Thesis (M.Sc. (Animal production)) --University of Limpopo, 2011 / A study was conducted to examine the effect of protein level of the diet of Naked neck hens on egg production, hatchability and chick productivity. The first part of the experiment determined the effect of protein level on feed intake, number of eggs produced, egg weight, egg white nitrogen content, egg yolk nitrogen content, egg hatchability and chick hatch-weight. A total of 25 hens aged 30 weeks were confined in cages and fed diets differing in protein content. A complete randomized design, comprising of diets differing in protein levels (P12.94%, P13.94%, P14.38%, P15.75% and P18.13% CP), replicated five times with one hen in each replicate was used. Semen was collected from one cock to fertilize all hens. Protein level had an effect on (P<0.05) feed intake and egg white nitrogen content. However, protein level of the diet of hens had no effect(P>0.05) on the number of eggs produced, egg white nitrogen content, egg yolk,egg weight, egg hatchability and chick hatch-weight. Quadratic analyses indicated that feed intake, number of eggs produced, egg weight, egg white nitrogen content, egg yolk nitrogen content, hatchability and chick hatch-weight were optimized at different protein levels of 14.7 (r2 = 0. 623),14.9 (r2 = 0.568),13.9 (r2 = 0.094), 18.2 (r2 = 0.563), 15.1(r2 = 0.424), 15.9 (r2 = 0.451) and 15.9 %(r2 = 0.898) , respectively. The second part of the experiment determined the effect of protein level of hens on productivity of their progenies from a day old up to 13 weeks of age. A total of 95 chicks hatched from the first part of the study were assigned to 20 floor pens according to the number of chicks hatched. Chicks had an average initial live weight of 35 ± 2 g per bird. The chicks were fed the same commercial grower diet and fresh water ad libitum up to seven weeks of age. Protein level of the diet of Naked neck hens had an effect (P<0.05) on feed intake, live weight and feed conversion ratio of chicks from a day old up to seven weeks of age. However, protein level of the diet of Naked neck hens had no effect (P>0.05) on growth rate and mortality of chickens from a day old to seven weeks of age. Feed intake, feed conversion ratio, growth rate and mortality of chickens were optimized atdifferent protein levels of 15.8 (r2 = 0.298), 16.1 (r2 = 0.236), 16.1 (r2 = 0.077) and 14.3 % (r2 = 0.617), respectively. Protein level of the diet of Naked neck hens had no effect (P>0.05) on feed intake, growth rate and feed conversion ratio of both their male and female progenies between eight and 13 weeks of age. Protein levels of the diet of hens had an effect (P<0.05) live weight of their male progenies and carcass weights of both their male and female progenies at 13 weeks of age. However, the level of protein of the diet of hens had no effect (P>0.05) on live weight of their male progenies, and breast meat yield, breast meat nitrogen content and fat pad weight of both their male and female progenies at 13 weeks of age. Live weight,breast meat yield, breast meat nitrogen content and fat pad weight of their male progenies at 13 weeks of age were optimized at different protein levels of the diets of hens of 18.9 (r2 = 0.666), 15.6 (r2 = 0.081), 15.4 (r2 = 0.786) and 17.7 %(r2 = 0.775), respectively. Similarly, live weight, carcass weight, breast meat yield, breast meat nitrogen content and fat pad weight of their female progenies at 13 weeks of age were optimized at different protein levels of 15.7 (r2 = 0.294),15.4 (r2 = 0.180), 15.8 (r2 = 0.059), 15.1 (r2 = 0.882) and 16.1 % (r2 = 0.405), respectively. It is concluded that protein level of the diet of the hen may affect its productivity and that of its progeny. However, the calculated protein levels for optimum productivity will depend on the production parameter in question. / National Research Foundation

Egg hatchability has been correlated with many factors, including clutch size, presence of helpers, timing of breeding and predation risk. Hatching failure is higher in a suburban population of Florida Scrub-Jays than in a wildland population, but the reasons for this pattern are unclear. An analysis of long-term demographic data on scrub-jays in both habitats revealed the factors that best explained variation in hatching failure, and an experiment tested whether two potential site factors, ambient temperature and predation risk, could increase hatching failure in the suburbs. Although a global model was best supported by the data for occurrence of partial hatching failure (PHF), clutch size and site were the most significant parameters in this model, which is consistent with the analysis of rates of PHF. I further examined two potential site differences, ambient temperature and predation risk, which might increase PHF in the suburbs. Human activity may increase the perception of predation risk, thus suburban jays may take fewer, longer off-bouts or make fewer incubation feedings to decrease this perceived risk. These behavioral changes may increase nest temperature, thus increase embryo mortality. I placed thermocouples and video cameras at nests during incubation to gauge both ambient and nest temperature and behavior of scrub-jays at each site. I predicted higher ambient temperatures in the suburbs, because suburban areas often serve as heat islands. I also predicted fewer, longer off-bouts and fewer feedings in the suburbs and where human activity was increased experimentally. Ambient temperatures were higher in the suburbs as a result of higher daily minimums rather than higher maximums. Furthermore, females exposed to increased human activity took fewer but not longer off-bouts than suburban or wildland controls; therefore, they increased their nest attentiveness.

Thesis (MSc. Agriculture (Animal Production)) -- University of Limpopo, 2015 / Three experiments were conducted to determine the effect of in ovo glucose injection on egg hatchability, chick hatch-weight, productivity and carcass characteristics of indigenous Potchefstroom koekoek chickens. A complete randomized design was used in all the three parts of the study (from incubation, 1-49 days old unsexed chickens and 50-91 days old female chickens). On day 18 of incubation the developing eggs were subjected to the following treatments: 0- (no glucose or water injected), 0+ (only water injected), 5, 10, 15 or 20 mg of glucose per egg. Each treatment had three replications and there were 20 eggs per replicate. A quadratic model was used to determine in ovo glucose injection levels for optimal egg hatchability, chick hatch-weight and chick to egg weight ratio of Potchefstroom koekoek chickens. In ovo glucose injection improved (P<0.05) egg hatchability, chick hatch-weight and chick to egg weight ratio of the chickens. Egg hatchability, chick hatch-weight and chick to egg weight ratio Potchefstroom koekoek chickens were optimized at different injection levels of 4.50, 10.43 and 12.00 mg of glucose per egg, respectively. Unsexed day-old chicks from the first experiment (according to their initial treatments and replicates) were used in a complete randomized design having six treatments, replicated three times, and having ten birds per replicate. Glucose injection levels increased (P<0.05) feed intake, growth rate, feed conversion ratio, live weight, metabolisable energy and nitrogen retention of female Potchefstroom koekoek chickens aged 1 to 49 days. However, growth rate, live weight, metabolisable energy intake and nitrogen retention of the chickens were optimized at glucose injection levels of 3.92, 4.36, 10.67 and 13.50 mg per egg, respectively. Female chickens from the second part of the study (according to their initial treatments and replicates) were used in a complete randomized design having six treatments, replicated three times, and having five birds per replicate. In ovo glucose injection levels improved (P<0.05) on feed intake, growth rate, feed conversion ratio, live weight, metabolisable energy and nitrogen retention of female Potchefstroom koekoek chickens aged 50 to 91 days. However, only feed conversion ratio and metabolisable energy intake of the chickens were optimized at glucose injection levels of 12.15 and 5.57 mg per egg, respectively. Injection level also improved (P<0.05) carcass, breast, v drumstick, thigh, wing, gizzard and liver weights of female Potchefstroom koekoek chickens aged 13 weeks. In ovo glucose injection increased (P<0.05) breast meat tenderness, juiciness and flavour of female Potchefstroom koekoek chickens aged 91 days. However, breast tenderness, juiciness and flavour of female Potchefstroom koekoek chickens were optimized injection levels of 13.50, 19.25 and 10.83 mg of glucose per egg, respectively. No chicken deaths were observe

Survival of females, nests, and ducklings strongly influence annual recruitment in North American ducks. Studies of cavity-nesting ducks using nest boxes, such as wood ducks (Aix sponsa), hooded merganser (Lophodytes cucullatus) and black-bellied whistling duck (Dendrocygna autumnalis) historically have investigated extrinsic factors, such as nest predation, and how it influenced nest success. For my study, I evaluated data from 1,403 monitored nest boxes collected from eight states, 2020–2022. I studied intrinsic characteristics related to reproduction, such as egg and clutch sizes, and eggshell strength in the 3 cavity-nesting ducks. Variables including clutch size, egg mass, parasitism, and onset of incubation influenced reproductive success of wood ducks. Latitude also influenced clutch size in wood ducks, where for every 14.3° increase in latitude, I found one more egg per clutch. Hooded mergansers had the strongest eggshells and eggshell composition varied across latitude in hooded merganser, but not in wood ducks.

Orientador: Nelson Luis Cappelli / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-13T07:46:45Z (GMT). No. of bitstreams: 1 Romanini_CarlosEduardoBites_M.pdf: 1656027 bytes, checksum: eacfb3ae714a9b008469fac75bd1149b (MD5) Previous issue date: 2009 / Resumo: Dentro do complexo econômico de produção de carnes, a avicultura se constitui na atividade mais dinâmica e o Brasil possui uma das mais desenvolvidas aviculturas comerciais do mundo. Diante das atuais exigências na qualidade e segurança do produto, a moderna indústria avícola brasileira tem progredido, essencialmente pela adoção crescente de novas tecnologias. Na cadeia toda, a incubação dos ovos representa a origem do processo, pois é responsável por transformar biologicamente ovos férteis em pintos de um dia de idade. Em escala industrial, utilizam-se máquinas incubadoras para reproduzir as condições naturais de incubação das aves, objetivando elevar, ao máximo, o índice de eclosão e a qualidade de nascimento dos pintos. Porém, o desenvolvimento embrionário no interior dos ovos é substancialmente afetado pelas condições ambientais da incubadora. Os embriões não são aptos para controlar as trocas térmicas e mássicas durante a incubação; assim, as principais variáveis ambientais que exercem influência no processo, como temperatura e umidade relativa do ar, necessitam ser criteriosamente ajustadas, pois manter as condições adequadas ao redor dos ovos é um ponto crítico de controle do processo. Conhecimentos das áreas de automação e controle são capazes de influenciar positivamente o rendimento na incubação, portanto, o sistema de controle deve garantir a estabilidade operacional para as condições do processo e suas variáveis, dentro de limites desejados. O controle fuzzy é o mais adequado, para processos que apresentam não-linearidades e comportamento transiente, uma vez que descrevem numa rotina, a experiência humana para controlar o processo. Diante desse contexto, propôs-se, no presente estudo, desenvolver uma arquitetura de automação composta por um sistema de controle fuzzy, para proporcionar um controle mais preciso das variáveis de interesse na incubação. O estudo foi desenvolvido em duas etapas, sendo: 1) ensaio experimental de identificação dinâmica e modelagem matemática de uma incubadora de estágio único; e 2) simulação do processo de incubação dos ovos. Foi desenvolvido um modelo computacional da incubadora composto pela representação matemática da incubadora, pelas interações de transferência de calor e massa entre os ovos e o ambiente e, pelo sistema de inferência fuzzy utilizado para controlar o processo de incubação. A simulação proporcionou a execução de diversos cenários operacionais da incubadora, possibilitando o ajuste adequado para o sistema de controle proposto. Obteve-se, como principal resultado o comportamento ao longo do tempo das seguintes variáveis: temperatura dos ovos e do ambiente, massa dos ovos, umidade relativa do ar, produção de calor embrionária, detalhes da interação entre ovo e ambiente e as condições de atuação da incubadora estudada. Os resultados obtidos foram comparados aos valores de referência da literatura, indicando diferenças mínimas entre a temperatura dos ovos e o seu valor de referência. Os resultados relativos à massa de ovos tiveram desempenho abaixo do esperado e, para tal, o sistema de controle precisa receber ajustes. De maneira geral, foram obtidos conhecimentos técnicos mais apurados da incubação, que podem ser úteis para implementação real do sistema de controle desenvolvido. / Abstract: Within the meat production economical complex broiler production is the most dynamic activity, and Brazil has one of the world most developed commercial broiler production. Facing today's needs in terms of quality and safety of the product, modern Brazilian poultry production has improved essentially by the increasing adoption of new technologies. In the whole chain eggs incubation represents the origin of the process; as it is responsible of transforming biologically fertile eggs intone day old chicks. In the industrial scale incubator machines are used to reproduce natural bird's incubation conditions with the objective of increasing at its maximum the hatching index as well birth quality of the broilers. However, the embryonic development inside the eggs is substantially affected by the environmental conditions within the incubator. Embryos are not apt to control heat or mass exchanges during incubation; then, the main ambient variables which influence the process such as air temperature and relative humidity need to be adjusted with criterion, as maintaining the adequate conditions around the eggs is a critical control point of the process. Knowledge on the automation and control areas is able to positively influence incubator efficiency; then, the control system must warrant operational stability for the process conditions as well as its variables, within certain wanted limits. fuzzy control is the most adequate use for the processes which present non-linearity and transient behavior, since it describes in a routine the human experience for controlling the process. In this context it was proposed in the present study to develop an automation architecture composed by a fuzzy control system in order to provide more precise control of the variables that are of interest on incubation. The study was developed in two stages, being 1) and experimental trial of dynamic identification and mathematical modeling of an incubator of single stage; and 2) process simulation of eggs incubation. It was developed a computer model of the incubator built from the mathematical representation of the incubator, the interaction of the heat and mass transfer between the eggs and the environment, and by the fuzzy inference system used for controlling the incubation process. Simulation led to built up various incubators operational scenarios providing the adequate adjustment for the proposed control. It was found as main result the behavior of the following variables along the time: eggs' and ambient temperatures, eggs mass, air relative humidity, embryonic heat production, details of the eggs and ambient, and the studied incubators performing conditions. The obtained results related to eggs mass were below the expected, and for that the control system needs to be adjusted. Generally technical knowledge regarding incubation were achieved, and they may be useful for implementing a real control system. / Mestrado / Maquinas Agricolas / Mestre em Engenharia Agrícola