Existem no mercado vários tipos de alimentos para cães, por isso a determinação de qual alimento fornecer e a quantidade deste que deve ser fornecida aos animais não uma tarefa das mais fáceis. Baseado nisto, o presente estudo visou determinar os efeitos de dois alimentos comerciais secos e dois tipos de fornecimento no consumo alimentar, peso vivo e metabólico, escore fecal e corporal e volume fecal. Para tanto foram utilizados quatro animais da raça Border Collie aos quais foram fornecidos dois alimentos, alimento A (“super premium") e alimento B (popular), distribuídos de duas formas “ad libitum" (AV) e controlada (C). Estes animais receberam os dois alimentos (A e B) fornecidos dos dois modos (AV e C) durante 4 períodos experimentais com 10 dias de duração cada (6 dias de adaptação e 4 de coleta). Os animais foram pesados e seu escore corporal foi observado nos dias coleta dos 4 períodos. Estes cães foram submetidos à atividade diária durante os 40 dias do experimento. Os alimentos eram fornecidos em dois horários 8:00h e 17:00h, sendo que as sobras da refeição anterior eram recolhidas e pesadas antes do fornecimento da próxima. Com isso foi possível a determinação do consumo diário dos animais. Nos dias de coleta foi realizada coleta total das fezes a fim de se determinar seu volume e escore. Os resultados foram analisados utilizando-se o programa SAS. Com a análise estatística pôde-se determinar que o alimento A é realmente de melhor qualidade que o alimento B, e que a quantidade de alimento fornecida foi suficiente para satisfazer as exigências diárias dos animais, mesmo tendo sido estipulada para animais em manutenção. / It is available in the market several types of foods for dogs, that the determination of which food to supply and the amount of this that should be supplied to the animals is not a simple task. Based on this, the aim of the present study was to determine the effects of two dry commercial foods and two supply types in the food consumption, in live and metabolic weights, fecal and corporal score and fecal volume. For so much four animals were used of the race Border Collie to which two foods were supplied, food A ("super premium") and food B (popular), distributed in two ways "ad libitum" (AV) and controlled (C). These animals received the two foods supplied of the two manners during 4 experimental periods with 10 days of duration each (6 days of adaptation and 4 of data collection). The animals were weighted and its corporal score was observed in data collection days of the 4 periods. These dogs were submitted to the daily activity during the all 40 days of the experiment. The foods were supplied in two schedules 8:00 AM and 5:00 PM, and the discard amount of the previous meal were picked up and weighed before the supply of the next. So it was possible the determination of the daily food consumption of the animals. In the days of collection, total collection of the feces was accomplished in order to determine its volume and score. The results were analyzed being used the SAS program. With the statistical analysis it could be determined that the food A is really of better quality than the food B, based mainly in the fecal volume and score, and that the amount of supplied food was enough to satisfy the daily demands of the active animals, even having been specified for animals in maintenance.

Existem no mercado vários tipos de alimentos para cães, por isso a determinação de qual alimento fornecer e a quantidade deste que deve ser fornecida aos animais não uma tarefa das mais fáceis. Baseado nisto, o presente estudo visou determinar os efeitos de dois alimentos comerciais secos e dois tipos de fornecimento no consumo alimentar, peso vivo e metabólico, escore fecal e corporal e volume fecal. Para tanto foram utilizados quatro animais da raça Border Collie aos quais foram fornecidos dois alimentos, alimento A (“super premium”) e alimento B (popular), distribuídos de duas formas “ad libitum” (AV) e controlada (C). Estes animais receberam os dois alimentos (A e B) fornecidos dos dois modos (AV e C) durante 4 períodos experimentais com 10 dias de duração cada (6 dias de adaptação e 4 de coleta). Os animais foram pesados e seu escore corporal foi observado nos dias coleta dos 4 períodos. Estes cães foram submetidos à atividade diária durante os 40 dias do experimento. Os alimentos eram fornecidos em dois horários 8:00h e 17:00h, sendo que as sobras da refeição anterior eram recolhidas e pesadas antes do fornecimento da próxima. Com isso foi possível a determinação do consumo diário dos animais. Nos dias de coleta foi realizada coleta total das fezes a fim de se determinar seu volume e escore. Os resultados foram analisados utilizando-se o programa SAS. Com a análise estatística pôde-se determinar que o alimento A é realmente de melhor qualidade que o alimento B, e que a quantidade de alimento fornecida foi suficiente para satisfazer as exigências diárias dos animais, mesmo tendo sido estipulada para animais em manutenção. / It is available in the market several types of foods for dogs, that the determination of which food to supply and the amount of this that should be supplied to the animals is not a simple task. Based on this, the aim of the present study was to determine the effects of two dry commercial foods and two supply types in the food consumption, in live and metabolic weights, fecal and corporal score and fecal volume. For so much four animals were used of the race Border Collie to which two foods were supplied, food A ("super premium") and food B (popular), distributed in two ways "ad libitum" (AV) and controlled (C). These animals received the two foods supplied of the two manners during 4 experimental periods with 10 days of duration each (6 days of adaptation and 4 of data collection). The animals were weighted and its corporal score was observed in data collection days of the 4 periods. These dogs were submitted to the daily activity during the all 40 days of the experiment. The foods were supplied in two schedules 8:00 AM and 5:00 PM, and the discard amount of the previous meal were picked up and weighed before the supply of the next. So it was possible the determination of the daily food consumption of the animals. In the days of collection, total collection of the feces was accomplished in order to determine its volume and score. The results were analyzed being used the SAS program. With the statistical analysis it could be determined that the food A is really of better quality than the food B, based mainly in the fecal volume and score, and that the amount of supplied food was enough to satisfy the daily demands of the active animals, even having been specified for animals in maintenance.

Made available in DSpace on 2014-08-20T14:38:43Z (GMT). No. of bitstreams: 1 Tese_Leonardo_Talavera_Campos.pdf: 765527 bytes, checksum: a64dcd74a213c1abd1bde1d1bf1ddd18 (MD5) Previous issue date: 2011-02-22 / Study was divided into two independent and complementary parts. The first objective was to evaluate the behavior of additive genetic trends for weight traits and selection indices in cattle population of Aberdeen Angus breed evaluated in PROMEBO®. Data were provided by the National Breeders Association (ANC), with animals produced from 1974 to 2010. The traits were: birth weight (BW), with 70,156; weight gain from birth to weaning (WWG), with 181,491; and post-weaning weight gain (PWG), with 113,323 animals, respectively. Characteristics were pre-adjusted for known environmental effects. Other variables were the weaning and final selection indexes. It was includes, beside WWG and PWG, scrotal circumference (SC) in the final stage (yearling) and visual scores collected at the weaning and yearling. Weighting percentages were applied for index constituents. The statistical model included additive genetic effects of sire and dam and environmental effects of contemporary groups. The estimates were obtained by Method GenSys, using a denomined gametic model on univariate analysis. In regression analysis using arithmetic means of breeding values or EPDs was used the least squares method weighted by the number of observations, obtained by PROC REG (SAS, 1996). Significant additive direct genetic trends estimated to the weight characters WWG, PWG and weight gain from birth to yearling (YWG = WWG + PWG) and selection indices at weaning and yearling, show that, as selection criteria, are providing moderate genetic progress in this population of Angus. Results for birth weight suggested that it is almost stabilized, which is desirable in order to avoid calving problems. The second part of the study was to evaluate a selection criterion for efficiency to weaning in beef cattle herds controlled by PROMEBO®. This criterion was the relationship between weight gain from birth to weaning of calves (WWG) and cow weight (CW), obtained in two ways, appear in the denominator of equation (1) real cow weight at weaning of their product, a percentage expressing this efficiency (EFF), or (2) metabolic weight of cow at weaning from each of their calves, resulting in the efficiency in metabolic weight (EMW). The bulls were evaluated by calves who have greater WWG (output), compared to the cost of production ("input"), measured by the metabolic weight of their mother cows for EMW, or actual bodyweight of cows for EFF. Records from performance data including weight of 10,350 calves and their mothers, referring to the progenies of 330 sires from Angus breed, produced between 1982 to 2002, in three herds from two farms located in the region Frontier West of Rio Grande do Sul. The mixed model solutions were obtained through a computer program PROC MIXED (SAS Institute Inc., 2001). The heritability was estimated by covariance between paternal half-siblings. The heritability estimates, of moderate magnitude, were 0,187±0,023 (18,69%) for EMW and 0,167±0,022 (16,73%) for EFF. Despite of difficulties and constraints statistics, selection criteria for efficiency analysis, in particular, efficiency in metabolic weight (EMW), showed reasonable heritability. This opens prospects for allowing a selection of sires that provide a greater return and economic efficiency, transmitting to their offspring genetic potential for a greater weight gain in relation step to the maintenance requirements of cows, mothers of their products. Ratios as EFF and EMW, due positive association with feed efficiency, indicate that were an important alternative for selection because the moderate heritability and ease of measurement in practice. / Este trabalho foi dividido em duas partes. O objetivo do primeiro estudo foi avaliar as tendências genéticas aditivas para características de crescimento e índices de seleção na população de bovinos da raça Aberdeen Angus, avaliados pelo PROMEBO®. Os dados foram disponibilizados pela Associação Nacional de Criadores (ANC), com animais produzidos entre os anos de 1974 e 2010. As características estudadas foram: peso ao nascer (PN); ganho de peso do nascimento à desmama (GND), e ganho de peso pós-desmama (GDS), com 70.156, 181.491 e 113.323 animais, respectivamente, sendo pré-ajustadas para efeitos ambientais conhecidos. Outras variáveis estudadas foram os índices de seleção à desmama e final. Incluem, além do GND e GDS, perímetro escrotal (PE) na fase final (ano ou sobreano) e escores de avaliação visual coletados nas fases de desmama e final. Ponderações percentuais foram aplicadas sobre as características para compor os índices. O modelo estatístico incluía os efeitos genéticos aditivos de touro e vaca e efeitos ambientais de grupos contemporâneos. As estimativas foram obtidas pelo Método GenSys, utilizando-se um modelo chamado de gamético, em análises univariadas. Nas análises de regressão, ao usar médias aritméticas dos valores genéticos ou DEPs, foi usado o método de quadrados mínimos ponderados, pelo número de observações, com base no PROC REG (SAS, 1996). As tendências genéticas aditivas diretas para as características de crescimento GND, GDS e ganho de peso do nascimento (sobre)ano (GNS = GND + GDS) e índices de seleção à desmama e final, foram significativas e indicam que, como critério de seleção, estão proporcionando moderado progresso genético nesta população da raça Angus. Resultados da avaliação genética para peso ao nascer indicam que o mesmo encontra-se praticamente estabilizado, o que é desejável visando-se evitar problemas de parto. A segunda parte do estudo teve como objetivo avaliar um critério de seleção para eficiência à desmama nos rebanhos controlados pelo PROMEBO®. O critério foi a relação entre o ganho de peso do nascimento à desmama do terneiro (GND) e o peso da vaca (PV), obtida de duas formas, constando no denominador da equação: (1) peso da vaca real na desmama de seu produto, expressando esta eficiência em percentagem (EFF); ou (2) peso metabólico da vaca na desmama de cada um de seus filhos, resultando na eficiência em peso metabólico (EPM). Os touros pais foram avaliados através de filhos que tenham maior GND ( output ), em relação ao custo de produção ( input ), medido através do peso metabólico de suas mães para EPM, ou peso corporal real das vacas para EFF. Foram analisados dados ponderais de 10.350 terneiros, e suas respectivas mães, referentes às progênies de 330 touros pais da raça Aberdeen Angus, produzidos entre os anos de 1982 a 2002, em três rebanhos de duas fazendas localizadas na região da Fronteira Oeste do Rio Grande do Sul. As soluções de modelos mistos foram obtidas através do programa PROC MIXED (SAS Institute Inc.,2001). O método de estimação da herdabilidade foi o da covariância entre meio-irmãos paternos. As estimativas de herdabilidade obtidas, de magnitude moderada, foram de 0,187±0,023 (18,69%) para EPM e 0,167±0,022 (16,73%) para EFF. Apesar de dificuldades e restrições estatísticas, os critérios de seleção para eficiência analisados, em especial, eficiência em peso metabólico (EPM), apresentaram razoável herdabilidade. Este fato abre perspectivas para, como característica do touro pai ou do produto, permitir a seleção de reprodutores que fornecem um maior retorno ou eficiência econômica, transmitindo à sua progênie potencial genético para um maior ganho de peso em relação às necessidades de mantença das mães de seus produtos. Relações como EFF e EPM - ao se pressupor, com base na literatura, uma positiva associação com eficiência alimentar -, indicam ser uma alternativa importante tanto pela herdabilidade moderada como pela facilidade de mensuração na prática.

Text in English / Cow size influences biological efficiency of individual animals, which influences herd composition and stock flow. This in turn influences the economic efficiency of the herd. This research followed the thread from animal size, to biological efficiency, to economic efficiency for beef cattle production under a typical production system in semi-arid South Africa. Cattle were grouped into three groups namely small, medium and large cattle, with mature weights of 300kg, 450kg and 600kg respectively. The net energy requirements of individual cattle were calculated for maintenance, growth, lactation and foetal production, for each of the three sizes. Growth rates, milk yield, reproduction rates, and management practices were assumed from existing research. Next the stock flow for a herd of small, medium and large cattle were calculated from the above. Income and expenses as commonly used in the research area were calculated from the stock flow. Gross profit above allocated costs were subsequently calculated for the three herds under the above-mentioned conditions. When assuming similar reproduction and growth rates for small, medium and large mature cattle, the following results were obtained: more heads of small cattle could be held on a set resource base, but the total live weight of a herd of large cattle that could be held on the same resource base was greater. This was mostly due to proportionately lower maintenance energy requirements in the herd of large cattle. In the simulation in this study, maintenance energy requirements for the herd of large cattle was 71.2%, compared to 72.0% for the herd of medium cattle and 73.1% for the herd of small cattle. Income from the herd of small cattle was the lowest, as less kilograms of beef were available to sell. Allocated costs for the herd of small cattle were the highest, due to a large number of expenses being charged per head of cattle. As a result, the herd of large cattle were more economically efficient than their smaller counterparts. Income above allocated costs for the herds of large, medium and small cattle were R1,182,865, R1,085,116 and R946,012 respectively. Larger cattle generally have a lower reproduction rate under similar conditions. No equation exists that directly links size to reproduction rates, especially considering the vast number of variables that influences reproduction rates. However, in the form of scenarios, it could be calculated that, given a reproduction rate of 80% for mature small cattle, when reproduction rates of large cattle were 24.7% lower than that of small cattle and the reproduction rates of medium cattle were 15.4% lower than that of small cattle, the large and medium herds became less profitable than the small herd. Smaller cattle mature faster than larger cattle which provides the opportunity for early breeding. When small cattle were bred early, at 15 months, at a calving rate of only 44.5% it was more profitable than when the same cows were bred at 24 months. When medium cattle were bred at 15 months, a calving rate of 37.0% was needed to be more profitable than when they were bred at 24 months. Even when the herd of small cattle were bred at 15 months with a reproduction rate of 100%, it could still not match the profitability of the herd of large cattle bred at 24 months given the reproduction rates of all other classes of animals were similar. When the herd of medium cattle were bred at 15 months, at a calving rate of 53.7%, it matched the profit of the herd of large cattle that were bred at 24 months, when the reproduction rates of other classes were equal. Scenarios were considered were feed intake was limited. When feed was limited to a specific amount, smaller cattle were more biologically efficient and cattle with potential for small mature sizes would grow to a larger size than cattle with potential for medium and large mature sizes. When feed was limited by a factor of the calculated energy requirements of small, medium and large cattle, large cattle were more effective. This is because large cattle use proportionately less energy for maintenance, which allows more energy to be allocated to growth, lactation and foetal production. When energy was limited to an amount per unit of metabolic weight, small cattle were more efficient than medium and larger cattle in the growth and production phases. Small, medium and large cattle were equally efficient (or inefficient) in the maintenance and lactation phases. Energy requirements of cattle in South Africa are commonly calculated using the Large Stock Unit (LSU). The LSU typically overestimates energy requirements for cattle, except in the lactation phase. When using the LSU to match small, medium or large cattle to a resource base, the LSU overestimates energy requirements of large cattle proportionately more than that of small and medium cattle. This is excluding the lactation phase, where energy requirements for all three sizes are underestimated and that of large cattle underestimated proportionately more. There are more considerations when matching cow size to managerial practices. A smaller body size is a natural adaptation to a semi-arid environment and this adaptation can be expressed in different ways. The number of animals on a resource base has implications on management practices. Having more heads of cattle on a resource base increases genetic variation of the herd, allowing for genetic progress to be made faster than in herd of fewer cattle. / Agriculture and  Animal Health / M.Sc. (Agriculture)