A carne do bagre pintado neotropical é muito apreciada e apresenta grande potencial comercial no mercado de peixe brasileiro. Embora o conhecimento do desenvolvimento inicial do trato digestório de larvas de pintado seja muito importante para a estratégia de produção da criação de peixes, há pouca informação sobre este assunto. Neste trabalho estudamos as modificações estruturais e funcionais do trato digestório do pintado entre o 3º e o 16º dia após a eclosão. As lâminas histológicas foram coradas para estudar a morfologia e a secreção ácida e neutra do trato digestório do pintado. O alimento foi encontrado no intestino a partir do 3º após a eclosão. As células que secretam muco ácido e neutro foram observadas no esôfago e seu número aumentou com idade. O estômago estava revestido com epitélio de secreção ácida e neutra. Do 11º dia após a eclosão para frente, glândulas gástricas tubulares com células oxintopépticas granular formam identificadas na mucosa do estômago. Neste momento a fração neutra do muco epitelial aumentou e sua fração ácida foi reduzida. No 13º após a eclosão o muco foi exclusivamente neutro. O segmento proximal do intestino no 3º dia após eclosão da larva estava anteriormente dilatado, formando a bolsa intestinal. A bolsa é revestida por enterócitos e células caliciformes que produzem muco ácido e neutro. O tamanho da bolsa intestinal diminui com o tempo e é grandemente reduzida no 16º DPE. Notou-se que a partir do 11º DPE o segmento intestinal distal é enovelado e a mucosa formam várias pregas revestidas de enterócitos e células caliciformes que secretam muco neutro ou ácido. Um curto segmento retal foi observado. A larva de pintado ingere alimento no início do 3º DPE, mas seu trato digestório somente parece estar completamente preparado para eficientemente processar o alimento no estômago, após o surgimento das glândulas gástricas no 13º DPE, quando este órgão desenvolve as características do estômago químico / The meat of the neotropical spotted catfish ("surubim pintado", Pseudoplatystoma coruscans) is very appreciated and shows great commercial potential in Brazilian fish market. Although the initial development of the pintado larvae digestive system is very important to the production strategies of fish farms, there is little information about this subject. Here, we studied the structural and functional modifications of the digestive tract of pintado Pseudoplatystoma coruscans larvae between 3rd and 16rd days after hatching (DAH). Histological slides of larvae were stained by toluidine blue, Alcian blue and Schiff reactive-periodic acid (PAS) stains in order to study the morphology and the acidic and neutral mucins secretion, respectively. Food was found in the gut after 3rd DAH. Mucous cells secreting acidic and neutral mucins were observed in the esophagus and their number increased with age. The stomach was lined by a mucus secreting epithelium with acidic and neutral mucins. From 11 DAH onward, tubular gastric glands with granular oxyntopeptic cells were identified in the stomach mucosa. At this time the neutral fraction of the epithelial mucins increased and their acidic fraction was reduced. At 13 DAH the mucins were exclusively neutral. The proximal segment of 3rd DAH larvae intestine forms an anterior swelling, the intestinal bulb. It is lined by enterocytes and goblet cells that produces acidic and neutral mucins. The size of the intestinal bulb decreases with time and is greatly reduced by the 16rd DAH. The distal intestinal segment is coiled and its mucosa forms several folds lined by enterocytes and goblet cells which secretes either neutral or acidic mucins. A short rectal segment is observed. The pintado larvae ingest food as early as the 3rd DAH, but its digestive system only appears to be fully prepared to efficiently process the food in the stomach after the gastric glands arise at the 13rd DAH, when this organ develops the histological features of a chemical stomach

Submitted by (lucia.rodrigues@ufrpe.br) on 2017-02-09T16:10:18Z No. of bitstreams: 1 Nivan Antonio Alves da Silva.pdf: 1743300 bytes, checksum: b072f6750488b491d2565ab1e9cc28bb (MD5) / Made available in DSpace on 2017-02-09T16:10:18Z (GMT). No. of bitstreams: 1 Nivan Antonio Alves da Silva.pdf: 1743300 bytes, checksum: b072f6750488b491d2565ab1e9cc28bb (MD5) Previous issue date: 2011-02-09 / The objective of this study was to describe the epidemiological, clinical, and ultrasound findings in 24 cattle affected with traumatic pericarditis. The epidemiological and clinical data were obtained from case histories and physical examinations. Was made the blood count and serum concentrations of total plasma protein and plasma fibrinogen. Ultrasound examination was performed in the left side over the ventral thorax and between the 4th to 8th intercostal spaces with a 3.5 MHz convex transducer. All affected animals were dairy female, mostly nursing, created semi-intensive, with a mean age of five years. The owners were main complaints of decreased appetite and milk production, being diagnosed mainly in the summer (dry season), with periods of disease ranging from one to 30 days. The main clinical findings were related to cardiovascular changes such as tachycardia, abnormalities in cardiac auscultation as muffled sounds and fluid, jugular vein distention and oedema in the submandibular region and brisket. The increase in fibrinogen and a neutrophilic leukocytosis were present in most cases. In the thoracic cavity, the ultrasound revealed distension of the pericardial sac varied by hypoechoic fluid content causing a medial displacement of the heart, fibrin deposits echogenic free fluid in the pericardial and/or adhered to the epicardium and the pericardial sac, hypoechoic pleural effusion, lung displacing dorsally, irregular structures and filaments of different echogenicity adhered to the pleura. In the abdominal cavity, the changes were located mainly in the ventral and cranial with dorsal displacement of the reticulum. Changes in the reticulum contour is characterized by the presence of masses irregular hypo-or hyperechoic, abscesses, fibrin strands, hypoechoic fluid or anaecóico latter being evidenced in cases of ascites. Reticular contractions showed disorders in the frequency, amplitude or speed being evidenced in isolation or combined. The interaction of information obtained from epidemiological, clinical and laboratory findings, coupled with the sonographic findings were sufficient for the diagnosis and prognosis of cattle suffering from traumatic pericarditis. / O objetivo deste trabalho foi descrever os achados epidemiológicos, clínicos e ultrassonográficos em 24 bovinos acometidos por reticulopericardite traumática. Os dados epidemiológicos e clínicos foram obtidos por meio das anamneses e exames físicos. Realizou-se o hemograma e dosagens das concentrações de proteína plasmática total e fibrinogênio plasmático. O exame ultrassonográfico foi realizado no antímero esquerdo sobre a região crânio ventral do tórax e do 4º ao 8º espaço intercostal com um transdutor convexo de 3,5 MHz. Todos os animais acometidos eram fêmeas leiteiras, sendo a maioria lactante, criadas semi-intensivamente, com média de idade de cinco anos. As principais queixas dos proprietários foram diminuição do apetite e produção láctea, sendo diagnosticada principalmente no verão (época seca), com período de evolução da doença variando de um até 30 dias. Os principais achados clínicos encontrados foram relacionados às alterações cardiovasculares como, taquicardia, anormalidades na ausculta cardíaca como abafamento e sons de líquidos, distensão da veia jugular e edemas na região submandibular e barbela. Os principais achados laboratoriais evidenciados foram leucocitose neutrofílica com desvio a esquerda regenerativo e hiperfibrinogenia. Na cavidade torácica, o exame ultrassonográfico revelou variada distensão do saco pericárdico por conteúdo líquido hipoecoíco levando ao deslocamento medial do coração, depósitos de fibrina ecogênicos livres no fluído pericárdico e/ou aderidos ao epicárdio e saco pericárdico, efusão pleural hipoecóica, deslocando pulmões dorsalmente, massas e filamentos de diferentes ecogênicidades aderidos à pleura. Na cavidade abdominal, as alterações se localizaram principalmente na região crânio ventral, com deslocamento dorsal do retículo. As alterações no contorno reticular se caracterizaram pela presença de massas sem contorno definido hipo ou hiperecóicas, abscessos, filamentos de fibrina, líquido hipoecóico ou anaecóico sendo este último evidenciado nos casos de ascite. As contrações reticulares apresentaram alterações quanto à frequência, amplitude ou velocidade sendo evidenciadas de forma isolada ou combinada. As informações obtidas dos dados epidemiológicos, clínicos e laboratoriais foram condizentes com a gravidade da enfermidade, contudo, os achados ultrassonográficos foram determinantes para a confirmação do diagnóstico e determinação do prognóstico dos bovinos acometidos por retículopericardite traumática.

Castro, PTO. Fatores de risco para infecção do sítio cirúrgico em cirurgias oncológicas do aparelho digestório do Hospital de Câncer de Barretos. 2009. 49 p. Dissertação (Mestrado). Faculdade de Medicina: Universidade de São Paulo, Ribeirão Preto. 2009. Infecção do sítio cirúrgico (ISC) é a infecção hospitalar (IH) de maior prevalência em pacientes cirúrgicos, determinando aumento do tempo de hospitalização, dos custos e da morbidade e letalidade. É importante conhecer os principais fatores de risco desta infecção para estabelecer medidas de prevenção através dos fatores que podem ser modificáveis. O objetivo do presente estudo foi descrever a ocorrência de ISC e estudar os seus fatores de risco em cirurgias oncológicas do aparelho digestório no Hospital de Câncer de Barretos. Indivíduos submetidos à cirurgia oncológica do aparelho digestório, no período de 01/08/2007 a 10/08/2008, foram acompanhados prospectivamente por 30 dias para diagnóstico de ISC. Simultaneamente, foram estudados possíveis fatores de risco, ligados ao paciente e ao procedimento cirúrgico. Foram avaliadas 210 cirurgias, com uma incidência global de ISC de 23,8% . As seguintes variáveis apresentaram associação independente de risco: tempo de cirurgia, tipo de cirurgia, radioterapia antes da cirurgia e tempo de experiência do cirurgião. Os fatores de risco encontrados neste estudo descrevem um grupo de indivíduos com maior risco de ISC, nos quais novos protocolos de prevenção devem ser considerados. / Castro, PTO. Risk factors for Surgical Site infection during oncology surgeries of digestive system at Barretos Cancer Hospital. 2009. 59 p. Dissertation (Master degree). School of Medicine : University of São Paulo. Ribeirão Preto. 2009. Surgical Site Infection (SSI) is the most prevalent hospital infection among surgical patients, and it increases length of stay hospitalization, higher cost and greater morbidity and mortality. It is important to know the main risk factors for such infections, in order to establish prevention measures through factors that can be modified. The objective of this study is to describe the occurrence of SSI and possible risk factors during oncology surgery of the digestive system, at Barretos Cancer Hospital. Between August 1 2007 and August 10 2008, individuals undergoing oncology surgery of the digestive system were followed up prospectively for 30 days in order to diagnose any SSI. Possible risk factors related to the patient and to surgery were studied. Two hundred ten operations were evaluated. The overall incidence of SSI was 23.8%. The following variables were independently associated with SSI: duration of surgery, type of surgery, radiotherapy prior to surgery and the surgeons length of experience. Risk factors found in this study describes a group of individuals with increased risk of ISC, in which new protocols of prevention should be considered.

Nesse projeto trabalhamos com uma β-glicosidase digestiva da larva da lagarta Spodoptera frugiperda (Sfβgli50, 50 kD - AF052729), expressa na forma de proteína recombinante em E.colli. O nosso objetivo foi estudar o papel de dois resíduos de aminoácidos envolvidos na atividade catalítica da Sfβgli50. O primeiro resíduo estudado foi o Y456, envolvido na afinidade pela porção redutora do substrato (aglicone), o segundo resíduo foi o N329 envolvido na modulação do pH ótimo. Estudo do papel do resíduo Y456 na afinidade pelo aglicone do substrato. O sítio-ativo da Sfβgli50 é formado por quatros subsítios (-1, +1, +2, e +3). O subsítio que acomoda a porção não-redutora do substrato (glicone) recebe numeração negativa (-1), já os subsítios que acomodam a porção redutora do substrato (aglicone) recebem números positivos (+1, +2 e +3). Trabalhando com duas β-glicosidases de plantas (milho e sorgo), Cicek et al. (2000) demonstraram que uma pequena porção da extremidade C-terminal destas β-glicosidases (462SSGYTERF469 - numeração da enzima do sorgo) está envolvida na especificidade pelo aglicone do substrato, sendo que muitos desses aminoácidos são conservados em outras β-glicosidases da família 1. O alinhamento das sequências destas duas enzimas com a Sfβgli50 sugere que Y456 pode fazer parte do sítio de ligação do aglicone nesta β-glicosidase de inseto. Utilizando experimentos de mutação sítio-dirigida, o Y456 foi substituído por uma alanina (mutante Y456A) sendo que este foi expresso na forma de proteína recombinante em bactérias BL21 DE3 utilizando o vetor pT7-7. O mutante Y456A foi parcialmente purificado através de uma cromatografia hidrofóbica em sistema de FPLC, e caracterizado utilizando diversos inibidores competitivos (glucono δ-lactona, celobiose, celotriose, pentilbglicosídeo e octilbtioglicosídeo). Comparando os Kis obtidos para a Sfβgli50 selvagem e mutante Y456A com os inibidores glucono δ-lactona, celobiose e celotriose, foi proposto que Y456 encontra-se no subsítio +1 do sítio ativo da Sfβgli50. Já através da comparação entre os inibidores octilβtioglicosídeo e pentilβglicosídeos constatou-se que Y456 interage com uma porção polar do aglicone do substrato, talvez através de uma ligação de hidrogênio. Baseando-se nestes Kis foi calculada a energia de associação de resíduos de glicose e grupos alquila nos subsítios +1 e +2, indicando que o subsítio +1 do mutante Y456A tem uma especificidade mais ampla frente à ligantes polares (glicose) e apolares (grupos butil) do que a enzima selvagem. Sabendo que este resultado foi obtido removendo-se um resíduo com um grupo polar na cadeia lateral (Y456), estes dados estão de acordo com a hipótese de que a especificidade dos subsítios da região de ligação do aglicone é determinada por um balanço entre resíduos polares e apolares (Marana et al., 2001). Estudo do papel do resíduo N329 na modulação do pH ótimo. O mecanismo de catálise da Sfβgli50 é dependente de dois resíduos de ácido glutâmico: um doador de prótons (E187 - pKa= 7,5) e um nucleófilo (E399 - pKa = 5,0). Sendo o pH ótimo da Sfβgli50 (6,2) uma média aritmética dos pKas destes dois resíduos catalíticos. Uma análise estrutural do sítio ativo da Sfβgli50 mostra que o resíduo N329 forma ligações de hidrogênio com o resíduo E187 (doador de prótons), talvez atuando na modulação do seu pKa. Para estudar o papel do resíduo N329 na atividade da Sfβgli50 foram construídos 3 mutantes, nos quais tal resíduo foi substituído por alanina (N329A), ácido aspártico (N329D) e uma glutamina (N329Q). Os mutantes foram expressos na forma de proteína recombinante em bactérias BL21 DE3 utilizando os vetores pT7-7 e pCal-n-Flag. Entretanto, tentativas de purificação das SfΒgli50 mutantes através de cromatografia hidrofóbica foram infrutíferas, sugerindo uma possível inativação destas enzimas. Esta hipótese foi reforçada pela purificação das Sfβgli50 mutantes e selvagem contendo o peptídeo de fusão CBP (calmodulin binding peptide) através de cromatografia de afinidade. Este experimento demonstrou que as enzimas mutantes eram de fato inativas. Frente à estes resultados não foi possível concluir a caracterização do efeito do pH na atividade catalítica das Sfβgli50 mutantes N329A, N329D e N329Q. Por fim, foi proposto que a inativação da Sfβgli50 devido à mutações na posição N329 pode resultar de uma desnaturação das enzimas mutantes ou do reposicionamento do ácido catalítico devido à perda ou alteração da interação com o resíduo 329. / In this project it was studied the role of two residues (N329 and Y456) in the catalytic activity of a digestive β-glycosidase from Spodoptera frugiperda (SfΒgli50 - AF052729). N329 is believed to modulate the enzyme pH optimum, whereas Y456 may participate in the binding of the substrate aglycone. Role of Y456 The peptide 462SSGYTERF469 of the sorghum β-glycosidase is proposed to be part of the aglycone binding site in that enzyme. Some of those residues are conserved in Sfβgli50, among them Y456. Using site-directed mutagenesis Y456 was replaced by A and this mutant (Y456A) expressed in bacteria. Following that, this mutant enzyme was partially purified using hydrophobic chromatography. Inhibition experiments showed that binding of δ-gluconolactone, which occupies subsite -1, is not affected by that mutation. In contrast, Ki values for cellobiose (that binds to subsites -1 and +1) and cellotriose (that binds to subsites -1, +1 and +2) are two-fold higher than those of wild-type enzyme, indicating that mutation Y456A decrease the interaction with these oligocellodextrins. Moreover, binding of pentyl and octylβglucosides is not affected by mutation Y456A, suggesting that Y456 interacts with aglycone polar groups. Finally, evaluation of glucose and butyl binding energies in subsite +1 revealed that mutant Y456A specificity is broader than that of wild-type enzyme. Role of N329 A structural model of Sfβgli50 active site revealed that catalytic proton donor (E187) may interact with N329. In order to study the role of this interaction in the activity of Sfβgli50, N329 was replaced by A, D and Q (mutants N329A, N329D and N329Q, respectively). These mutants were expressed as recombinant proteins in bacteria and purified through affinity chromatography, revealing that Sfβgli50 was inactivated by those mutations. It was proposed that this inactivation may be due to protein desnaturation or a wrong positioning of the catalytic proton donor.

Probiotics are viable nonpathogenic microbes that positively affect host health. Probiotics inhibit infection, activate immunity, and promote mucosal-barrier development. Many microbes have probiotic activity. Nonetheless, the selection of stable strains and their specific mechanism(s) of action are not fully elucidated. Bacteria from ‘Amabere amaruranu’ cultured milk from Kenya were isolated and identified by PCR sequence analysis of the 16S rRNA gene. Isolates were examined for stability to acid and bile, antimicrobial activity, mucin production, and degradation and sensitivity to antibiotics, hence their potential for probiotics. Lactobacillus isolates were acid unstable, bile-stable, nonmucinolytic, and presented antibacterial activity. L. rhamnosus cell fractions increased MUC4 and MUC3 expression in colon cells. Bacillus isolates were acid and bile stable, nonmucinolytic and lacked antimicrobial activity. In conclusion, Lactobacillus isolates that were nonmucinolytic, stable in bile, demonstrated antibacterial activity, sensitive to antibiotics, and stimulated increase MUC4 and MUC3 levels in colon cells could be potential probiotics.

MUCDHL est une cadhérine atypique encore peu étudiée. Les données obtenues à ce jour suggèrent que ce gène joue un rôle suppresseur de tumeurs dans l’intestin, notamment par son interaction et son effet inhibiteur sur la β-caténine, et que son expression est fréquemment diminuée dans les cancers colorectaux (CCR). Parallèlement à cette fonction anti-oncogénique, d’autres travaux ont suggéré que MUCDHL est impliquée dans la structuration de la bordure en brosse (BB) intestinale, en contribuant à la formation d’un complexe d’interaction inter-microvillositaire. Notre objectif était de déterminer la fonction et le mode d’action de MUCDHL dans le système digestif. Par la caractérisation détaillée de l’interaction avec la β-caténine, nous avons montré que le mode d’action anti-oncogénique de MUCDHL est plus complexe qu’une simple séquestration membranaire de la β-caténine. De plus, nous avons confirmé le rôle suppresseur de tumeurs de MUCDHL sur une cohorte importante de CCR humains et montré pour la première fois que sa perte amplifie la tumorigenèse intestinale dans un model murin. Par ailleurs, l’étude phénotypique des souris Mucdhl-/- a démontré son importance dans l’homéostasie du système digestif. En effet, l’absence de MUCDHL cause des altérations morphologiques de la BB intestinale, mais également de nombreuses perturbations métaboliques. Ces travaux apportent donc des informations inédites sur la fonction et le mode d’action de MUCDHL dans le système digestif. / MUCDHL is an atypical cadherin that has been poorly studied. The data obtained so far suggest that this gene has tumor suppressive activity in the intestine, namely by its interaction and inhibitory effect on β-catenin, and that its expression is frequently decreased in colorectal cancers (CCR). In parallel to this anti-oncogenic function, other studies have suggested that MUCDHL is involved in the assembly of the intestinal brush border (BB), by contributing to the formation of an inter-microvilli interaction complex. Our objective was to determine the function and mode of action of MUCDHL in the digestive system, Through a detailed characterization of the interaction with β-catenin, we showed that the anti-oncogenic mode of action of MUCDHL is more complex than a simple membrane sequestration of β-catenin. In addition, we confirmed the tumor suppressive function of MUCDHL on a very large cohort of human CCR and showed for the first time that its loss amplifies intestinal tumorigenesis in a murine model. Moreover, the study of the phenotype of Mucdhl-/- mice allowed us to demonstrate the importance of MUCDHL in the homeostasis of the digestive system. Indeed, the absence of MUCDHL causes morphological alterations of the intestinal BB, but also numerous metabolic disturbances. Thus, this work provides new information on the function and mode of action of MUCDHL in the digestive system.

Ingestion and dispersal of seeds of desirable species by domestic livestock is potentially important as a range improvement practice, but the passage of seed by livestock has only been studied in a fragmented way, particularly for species adapted to rangelands of western North America. The objectives of this research were to examine the effects of different periods of exposure to in vitro and in vivo digestion processes in cattle on the germinability of several grass species, and determine if the in vitro incubation technique is a good predictor of seed fate following passage through the ruminant digestive tract. Seeds of 13 grass species adapted to the Intermountain West were exposed to in vitro incubation for 24, 48, and 72 hours, and then tested for germination at an optimal temperature regime (10°C night/20°C day) in a controlled environment chamber. Germination responses varied considerably among grass species with changes in length of exposure to in vitro incubation, but germination decreased for incubated seed compared to untreated seed for all species. Five species with the highest germination in in vitro incubation trials were fed to Holstein steers in in vivo digestion trials. Approximately 20% of the ingested seeds were recovered for all species 6 days after feeding, and the highest recovery occurred 2 and 3 days after feeding. Germination of undamaged, recovered seeds decreased as passage time through the digestive tract increased. Of the species tested, seeds of Psathyrostachys juncea, Thinopyrum ponticum, Agropyron cristatum X A. desertorum, and Elytrigia repens X Pseudoroegneria spicata have the greatest potential to survive passage through the digestive tract and germinate in appreciable numbers. The in vitro incubation technique may be used as a crude indicator of seed fate following passage through the digestive tract.

The anticancer activity of several platinum compounds is due to the formation of complexes with DNA. We hypothesize that the size and shape of the platinum compounds would impact interaction with proteins, and these interactions may be partly responsible for the anticancer activity. Chymotrypsin and subtilisin are serine proteases that have a histidine residue in the active site. We are investigating the inhibition of the digestive enzymes chymotrypsin and subtilisin by analogs of the anticancer drug cisplatin and trying to discern trends in the inhibition as the active site residues vary. In our research, we found that the enzyme subtilisin did not show any significant inhibition with different platinum compounds we used, while chymotrypsin showed inhibition only with the potassium tetrachloroplatinate and this inhibition is concentration dependent

Bovine pancreatic ribonuclease A (RNase A, EC 3.1.27.5) has been extensively studied from the structural, mechanistic and functional points of view. Within the protein folding context, it constitutes a good model of study although a rather complicated one due to the presence in the native state of four disulphide bonds and the existence of two X-proline peptide bonds in cis conformation. Most of these studies has focused on the alteration of cysteine or proline residues to study, from a kinetic point of view, the formation of the disulphide bonds or the characterization of the species present in the heterogeneous non-reduced unfolded state, respectively. In these work we have used site-directed mutagenesis to change the characteristics of a postulated chain folding initiation site (CFIS) in RNase A / La ribonucleasa A de pàncrees boví (RNasa A, EC 3.1.27.5) ha estat extensament estudiada des de punts de vista estructurals, mecanístics i funcionals. Dins del marc del plegament proteic, la RNasa A ha estat un bon model per als estudis de plegament/desplegament proteic, malgrat que força complicat a causa de la presència en l'estat natiu de quatre enllaços disulfur i l’existència de dos enllaços peptídics X-prolina en conformació cis. La major part d'aquests estudis s'han centrat en l'alteració de residus de cisteïna o de prolina per estudiar, des d'un punt de vista cinètic, la formació dels enllaços disulfur o la caracterització de les espècies presents en l'heterogeni estat desplegat de la proteïna amb els enllaços disulfur intactes, respectivament. En aquest treball hem utilitzat la mutagènesi dirigida per oligonucleòtid per canviar les característiques d'una regió de la RNasa A postulada com a iniciadora del plegament

Objectives were to characterize residual feed intake (RFI) and determine the phenotypic correlation between performance, feed efficiency, and other biological measurements in Brahman heifers, as well as the relationship between RFI determined in confinement and measurements of grazing activity on pasture. Three separate 70 d feeding trials were performed, and RFI was determined as the residual between actual and predicted dry matter intake (DMI) for a given level of production. Brahman heifers (n = 103; 5-to-9 mo of age) were individually limit-fed a pelleted 12% CP complete ration daily in Calan gates. Weekly body weight (BW) and DMI data were collected, and predicted DMI was determined by linear regression of actual DMI on mid-test metabolic BW. Ytterbium chloride was used to evaluate digestive kinetics, and fecal samples were collected to determine fecal volatile fatty acids (VFA) concentration and determine apparent dry matter digestibility (DMD) utilizing acid insoluble ash as an internal marker. Measurements of temperament were evaluated on all heifers at weaning. High (n = 6) and low (n = 6) RFI heifers (Exp. I) grazed fescue and ryegrass to determine variation in grazing behavior, DMI, and apparent DMD. Data from all three experiments were pooled, and RFI was not correlated with average daily gain (ADG), DMI, BW, partial efficiency of gain, feed conversion ration, fecal VFA concentration, or any measures of temperament. There were no significant differences in digestive kinetics between the RFI efficiency groups. Fecal samples taken for acid detergent insoluble ash (ADIA) determination were not collected at frequent enough intervals to account for weekly variation in fecal ADIA concentration. Pasture measurements were not different between the efficiency groups for heifers evaluated for grazing behavior, as well as estimated intake as a proportion of BW, or apparent DMD. Results of this study suggest that Bos indicus cattle appear to have similar efficiency traits as Bos taurus and Bos indicus influenced cattle, making this measure of efficiency equally as valid for use in both types of cattle. This indicates that selection based on RFI can be made to increase feed efficiency without affecting ADG or BW in Brahman cattle.