results demonstrate the inclusion level of 0.025% of CLA is safe for use in breeders and may bring benefits to their progeny. / Foram conduzidos dois experimentos para avaliar os efeitos da inclusão de ácido linoleico conjugado (CLA) na dieta de matrizes e frangos de corte, e as alterações causadas pelo jejum pós-eclosão. No primeiro experimento, foram acompanhados dois lotes de matrizes com 58 semanas de idade, sendo um suplementado 26 dias com 0,025% de CLA. Ao final da suplementação, adotou-se o delineamento inteiramente casualizado, composto por dois tratamentos (0 e 0,025% CLA), para avaliação da qualidade física e da composição dos ovos. Posteriormente, 270 ovos por tratamento foram distribuídos em duas incubadoras, aplicando-se o delineamento em blocos casualizados, determinados pela incubadora utilizada. Avaliaram-se os parâmetros de incubação e determinou-se o perfil de ácidos graxos da ração, gema e saco vitelínico. Após a eclosão, dietas pós-eclosão (0 ou 0,025% de CLA) foram fornecidas por 12 horas, e 320 pintos foram alojados em delineamento inteiramente casualizado e esquema 2x2 (CLA materno x CLA pós-eclosão), totalizando quatro tratamentos e oito repetições de 10 aves cada. Avaliou-se o peso relativo de órgãos, o desenvolvimento intestinal e a imunidade humoral e celular em embriões, neonatos, após 12 horas, e aos sete dias de idade, e o desempenho pré-inicial. A inclusão de CLA na dieta foi capaz de alterar características físicas e bromatológicas dos ovos e sacos vitelínicos da progênie de matrizes suplementadas, causando também alteração do perfil de ácidos graxos, porém sem provocar a morte dos embriões. O intestino também foi influenciado pelo CLA, tanto macroscopicamente, quanto a nível histológico. O CLA oferecido às matrizes influenciou o desenvolvimento intestinal dos pintos desde a fase embrionária e continuou a exercer efeito após a eclosão, aliado à suplementação conjunta da progênie. A suplementação da matriz garantiu melhor desempenho pré-inicial da progênie. No segundo experimento, 320 pintos machos e fêmeas foram distribuídos em delineamento inteiramente casualizado, em esquema fatorial 2x2, considerando os fatores jejum alimentar pós-eclosão (acesso à água por 12 horas; acesso à água e alimento por 12 horas) e a dieta pré-inicial (0; 0,025% de CLA). As aves foram vacinadas aos 15 dias de idade contra o vírus da doença de Newcastle. Avaliou-se a metabolizabilidade das dietas de quatro a sete dias de idade, e o desenvolvimento intestinal e dos órgãos, e a imunidade celular e humoral, semanalmente até os 35 dias de idade. O jejum pós-eclosão afetou o desempenho, e o CLA não foi capaz de minimizar os efeitos negativos do jejum. No entanto, as aves conseguiram se recuperar até os 35 dias de idade. O jejum pós-eclosão prejudicou a resposta imune das aves. Nos dois ensaios, de modo geral, o CLA influenciou positivamente a imunidade humoral e celular. Entre os órgãos avaliados, o fígado foi o principal a sofrer alterações em seu peso relativo em decorrência da utilização de CLA. A prática de suplementar apenas a progênie não trouxe tantos benefícios quando comparada à suplementação da matriz ou de ambos. Os resultados aqui obtidos demonstraram que o nível de inclusão de 0,025% de CLA é seguro para utilização em matrizes e pode trazer benefícios à progênie.