Dois experimentos foram conduzidos com o objetivo de avaliar os efeitos da inclusão de óleos essenciais (OE) extraídos das folhas e dos frutos da aroeira em dietas de alto concentrado sobre o desempenho e características de carcaça de cordeiros confinados. Experimento I: Foram utilizados 44 cordeiros, 16 machos e 28 fêmeas, sendo o delineamento experimental de blocos completos casualizados, com 4 tratamentos e 11 repetições. O experimento teve a duração de 56 dias, divididos em 2 períodos de 28 dias cada. Os animais foram alimentados com as dietas experimentais compostas por 10% de volumoso (feno de coastcross) e 90% de concentrado. Os tratamentos foram definidos pela inclusão de: 8 ppm de monensina sódica (MON) e as doses 0,140% (140 OE), 0,280% (280 OE), 0,420% (420 OE) do OE das folhas de aroeira (em % na matéria seca (MS). Ao final dos 56 dias, 31 animais foram abatidos para a mensuração dos parâmetros de carcaça. Os tratamentos não afetaram (P > 0,05) o ganho de peso médio diário, consumo de matéria seca e eficiência alimentar. A infestação por coccidiose foi menor (P <0,05) no tratamento com monensina. O rendimento de carcaça fria foi maior (P < 0,05) nos animais alimentados com maiores doses de OE. Os demais parâmetros de carcaça avaliados não foram afetados pelos tratamentos (P > 0,05). As maiores doses de OE das folhas de aroeira aumentaram (P < 0,05) a porcentagem de proteína bruta e matéria mineral na composição química da carne dos cordeiros. Apesar de não alterar o desempenho dos cordeiros, a inclusão das doses mais elevadas de OE das folhas de aroeira apresentaram respostas positivas para o rendimento de carcaça fria, demonstrando o potencial de utilização desse aditivo em dietas para cordeiros confinados. Experimento II: Foram utilizados 48 cordeiros, 24 machos e 24 fêmeas, sendo o delineamento experimental de blocos completos casualizados, com 4 tratamentos e 12 repetições. O experimento teve duração de 56 dias, divididos em 2 períodos de 28 dias cada. Os animais foram alimentados com as dietas experimentais compostas por 10% de volumoso (feno de coastcross) e 90% de concentrado. Os tratamentos foram definidos pela inclusão de: 8 ppm de monensina sódica (MON) e as 11 doses 0,140% (140 OE), 0,280% (280 OE), 0,420% (420 OE) do OE dos frutos de aroeira (em % na MS). Ao final dos 56 dias, 32 animais foram abatidos para a mensuração dos parâmetros de carcaça. Não houve efeito (P > 0,05) dos tratamentos no ganho de peso médio diário, consumo de matéria seca, eficiência alimentar, coccidiose e parâmetros de carcaça. A infestação por coccidiose não interferiu (P < 0,05) no ganho médio diário e consumo de matéria seca. Os tratamentos com as maiores doses de OE dos frutos de aroeira reduziram o teor de matéria mineral da carne dos cordeiros em relação à monensina. O desempenho e os parâmetros de carcaça dos cordeiros alimentados com as dietas contendo OE dos frutos de aroeira foram semelhantes aos que receberam monensina sódica. / Two experiments were carried out to evaluate the effects of the inclusion of essential oils (EO) extracted from leaves and fruits of aroeira on performance and carcass characteristics of feedlot sheep fed high concentrate diets. Experiment I: Fourty-four lambs (16 males and 28 females) were assingned in a randomized complete block design to receive one of treatments: 8 ppm of sodium monensin (MON) and doses of 0.140% (140 EO), 0.280% (280 EO) and 0.420% (420 EO) of aroeira leaves EO (% in a DM basis). The experiment lasted 56 days, divided in 2 periods of 28 days each. The animals were fed a diet containing 10% roughage (coastsross hay) and 90% concentrate. At the end of experiment, 31 lambs were slaughtered to access the carcasses characteristics. The treatments did not affect (P > 0.05) the average daily gain, the dry matter intake and the feed efficiency. Infestation by coccidiosis was lower (P < 0.05) in the monensin treatment. Cold carcass dressing was higher (P < 0.05) for the animals fed higher doses of EO. The other carcass parameters were not affected by the treatments (P > 0.05). The higher doses of aroeira leaves EO increased (P < 0.05) the percentage of crude protein and mineral matter in the meat. Despite did not affect the lambs performance, the inclusion of aroeira leaves EO at the higher doses did present positive results for the cold carcass dressing, showing a potential of this additive in feedlot sheep diets. Experiment II: fourty-eight lambs (24 males and 24 females) were assingned in a randomized complete block design to recive one of treatments: 8 ppm of sodium monensin (MON) and doses of 0.140% (140 EO), 0.280% (280 EO) and 0.420% (420 EO) of aroeira fruits EO (% in a DM basis). The experiment lasted 56 days, divided in 2 periods of 28 days each. The animals were fed a diet containing 10% roughage (coastsross hay) and 90% concentrate. At the end of the experiment, 32 lambs were slaughtered to access the carcasses characteristics. The treatments did not affect (P > 0.05) the average daily gain, dry matter intake, feed efficiency, the coccidiosis infestation and the carcasses parameters. In addition, the infestation by coccidiosis did not interfere (P < 0.05) on average daily gain and dry matter intake. The treatments with 13 higher doses of the EO from aroeira fruits reduced the percentage of mineral matter of meat compared to monensin. The performance and carcass parameters of the lambs fed diets containing essential oils were similar to those fed monensina.

Previous work in our group has been directed towards the synthesis of crown-ethers for use in the selective complexation of metal ions and as chiral ligands for use in asymmetric catalysis. The development of a modular approach to macrocycle assembly has enabled the synthesis of a library of pyridine-based macrocycles possessing multiple donor sites where chirality was readily introduced from simple amino acids.The nucleophilic ring opening of aziridines 181, 193 or 194, allowed the highly selective synthesis of thioether-based spacers and macrocycles. Extension of this basic approach to the synthesis of seleno-crown ethers was also investigated. The use of chiral-pool starting materials derived from D- or L-alanine, provided access to optically pure macrocycles. The use of the Sharpless-Huisgen 'click' reactions allowed the attachment of a carbohydrate residue directly to a macrocycle via a triazole unit. We hope to attach a macrocycle, carbohydrate residue and azo dye together, to be able to examine further diseases such as Alzheimer's. We have so far succeeded in attaching a macrocycle and sugar to a central scaffold by performing a one-pot double 'click' reaction. The distance between the points of attachment of the chromophore to the macrocycle metal binding site is probably, in this first generation sensor, too great to enable a metal-macrocycle binding event to be reported.

Molecular recognition at biomembranes is one of the more poorly understood aspects of fundamental research in physical organic chemistry. Our aim was to improve our understanding of the molecular recognition of polysaccharides at biomembranes, in particular developing synthetic lipids that will recognise and report on the presence of glycosaminoglycans (GAG polysaccharides), like heparin and hyaluronic acid. Elevated levels of hyaluronic acid have been implicated in bladder carcinoma and osteoarthritis, and the use of heparin for medical applications is well documented. We synthesised a boronic acid capped lipid that also bore a fluorinated fluorescent reporter group, which could report on multivalent recognition events at bilayer membranes by fluorescent quenching and changes in the lateral distribution of the reporter groups. These preliminary studies showed these boronic acid capped fluorinated lipids gave a fluorescent signal upon interaction with simple mono- and poly- saccharides, albeit with unexpectedly weak binding to these saccharides. To understand and quantify the weaker binding of saccharides to membrane bound boronic acids a series of novel fluorescent and chromogenic lipids were synthesised that bore the reporter group close to the boronic acid. These studies revealed several underlying factors that had important roles in the recognition of oligosaccharides by boronic acid capped lipids. For the first time the effect of the bilayer on saccharide/boronic acid recognition was quantified, with the membrane weakening the interaction 33-fold. We were able to propose a model for the interaction of saccharides for membrane bound boronic acids that explained many of these unexpected observations.We also devised a parallel approach using GAGs to open or close synthetic membrane channels. Using a GAG to switch on the release of an ion or dye would generate a fluorescent signal that amplifies the original recognition event and improves sensitivity for GAGs. Proof-of-principle studies using palladium ions to open dye-transporting channels were successful and these studies were followed by the synthesis of boronic acid-capped cholates. Incorporation of boronic acid-capped cholates into membranes caused changes in the rate of release of alkali metal ions, which caused an enclosed fluorescent dye to give a signal, in the presence or absence of saccharides. These compounds successfully gave a response to the simple saccharide D-fructose but gave no response to other saccharides tested, including various hyaluronic acids. Although we were not able to develop a selective sensor for GAGs, we have developed a model for saccharide/boronic acid interactions that is a valuable addition to the physical organic chemistry of membranes.

Fusarium head blight is a devastating fungal disease of cereals caused by the pathogen Fusarium graminearum that leads to important economic losses due to diminished yields and grain downgrading. F. graminearum deploys several secondary metabolites known as virulence factors to facilitate its invasion of host tissues. These include the gramillins, a group of bicyclic lipopeptide ionophores that cause cell death and increased virulence in Arabidopsis, maize, and barley, but not wheat. Ionophores are involved in many plant-microbe interactions, but current knowledge of the molecular mechanisms governing host response to these molecules is limited. Susceptibility to gramillin varies among cultivars of affected species, but the basis for insensitivity has not yet been described, nor has the function of gramillin during infection. Here, we establish ion leakage as a method to survey Canadian barley for sensitivity, demonstrate that insensitivity to gramillin is likely mediated by a plant protease rather than inducible immune responses, and suggest a possible function of gramillin in positively regulating the expression of other fungal virulence factors during infection. This contributes to deepening our understanding of cyclic lipopeptide ionophores and their role during plant-microbe interactions.

Foram estudados os efeitos da flavomicina ou da monensina sobre a fermentação e digestão ruminal e total em bovinos. Doze fêmeas bovinas não gestantes e não lactantes, portadoras de fístula ruminal, pesando em média 736 kg, foram distribuídas inteiramente ao acaso em três grupos experimentais: controle (ausência de antibiótico), tratado com flavomicina (antibiótico não-ionóforo) e outro tratado com monensina (antibiótico ionóforo). Foram administradas doses de 20mg e 300mg/animal/dia, de flavomicina e monensina, respectivamente. Utilizou-se um período experimental de 21 dias, sendo os 16 primeiros destinados à adaptação dos animais à dieta, composta de 60% de concentrado (milho, farelo de soja e mistura mineral) e 40% de volumoso (basicamente de cana-de-açúcar). O 21° dia foi utilizado para avaliação do consumo de MS e colheitas de líquido ruminal, realizadas às 0; 2; 4; 6; 8; 10 e 12 horas após a primeira refeição. Os 10 últimos dias foram destinados à aplicação do marcador (15g de óxido crômico/animal/dia), e os 5 últimos, destinados à avaliação do consumo de MS, colheita de fezes, amostragem dos alimentos e também à avaliação da digestão ruminal (degradabilidade in situ), pela técnica dos sacos de nylon, incubando-se cana-de-açúcar, milho em grãos ou farelo de soja. A monensina diminuiu a proporção molar de ácido acético e aumentou a de propiônico (27,2%), em relação ao grupo controle, e aumentou a degradabilidade efetiva ruminal do amido dos grãos de milho, em relação à flavomicina. A flavomicina diminuiu a taxa de degradação da PB do farelo de soja, em relação ao controle e monensina. Nenhum dos antibióticos testados alterou a concentração total dos AGVs, ácido butírico, pH, concentração ruminal de N-NH3 ou consumo de MS. Tão pouco foram alteradas a degradabilidade efetiva da FDN da cana-de-açúcar, CMS digestível, digestibilidade da MS, PB, EE, EÑN, FB, FDA, FDN, EB, amido ou o NDT da dieta. / The effects of flavomycin or monensin on ruminal fermentation and ruminal and total digestion in bovines were investigated. Twelve non-pregnant and non-lactating rumen-fistulated cows (736 kg of BW) were randomly assigned to three treatment groups: control (no antibiotic), flavomycin-treated (non-ionophore antibiotic) and monensin-treated (ionophore antibiotic). Treatment doses were 20 and 300mg/animal/day of flavomycin and monensin, respectively. Twenty-one day subperiod was used, the first sixteen for diet adaptation. Diet was composed by 60% concentrate (corn, soybean meal and mineral mixture) and 40% roughage (basically sugar cane). The 21st day was used for the evaluation of DMI and for ruminal fluid sampling at 0, 2, 4, 6, 8, 10 and 12 hours after the first meal. The last 10 days were used for external marker administration (15g of chromic oxide/ animal/day), and the last 5 days, for DMI evaluation, feces collection, feed sampling and evaluation of ruminal degradability using the nylon bag technique. Bags containing corn grain, soybean meal or sugar cane were incubated through the rumen fistula from the 17th up to the 21st day. Monensin decreased the molar proportion of acetic acid and increased the propionic acid in 27.2%, compared to control group and increased the effective degradability of corn grain starch, compared to flavomycin. Flavomycin decreased the degradation rate of soybean meal crude protein compared to control and monensin groups. Total VFA concentrations, molar proportion of butyric acid, pH, ammoniacal-N concentration or DMI were not influenced by the addition of either antibiotics; neither were the effective degradability of sugar cane NDF, digestible DMI or DM, CP, EE, NFE, CF, ADF, NDF, GE and starch digestibility nor the TDN of the diet.

Foram estudados os efeitos da flavomicina ou da monensina sobre a fermentação e digestão ruminal e total em bovinos. Doze fêmeas bovinas não gestantes e não lactantes, portadoras de fístula ruminal, pesando em média 736 kg, foram distribuídas inteiramente ao acaso em três grupos experimentais: controle (ausência de antibiótico), tratado com flavomicina (antibiótico não-ionóforo) e outro tratado com monensina (antibiótico ionóforo). Foram administradas doses de 20mg e 300mg/animal/dia, de flavomicina e monensina, respectivamente. Utilizou-se um período experimental de 21 dias, sendo os 16 primeiros destinados à adaptação dos animais à dieta, composta de 60% de concentrado (milho, farelo de soja e mistura mineral) e 40% de volumoso (basicamente de cana-de-açúcar). O 21° dia foi utilizado para avaliação do consumo de MS e colheitas de líquido ruminal, realizadas às 0; 2; 4; 6; 8; 10 e 12 horas após a primeira refeição. Os 10 últimos dias foram destinados à aplicação do marcador (15g de óxido crômico/animal/dia), e os 5 últimos, destinados à avaliação do consumo de MS, colheita de fezes, amostragem dos alimentos e também à avaliação da digestão ruminal (degradabilidade in situ), pela técnica dos sacos de nylon, incubando-se cana-de-açúcar, milho em grãos ou farelo de soja. A monensina diminuiu a proporção molar de ácido acético e aumentou a de propiônico (27,2%), em relação ao grupo controle, e aumentou a degradabilidade efetiva ruminal do amido dos grãos de milho, em relação à flavomicina. A flavomicina diminuiu a taxa de degradação da PB do farelo de soja, em relação ao controle e monensina. Nenhum dos antibióticos testados alterou a concentração total dos AGVs, ácido butírico, pH, concentração ruminal de N-NH3 ou consumo de MS. Tão pouco foram alteradas a degradabilidade efetiva da FDN da cana-de-açúcar, CMS digestível, digestibilidade da MS, PB, EE, EÑN, FB, FDA, FDN, EB, amido ou o NDT da dieta. / The effects of flavomycin or monensin on ruminal fermentation and ruminal and total digestion in bovines were investigated. Twelve non-pregnant and non-lactating rumen-fistulated cows (736 kg of BW) were randomly assigned to three treatment groups: control (no antibiotic), flavomycin-treated (non-ionophore antibiotic) and monensin-treated (ionophore antibiotic). Treatment doses were 20 and 300mg/animal/day of flavomycin and monensin, respectively. Twenty-one day subperiod was used, the first sixteen for diet adaptation. Diet was composed by 60% concentrate (corn, soybean meal and mineral mixture) and 40% roughage (basically sugar cane). The 21st day was used for the evaluation of DMI and for ruminal fluid sampling at 0, 2, 4, 6, 8, 10 and 12 hours after the first meal. The last 10 days were used for external marker administration (15g of chromic oxide/ animal/day), and the last 5 days, for DMI evaluation, feces collection, feed sampling and evaluation of ruminal degradability using the nylon bag technique. Bags containing corn grain, soybean meal or sugar cane were incubated through the rumen fistula from the 17th up to the 21st day. Monensin decreased the molar proportion of acetic acid and increased the propionic acid in 27.2%, compared to control group and increased the effective degradability of corn grain starch, compared to flavomycin. Flavomycin decreased the degradation rate of soybean meal crude protein compared to control and monensin groups. Total VFA concentrations, molar proportion of butyric acid, pH, ammoniacal-N concentration or DMI were not influenced by the addition of either antibiotics; neither were the effective degradability of sugar cane NDF, digestible DMI or DM, CP, EE, NFE, CF, ADF, NDF, GE and starch digestibility nor the TDN of the diet.

Die vorliegende Arbeit befasst sich mit der Synthese und Charakterisierung von amid- und esterfunktionalisierten Aminen. Dabei steht vor allem die Verwendung dieser Verbindungsklasse als Ionophore in der chemischen Sensorik im Vordergrund. Durch geeignete Voruntersuchungen, wie die Bestimmung der Lipophilie und UV/Vis-Spektroskopie, war es möglich, eine Selektion der Vielzahl von synthetisierten Ionophoren durchzuführen. Dennoch war es nur durch systematische Untersuchungen erreichbar, die für den Einsatz in der ISE am besten geeigneten Ionophore zu bestimmen. Die Anwendung als Katalysatorträgermoleküle für die Suzuki-Miyaura-Reaktion wurde nur von den ferrocenfunktionalisierten Molekülen in Betracht gezogen. Diese wurden an Palladiumallylchlorid koordiniert und auf ihr katalytisches Verhalten untersucht. Es konnte gezeigt werden, dass mit Zunahme der funktionellen Endgruppen im Molekül ein negativer dendritischer Effekt auftritt.

L’ionomycine est un ionophore produit par la bactérie gram-positive streptomyces conglobatus. Sa synthèse représente un défi, car il possède plusieurs centres chiraux dans un motif polypropylène. De plus, la grande densité d’oxygène sur celui-ci oblige l’utilisation de plusieurs protections orthogonales. Notre stratégie divise l’ionomycine en quatre fragments, trois possédant le motif polypropylène, ainsi qu’un quatrième, bis-tétrahydrofuranne. Les trois premiers sont synthétisés en utilisant une méthodologie puissante développée dans le laboratoire du Pr Spino, qui utilise l’addition d’alkylcyanocuprates sur les carbonates allyliques dérivés de la menthone. Celle-ci permet l’introduction d’une unité propylène, avec un excellent contrôle du centre chiral introduit. Cette méthode est utilisée de manière itérative, afin d’introduire plusieurs unités propylènes. De plus, notre stratégie est hautement convergente, puisque des intermédiaires des fragments plus courts servent de produit de départ pour la synthèse des fragments plus longs. Le dernier fragment, bis-tétrahydrofuranne, a été fabriqué à partir de l’acétate de géranyle, par une polycyclisation d’un diépoxyde chiral, les époxydes ayant été introduits par une époxydation de Shi. Cette synthèse, si complétée, serait la plus courte publiée, avec 24 étapes pour la séquence linéaire la plus longue (51 au total).

Foram realizados dois experimentos para comparar os efeitos da Monensina (MON, DSM Nutritional Products Ltd.), uma mistura de óleos funcionais (OF; Crina® Ruminants, DSM Nutritional Products Ltd.) isoladamente ou associado com enzima amilolítica (OFA; Crina- Ronozyme Rumistar™) em dietas de vacas em lactação. No experimento 1, oito vacas holandesas multíparas (576 ± 100 Kg peso corporal, e 146,5 ± 35,1 dias em lactação e 35.1 ± 4,0 kg/d de produção de leite no início do experimento) canuladas no rúmen foram distribuídas em quadrado latino replicado com períodos experimentais de 21 dias para determinar os efeitos da MON, OF e OFA sobre a digestibilidade dos nutrientes, fermentação ruminal, síntese de proteína microbiana, metabolitos sanguíneos, produção e composição do leite, utilização de energia e nitrogênio de vacas em lactação. Os tratamentos nos experimentos foram: controle (CON), sem aditivo; monensina (MON), adição de 13mg/Kg MS de monensina; óleos funcionais (OF), fornecimento de 44 mg Crina/Kg MS e óleos funcionais associado a enzima amilolítica (OFA), adição de 44 mg Crina/Kg e 330 KNU de enzima com atividade amilolítica por Kg de MS. Os dados foram analisados através de contrastes ortogonais para avaliar o efeito de aditivos (C1), comparar ionóforo com óleos funcionais (C2) e óleos funcionais isolados ou combinados com enzima amilolítica (C3). Embora não tenha sido encontrado efeito sobre a ingestão de nutrientes, os aditivos tenderam a aumentar (P=0,058) a digestibilidade da proteína bruta. No entanto, MON tendeu a aumentar (P=0,085) a digestibilidade da fibra em detergente neutro em comparação a OF e OFA. Os aditivos diminuíram (P=0,026) a concentração de nitrogênio amoniacal (NH3-N) no rúmen, notadamente a MON e OFA. Os tratamentos contendo OF apresentaram menor pH (P=0,017) e maior NH3-N no rúmen (P=0,004). Não foram encontradas diferenças na produção e composição do leite, mas o fornecimento de aditivos melhorou a eficiência produtiva (P= 0,004). No experimento 2, trinta vacas multíparas da raça holandesa (574±68 Kg peso corporal, 30.9±4,1 Kg/dia de produção de leite e 152,2 ± 54,1 dias em lactação no início do experimento) foram distribuídas em um delineamento em blocos ao acaso em três tratamentos: MON, OF e OFA, previamente descrito no experimento 1. Os tratamentos foram proporcionados ao longo de 9 semanas. Contrates ortogonais foram utilizados para comparar MON com óleos funcionais isolados ou com amilase. Não foram observadas diferenças na ingestão de nutrientes e digestibilidade quando comparado MON com os tratamentos com OF. No entanto, tratamentos contendo óleos funcionais tendem a aumentar (P=0,062) a ingestão de MS das vacas. Não foi observado efeito de interação tempo tratamento. Os tratamentos contendo óleos funcionais apresentaram menor teor de lactose e proteína no leite (P≤0.039) em comparação a MON. Concluindo, todos os aditivos tiveram pequeno efeito sobre a digestibilidade e ingestão de nutrientes, sem alterar a produção de leite das vacas. Contudo, os aditivos diminuíram a concentração de amônia ruminal, em especial a MON. Não foi encontrado efeito sinérgico quando se combinou óleos funcionais com enzima amilolítica. / Two experiments were carried out to compare the effects of monensin (MON, DSM Nutritional Products Ltd.,), a blend of functional oils (FO; Crina® Ruminants, DSM Nutritional Products Ltd.) alone or associated with amylolytic enzyme (FOA; Crina- Ronozyme Rumistar™) in a dairy cow diet. In experiment 1, eight multiparous Holstein cows (576±100 kg LW, 146±35 DIM, and 35.1±4.0 kg/d milk yield at the start of experiment, cannulated in the rumen were assigned into a replicated Latin square experiment design with 21-d periods in order to determine the effects of MON, FO or FOA on nutrient digestibility, ruminal fermentation, microbial protein synthesis, blood metabolites, milk yield and composition, energy and nitrogen utilization of dairy cows. Treatments in experiments were: control (CON), with no additive; MON, addition of 13 mg monensin/kg diet DM; FO, provision of 44 mg Crina/kg diet DM and FOA, addition of 44 mg Crina and 330 KNU of enzyme with amylolytic activity per kg diet DM. Data were analyzed through orthogonal contrasts to evaluate the effect of additives (C1), compare ionophore with functional oils (C2), and contrast functional oils alone or with amylolytic enzyme (C3). Although no effects were found on nutrient intake, additives tended to increase (P=0.058) crude protein digestibility. Yet, MON tended to increase (P=0.085) neutral detergent fiber digestibility in comparison with FO and FOA. Additives decreased (P=0.026) ammonia nitrogen concentration (NH3-N) in rumen, notably due to MON and FOA. Treatments containing FO showed lower (P=0.017) pH and higher (P=0.004) NH3-N in rumen. No differences were found on milk yield and composition, but the provision of additives improved (P=0.04) productive efficiency (kg milk ÷ kg DM intake) of cows. In experiment 2, thirty multiparous Holstein cows (574±68 kg LW, 152,2±54,1 DIM and 30.9±4.1 kg/d milk yield at the start of experiment) were assigned to a randomized block design experiment and distributed to three treatments: MON, FO or FOA, as previously described in Experiment 1. Treatments were provided throughout 9 weeks. Orthogonal contrasts were also used to compare MON with functional oils (C1) and essential oils alone or with amylase(C2). No differences were detected on nutrient intake and digestibility when comparing MON with FO-treatments. However, treatments containing functional oils tended to increase (P=0,062) DM intake of cows. No treatment by time interaction effect was observed. Treatments containing functional oils had lower (P≤0.039) lactose and protein content in milk than MON. In conclusion, all additives had small effect on nutrient intake and digestibility, without altering milk production of cows. Nonetheless, feed additives decreased ammonia concentration in rumen notably because of MON. No synergetic effect was found when combining FO with amylolytic enzyme.

A avicultura de corte brasileira tem apresentado elevados índices de crescimento. No intuito de garantir uma maior eficiência da produção de aves, medicamentos veterinários são administrados para tratamento e prevenção de doenças. A coccidiose é uma dessas doenças, a qual é causada por várias espécies do protozoário do gênero Eimeria. Os poliéteres ionóforos são antibióticos largamente administrados no controle desses microrganismos. No entanto, a administração contínua de doses subterapêuticas dessa classe de fármacos pode acarretar no acúmulo de resíduos nos tecidos dos frangos de corte. No intuito de garantir a segurança dos consumidores, são definidos Limites Máximos de Resíduos (LMRs) por órgãos internacionais como: Food and Drug Administration (FDA), Commission Regulation, Codex Alimentarius; e nacionais como Ministério da Agricultura Pecuária e Abastecimento (MAPA). Dessa forma, este estudo teve por objetivo o desenvolvimento, validação e aplicação de um método para determinação em peito de frango de resíduos de Lasalocida (LAS), Monensina (MON), Salinomicina (SAL) e Narasina (NAR) por cromatografia líquida acoplada a espectrometria de massas sequencial com ionização por eletrospray (LC-ESI-MS/MS). Nigericina (NIG) foi utilizada como padrão interno do método analítico. As amostras foram liofilizadas, trituradas e tamisadas, sendo utilizadas no método amostras com tamanho de partículas entre 125 ?m e 250 ?m. Os resíduos foram extraídos com metanol e uma alíquota do extrato foi evaporada e reconstituída para análise em LC-ESI-MS/MS no modo positivo de monitoramento de reação selecionada (SRM). A etapa de clean up foi realizada por meio de filtração do extrato em membrana de PTFE 0,22 ?m. O método apresentou-se linear no intervalo de concentração de 0,0 a 40,0 ?g kg-1 para LAS, de 0,0 a 20,0 ?g kg-1 para MON, de 0,0 a 200,0 ?g kg-1 para SAL e de 0,0 a 30,0 ?g kg-1 para NAR. Para todos os antibióticos o coeficiente de correlação linear (r) esteve de acordo com as diretrizes para métodos bioanalíticos (r >= 0,98). A repetitividade foi avaliada em três concentrações de fortificação para cada antibiótico ionóforo, sendo realizada em três dias consecutivos. Foi obtida boa reprodutibilidade intralaboratorial, com coeficiente de variação (CV) de 4,5% para NAR (22,5 ?g kg-1) e 15,2% para LAS (10,0 ?g kg-1). A recuperação ficou acima de 90,0% para todos os antibióticos, sendo de 91,5% para LAS (10,0 ?g kg-1) e 99,1% para MON (15 ?g kg-1). Valores satisfatórios para o limite de decisão (CC?) e capacidade de detecção (CC?) foram obtidos, sendo CC? de 11,8 ?g kg-1 e 115,2 ?g kg-1 para MON e SAL, respectivamente, e CC? de 13,6 ?g kg-1 e 130,3 ?g kg-1 para os mesmos antibióticos. Os limites de detecção (LD) e os limites de quantificação (LQ) foram determinados a partir de dados da curva de calibração. Todos os antibióticos apresentaram LQ inferior ao seu respectivo LMR. O método foi aplicado em 18 amostras disponíveis comercialmente em Ribeirão Preto, SP. De todas as amostras analisadas apenas uma apresentou resíduo de NAR com concentração acima do seu respectivo LD. / The Brazilian poultry industry has shown high rates of growth. In order to ensure greater efficiency of poultry production, veterinary drugs are administered for the treatment and prevention of diseases. Coccidiosis is one of those diseases, which is caused by various species of protozoa of the genus Eimeria. Polyether ionophore antibiotics are widely administered to control these microorganisms. Continuous administration of subtherapeutic doses of this class of drugs may result in the accumulation of residues at low concentration levels in the tissues of broiler. In order to ensure consumer safety, are set Maximum Residue Limits (MRLs) by international organizations such as Food and Drug Administration (FDA), Commission Regulation (EU), Codex Alimentarius; and national such as Ministério da Agricultura e Pecuária (MAPA). Thus, this study aimed to develop, validate and apply a simple method for determination of residues of Lasalocid (LAS), Monensin (MON), Salinomycin (SAL) and Narasin (NAR) in chicken meat by liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). Nigericin (NIG) was used as qualitative internal standard. Samples were lyophilized, powdered and sieved. Particles size between 125 ?m and 250 ?m were used. Residues were extracted with methanol and aliquots of the extracts were evaporated and reconstituted for injection in the LC-ESI-MS/MS operated in positive selected reaction monitoring (SRM). From the molecular ion were obtained two fragment ions and that of higher relative abundance was used in quantification process. Clean-up step was performed by filtration on 0.22 ?m PTFE membrane. In the validation process, this method showed linearity over the concentration range from 0.0 to 40.0 ?g kg-1 for LAS; 0.0 to 20.0 ?g kg-1 for MON; 0.0 to 200.0 ?g kg-1 for SAL and 0.0 to 30.0 ?g kg-1 for NAR. For all antibiotics the coefficient of linear correlation (r) was in accordance with the guidelines for bioanalytical methods (r >= 0.99). The intra-day precision was evaluated at three spiked concentrations for each ionophore antibiotic and was determined in three consecutive days. Good inter-day precision was obtained, with relative standard deviations from 4.5% for NAR (22.5 ?g kg-1) and 15.2% for LAS (10.0 ?g kg-1). For all antibiotics recovery above 90.0% was obtained, which were 91.5% for LAS (10.0 ?g kg-1) and 99.1% for MON (15.0 ?g kg-1). Satisfactory results of decision limit (CC?) and detection capability (CC?) were determined, which were CC? 11.8 ?g kg-1 and 115.2 ?g kg-1 for MON and SAL, respectively; CC? 13.6 ?g kg-1 and 130.3 ?g kg-1 for the same drugs. The limit of detection (LD) and limit of quantification (LQ) were determined from data of the calibration curve. All the LQs were remarkably below the MLRs for each antibiotic. The method was applied to 18 samples acquired in Ribeirão Preto, SP. Of all analyzed samples only one exhibited traces of NAR with concentration above its respective LD. Thus, the proposed method can be applied in routine analysis on samples of commercial chicken meat.