No abstract available. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2008.

With the worldwide increase in consumption of poultry meat in recent years, the production of hatchable eggs from broiler breeding stock has become a critically important component of the poultry industry. Surprisingly, a perusal of the literature pertaining to broiler breeder nutrition leads to the conclusion that research nutritionists have neglected these birds. It has been assumed in many cases that the research on laying hens is applicable to broiler breeders. However, fundamental differences are apparent between the two strains that should be investigated more comprehensively if the potential of broiler breeder hens is to be achieved. Commercial laying hens have been selected predominantly for increased egg production whereas broilers have been selected for early rapid growth rate. By selecting for improved growth rate, both food consumption and mature weight of these birds has increased (Reddy, 1996), but because of the negative genetic correlation between body weight and egg production (Robinson et al, 1993) reproductive performance has not been improved. Broiler breeder hens differ from commercial laying hens, by their non-normal frequency distribution of egg outputs, their considerable lipid reserves, and by the fact that many do not lay in closed cycle. The practice of restricting feed intake during both the rearing and laying periods has become a standard management procedure in commercial broiler breeder operations and this differs from the manner in which commercial hens are fed. This raises important issues regarding the requirements of these birds for energy, amino acids and other essential nutrients, as the birds do not have the opportunity of meeting their nutrient requirements by adjusting food intake upwards when one or more of these nutrients is deficient in the feed. It is the duty of the nutritionist to provide the correct daily allowance of each nutrient in order to achieve maximum egg output by the flock, but given the variation between hens within a flock, such decisions need to be made on both biological and economic grounds. Improved strains are continually being produced by breeder companies, which exhibit better growth, feed efficiency and productivity. The way in which broiler breeder hens were fed in the past might not be the most effective way to feed the latest strains. Getting the right amount of feed with the right nutrient levels at the right time is the most important part of feeding broiler breeders, and to succeed their daily nutrient requirements need to be known. Information concerning the nutritional requirements of broiler breeder hens is limited in comparison to other types of domesticated poultry. However, enough information is available concerning energy and amino acid nutrition of this type of poultry to enable one to develop models useful for constructing accurate feeding programmes. The most appropriate way of estimating the nutrient requirement of broiler breeder hens during the laying period, or of optimising a feeding strategy, is by the use of simulation models. Emmans and Fisher (1986) suggested that a better approach to the problem of describing requirements and of expressing them quantitatively can be achieved by considering: firstly, the bird’s characteristics, secondly by defining resource scales carefully and thirdly by considering the quantities of each resource needed per unit of function. This approach has a greater chance of success than attempting to measure requirements by direct experimentation. Energy and amino acids are required for growth of tissues, egg production, maintaining normal body temperature, vital life functions and activity. For development of feeding programmes, we are most concerned with the three primary components, maintenance, growth and egg output. There are a number of factors that impact on the total nutrient requirement of the breeder. The maintenance component is affected by body size, environmental temperature, level of activity (housed in floor pens vs. cages) and possibly breed. Regarding the growth component, in the case of broiler breeders during lay the composition of growth needs to be addressed: whether this is only lipid gain or also includes protein gain. Lastly, the egg component is influenced by egg mass and hen age. In order to calculate energy and amino acid requirements, one must have knowledge of the requirements per unit of body protein weight, growth rate and egg mass. By continually monitoring the environmental conditions in the broiler breeder house, as well as body weight, egg weight and egg number, it is possible to estimate the state of the hens at any time and hence the optimum nutrient concentrations that should be fed the next day of the laying period by using the Breeder Model presented in this thesis. Optimising the feeding of broiler breeders during the laying period is made difficult because of the many interacting factors influencing their performance All the hens are not the same, they are not housed in the same environments, and the costs of feeding and the revenue derived from the sale of the product differs from one locality to another. The solution to this problem lies in the use of simulation models to describe the causal relationship between inputs and the predicted responses. This thesis explored new concepts and components for a simulation model to predict the nutrient requirement and performance of broiler breeders after sexual maturity. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2007.

There are negative influences of selection for broiler growth on the reproductive ability of broiler breeder parents. This is mostly due to problems related to excessive body weight, such as an inability to achieve successful cloacal contact during natural mating. There is also an age-related decline in fertility of broiler breeders. In attempts to prolong the fertile period of the breeders, various forms of management techniques have been employed. These include tools such as feed restriction, photoperiod management, spiking, and possibly even using artificial insemination. The first objective of this thesis was to investigate the possible benefits of feeding broiler breeder males diets containing lower crude protein levels, than given to the females, as a means of possibly tempering growth rate or improving semen quality and fertility. There was a definite improvement in the ability of the spermatozoa of the males on a lower crude protein diet to survive in the female reproductive tract. Males that received higher levels of crude protein were at a disadvantage in that fewer males yielded semen in response to abdominal massage. The second objective of this thesis was to assess the possible benefits in semen quality and fertility, when supplementing the male diets with additional vitamin E or Se in the form of Sel-Plex®. No significant effect of treatment was observed on egg fertility or semen quality. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2008.

Breeding companies advertise their chickens as having been selected for heavier breast meat. However, when comparisons are made between strains, these are normally made at a common age, and under these conditions the heaviest birds will have the heaviest breast meat yield. More meaningful comparisons would be made by relating breast weight to body protein weight, as these are allometrically related. Two experiments were conducted to test the hypothesis that the allometric relationship for each body part is the same irrespective of strain, sex and feed protein content, i.e. that geneticists have not been successful in changing the allometric relationship between breast meat weight and body protein weight. In the first trial, three strains, two sexes and four feed protein levels were used to 6 weeks of age, and in the second, four strains, two sexes and three feed protein levels were used to 12 weeks. Birds were sampled weekly, and the weights of breast meat (no skin or bone) and the meat and skin of the thigh, drum and wing were recorded before determining the body protein content of each of 1526 broilers. The hypothesis could not be corroborated when the data from the two trials were combined so a further trial was conducted to determine the amount of lipid that is deposited in the meat and skin of each of the commercially important parts of the broiler, on the assumption that differences in lipid deposition between strains, sexes and feed protein levels in the various physical parts would assist in explaining the anomalies in the analyses. It was confirmed in the third trial that the small differences between the observed and predicted weights of the physical parts may be accounted for through varying amounts of lipid deposition in these parts, depending on strain, sex and feed protein level, which must be accounted for when using allometry to predict the weights of the physical parts of the broiler at different stages of growth. The data collected in this series of trials may be used to predict the weights of these physical parts more accurately than has been the case to date. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2009.

Orientador: Irenilza de Alencar Naas / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola / Made available in DSpace on 2018-08-21T13:32:11Z (GMT). No. of bitstreams: 1 Silva_RaquelBaracatTosiRodriguesda_D.pdf: 742043 bytes, checksum: 1043db2ae5fa35bde37fa4ea48edba82 (MD5) Previous issue date: 2012 / Resumo: Os últimos trinta anos no Brasil foram marcados por uma avicultura intensiva, que alcançou os atuais níveis produtivos através da utilização de tecnologias avançadas, atingido um máximo de desempenho e se transformando em uma atividade altamente produtiva, especializada e industrializada. A aquisição de conhecimentos específicos das áreas de nutrição, genética e manejo, permitiu que índices positivos fossem alcançados, juntamente com os conhecimentos adquiridos relacionados à sanidade e alojamento. Grande parte da produção avícola é destinada à exportação, seja em carcaça ou sob a forma de corte específica, necessitando atender a determinadas demandas internacionais. Muitas dessas demandas estão baseadas em normas e legislações dissociadas da realidade brasileira, requerendo a necessária adaptação. Este trabalho teve como objetivo a seleção de conteúdo para normas de bem-estar animal para produção de frangos de corte, atendendo às condições brasileiras, visando características de exportação, a fim de se encontrar consonâncias com normas internacionais e, sendo assim, padronizar as normas e legislações de alojamento brasileiras. Um questionário, com perguntas sobre bem-estar animal ao consumidor foi enviado ao público consumidor em geral, também incluindo pessoas envolvidas com bem-estar e pesquisadores, de forma a ter-se um retorno de 200 questionários, para se colher informações sobre a questão do bem-estar animal. Os principais manuais de guias práticos europeus e americanos foram estudados e avaliados. O sistema de comparação estabelecido foi baseado em escores (notas), sendo aplicadas notas de 1 a 5 (muito ruim a muito bom) em função da existência de manuais e suas normas para cada país (Brasil e EUA) e/ou bloco econômico (UE), para cada tipo de exigência, relativas ao nível de consciência do aplicador da norma aos problemas enfrentados. Foi aplicada a análise comparativa da média dos escores das normas utilizadas nos manuais. Para a seleção dos itens normativos, foi utilizado o Analytic Hierarchy Process (AHP) para, a partir de determinados critérios selecionar itens apropriados dessas normas e, finalmente, a partir dos resultados, foram propostas normas adaptadas para as condições brasileiras / Abstract: The last thirty years in Brazil have been known by an intensive poultry industry which has reached the current production levels through the use of advanced technologies, achieving a maximum performance and becoming highly productive, specialized and industrialized. The achievement of know-how in the areas of nutrition, genetics and management enabled positive results that were achieved together with the knowledge related to health and rearing. Moreover, most of the poultry production is exported, either in carcass or in specific cuts, to attend certain international demands. Many of these demands are based on standards and legislation dissociated from the Brazilian reality, and requiring the necessary adaptation. This study aimed to develop standards contents for animal welfare applied in broiler production with regard to the rearing conditions in Brazil, aiming to meet export standards, to find consonance with international standards norms, and, therefore, to standardize the Brazilian rearing rules. A questionnaire was developed with questions related to animal welfare to near two thousand consumers in general, also including those involved with welfare and researchers, in such way to have a return of near 200 questionnaires to gather information about the welfare issue. The good European and American guidelines practices were studied and evaluated. The established system of comparison was based on given scores varying from 1-5 (very bad to very good) as function of norms and guidelines existence for each country (Brazil and EUA) and economic block (EU); for each type of requirement, relative to the consciousness of the writer to the specific problem. The comparative analysis was applied to the scores average of the standards norms used at the guidelines. The study used the Analytic Hierarchy Process (AHP) to determine the practicality of implementing these standards and, finally, from the results, the normative scenario adapted to Brazilian conditions will be reached / Doutorado / Construções Rurais e Ambiencia / Doutora em Engenharia Agrícola

Thesis (M.S.)--University of Missouri-Columbia, 2003. / Typescript. Includes bibliographical references (leaves 80-89). Also available on the Internet.

Thesis (M.S.)--University of Missouri-Columbia, 2003. / Typescript. Includes bibliographical references (leaves 80-89). Also available on the Internet.

Title from PDF of title page (University of Missouri--Columbia, viewed on Feb 18, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Thesis advisor: Dr. Jeffre Firman. Includes bibliographical references.

Thesis (M.S.)--University of Tennessee, Knoxville, 2003. / Title from title page screen (viewed Mar., 19, 2004). Thesis advisor: Robert T. Burns. Document formatted into pages (xiv, 148 p. : ill. (some col.)). Vita. Includes bibliographical references.

Experiments were conducted to investigate the effects of dietary fat, vitamin E(Vit. E) and selenium(Se) supplementation on the performance, fatty acid(FA) composition, lipid oxidation on blood and the oxidative stability of muscle tissues (breast and thigh) during refrigerated storage of broiler chickens fed high levels of flaxseed(FXS). Four hundred and eighty d-old broiler chicks were fed experimental diets for a 3 wk period, which consisted of the combination of two dietary fat sources: fullfat soybean(FFSB) and FXS; 3 Vit. E levels: 10, 40 and 80 IU/kg and two Se levels: 0.15 and 0.30ppm (Exp. I). Four hundred and forty d-old chicks were fed on FFSB diets supplemented with 10, 80, and 160 IU of Vit. E/kg, FXS diets supplemented with 10, 40, 80, 120, 160 and 200 IU of Vit. E/kg, corn-soybean based diet (control), and on a commercial diet for 21 days (Exp. II). For Exp. III, 1680 (840 of each sex) d-old broiler chicks were raised up to 41d. Three basal diets containing 10% FXS and 3 levels of Vit. E: 60-, 90- and 160 IU/kg were formulated for 3 age periods: starter (0--3wk), grower (3--5 wk) and finisher (5--6wk). Three groups of birds were fed these basal diets, while 3 other groups were fed the diet containing 160 IU of Vit. E either during the starter, grower or finisher phase (diets supplemented with 60 IU/kg were given in the two remaining phases). (Abstract shortened by UMI.)