Objetivou-se estudar a substituição do milho por polpa cítrica peletizada no concentrado de vacas leiteiras em lactação, durante a estação chuvosa do ano, em pastejo de capim-elefante. Os trabalhos foram conduzidos no Departamento de Zootecnia da ESALQ/USP. O delineamento estatístico foi em Quadrado Latino 4 x 4, analisados utilizando-se o Proc GLM (SAS, 1999). Foi utilizada uma área de 7,8 ha de pastagem dividida em 39 piquetes de 0,2 ha cada, adubada com 80 kg N ha mês-1. Experimento I: Foram utilizadas oito vacas Holandesas com média de 82 dias de lactação e 522,9 kg de PV, no início do período experimental. Os tratamentos continham as seguintes proporções de milho e polpa cítrica: 100:0 (T0); 75:25 (T25); 50:50 (T50); 25:75 (T75). As vacas receberam 7,00 kg de concentrado dia-1 (6,3 kg MS), fracionado em duas vezes ao dia. A pastagem foi adubada com 80 kg N ha.mês-1. Não houve diferença (P>0,05) no tempo de pastejo (7h22’), ruminação (8h36’), ócio (5h56’) e taxa de bocados (34,4 movimentos min-1). A temperatura retal (38,74 e 39,64ºC) e freqüência respiratória (47,44 e 61,20 movimentos min-1), mensuradas as 8:00 e as 15:30 horas, respectivamente, não foram afetadas pelos tratamentos (P>0,05). Não houve diferença (P>0,05) na produção de leite corrigida para 3,5% de gordura (18,5 kg vaca dia-1), percentagens de gordura (3,5%), proteína (3,06%), lactose (4,40%), sólidos totais (13,02%), N-uréico (15,01 mg dL-1) e contagem de células somáticas (203.000 mL-1). O peso vivo (536,8 kg), condição corporal (2,51), glicose plasmática (75,90 mg dL-1), N-uréico plasmático (16,96 mg dL-1) e ácidos graxos livres no plasma (456,12 mEq L-1) também não foram afetados pelos tratamentos (P>0,05). Experimento II: Foram utilizadas 11 vacas (7 Holandesas e 4 Jersey), com 427,5 kg de PV e 153,22 dias de lactação, no início do período experimental. Os concentrados continham 21,8% de PB e as respectivas proporções de milho e polpa cítrica: 100:0 (T0); 75:25 (T25); 50:50 (T50); 25:75 (T75). As vacas receberam 6,1 kg de concentrado dia-1 (5,5 kg de MS), fracionado em duas vezes ao dia, fornecido após cada ordenha. A pastagem era adubada com 80 kg N ha mês-1. Não houve diferença (P>0,05) na produção de leite corrigida para 3,5% de gordura (13,7 kg vaca dia-1), percentagens de gordura (3,8%), proteína (3,37%), sólidos totais (13,27%), N uréico (14,34 mg dL-1) e contagem de células somáticas (140.450 mL-1). A percentagem de lactose foi diferente (P<0,05) para a maior dose de substituição. O peso vivo (427,2 kg), condição corporal (2,74), glicose plasmática (74,63 mg dL-1), N uréico plasmático (16,74 mg dL-1), e ácidos graxos livres no plasma (417,81 mEq L-1) não foram afetados pelos tratamentos (P>0,05). Não houve diferença (P>0,05) no tempo de pastejo (7h51’), ruminação (7h59’), ócio (6h) e taxa de bocados (37,91 movimentos min-1). A Temperatura retal (38,76 e 39,61ºC) e freqüência respiratória (53,57 e 71,50 movimentos min-1), mensuradas às 8:00 e às 15:30 horas, respectivamente, não foram afetadas pelos tratamentos (P>0,05). O milho pode ser substituído pela polpa cítrica sem depreciar a produção e composição do leite. / Two experiments were conducted to study the partial substitution of fine ground corn by peleted pulp citric in the concentrate of lactating cows in middle lactation (Experiment I) and in late lactation (Experiment II), grazing elephant - grass pasture. The trials were conducted at the Animal Science Department of ESALQ/USP. In both experiments, the animals were grouped according to milk yield, days in milk and parturition order. The statistical designs were repeated 4 x 4 Latin Square. The data were analysed using the Proc GLM of SAS (1999). Experiment I: Eight Holstein cows (82 DIM and 522.9 kg LBW), at the beginning of the trial were used. The concentrates contained the following corn:peleted citrus pulp proportions: 100:0 (T0); 75:25 (T25); 50:50 (T50); 25:75 (T75). The cows received 7 kg of concentrate day-1 (6.3 kg of DM), fractionated in 2 daily meals. The pasture was fertilized with 80 kg N ha.month-1. The forage offer was of 33,6 kg DM of green leaves cow day-1. There was not difference (P>0.05) in the grazing time (7h22’), rumination time (8h36’), leisure time (5h56’) and biting rate (34.4 movements min-1). The rectal temperature (38.74 and 39.64ºC) and respiratory frequency (47.44 and 61.20 movements min-1), measured at 8:00 AM and at 3:30 PM, respectively, were not affected by treatments (P>0.05). There was not difference (P>0.05) in 3.5 % FCM yield (18.5 kg cow day-1), in the contents of milk fat (3.5%), protein (3.06%), lactose (4.40%) and total solids (13.02%), milk urea-N (15.01 mg dL-1) and of somatic cells (203.000 mL-1) were not affected by treatments (P>0.05). The LBW (536.8 kg), BCS (2.51), plasma glucose (75.90 mg dL-1), plasma urea-N (16.96 mg dL-1) and plasma free fat acids (456.12 mEq L-1) were not affected by treatments (P>0.05). Experiment II: Eleven cows were used, 7 Holstein and 4 Jersey (427.5 kg LBW and 153.22 DIM), at the beginning of the trial. The concentrates were 21.8% of CP (DM bases), and the respective corn:peleted citric pulp ratio were: 100:0 (T0); 75:25 (T25); 50:50 (T50); 25:75 (T75). The cows were fed 6.1 kg day-1 of concentrate (5.5 kg of DM), fractionated in 2 daily meals, after each milking. There was not difference (P>0.05) in 3.5 FCM yield (13.7 kg cow day-1), in the content of milk fat (3.8%), protein (3.37%) and total solids (13.27%), milk urea-N (14.34 mg dL-1) and somatic cells (140,450 mL-1). The lactose content was lower (P<0.05) for the 25:75 diet. The LBW (427.2 kg), BCS (2.74), plasma glucose (74.63 mg dL-1), plasma urea-N (16.74 mg dL-1), and plasma free fat acids (417.81 mEq L-1) were not affected by treatments (P>0.05). There were no difference (P>0.05) in the grazing time (7h51’), rumination time (7h59’), leisure time (6h) and biting rate (37.91 movements min-1). The rectal temperature (38.76 and 39.61ºC) and respiratory frequency (53.57 and 71.50 movements min-1), measured at 8:00 and at 15:30 hours, respectively, were not affected by treatments (P>0.05). The corn can be substituted by the citric pulp without depreciating the milk yield and content.

Thèse (M.A.)--Université Laval, 2000. / Comprend des réf. bibliogr.

The novel hypothesis that antimicrobial growth promoters (AGP) function by modulating the mammalian immune system was tested. Sampling methods to characterize the mucosa-associated microbiota of the murine intestine by terminal restriction fragment length polymorphism (T-RFLP) analysis indicated that direct plug extraction was superior to wash methods. Using T-RFLP analysis, non-therapeutic administration of chlortetracycline (CTC) and sulfamethazine to beef cattle did not affect the composition of bacterial communities associated with intestinal mucosa and in digesta, with exception of those associated with mucosa of the proximal jejunum. Similarly, oral administration of non-therapeutic concentrations of CTC did not affect the mucosa-associated microbiota of the murine intestine. Oral administration of nontherapeutic concentrations of CTC prevented weight loss, reduced pathologic changes, modulated transcription levels of inflammatory cytokines in C. rodentium-infected mice, and did not consistently affect the colonic microbiota. These findings support the hypothesis that AGP primarily function by modulating the intestinal immune system. / xiv, 160 leaves ; 29 cm

The use of veterinary drugs continues to be a challenge since some farmers use drugs for medicinal purposes, while others use them as growth promoters without observing the set withdrawal times. In emerging economies, challenges are experienced in residue testing to ensure residue free animal products. It is therefore necessary to develop a simple, environmentally friendly and cost effective extraction method for veterinary drugs residues. A dispersive liquid-liquid micro-extraction method for simultaneous determination of chloramphenicol, florfenicol and thiamphenicol residues in water, bovine muscle and milk was developed optimised and validated. Analysis was performed with liquid chromatography coupled to electron spray ionization tandem mass spectrometry in negative ion multiple reaction monitoring mode. Dispersive liquid-liquid micro-extraction method development involved optimisation of parameters such as type and volume of extraction solvent, type and volume of disperser solvent and pH. The optimum extraction solvent was dichloromethane at a volume of 250 μL while the optimum disperser solvent was acetonitrile (1 mL) Extraction was found to be optimum at pH 7. The developed method was validated according to Commission decision 2002/657/EC. Linearity. Linearity was observed for water, bovine milk and muscle in the ranges of 0.3 μg kg-1 to 0.9 μg kg-1, 25 μg kg-1 to 100 μg kg-1 and 50 μg kg-1 to 200 μg kg-1 for chloramphenicol, thiamphenicol and florfenicol respectively with regression coefficients ranging between 0.9941 and 0.9999. Limit of detections for CAP, FFC & THAP were 0.082, 3.31, and 2.21 μg kg-1 respectively while Limit of quantifications were 0.163, 7.51 and 6.84 μg kg-1 respectively. The recoveries for water, bovine milk and bovine muscle ranged between 87.2% and 102%. In this study the validated dispersive liquid-liquid micro-extraction has been found to perform very well not only in the water matrix but also in the more complex matrices like bovine milk and muscle. / Chemistry / M. Sc. (Chemistry)

In the Czech Republic the food production is one of the most important branches of processing industry. The effort of producers, distributors and inspecting authorities is to limit the production of insanitary products as much as possible. That?s why there are a lot of inspecting mechanisms within the Czech Republic and also within the whole European Union. Their major aim is to reveal these insanitary and deceptively marked products and withdraw them from circulation. The requirements for marking of products aren?t simply and completely clearly defined even today, after the progressive harmonization with the prescriptions of the European Union. Concrete requirements for marking of foodstuff can be found in the Food Act No. 110/1997 Coll. and its implementing decrees including a special decree about the forms of marking of foodstuff No. 113/2005 Coll. Specific demands for marking of individual groups of products are given in decrees for particular commodities. It isn?t easy to draw up a comprehensive picture of all requirements for marking of a concrete product. In order to use the text on the cover, the consumer needs to know what?s hiding under certain words and what do the individual marks on the cover mean. The aim of the diploma thesis was to judge the compliance of legislation for marking of selected food products ? meat products, dairy products, spices and spice mixtures. The acquired information have been compared with a questionnaire research among consumers. It was an important finding that almost three quarters of respondents never had to reclaim a deceptively marked product. Unfortunately, 26.25 % of respondents met a deceptively marked product and that?s why they reclaimed it. In most cases the claim has been delt by repaying or exchange of goods; unfortunately, the claim of 9.5 % respondents hasn?t been accepted.

Made available in DSpace on 2014-06-11T19:24:46Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-12-07Bitstream added on 2014-06-13T19:52:28Z : No. of bitstreams: 1 lourenco_atc_me_sjrp.pdf: 715101 bytes, checksum: f6eda809d57aeb01f984d341986bcc68 (MD5) / Ministerio de Asuntos Exteriores Y de Cooperacion / A bovinocultura de corte apresenta importância e crescimento de destaque no agronegócio brasileiro, liderando desde 2004 as exportações mundiais de carne bovina. Algumas áreas podem e devem evoluir para que o Brasil se consolide como sinônimo de carne bovina segura, de alta qualidade e com produtos de alto valor agregado. Neste sentido, este trabalho propôs avaliar o uso do ultrassom de alta intensidade para reduzir a carga microbiana em derivado de carne bovina sem o uso de temperaturas extremas, necessárias no tratamento térmico convencional. Considerando que a tecnologia de ultrassom disponível está relativamente bem adaptada para alimentos fluidos, estudou-se o efeito letal do ultrassom de alta intensidade sob pressão (manossonicação – MS) e em combinação com temperatura e pressão (manotermossonicação - MTS) na redução de Listeria monocytogenes em extrato de carne bovina diluído. Os tratamentos variaram quanto à amplitude da onda gerada com intensidades de potência transferida ao meio variando entre 92 e 240 W (ou 4 W/ml e 10,4 W/ml), pressão entre 1,0 a 4,0 bar e temperatura entre 40 a 60 o C. Os resultados foram expressos em função do tempo para a redução de um ciclo logarítmico ou 90% da população inicial de microrganismos (valor D). Os tratamentos proporcionaram até 4 ciclos de redução logarítmica da Listeria monocytogenes no extrato de carne bovina. Os menores tempos de redução logarítmica obtidos foram D MS de 1,12 minutos, determinado a 240 W (10,4 W/ml) e 3,5 bar, e DMTS de 0,16 minutos a 162 W, 2,5 bar e 60ºC. A manotermossonicação mostrou forte influência da temperatura do tratamento, com 2 ciclos de redução logarítmica em 5 minutos a 40 o C e 4 ciclos em 40 segundos a 60 o C, demonstrando um efeito sinérgico significativo ao redor de 60% entre... / The beef cattle industry is an important sector of economic growth on Brazilian agribusiness, leading, since 2004, the world beef exports. Some areas can and should evolve to consolidate Brazil as a synonym of high quality safe beef and high value-added products. This research project proposed to evaluate the use of ultrasound to reduce microbial load on a beef by-product without the use of extreme temperatures, usually required in conventional thermal treatments. Considering that the ultrasound technology is relatively well adapted to fluid foods, the lethal effect of high intensity ultrasound under pressure (manosonication - MS) and temperature (manothermosonication - MTS) was investigated to reduce Listeria monocytogenes in diluted beef extract. The intensities of the treatments varied according to the amplitude of wave generated, at power level of energy transferred to the medium varying from 92 W and 240 W (or 4 W/ml and 10.4 W/ml), pressure from 1.0 to 4.0 bar, and in the temperature range of 40 to 60 o C. The results were expressed in terms of the time required for one log cycle reduction or 90% of the initial microorganism population reduction (D-value). The treatments resulted up to 4 log-cycles reduction of Listeria monocytogenes in beef extract. The shortest logarithmic reduction times obtained were DMS of 1.12 minutes, determined at 240 W (10.4 W/ml) at 3.5 bar, and a DMTS of 0.16 minutes at 162 W, 2.5 bar and 60ºC. The manothermosonication showed a strong influence of treatment temperature, with a 2-log cycle reduction in 5 minutes at 40 o C, and a 4-log cycle reduction in 40 seconds at 60 o C demonstrating a significant synergic effect around 60% between 50 o C and 60 o C. Within the experimental operational conditions used, the manosonication and manothermosonication showed to be effective... (Complete abstract click electronic access below)

Orientador: Roger Darros-Barbosa / Banca: José Antonio Gomes Vieira / Banca: Ricardo Tokio Higuti / Resumo: A bovinocultura de corte apresenta importância e crescimento de destaque no agronegócio brasileiro, liderando desde 2004 as exportações mundiais de carne bovina. Algumas áreas podem e devem evoluir para que o Brasil se consolide como sinônimo de carne bovina segura, de alta qualidade e com produtos de alto valor agregado. Neste sentido, este trabalho propôs avaliar o uso do ultrassom de alta intensidade para reduzir a carga microbiana em derivado de carne bovina sem o uso de temperaturas extremas, necessárias no tratamento térmico convencional. Considerando que a tecnologia de ultrassom disponível está relativamente bem adaptada para alimentos fluidos, estudou-se o efeito letal do ultrassom de alta intensidade sob pressão (manossonicação - MS) e em combinação com temperatura e pressão (manotermossonicação - MTS) na redução de Listeria monocytogenes em extrato de carne bovina diluído. Os tratamentos variaram quanto à amplitude da onda gerada com intensidades de potência transferida ao meio variando entre 92 e 240 W (ou 4 W/ml e 10,4 W/ml), pressão entre 1,0 a 4,0 bar e temperatura entre 40 a 60 o C. Os resultados foram expressos em função do tempo para a redução de um ciclo logarítmico ou 90% da população inicial de microrganismos (valor D). Os tratamentos proporcionaram até 4 ciclos de redução logarítmica da Listeria monocytogenes no extrato de carne bovina. Os menores tempos de redução logarítmica obtidos foram D MS de 1,12 minutos, determinado a 240 W (10,4 W/ml) e 3,5 bar, e DMTS de 0,16 minutos a 162 W, 2,5 bar e 60ºC. A manotermossonicação mostrou forte influência da temperatura do tratamento, com 2 ciclos de redução logarítmica em 5 minutos a 40 o C e 4 ciclos em 40 segundos a 60 o C, demonstrando um efeito sinérgico significativo ao redor de 60% entre... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The beef cattle industry is an important sector of economic growth on Brazilian agribusiness, leading, since 2004, the world beef exports. Some areas can and should evolve to consolidate Brazil as a synonym of high quality safe beef and high value-added products. This research project proposed to evaluate the use of ultrasound to reduce microbial load on a beef by-product without the use of extreme temperatures, usually required in conventional thermal treatments. Considering that the ultrasound technology is relatively well adapted to fluid foods, the lethal effect of high intensity ultrasound under pressure (manosonication - MS) and temperature (manothermosonication - MTS) was investigated to reduce Listeria monocytogenes in diluted beef extract. The intensities of the treatments varied according to the amplitude of wave generated, at power level of energy transferred to the medium varying from 92 W and 240 W (or 4 W/ml and 10.4 W/ml), pressure from 1.0 to 4.0 bar, and in the temperature range of 40 to 60 o C. The results were expressed in terms of the time required for one log cycle reduction or 90% of the initial microorganism population reduction (D-value). The treatments resulted up to 4 log-cycles reduction of Listeria monocytogenes in beef extract. The shortest logarithmic reduction times obtained were DMS of 1.12 minutes, determined at 240 W (10.4 W/ml) at 3.5 bar, and a DMTS of 0.16 minutes at 162 W, 2.5 bar and 60ºC. The manothermosonication showed a strong influence of treatment temperature, with a 2-log cycle reduction in 5 minutes at 40 o C, and a 4-log cycle reduction in 40 seconds at 60 o C demonstrating a significant synergic effect around 60% between 50 o C and 60 o C. Within the experimental operational conditions used, the manosonication and manothermosonication showed to be effective... (Complete abstract click electronic access below) / Mestre

Com a crescente preocupação do consumidor e da Organização Mundial da Saúde (OMS) com relação às doenças cardiovasculares, surge a necessidade de reduzir a quantidade de sódio nos produtos cárneos. O acordo entre o Ministério da Saúde, Agência Nacional de Vigilância Sanitária (ANVISA) e a Associação Brasileira das Indústrias de Alimentação (ABIA) prevê para 2017, a quantidade de sódio que o presunto cozido deve conter é de 1160mg a cada 100g de produto. Uma das maneiras de reduzir a quantidade de sódio é substituir parcialmente o NaCl por outros sais, como KCl, porém, dependendo da quantidade pode provocar alterações tecnológicas no produto. O objetivo deste estudo foi desenvolver um presunto cozido com reduzido teor de sódio e características sensórias desejáveis. As formulações substituindo o sal pelo sal light (50% KCl e 50% NaCl) foram: Padrão (0%), F1 (10%), F2 (18%), F3 (26%) e F4 (34%). Nas análises de caracterização (umidade, cinzas, proteína, lipídios, atividade de água) do presunto cozido, não houve diferenças significativas (p<0,05) entre as formulações. Também não foi observado diferenças significativas (p<0,05) de pH, capacidade de retenção de água (CRA) e sinerese. Na análise de cor, utilizando o sistema CIElab, houve diferença significativa (p<0,05) de L*, a* e b* das formulações F3 (26%) e F4 (34%) em relação a Padrão. Na análise de textura, as formulações com as maiores substituições, apresentaram a menor dureza, quando comparadas ao padrão. Nas análises para avaliação da vida útil, os resultados físico-químicos e microbiológicos encontrados atendem a legislação e garantem a segurança microbiológica e a qualidade durante toda a vida útil do presunto cozido. Na análise sensorial teste triangular para os atributos cor e textura, não houve diferença entre as formulações (p<0,05). As substituições de sal light de 26 (F3) e 34% (F4) apresentaram as maiores reduções de sódio (137,66 e 176mg, respectivamente) e diferença sensorial quanto ao atributo sabor. Diante da diferença sensorial percebida no Teste Triangular, foi adicionado a essas formulações o mascarador de KCl. A adição do mascarador de KCl, possibilitou uma aceitação sensorial semelhante a formulação padrão. Demonstrando, que o sal light em conjunto com o mascarador de KCl, é uma boa alternativa para a redução de sódio no presunto cozido. / With increasing consumer awareness and the World Health Organization (WHO) in relation to cardiovascular disease, there is a need to reduce of sodium in meat products. The accord between the Ministry of Health, National Health Surveillance Agency (ANVISA) and Brazilian Association of Food Industries (ABIA) provides for 2017, the amount of sodium that the cooked ham should contain is 1160mg every product 100g. One way to reduce the amount of sodium is partially replaced by other salts NaCl, KCl like, however, can cause some technological product changes. The objective of this study is to develop a cooked ham with reduced sodium content and desirable sensory characteristics. The formulations salt by substituting light salt (50% KCl and 50% NaCl) were: Test (0%), F1 (10%), F2 (18%), F3 (26%) and F4 (34%). The characterization analysis (humidity, ash, protein, lipids, water activity) of cooked ham, there were no significant differences (p <0.05) between formulations. It was also not observed significant differences (p <0.05) pH, water retention capacity (WRC) and syneresis. In the color analysis, using the CIElab system, there was a significant difference (p <0.05) L *, a * and b * the formulations F3 and F4 relative to P. The texture analysis, formulations with higher substitutions, showed the lowest hardness when compared to test. In the analyzes to assess the shelf life, the physical and chemical results and found microbiological meet legislation and ensure microbiological safety and quality throughout the life of cooked ham. A sensory analysis Triangular Test for the attributes color and texture, there was no difference between formulations (p <0.05). Light salt substitutions of 26 (F3) and 34% (F4) had the highest sodium reductions (137.66 and 176mg, respectively) and sensory difference in flavor attribute. Before the sensory perceived difference in Triangular Test, was added to these formulations the KCl masking. The addition of KCl masking, has enabled a similar sensory acceptance test formulation. Demonstrating that the light salt with the KCl masking, is a good alternative to sodium reduction in cooked ham.

Objetivou-se estudar a substituição do milho por polpa cítrica peletizada no concentrado de vacas leiteiras em lactação, durante a estação chuvosa do ano, em pastejo de capim-elefante. Os trabalhos foram conduzidos no Departamento de Zootecnia da ESALQ/USP. O delineamento estatístico foi em Quadrado Latino 4 x 4, analisados utilizando-se o Proc GLM (SAS, 1999). Foi utilizada uma área de 7,8 ha de pastagem dividida em 39 piquetes de 0,2 ha cada, adubada com 80 kg N ha mês-1. Experimento I: Foram utilizadas oito vacas Holandesas com média de 82 dias de lactação e 522,9 kg de PV, no início do período experimental. Os tratamentos continham as seguintes proporções de milho e polpa cítrica: 100:0 (T0); 75:25 (T25); 50:50 (T50); 25:75 (T75). As vacas receberam 7,00 kg de concentrado dia-1 (6,3 kg MS), fracionado em duas vezes ao dia. A pastagem foi adubada com 80 kg N ha.mês-1. Não houve diferença (P>0,05) no tempo de pastejo (7h22’), ruminação (8h36’), ócio (5h56’) e taxa de bocados (34,4 movimentos min-1). A temperatura retal (38,74 e 39,64ºC) e freqüência respiratória (47,44 e 61,20 movimentos min-1), mensuradas as 8:00 e as 15:30 horas, respectivamente, não foram afetadas pelos tratamentos (P>0,05). Não houve diferença (P>0,05) na produção de leite corrigida para 3,5% de gordura (18,5 kg vaca dia-1), percentagens de gordura (3,5%), proteína (3,06%), lactose (4,40%), sólidos totais (13,02%), N-uréico (15,01 mg dL-1) e contagem de células somáticas (203.000 mL-1). O peso vivo (536,8 kg), condição corporal (2,51), glicose plasmática (75,90 mg dL-1), N-uréico plasmático (16,96 mg dL-1) e ácidos graxos livres no plasma (456,12 mEq L-1) também não foram afetados pelos tratamentos (P>0,05). Experimento II: Foram utilizadas 11 vacas (7 Holandesas e 4 Jersey), com 427,5 kg de PV e 153,22 dias de lactação, no início do período experimental. Os concentrados continham 21,8% de PB e as respectivas proporções de milho e polpa cítrica: 100:0 (T0); 75:25 (T25); 50:50 (T50); 25:75 (T75). As vacas receberam 6,1 kg de concentrado dia-1 (5,5 kg de MS), fracionado em duas vezes ao dia, fornecido após cada ordenha. A pastagem era adubada com 80 kg N ha mês-1. Não houve diferença (P>0,05) na produção de leite corrigida para 3,5% de gordura (13,7 kg vaca dia-1), percentagens de gordura (3,8%), proteína (3,37%), sólidos totais (13,27%), N uréico (14,34 mg dL-1) e contagem de células somáticas (140.450 mL-1). A percentagem de lactose foi diferente (P<0,05) para a maior dose de substituição. O peso vivo (427,2 kg), condição corporal (2,74), glicose plasmática (74,63 mg dL-1), N uréico plasmático (16,74 mg dL-1), e ácidos graxos livres no plasma (417,81 mEq L-1) não foram afetados pelos tratamentos (P>0,05). Não houve diferença (P>0,05) no tempo de pastejo (7h51’), ruminação (7h59’), ócio (6h) e taxa de bocados (37,91 movimentos min-1). A Temperatura retal (38,76 e 39,61ºC) e freqüência respiratória (53,57 e 71,50 movimentos min-1), mensuradas às 8:00 e às 15:30 horas, respectivamente, não foram afetadas pelos tratamentos (P>0,05). O milho pode ser substituído pela polpa cítrica sem depreciar a produção e composição do leite. / Two experiments were conducted to study the partial substitution of fine ground corn by peleted pulp citric in the concentrate of lactating cows in middle lactation (Experiment I) and in late lactation (Experiment II), grazing elephant – grass pasture. The trials were conducted at the Animal Science Department of ESALQ/USP. In both experiments, the animals were grouped according to milk yield, days in milk and parturition order. The statistical designs were repeated 4 x 4 Latin Square. The data were analysed using the Proc GLM of SAS (1999). Experiment I: Eight Holstein cows (82 DIM and 522.9 kg LBW), at the beginning of the trial were used. The concentrates contained the following corn:peleted citrus pulp proportions: 100:0 (T0); 75:25 (T25); 50:50 (T50); 25:75 (T75). The cows received 7 kg of concentrate day-1 (6.3 kg of DM), fractionated in 2 daily meals. The pasture was fertilized with 80 kg N ha.month-1. The forage offer was of 33,6 kg DM of green leaves cow day-1. There was not difference (P>0.05) in the grazing time (7h22’), rumination time (8h36’), leisure time (5h56’) and biting rate (34.4 movements min-1). The rectal temperature (38.74 and 39.64ºC) and respiratory frequency (47.44 and 61.20 movements min-1), measured at 8:00 AM and at 3:30 PM, respectively, were not affected by treatments (P>0.05). There was not difference (P>0.05) in 3.5 % FCM yield (18.5 kg cow day-1), in the contents of milk fat (3.5%), protein (3.06%), lactose (4.40%) and total solids (13.02%), milk urea-N (15.01 mg dL-1) and of somatic cells (203.000 mL-1) were not affected by treatments (P>0.05). The LBW (536.8 kg), BCS (2.51), plasma glucose (75.90 mg dL-1), plasma urea-N (16.96 mg dL-1) and plasma free fat acids (456.12 mEq L-1) were not affected by treatments (P>0.05). Experiment II: Eleven cows were used, 7 Holstein and 4 Jersey (427.5 kg LBW and 153.22 DIM), at the beginning of the trial. The concentrates were 21.8% of CP (DM bases), and the respective corn:peleted citric pulp ratio were: 100:0 (T0); 75:25 (T25); 50:50 (T50); 25:75 (T75). The cows were fed 6.1 kg day-1 of concentrate (5.5 kg of DM), fractionated in 2 daily meals, after each milking. There was not difference (P>0.05) in 3.5 FCM yield (13.7 kg cow day-1), in the content of milk fat (3.8%), protein (3.37%) and total solids (13.27%), milk urea-N (14.34 mg dL-1) and somatic cells (140,450 mL-1). The lactose content was lower (P<0.05) for the 25:75 diet. The LBW (427.2 kg), BCS (2.74), plasma glucose (74.63 mg dL-1), plasma urea-N (16.74 mg dL-1), and plasma free fat acids (417.81 mEq L-1) were not affected by treatments (P>0.05). There were no difference (P>0.05) in the grazing time (7h51’), rumination time (7h59’), leisure time (6h) and biting rate (37.91 movements min-1). The rectal temperature (38.76 and 39.61ºC) and respiratory frequency (53.57 and 71.50 movements min-1), measured at 8:00 and at 15:30 hours, respectively, were not affected by treatments (P>0.05). The corn can be substituted by the citric pulp without depreciating the milk yield and content.

Die Rückstandsanalytik tierischer Lebensmittel ist eine anspruchsvolle Aufgabe aufgrund des hohen Lipidanteils der Proben sowie des sich stetig vergrößernden Wirkstoffspektrums. Heutzutage werden für die Probenaufarbeitung die DFG S 19 Methode, mit der vorrangig unpolare Analyten nachgewiesen werden und zunehmend die QuEChERS Methode eingesetzt, die insbesondere auf die Erfassung polarer Pestizide abzielt. In dieser Arbeit wurde eine moderne Multirückstandsmethode für Hühnereier entwickelt, um sowohl gas- als auch flüssigkeitschromatographisch (GC, LC) erfassbare Wirkstoffe zu analysieren. Dazu gehören unpolare PCBs, Pyrethroide und Organochlorpestizide, aber auch polarere Organophosphate, Triazole und Carbamate. Das Verfahren basiert auf der Extraktion mittels Matrix Solid Phase Dispersion, der Reinigung auf Grundlage einer modifizierten Gelpermeationschromatographie (GPC) und zwei verschiedenen Festphasenextraktionen (SPEs) für GC- und LC-erfassbare Pestizide sowie der Quantifizierung mittels GC- und LC-MS/MS. Dünnschichtchromatographisch wurde die effektive Entfernung hochmolekularer Lipide durch die modifizierte GPC und niedrigmolekularer Fette durch die SPEs belegt. Laut der für Ei durchgeführten Validierung erfüllten 164 der 172 untersuchten Pestizide und alle sechs PCBs die Leistungskriterien für die amtliche Rückstandskontrolle - zumeist am niedrigsten validierten Level (5 µg/kg bzw. 0,5 µg/kg). Ausnahmen bildeten sehr polare LC-Pestizide (z.B. Aminopyralid, Clopyralid, MCPA, Quinmerac) und pH-Wert-abhängige GC-Analyten (Nicotin, Tolylfluanid, Dichlofluanid), die auch mit den etablierten Verfahren schwierig zu analysieren sind. Weiterhin verdeutlichte die erfolgreiche Untersuchung von verschiedenen Ringversuchsmaterialien, dass die ursprünglich für Eier entwickelte Methode auch für mageres Geflügelfleisch und Sahne genutzt werden kann. Gegenüber den etablierten Verfahren wies die neue Methode deutliche Vorzüge auf. So belegte die Dünnschichtchromatographie, dass mit der neuen Methode Cholesterin, aber auch freie Fettsäuren besser abgetrennt werden als mit den etablierten Verfahren. Die neue Methode verbrauchte im Vergleich zur DFG S 19 Methode 46 % weniger Lösungsmittel und ermöglichte eine Verdopplung des Probendurchsatzes innerhalb von 8 h. Zudem eignete sich das entwickelte Verfahren laut den Validierungsdaten für GC-Analyten deutlich besser als die QuEChERS Methode und etwas besser als die DFG S 19 Methode (v.a. für Pyrethroide). Hinsichtlich der LC-Analyten unterschieden sich die neue und die QuEChERS Methode nur bei wenigen Analyten. Mit dem neuen Verfahren konnten folglich im Gegensatz zu den etablierten Methoden sowohl unpolare GC- als auch polare LC-Analyten sicher erfasst werden.