Master of Science / Department of Animal Sciences and Industry / James S. Drouillard / Escherichia coli O157, a food-borne human pathogen, causes hemorrhagic colitis and hemolytic uremic syndrome. Cattle are a major reservoir and the organism resides in the hindgut and is shed in the feces. Cattle feces are a major source of food and water contamination. Houseflies feed on cattle manure and are a source of E. coli O157 transmission. We have observed that houseflies have an affinity for a steam-flaked corn product (SFC-36) made from tempered whole corn that is more ruminally digestible than the traditional SFC (SFC-18). Therefore, we investigated whether SFC-36 diets contained and resulted in higher E. coli concentrations in the feces of cattle compared to SFC-18 diets. Concentrations of E. coli were not different between the two SFC diet samples, but resulted in higher coliforms in diets containing the SFC-36 after exposure to the environment. However, E. coli concentrations in feces from cattle fed the two diets were similar. In fact, cattle fed the diet containing SFC-18 flakes actually shed higher concentrations of coliforms. This led us to speculate that starch digestion may have an effect on the growth of E. coli O157 in the hindgut. We determined whether fecal E. coli O157 was related to fecal starch concentration. Steers (n=263) were sampled for E. coli O157 and fecal starch concentration determinations. Steers positive for E. coli O157 contained 21% more (P < 0.05) fecal starch than steers that were negative for E. coli O157. We attempted to alter the concentration of starch escaping rumen fermentation by feeding diets based on SFC and dry-rolled corn (DRC) to 30 heifers prescreened for being culture positive for fecal E. coli O157. Heifers were sampled for feces and by rectoanal mucosal swab (RAMS) weekly to monitor fecal pH and fecal starch concentration, and prevalence of E. coli O157. Based on RAMS, prevalence of E. coli O157 tended to be higher (P = 0.08) for heifers fed SFC than DRC diet. Fecal starch and pH were similar (P > 0.05) between positive- or negative-E. coli O157 heifers. Apparently, fecal E. coli O157 was not related to fecal pH or starch concentration in cattle.

O consumo alimentar residual (CAR) é uma medida de eficiência alimentar independente da taxa de crescimento e do peso adulto. Pouco se sabe sobre associações entre o CAR e as características de produtividade dos animais selecionados para este parâmetro, bem como os mecanismos relacionados ao aumento na eficiência alimentar dos animais selecionados para o CAR. O objetivo deste estudo foi avaliar as associações entre CAR, desempenho, crescimento dos componentes da carcaça e digestão do amido em bovinos Nelore, em confinamento, e avaliar a utilização dos parâmetros fecais, (porcentagem de amido, proteína, matéria seca e pH), como indicadores da digestão do amido. Noventa e seis touros da raça Nelore selecionados como elite ou superior na prova de ganho de peso a pasto e classificados quanto ao seu temperamento, medido pela distância mínima de aproximação, foram confinados e alimentado ad libitum (68% NDT, 13,5% PB, 28,1% amido) durante 68 dias com peso vivo médio inicial de 408±33 e idade de 645±52 dias. A ingestão de matéria seca (IMS) e o ganho médio diário (GMD) foram medidos individualmente. As pesagens e as mensurações da espessura de gordura subcutânea (EGS), espessura de gordura na picanha (EGP) e a área de olho de lombo (AOL) foram realizadas a cada 21 dias. Os animais foram classificados como sendo de alto CAR (DP>0,5), baixo CAR (DP<0,5) e intermediário. O amido das amostras da ração e da sobra coletadas durante sete dias consecutivos, no final do experimento, foi determinado por análise laboratorial e a quantificação do amido fecal foi feita através do NIRS e a digestão do amido estimada. Durante o confinamento, novilhos com baixo CAR tiveram menores IMS e conversão alimentar que novilhos com alto CAR, mas nenhuma diferença foi observada no GMD, no PV final, AOL, EGP, EGS, temperamento e ganho de peso durante a prova de ganho de peso. Animais mais eficientes também não diferiram dos demais quanto à digestão do amido, no entanto, animais mais eficientes tiveram menores quantidades de proteína fecal. O CAR foi positivamente correlacionado com a IMS, consumo de amido, proteína fecal e eficiência alimentar e negativamente correlacionado com a conversão alimentar, no entanto não houve correlação entre o CAR e o GMD na prova de ganho de peso a pasto e temperamento. A digestão do amido foi positivamente associada com a PB fecal e negativamente correlacionada com a MS e o amido fecal. Não houve associação entre o CAR, o GMD a pasto e o temperamento, talvez porque são filhos de vacas selecionadas para essas características e também foram os que tiveram os melhores desempenhos na prova a pasto. / Residual feed intake (RIF) is a trait of efficiency independent of growth rate and mature weight. Little is known about the association between RFI and productivity and the mechanisms associate on improve efficiency in RFI. This work aimed to study the association between RFI, performance, growth of carcass traits and starch digestion in Nellore bulls and to investigate the utilization of fecal parameters like crude protein, dry matter and pH, as indicators of starch digestion. Ninety six Nellore bulls, with 645±52 days, 408±33kg initial body weight, previously selected as elite or superior in performance test on pasture and classified according to their temperament, were fed a finishing ration (68% TDN, 13,5%CP and 28,1% starch) on an ad libitum basis, for 68 days. Daily dry matter intake (DMI) and body weight gain (BWG) were measured individually. All animals were weighed and had ultrasonic measurements of Longissimus muscle area (REA) and backfat thickness (BF) on the 12th and 13th ribs obtained every 21 days. RFI was calculated as the difference between actual DMI and predicted DMI for a common mid-test BW0.75 and daily BWG and the animals were classified as high (SD>0,5), low (SD<0,5) and intermediary RFI. The starch of the diet and orts was determinate by laboratory analyses and the fecal starch was determinate with NIRS, and the starch digestion estimated. Low RFI bulls had low DMI and feed:gain than high RFI bulls, but no difference were observe in daily BWG, final BW, REA, BF, temperament and daily gain in the pasture performance test. More efficient bulls had no difference in starch digestion, however low RFI bulls had lower crude protein in the feces. RFI was positively correlated with DMI, starch intake and feed efficiency, but RFI was not correlated with daily BWG in the pasture performance test and temperament. Starch digestion was positively associated with Fecal CP and negatively associated with DM and starch. There was no association between RFI and daily BWG on pasture and temperament, perhaps because these animals belonged to a herd that was selected for these characteristics and also were the animals that had the best performance on pasture test.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-09-05T20:30:53Z No. of bitstreams: 1 2016 - Ana Carla Chaves Dias.pdf: 1946070 bytes, checksum: 4954b82fc85ca253a40546487884c3bb (MD5) / Made available in DSpace on 2017-09-05T20:31:07Z (GMT). No. of bitstreams: 1 2016 - Ana Carla Chaves Dias.pdf: 1946070 bytes, checksum: 4954b82fc85ca253a40546487884c3bb (MD5) Previous issue date: 2016-09-30 / CAPES / The aim of this research was to evaluate the effects of prebiotic fructo-oligosaccharide (FOS) on the performance of suckling foals, and fecal pH and the physical and chemical characteristics of faeces from foals.. The experiment was carried out at the Cabral's Haras, farm located in Rio Claro, Rio de Janeiro. Sixteen Mangalarga Marchador foals were used in a completely randomized designwith two treatments and eight repetitions (animals). The treatments were: Treatment I - suplly the FOS once a day orally; Treatment II (control) - the animals received aqueous solution, orally, without FOS additive. The trial period was 75 days of duration, starting supplementation at birth. From birth to the 30th day, daily stool samples were collected directly from rectum. The 30th day onwards, samples were collected every 4 days until the 75th day of age. Immediately after the faeces samples the consistency and its color was written down in a collection form . The pH was mensured from samples previously diluted with equal amounts of distilled water using a digital potentiometer. For chemical analysis the samples were homogenized in weekly composite samples and it was performed chemical analyzes In the performance parameters foals were weighed and it was performed morphometric measurements of height and perimeter. The results were submitted to analysis of variance in a split plot scheme and means were compared by the Student Newman Keuls test, at5% probability. The values of fecal characteristics were compared using the Wilcoxon test in the analysis of the treatment and compared by Kruskal-Wallis test in the analysis of the collection times. There were no significant effects (p <0.05) of supplementation and interaction age versus supplementation for all variables. The average daily gain weight was 0.63 kg during the trial period. The morphometric variables showed average growth of 17.8, 18.7, and 27.5 cm in height at the withers, hip height, body length and chest girth, respectively, from birth to 75 days old. Growth percentage of 31.1, 53.8, 15.6, 22.4, 12 and 12.3% were observed for height and width of the side, the empty substernal height, forearm girth, knee girth and shin girth, respectively . The use of prebiotic fructooligosaccharide did not affect the faecal pH, with average values of 7.22. There was no significant difference (P <0.05) in the physical and chemical characteristics of the stool. The use of prebiotic fructooligosaccharides does not influence the performance of newborn foals to 75 days of age. Further investigation should be conducted to evaluate the responses obtained through fecal parameters and their relationship as an indicator of gastrointestinal health. It prove to be safe in the dose used, it does not promote diarrhea or other gastrointestinal disorders in infants foals. / O objetivo desse estudo foi avaliar os efeitos do prebi?tico Frutooligossacar?deo (FOS) no desempenho dos potros lactentes bem como no pH fecal e nas caracter?sticas f?sicas e qu?micas das fezes dos potros. O experimento foi realizado no Haras do Cabral em Rio Claro, RJ. Foram utilizados 16 potros Mangalarga Marchador em delineamento experimental inteiramente casualizado, com dois tratamentos e oito repeti??es (animais). Tratamento I - fornecimento uma vez ao dia, via oral, do aditivo FOS e o Tratamento II (controle) ? os animais recebiam solu??o aquosa, via oral, sem o aditivo FOS. O per?odo experimental foi de 75 dias, iniciando a suplementa??o ao nascimento. Amostras di?rias de fezes foram coletadas diretamente do reto do nascimento at? o 30o dia de idade. Do 30o dia em diante, as coletas ocorreram a cada 4 dias, at? os 75o dia de idade. Imediatamente ap?s a coleta anotou-se em uma ficha de coleta a consist?ncia e colora??o das amostras. O pH foi avaliado a partir das amostras previamente dilu?das em iguais quantidades de ?gua destilada atrav?s de um potenci?metro digital. Para an?lises qu?micas as amostras foram homogeneizadas em amostras compostas semanais e realizadas an?lises bromatol?gicas. O desempenho dos potros foi avaliado atrav?s do peso vivo e por meio de medidas morfom?tricas lineares e de per?metros. Os resultados foram submetidos ? an?lise de vari?ncia em esquema de parcelas subdivididas e, as m?dias comparadas pelo teste Student Newman Keuls, a 5% de probabilidade. Os valores da caracteriza??o fecal foram comparados pelo teste de Wilcoxon na an?lise entre os tratamentos e, comparados pelo teste de Kruskal-Wallis na an?lise entre os tempos de coleta. N?o foram observados efeitos significativos (p<0,05) na suplementa??o e intera??o idade versus suplementa??o para todas as vari?veis analisadas. O ganho de peso m?dio di?rio foi de 0,63 kg durante o per?odo experimental. As vari?veis morfom?tricas apresentaram crescimento m?dios de 17,8, 18,7, e 27,5 cm para altura da cernelha, altura da garupa, comprimento do corpo e per?metro tor?cico, respectivamente, do nascimento aos 75 dias de idade. Percentuais de crescimento m?dio de 31,1, 53,8, 15,6, 22,4, 12 e 12,3% foram observados para altura e largura do costado, altura do vazio subesternal, per?metros do antebra?o, joelho e canela, respectivamente. O uso do prebi?tico frutooligossacar?deo n?o influenciou no pH fecal, apresentando valores m?dios de 7,22. N?o houve diferen?a significativa (P<0,05) nas caracter?sticas f?sicas e qu?micas das fezes. O uso do prebi?tico frutooligossacar?deo n?o influencia no desempenho de potros lactentes do nascimento aos 75 dias de idade. Maiores investiga??es devem ser realizadas para avaliar as respostas obtidas atrav?s de par?metros fecais e sua rela??o como indicador da sa?de gastrointestinal. A dose utilizada de frutooligossacar?deo n?o promove diarr?ias e dist?rbios gastrointestinais em potros lactentes.

O consumo alimentar residual (CAR) é uma medida de eficiência alimentar independente da taxa de crescimento e do peso adulto. Pouco se sabe sobre associações entre o CAR e as características de produtividade dos animais selecionados para este parâmetro, bem como os mecanismos relacionados ao aumento na eficiência alimentar dos animais selecionados para o CAR. O objetivo deste estudo foi avaliar as associações entre CAR, desempenho, crescimento dos componentes da carcaça e digestão do amido em bovinos Nelore, em confinamento, e avaliar a utilização dos parâmetros fecais, (porcentagem de amido, proteína, matéria seca e pH), como indicadores da digestão do amido. Noventa e seis touros da raça Nelore selecionados como elite ou superior na prova de ganho de peso a pasto e classificados quanto ao seu temperamento, medido pela distância mínima de aproximação, foram confinados e alimentado ad libitum (68% NDT, 13,5% PB, 28,1% amido) durante 68 dias com peso vivo médio inicial de 408±33 e idade de 645±52 dias. A ingestão de matéria seca (IMS) e o ganho médio diário (GMD) foram medidos individualmente. As pesagens e as mensurações da espessura de gordura subcutânea (EGS), espessura de gordura na picanha (EGP) e a área de olho de lombo (AOL) foram realizadas a cada 21 dias. Os animais foram classificados como sendo de alto CAR (DP>0,5), baixo CAR (DP<0,5) e intermediário. O amido das amostras da ração e da sobra coletadas durante sete dias consecutivos, no final do experimento, foi determinado por análise laboratorial e a quantificação do amido fecal foi feita através do NIRS e a digestão do amido estimada. Durante o confinamento, novilhos com baixo CAR tiveram menores IMS e conversão alimentar que novilhos com alto CAR, mas nenhuma diferença foi observada no GMD, no PV final, AOL, EGP, EGS, temperamento e ganho de peso durante a prova de ganho de peso. Animais mais eficientes também não diferiram dos demais quanto à digestão do amido, no entanto, animais mais eficientes tiveram menores quantidades de proteína fecal. O CAR foi positivamente correlacionado com a IMS, consumo de amido, proteína fecal e eficiência alimentar e negativamente correlacionado com a conversão alimentar, no entanto não houve correlação entre o CAR e o GMD na prova de ganho de peso a pasto e temperamento. A digestão do amido foi positivamente associada com a PB fecal e negativamente correlacionada com a MS e o amido fecal. Não houve associação entre o CAR, o GMD a pasto e o temperamento, talvez porque são filhos de vacas selecionadas para essas características e também foram os que tiveram os melhores desempenhos na prova a pasto. / Residual feed intake (RIF) is a trait of efficiency independent of growth rate and mature weight. Little is known about the association between RFI and productivity and the mechanisms associate on improve efficiency in RFI. This work aimed to study the association between RFI, performance, growth of carcass traits and starch digestion in Nellore bulls and to investigate the utilization of fecal parameters like crude protein, dry matter and pH, as indicators of starch digestion. Ninety six Nellore bulls, with 645±52 days, 408±33kg initial body weight, previously selected as elite or superior in performance test on pasture and classified according to their temperament, were fed a finishing ration (68% TDN, 13,5%CP and 28,1% starch) on an ad libitum basis, for 68 days. Daily dry matter intake (DMI) and body weight gain (BWG) were measured individually. All animals were weighed and had ultrasonic measurements of Longissimus muscle area (REA) and backfat thickness (BF) on the 12th and 13th ribs obtained every 21 days. RFI was calculated as the difference between actual DMI and predicted DMI for a common mid-test BW0.75 and daily BWG and the animals were classified as high (SD>0,5), low (SD<0,5) and intermediary RFI. The starch of the diet and orts was determinate by laboratory analyses and the fecal starch was determinate with NIRS, and the starch digestion estimated. Low RFI bulls had low DMI and feed:gain than high RFI bulls, but no difference were observe in daily BWG, final BW, REA, BF, temperament and daily gain in the pasture performance test. More efficient bulls had no difference in starch digestion, however low RFI bulls had lower crude protein in the feces. RFI was positively correlated with DMI, starch intake and feed efficiency, but RFI was not correlated with daily BWG in the pasture performance test and temperament. Starch digestion was positively associated with Fecal CP and negatively associated with DM and starch. There was no association between RFI and daily BWG on pasture and temperament, perhaps because these animals belonged to a herd that was selected for these characteristics and also were the animals that had the best performance on pasture test.