published_or_final_version / abstract / Biological Sciences / Master / Master of Philosophy

Poultry have many behavioural, structural and biological features that are ideal for domestication and for meat and egg production (Appleby et al., 1992). Because of the importance of poultry meat and eggs to the human population, breeders and farmers are always looking for ways of improving these traits. Artificial selection is the primary method of trait improvement, and involves selecting individuals with the highest breeding values as parents in each generation. There are a number of different methods of artificial selection, including: individual selection, between family selection, within family selection, family-index selection and index selection. In order to maintain a good response to selection breeders are constantly striving to improve the effectiveness and accuracy of the different methods of artificial selection for traits of economic importance. One method of achieving this goal is the use of computer models. Computer models can be used to simulate selection strategies and to predict what strategy will be the most appropriate for the improvement of a particular trait. This is important as all traits are influenced by many different genetic and environmental factors (Falconer and Mackay, 1996). This investigation was designed to compare the effectiveness of five different artificial selection strategies, namely individual selection, between family selection, within family selection, family index selection and index selection. Five computer models were developed using Microsoft Excel 2000 and these models were then used to compare the efficiencies of the five selection strategies for four different traits. The selection techniques were applied to an artificially, randomly generated population of 500 chickens. The four traits were egg weight with a heritability of 0.51, egg production with a heritability of 0.22, age at first egg with a heritability of 0.41 and body weight with a heritability of 0.55. Firstly, each of these traits were selected for independently using the first four selection methods and secondly the traits were selected for two at a time using index selection. The most significant results obtained from the single trait simulations were that for all traits family-index selection produced the best response to selection in the initial generations and between family selection produced the best response in the later generations. The traits with a higher heritability (egg weight and body weight) responded better to individual selection than they did to within family selection and between family selection in the initial generations. However, within family selection and between family selection proved to be more effective for traits with a low heritability such as egg production. Individual selection and family-index selection resulted in a very rapid decline in the standard deviation of all the traits. Between family selection resulted in the slowest drop in the standard deviation of all the traits, which is why this technique produced the best responses to selection in the later generations. The impact of the correlations between the economically important traits were evident from the results of index selection. For example, egg production is negatively correlated with egg weight making it difficult to gain a correlated response in both these traits simultaneously. Furthermore, egg production is negatively correlated with age at first egg implying that early maturing birds will lay more eggs, however, these eggs will be lighter. The majority of the results obtained were to be expected. Family-index selection takes all the information about an individual's breeding value into account resulting in this method of selection consistently identifying the most desirable individuals being selected. It is therefore the preferred method of selection under all circumstances. It is, however, often not economically and practically efficient to incorporate this technique and the use of another method of selection usually proves to be more beneficial. Individual selection proved to be most effective when applied to traits with high heritabilities, due to the fact that this method selects individuals based on their own phenotypic values. For traits with a high heritability, an individual with a good phenotypic value will have a good breeding value. Between family selection and within family selection proved better for traits with lower heritabilities. For traits with a low heritability the phenotypic value of an individual is a poor indicator of its breeding value. Information from a number of relatives may thus improve the accuracy of prediction of the breeding value by accounting for the influence of environmental effects. The use of computer models to simulate the selection techniques proved very successful in illustrating the effectiveness of the different selection techniques under various genetic and environmental conditions. The models may also prove to be very effective from an educational perspective. / Thesis (M.Sc.)-University of Natal, Pietemaritzburg, 2003.

A presente pesquisa foi conduzida utilizando-se 288 galinhas poedeiras da linhagem Hisex White com 32 semanas de idade, pelo período de 10 semanas, com o objetivo de estudar o enriquecimento da gema do ovo em ácidos graxos a partir de rações suplementadas com óleo de peixe (OP) ou alga marinha (AM) em cinco níveis de DHA (120, 180, 240, 300 e 360 mg/100 g dieta). Foi aplicado modelo fatorial 2 x 5, inteiramente casualizado, com três repetições de oito aves por tratamento, de modo a constituir os grupos: OP120, OP180, OP240, OP300, OP360, AM120, AM180, AM240, AM300 e AM360. Um grupo controle submetido à ração basal de milho e soja (CON) e outro, acrescido de AM, contendo 420 mg de DHA/100 g dieta (AM420) foram também utilizados. Os seguintes parâmetros foram avaliados: postura, peso do ovo, consumo alimentar, conversão alimentar, qualidade externa e interna dos ovos e qualidade organoléptica dos mesmos. O peso médio do ovo assinalado para o grupo CON (63,30 g) decresceu linearmente de forma significativa (Y = - 0,0051X + 63,8560, R2 = 0,97) em resposta à suplementação de níveis crescentes de DHA da fonte OP, atingindo valor mínimo de 62,13 g no grupo OP360. O índice de postura das aves de 88,10% (CON) não foi influenciado pelas fontes de DHA na ração. A qualidade interna do ovo, avaliada em unidades Haugh, apresentou melhora significativa (P<0,05) com a adição de teores crescentes de AM igual ou superior a 1% na dieta das aves. Quanto aos teores de DHA na gema do ovo de aves suplementadas com OP, foi observado aumento significativo de 22,64 mg/ gema (CON), para 187,91 mg/ gema no grupo OP360. Os PUFAs n-3 apresentaram acréscimo significativo no contraste entre CON (62,16 mg/gema) e OP360 (218,62 mg/gema). Para a fonte AM, as médias de DHA também mostraram linearidade (Y = 0,23X + 1,27, R2 = 0,86), oscilando entre 22,64 mg/gema (CON) e 149,75 mg/gema (AM420), enquanto que o total de PUFAs n-3 oscilou de 104,18 mg/gema (AM120) a 175,32 mg/gema (AM420). O inverso ocorreu com os ácidos araquidônico, linoléico e PUFAs n-6 que mostraram decréscimos significativos (P<0,05) com o aumento de OP na dieta, variando, respectivamente, de 98,71 mg, 987,70 mg e 1108,92 mg/ gema na dieta CON a 38,87 mg, 734,22 mg e 802,79 mg/ gema, para o grupo OP360. O percentual de incorporação de DHA na gema dos ovos decresceu linearmente com o aumento dos níveis de DHA na ração suplementada com OP e AM, de 85,11% (OP120) e 65,28% (AM120) para 49,45% (OP360) e 34,06% (AM420). Melhora significativa (P<0,05) foi consignada na relação n-6/n-3, variando de 17,50 no grupo CON para 3,72 e 6,36 para tratamentos OP360 e AM420, respectivamente. A avaliação sensorial não detectou qualquer sabor ou odor estranho nos ovos dos diferentes tratamentos ou fontes utilizados, exceto para a análise qualitativa do grupo OP360 onde foi detectado grau de intensidade regular de sabor de peixe, diferindo significativamente (P<0,05) do grupo CON. / This experiment was conducted using two hundreds eighty eight 32-wk-old Hisex White laying hens for a period of ten weeks, with the objective of studying the fatty acid enrichment of the egg yolk of hens fed diets supplemented with fish oil (OP) or marine algae (AM) to provide five levels of DHA (120, 180, 240, 300 and 360 mg/100 g diet) for each source. A 2 X 5 completely randomized factorial design with three replicates of eight birds per treatment was applied in order to have the following groups: OP120, OP180, OP240, OP300, OP360, AM120, AM180, AM240, AM300 and AM360. A control group submitted to a corn/soy basal diet (CON) and another one supplemented with AM at the level of 420 mg of DHA/100 g diet (AM420) were also used. Egg production, egg weight, feed intake, feed conversion, external and internal egg quality and the organoleptic quality of the eggs were evaluated. The egg weight mean obtained for group CON (63.30 g), decreased linearly (Y = - 0.0051X + 63.8560, R2 = 0.97) as the supplemented DHA levels from the OP source increased, reaching the lowest egg weight mean of 62.13 g for the group OP360. The egg production of the control group hens (88.10%) was not influenced by the source of DHA. The internal quality of the egg evaluated by Haugh units presented significant improvement (P<0.05) with the increase of the AM source to 1% or more. The amounts of DHA into the egg yolk in birds fed OP diets, were significantly increased from 22.64 mg/egg yolk (CON), to 187.91 mg/egg yolk (OP360). The egg yolk PUFAs n-3 of the control group (62.16g) increased significantly as compared to the OP360 group (218.62 mg/yolk). The AM source showed DHA means also linear (Y = 0.23X + 1.27, R2 = 0.86), ranging from 22.64 mg/yolk (CON) to 149.75 mg/yolk (AM420), while the PUFAs n-3 ranged from 104.18 mg/yolk (AM120) to 175.32 mg/yolk (AM420). The araquidonic acid, linoleic acid and PUFAs n-6 showed significant decrease (P<0.05) with the increase of OP into the diet, ranging from 98.71 mg, 987.70 mg and 1108.92 mg/egg yolk for the CON group to 38.87 mg, 734.22 mg and 802.79 mg/egg yolk, for the OP360 group. The percentage of DHA incorporation into the egg yolk decreased linearly as the DHA levels increased into the diet. Thus, for the OP and AM sources, mean values of 85.11% (OP120) and 65.28% (AM120) decreased to 49.45% (OP360) and 34.06% (AM420). Significant improvement (P<0.05) was found in the ratio n-6/n-3, ranging from17.50 (CON) to 3.72 (OP320) and 6.36 (AM420). The sensorial evaluation of eggs did not detect any different flavor or odor in eggs among treatments or sources, except for the qualitative analysis of group OP360 which showed fish flavor, significantly different (P<0.05) from the control group.

Os ovos são alimentos de alto valor nutricional, já que possuem todas as vitaminas, aminoácidos e minerais essenciais. Os consumidores dão preferência, ovos com gema bem pigmentadas. A cultura popular trata o urucum como um poderoso agente anticolesterolemico, além de ser amplamente utilizado na forma de pigmento para a indústria. O presente trabalho avaliou os efeitos da adição de urucum (Bixa orellana L.) na ração de galinhas, verificando possível interferência na qualidade dos ovos, alteração de colesterol e cor e nas gemas e teores de vitamina A e ferro, inclusive com relação ao tempo. Para a obtenção das amostras foram utilizados 125 animais divididos em quatro tratamentos com adição de urucum na ração (0,5% - T2; 1,0% - T3; 1,5% - T4 e 2,0% - T5) e 1 controle (0% - T1). Os animais foram separados aleatoriamente em cinco blocos de cinco animais, totalizando 25 animais por parcela. Os ovos após serem colhidos passaram por análise de qualidade e padronização: pesados, classificados pelo ovoscópio, análise gravimétrica, unidade Haugh, altura de albúmen e gema, espessura da casca, diâmetro e índice de gema. O colesterol foi medido por método colorimétrico e a alteração da cor da gema, foi medida em colorímetro. Foi utilizado Teste de Tukey em nível de 5% para comparação de médias, utilizando o software SAS. Com relação à análise de qualidade dos ovos, não apresentou diferença significativa entre os tratamentos. A unidade Haugh e o índice de gema apresentaram diferença que, não se deve à adição do urucum por não ser uma resposta linear. Com relação ao colesterol, os tratamentos T2 e T3 (0,5% e 1,0% respectivamente) não apresentaram diferença significativa entre si, porém todos os tratamentos se diferenciaram em relação ao controle, apresentando diminuição no nível de colesterol, com o aumento da porcentagem de urucum na ração. Ao longo do tempo, o colesterol, mesmo administrando-se urucum para os animais, apresentou aumento significativo. Em relação a cor, determinada através do colorímetro Minolta, foram encontrados os seguintes resultados: para L, T1 e T2 apresentaram os valores superiores e, T4 e T5 os mais baixos; para a*: T4 e T5 apresentaram os maiores valores, diferindo dos demais; para b*: T1 e T2 apresentaram os maiores valores diferindo dos demais. Foi calculado também o Croma (cor) e Hue-Angle (saturação da cor). Para carotenóides (&#946; e &#945; caroteno), T5 apresentou valores superiores aos demais, diferindo estatisticamente (p<0,05). Com relação ao ferro total, T5 apresentou valores superiores aos demais, além do ferro dialisável, que provavelmente pela presença do aumento de carotenóides, também apresentou-se superior. Assim, pode-se concluir que a utilização de urucum na ração de poedeiras é útil, pois não interfere na qualidade dos ovos, influi na redução do colesterol, promove a cor das amostras, aumento de carotenóides e conteúdo de ferro. / The poultry meat and eggs are foods of high nutritional value, because they have all vitamins, amino acids and essential minerals to constitute a life. The popular culture treats the anatto like a power agent anticholesterolemic, there to be amply utilized like color source amount in the kitchen whatever in poultry farmer industry like a pigment, cosiderated that national and foreigner consumers have preference eggs with yolk yellow-orange and chickens with skin pigmented well. This research evaluated the effects of addition of anatto (Bixa orellana L.) add in ration of laying hens, relating the possible interference of the anatto in egg quality, cholesterol color and level in the yolk and tenor of vitamin A and iron, including the relationship with the time. The samples were obtained from 125 animal divided in 4 treatments with adittion of anatto (0.5% - T2; 1.0% - T3; 1.5% - T4 and 2.0% - T5 of anatto added in the ration) and 1 control (0% - T1 of anatto). The animals were separated aleatoric in 5 blocks, each block with 5 animals, with total 25 animals by parcel. The eggs harvesters were submeted by analysis of quality and standardization: they were weighty, classified by the eggscopic, gravimetric analysis, Haugh unit, albumen and yolk height, thickness of the shell, diameter and index yolk; the cholesterol was measured by a color methodology and the alteration of the yolk color, was measured in colorimeter. The statistic analysis was maked employing the Turkey test, level 5%, to compair means, utilized the SAS program. About the eggs quality analysis, they don’t showed significative difference between the treatments. The Haugh unit and the yolk index showed difference but it was not relationed to anatto add in ration. About the cholesterol, it decreased with the addition of anatto, but it increase with the time, even administrating anatto for the animals, there’s a significative increase at the cholesterol level. The color determined by the colorimeter, is dividing in 3 parts the prism: L, a* e b*: to L, T1 e T2 (control and 0.5% respectively) presented lower levels and, T4 and T5 (1.5% e 2.0% respectively) the highest. To a*: only T4 and T5 (1.5% and 2.0% respectively) don’t have difference of all. To b*: T1 and T2 (control and 0.5% respectively) presented the minimum value difering of all. There was calculated either, Croma (color) and Hue-Angle (color saturation). About the carotenes (&#946; and &#945; carotene), T5 showed higher values of the other, disagree of the statistics. About the total iron, T5 showed higher to the others, besides of the dialysable iron, that probably because of the presence of the increase of carotenes, showed higher either. So, can conclude that the utilization of anatto in ration of laying hens is very interesting, because it doesn’t interfere in the eggs quality, flow into the cholesterol reduction and color of the samples and increase carotenes and iron.

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.

This study was designed to devise a method by which the optimum combination of dietary energy and protein could be found that maximises the margin over feeding cost in an egg production enterprise. It was necessary to be able to predict feeding costs and revenue associated with the use of a wide range of feeds varying in protein and energy. To this end, two experiments were conducted using 256 Lohmann (128 White and 128 Brown) in the first, and 1296 Hy-line Brown laying birds in the second trial, that were 33 and 38 weeks old at the beginning of the two trials. Using the WinFeed 1.1 (1996) feed formulation programme, four basal (corner) feeds were formulated in both experiments, from which four protein and four energy contents (16 feeds) were produced in the first experiment, and six protein and three energy contents ( 18 feeds) were used in the second. Each feed was given to three replicates of 16 birds in the first trial, and to three replicates of 24 birds in the second. The trials each lasted ten weeks, and the data collected included food intake, change in body weight, egg weight and rate of laying. Using the results from these two experiments and from previously published research, the effects of dietary protein and energy on food intake were predicted independently, and these predictions were then used to determine the cost of feeding. Similarly, egg weight and rate of lay were predicted independently for changes in dietary protein and energy, from which the revenue could be calculated over the range of energy and protein contents. It is understood that a more integrated approach would be more accurate for this purpose, but such an approach was beyond the scope of this investigation. The use of contour plots based on regression analyses of the estimated income-minus-feeding cost on changes in dietary protein and energy enabled evaluations to be made of the effect on profitability of changes in egg price and maize price. And it was deduced that under conditions in which the maize price is high, maximum profitability is achieved with high energy and high protein content, irrespective of the price paid for eggs. When the maize price is reduced, the combination of protein and energy that yields the highest return over feed cost changes to low protein and low energy feeds. This change is defensible on the grounds that the price of high-density feeds does not change as much as that of low-density feeds when the maize price is lowered, whereas production, and hence returns, remains the same, hence the low density feeds yield higher returns under such circumstances. The method applied in this study appears to be a useful tool for decision-making by egg producers and nutritionists. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.

Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-06-05T13:02:46Z No. of bitstreams: 1 2007 - Ana Paula Carvalho Magalh?es.pdf: 895321 bytes, checksum: 5c79ed9139248935b594927ccbd21bb4 (MD5) / Made available in DSpace on 2017-06-05T13:02:47Z (GMT). No. of bitstreams: 1 2007 - Ana Paula Carvalho Magalh?es.pdf: 895321 bytes, checksum: 5c79ed9139248935b594927ccbd21bb4 (MD5) Previous issue date: 2007-09-27 / The aim of this work was evaluate the internal and external quality of table eggs (unfertile) with or without microfissures, packed in conventional cardboard pulps or with plastic films (PVC), and stored for one or 14 days. Were used 160 white table eggs of Light Layers (Hy line-W36), collected in four different periods. Each fifteen days, 40 eggs from the same portion, separated by weight (between 52 and 58 grams), and selected according with the shell integrity, were classified as fissured or not fissured, by macroscopic visualization (twenty eggs per category). The evaluations that the present work handles, were carried out in the 1st and in the 14th day, after the laying, respectively. The experimental design was randomized blocks, with factorial arrangement (2x2x 2). The variables studied were: Haugh Unit (UH), yolk index (YI), albumen index (AI), Yolk pH (YpH), pH albumen (pHA), fungus incidence (FI), shell percentage (SP), shell thickness (ST) and air chamber (AC). There was effect (P<0.05) of the shell integrity on the SP and FI. Was observed an increase (P<0.05) in the SP to the eggs without fissure when compares to those with fissures, probably because of the higher water loss, promoted by the fissures. For the results of FI it was seen that there was a decrease (P<0.05) on fungus values to the eggs without shell fissure in relation to the fissured eggs. It was observed effect (P<0.05) of the packaging type on the variables UH and TS, with higher results seen in these variables when eggs were revested by PVC film. The time storage influenced (P<0.05) the UH, AC, YpH, ApH, YI and AI. Presenting higher results for (UG, YI and AI), and lower results for (AC, YpH, ApH) in the first day of storage.There was interaction of the packaging type time X of storage, when the eggs aconditionated in open packaging for 14th days presented higher values for fungus incidence, due to environment exposition and excess of humidity, allowing proliferation of these microorganisms. / Um experimento foi conduzido com o objetivo de se avaliar a qualidade interna e externa de ovos de mesa ?ntegros de casca ou com microfissuras, em embalagens convencionais de polpas de papel?o ou cobertos com filmes pl?sticos (PVC), armazenados por um ou 14 dias. Foram utilizados 160 ovos de mesa (inf?rteis) brancos, de poedeiras da linhagem Hy line- W36, coletados em 4 ?pocas diferentes. Quinzenalmente 40 ovos, provenientes sempre do mesmo lote foram separados por peso (entre 52 e 58 gramas ) para comporem os diversos tratamentos em igualdade de peso, no conjunto. Vinte desses ovos foram selecionados tamb?m de acordo com a integridade da casca, classificados como fissurados, por visualiza??o macrosc?pica e os restantes constitu?dos de casca integra. De cada uma dessas categorias descritas acima, 10 ovos foram acondicionados em embalagens de polpa de papel?o revestida por filme pl?stico (PVC) e os outros 10 no mesmo tipo de embalagem por?m sem filme de cobertura. As avalia??es de que trata o objetivo do presente trabalho, foram realizadas no 1? e no 14? dia ap?s a postura, respectivamente, com metade dos ovos de cada uma das embalagens citadas.O delineamento utilizado foi em blocos casualizados em esquema fatorial (2x2x2): 2 tipos de integridade de casca x 2 tipos de embalagens x 2 per?odos de armazenamento com 4 repeti??es cada um. As vari?veis estudadas foram: Unidade Haugh (UH), indice de gema (IG), indice de alb?mem (IA), pH gema (pHG), pH alb?mem (pHA), incid?ncia de fungos (IC), porcentagem de casca (PC), espessura de casca (EC) e tamanho da c?mara de ar (CA). Foi observado efeito significativo (P<0,05) da integridade da casca sobre as vari?veis PC e IC. Houve aumento significativo (P<0,05) na PC dos ovos sem fissura em rela??o aos ovos com fissuras, provavelmente decorrente da maior perda de ?gua, promovida pelas fissuras. Para os valores de IC, observou-se que houve decr?scimo de fungos na casca dos ovos sem fissura em rela??o aos ovos fissurados. Foi observado efeito (P<0,05) do tipo de embalagem sobre as vari?veis UH e EC, com maiores valores observados nessa variaveis quando revestidas por filme de PVC. P?de ser observado tamb?m, efeito (P<0,05) do tempo de armazenamento sobre as vari?veis UH, CA, pHG, pHA, IG e IA. Apresentando maiores valores para (UH, IG e IA) e menores valores para (CA, pHG e pHA) no 1? dia de armazenamento. Houve intera??o do tipo de embalagem X tempo de armazenamento, quando nos ovos acondicionados por 14 dias e embalagem aberta apresentaram maior contamina??o de fungos devido sua exposi??o ao ambiente e ao excesso de umidade, permitindo assim uma maior prolifera??o desses microoganismos.

Os ovos são alimentos de alto valor nutricional, já que possuem todas as vitaminas, aminoácidos e minerais essenciais. Os consumidores dão preferência, ovos com gema bem pigmentadas. A cultura popular trata o urucum como um poderoso agente anticolesterolemico, além de ser amplamente utilizado na forma de pigmento para a indústria. O presente trabalho avaliou os efeitos da adição de urucum (Bixa orellana L.) na ração de galinhas, verificando possível interferência na qualidade dos ovos, alteração de colesterol e cor e nas gemas e teores de vitamina A e ferro, inclusive com relação ao tempo. Para a obtenção das amostras foram utilizados 125 animais divididos em quatro tratamentos com adição de urucum na ração (0,5% - T2; 1,0% - T3; 1,5% - T4 e 2,0% - T5) e 1 controle (0% - T1). Os animais foram separados aleatoriamente em cinco blocos de cinco animais, totalizando 25 animais por parcela. Os ovos após serem colhidos passaram por análise de qualidade e padronização: pesados, classificados pelo ovoscópio, análise gravimétrica, unidade Haugh, altura de albúmen e gema, espessura da casca, diâmetro e índice de gema. O colesterol foi medido por método colorimétrico e a alteração da cor da gema, foi medida em colorímetro. Foi utilizado Teste de Tukey em nível de 5% para comparação de médias, utilizando o software SAS. Com relação à análise de qualidade dos ovos, não apresentou diferença significativa entre os tratamentos. A unidade Haugh e o índice de gema apresentaram diferença que, não se deve à adição do urucum por não ser uma resposta linear. Com relação ao colesterol, os tratamentos T2 e T3 (0,5% e 1,0% respectivamente) não apresentaram diferença significativa entre si, porém todos os tratamentos se diferenciaram em relação ao controle, apresentando diminuição no nível de colesterol, com o aumento da porcentagem de urucum na ração. Ao longo do tempo, o colesterol, mesmo administrando-se urucum para os animais, apresentou aumento significativo. Em relação a cor, determinada através do colorímetro Minolta, foram encontrados os seguintes resultados: para L, T1 e T2 apresentaram os valores superiores e, T4 e T5 os mais baixos; para a*: T4 e T5 apresentaram os maiores valores, diferindo dos demais; para b*: T1 e T2 apresentaram os maiores valores diferindo dos demais. Foi calculado também o Croma (cor) e Hue-Angle (saturação da cor). Para carotenóides (&#946; e &#945; caroteno), T5 apresentou valores superiores aos demais, diferindo estatisticamente (p<0,05). Com relação ao ferro total, T5 apresentou valores superiores aos demais, além do ferro dialisável, que provavelmente pela presença do aumento de carotenóides, também apresentou-se superior. Assim, pode-se concluir que a utilização de urucum na ração de poedeiras é útil, pois não interfere na qualidade dos ovos, influi na redução do colesterol, promove a cor das amostras, aumento de carotenóides e conteúdo de ferro. / The poultry meat and eggs are foods of high nutritional value, because they have all vitamins, amino acids and essential minerals to constitute a life. The popular culture treats the anatto like a power agent anticholesterolemic, there to be amply utilized like color source amount in the kitchen whatever in poultry farmer industry like a pigment, cosiderated that national and foreigner consumers have preference eggs with yolk yellow-orange and chickens with skin pigmented well. This research evaluated the effects of addition of anatto (Bixa orellana L.) add in ration of laying hens, relating the possible interference of the anatto in egg quality, cholesterol color and level in the yolk and tenor of vitamin A and iron, including the relationship with the time. The samples were obtained from 125 animal divided in 4 treatments with adittion of anatto (0.5% - T2; 1.0% - T3; 1.5% - T4 and 2.0% - T5 of anatto added in the ration) and 1 control (0% - T1 of anatto). The animals were separated aleatoric in 5 blocks, each block with 5 animals, with total 25 animals by parcel. The eggs harvesters were submeted by analysis of quality and standardization: they were weighty, classified by the eggscopic, gravimetric analysis, Haugh unit, albumen and yolk height, thickness of the shell, diameter and index yolk; the cholesterol was measured by a color methodology and the alteration of the yolk color, was measured in colorimeter. The statistic analysis was maked employing the Turkey test, level 5%, to compair means, utilized the SAS program. About the eggs quality analysis, they don’t showed significative difference between the treatments. The Haugh unit and the yolk index showed difference but it was not relationed to anatto add in ration. About the cholesterol, it decreased with the addition of anatto, but it increase with the time, even administrating anatto for the animals, there’s a significative increase at the cholesterol level. The color determined by the colorimeter, is dividing in 3 parts the prism: L, a* e b*: to L, T1 e T2 (control and 0.5% respectively) presented lower levels and, T4 and T5 (1.5% e 2.0% respectively) the highest. To a*: only T4 and T5 (1.5% and 2.0% respectively) don’t have difference of all. To b*: T1 and T2 (control and 0.5% respectively) presented the minimum value difering of all. There was calculated either, Croma (color) and Hue-Angle (color saturation). About the carotenes (&#946; and &#945; carotene), T5 showed higher values of the other, disagree of the statistics. About the total iron, T5 showed higher to the others, besides of the dialysable iron, that probably because of the presence of the increase of carotenes, showed higher either. So, can conclude that the utilization of anatto in ration of laying hens is very interesting, because it doesn’t interfere in the eggs quality, flow into the cholesterol reduction and color of the samples and increase carotenes and iron.

This study was conducted to determine the effect of egg weight on hatchability and chick hatch-weight of Cobb 500 broiler chickens. A total of 396 Cobb 500 hatchable eggs classified according to three different egg weight groups as small: (<49 g) medium: (50-59 g) and large: (60-69 g) were used in the experiment. A complete randomized design of three treatments with three replicates and each replicate having” 44 eggs was used for the experiment. Simultaneously a linear type equation was used to determine the relationship between egg size and responses in hatchability values and chick hatch-weight. Results indicated that large-sized eggs produced chicks with higher (P<0.05) hatch-weight than medium and small-sized eggs. However, no differences were detected with fertility rate percentage, hatchability percentage and percentage hatch of fertile. It was therefore concluded from the result of the present study that sorting of Cobb 500 broiler chicken breeder eggs by weight prior to incubation might be advantageous in producing uniform size Cobb 500 broiler chicken hatchlings to meet specific market demands with improved efficiency. / Agriculture and  Animal Health / M. Sc. (Agriculture)

Assignment (MPhil)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: The study conducted was aiming on evaluating the influence of different levels of energy and amino acids, mainly lysine and methionine, on production performance of the layer bird. There were three treatments, namely the Control diet, a high energy, lysine and methionine diet (High spec.) and a low energy, lysine and methionine diet (Low spec.). The energy levels were 11.2 MJ/kg, 11.5 MJ/kg and 10.9 MJ/kg respectively. Lysine levels were 0.67%, 0.73% and 0.63% whereas methionine levels were 0.36%, 0.38% and 0.34% respectively. The experimental design was 3 x 4 factorial, which is 3 treatments with 4 replicates each. Results showed no significant difference (P>0.05) between treatments in egg production, egg mass, egg output, bodyweight and mortality. Feed intakes of the High spec. diet were significantly lower (P<0.05) than that of the control diet and the Low spec. diet. / AFRIKAANSE OPSOMMING: Hierdie studiestuk handeloor die evaluering van die invloed wat die verskillende vlakke van die energie en aminosure, veraiiisien en methionine op die produksie van 'n lê hoender het. Daar was gebruik gemaak van drie behandelings, naamlik die kontrole dieet, 'n hoë energie, lisien en methionien dieet (Hoë spesifikasie), en 'n lae energie, lisien en methionien dieet (Lae spesifikasie). Die energievlakke was 11.2 MJ/kg, 11.5 MJ/kg en 10.9 MJ/kg onderskeidelik. Lisienvlakke was 0.67%, 0.73% en 0.63% waarby methionienvlakke was 0.36%, 0.38% and 0.34% onderskeidelik. Die eksperimentele ontwerp was 3 x 4 fakulteitsfunksies: 3 behandelings met 4 replikas elk. Die resultate het geen noemenswaardige verskille (P>0.05) tussen die behandelinge in eierproduksie, eiergewig, eier-uitset, liggaamsgewig en mortaliteite nie. Die voerinnames van die hoë spesifikasie dieet was aansienlik laer (P<0.05) as die van die kontrole en lae spesifikasie dieet.