RESUMO

The aim was to evaluate the animal response and the chemical and physical changes of free-choice mineral mixtures fed to grazing cattle. Growing beef cattle were fed either powder (POW) or agglomerated (AGL) mineral mixtures in three different experiments (Exp.), carried out in pastures of Brachiaria grass. In Exp. 1 and 2, the mineral mixtures were disposed in unsheltered troughs (POWun vs. AGLun), being delivered once (D0, Exp.1) or twice (D0 and D8, Exp. 2), throughout 14-day periods. In Exp. 3, POWun and AGLun were additionally compared to POW in sheltered troughs (POWshe), and the mineral mixtures were disposed in D0, throughout 21-day periods. Non-consumed supplement was removed and sampled on D14 (Exp. 1 and 2) or D21 (Exp. 3). Evaluations included average daily body weight gain (ADG), daily disappearance of the supplement (DSD), penetration force of the supplement mass, faecal chemical composition and serum levels of Ca, P and Mg. In Exp. 1, no effects were observed on ADG and faecal mineral concentrations, however, changes in mineral concentrations and a 40% reduction in Na concentration in the supplement were observed, compared to the initial concentration. AGLun had a lower penetration force. In Exp. 2, there were no effects on DSD and faecal mineral concentrations. POWun showed a smaller reduction in Na content compared to AGLun, and AGLun showed lower penetration force. In Exp. 3, the treatments did not affect ADG, but there was a trend towards higher DSD and serum phosphorus (P) concentration for AGLun (p = 0.08). Higher faecal Na concentration was observed for AGLun and higher Na concentration occurred in non-consumed mixture of POWshe. Mineral supplements offered in uncovered troughs showed altered chemical and physical characteristics, with possible effects on supplement intake. However, the general changes are unlikely to alter animal performance.

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In this work, lemon and onion biomasses commonly found in street markets are for the first time used to develop a facile, fast and low-cost one-step microwave-assisted carbonization method for synthesis of highly fluorescent carbon dots (CDs). The structure and optical properties of CDs were investigated by TEM, XRD, XRF, UV-Vis, FTIR, and fluorescence spectroscopy. CDs displayed satisfactory optical proprieties, a high quantum yield of 23.6%, and excellent water solubility, and the particle size was 4.23-8.22 nm with an average diameter of 6.15 nm. An efficient fluorescent resonance energy transfer (FRET) between the CDs and riboflavin was achieved with CDs acting as donor and riboflavin as acceptor. A linear relationship between FRET and the riboflavin concentration from 0.10 to 3.0 µg/mL was observed, allowing the development of an accurate and fast analytical method to determine this vitamin in multivitamin/mineral supplements. Despite the potential interferences in these supplements, CDs were selective for riboflavin under optimized conditions. A paired t-test at a 95% confidence level indicated no statistically significant difference between the proposed and the reference methods. Recovery test presented values ranged from 96.0% to 101.4%. The limit of detection and relative standard deviation were estimated at 1.0 ng/mL and <2.6% (n = 3), respectively. CDs were successfully synthesized in a domestic microwave oven (1450 W, 6 min), presenting satisfactory parameters when compared with results of other studies reported in the literature, suggesting that the proposed method is a potentially useful method for the synthesis of CDs and determination of riboflavin.

RESUMO

Subclinical hypocalcemia is a metabolic disorder characterised by a decrease in serum calcium (Ca) levels, with no clinical symptoms. The aim of this study was to determine the punctual prevalence of subclinical hypocalcemia in dairy cows, in the Sousa city micro-region, Paraíba state. Samples were collected from 29 dairy farms, consisting of 153 and 296 blood samples in the pre- and postpartum period respectively. In relation to the mineral supplementation profile, 89.25% of the properties use a commercial supplement. On average, 40.53% of lactating cows presented total serum Ca levels under the lower limit of 8.0 mg/dL, with an exclusive supplement of NaCl resulting in a higher percentage of cows, 61.11%, with the condition of subclinical hypocalcemia. For ionized Ca, the average prevalence of subclinical hypocalcemia was 21.16%. The prevalence of subclinical hypocalcemia for total serum Ca was 37.25 and 42.23% of cows in the pre- and postpartum period respectively. The type of mineral supplement did not influence (P > .05) total and ionized serum Ca levels in lactating cows. There was no significant difference (P > .05) for total and ionized serum Ca levels as a function of the reproductive period in lactating cows. Subclinical hypocalcemia was evident in the dairy cows under evaluation and occurred with an average punctual prevalence of 40.34%. Commercial supplement is the most common form of mineral mixture used; however, it was not able to promote an increase in the levels of total and ionized serum Ca levels due to errors in managing the supply.

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RESUMO

Apparent digestibility of nutrients in several protein ingredients and inorganic phosphates were compared in three Nile tilapia different development stage. The ingredients tested were fish meal, chicken by-product meal, meat and bone meal, corn gluten, soybean meal, cotton seed meal, monobi-calcium phosphate, bi-calcium phosphate, mono-potassium phosphate and phosphoric acid. The apparent digestibility coefficients of dry matter, crude protein, gross energy, phosphorus, calcium and magnesium were determined with 25g, 250g and 500g fish. It was concluded that, the capacity of Nile tilapia to digesting feed and absorbing nutrients is dependent on the body weight and characteristics of food evaluated. There was a trend to better utilization of nutrients from animal origin foods and inorganic sources by 25g fish. The fishes with 250g and 500g showed better use of plant protein sources than 25g fish.

A digestibilidade aparente dos nutrientes de ingredientes proteicos e fosfatos inorgânicos foi comparada em três diferentes fases de desenvolvimento da tilápia-do-nilo. Os ingredientes testados foram farinha de peixe, farinha de vísceras de aves, farinha de carne e ossos, glúten de milho, farelo de soja, farelo de algodão, fosfato monobicálcico, fosfato bicálcico, fosfato monopotássico e ácido fosfórico. Os coeficientes de digestibilidade aparente (CDAs) de matéria seca, proteína, energia, P, Ca e Mg foram determinados com peixes de 25 g, 250 g e 500 g. Concluiu-se que a capacidade da tilápia-do-nilo de digerir os alimentos e absorver os nutrientes é dependente do peso corporal e das características do alimento avaliado. Houve tendência de melhor aproveitamento de nutrientes dos alimentos de origem animal e das fontes inorgânicas pelos peixes de 25 g. Os peixes de 250 g e 500 g mostraram melhor aproveitamento dos nutrientes das fontes proteicas de origem vegetal, quando comparados aos peixes de 25 g.

Assuntos

RESUMO

Apparent digestibility of nutrients in several protein ingredients and inorganic phosphates were compared in three Nile tilapia different development stage. The ingredients tested were fish meal, chicken by-product meal, meat and bone meal, corn gluten, soybean meal, cotton seed meal, monobi-calcium phosphate, bi-calcium phosphate, mono-potassium phosphate and phosphoric acid. The apparent digestibility coefficients of dry matter, crude protein, gross energy, phosphorus, calcium and magnesium were determined with 25g, 250g and 500g fish. It was concluded that, the capacity of Nile tilapia to digesting feed and absorbing nutrients is dependent on the body weight and characteristics of food evaluated. There was a trend to better utilization of nutrients from animal origin foods and inorganic sources by 25g fish. The fishes with 250g and 500g showed better use of plant protein sources than 25g fish.(AU)

A digestibilidade aparente dos nutrientes de ingredientes proteicos e fosfatos inorgânicos foi comparada em três diferentes fases de desenvolvimento da tilápia-do-nilo. Os ingredientes testados foram farinha de peixe, farinha de vísceras de aves, farinha de carne e ossos, glúten de milho, farelo de soja, farelo de algodão, fosfato monobicálcico, fosfato bicálcico, fosfato monopotássico e ácido fosfórico. Os coeficientes de digestibilidade aparente (CDAs) de matéria seca, proteína, energia, P, Ca e Mg foram determinados com peixes de 25 g, 250 g e 500 g. Concluiu-se que a capacidade da tilápia-do-nilo de digerir os alimentos e absorver os nutrientes é dependente do peso corporal e das características do alimento avaliado. Houve tendência de melhor aproveitamento de nutrientes dos alimentos de origem animal e das fontes inorgânicas pelos peixes de 25 g. Os peixes de 250 g e 500 g mostraram melhor aproveitamento dos nutrientes das fontes proteicas de origem vegetal, quando comparados aos peixes de 25 g.(AU)

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RESUMO

Uma formulação mineral de qualidade para bovinos precisa ser isenta de metais tóxicos e ter em sua composição a correta relação dos elementos fósforo e flúor. Além da obediência a legislação brasileira, é importante primar pela pureza das matérias-primas que compõem qualquer suplemento mineral, para que na cadeia trófica alimentar não haja vulnerabilidade ao consumo de carne e leite pelo ser humano. Para tanto, se faz necessário monitorar os suplementos minerais disponíveis no amplo mercado bovino pecuário, investigando os componentes e suas respectivas relações. Nesta finalidade, a presente pesquisa quantificou os elementos fósforo e flúor em formulações minerais comercializadas na cidade de Londrina, estado do Paraná, onde há expressivo comércio de insumos para a pecuária. Em oito importantes marcas comerciais, os autores encontraram algumas formulações com níveis elevados de flúor, promovendo alteração na relação com o elemento fósforo, caracterizando produtos com padrões fora das normas brasileiras vigentes.

A quality mineral formulation for cattle must be free of toxic metals in their composition and have the correct ratio of phosphorus and fluoride. As well as complying with the Brazilian law, it is important to strive for the purity of the raw materials that make up any mineral supplement, so that the food chain has no vulnerability to the consumption of meat and milk by humans. Therefore, it is necessary to monitor mineral supplements available on the large livestock cattle market, investigating the components and their relationships. With this purpose, the present study quantified phosphorus and fluoride found in mineral formulations marketed in the city of Londrina, Parana, where there is significant trade of inputs for livestock. In eight important brands, the authors found some formulations with high levels of fluoride, promoting change in relation to phosphorus, featuring products with patterns that are not compliant with the current Brazilian standards.

Una formulación mineral de calidad para bovinos necesita ser exenta de metales tóxicos y tener en su composición la correcta relación de los elementos fósforo y flúor. Además de obediencia a la legislación brasileña, es importante preciar por la pureza de las materias primas que componen cualquier suplemento mineral, para que en la cadena trófica alimentar no haya vulnerabilidad al consumo de carne y leche por el ser humano. Por lo tanto, se hace necesario monitorear los suplementos minerales disponibles en el amplio mercado bovino pecuario, investigando los componentes y sus respectivas relaciones. Así, esa investigación cuantificó los elementos fósforo y flúor en formulaciones minerales comercializadas en la ciudad de Londrina, estado de Paraná, donde hay expresivo comercio de insumos para la ganadería. En ocho marcas comerciales importantes, los autores encontraron algunas formulaciones con niveles elevados de flúor, promoviendo alteración en la relación con el elemento fósforo, caracterizando productos con estándares fuera de las normas brasileñas vigentes.

Assuntos

RESUMO

Uma formulação mineral de qualidade para bovinos precisa ser isenta de metais tóxicos e ter em sua composição a correta relação dos elementos fósforo e flúor. Além da obediência a legislação brasileira, é importante primar pela pureza das matérias-primas que compõem qualquer suplemento mineral, para que na cadeia trófica alimentar não haja vulnerabilidade ao consumo de carne e leite pelo ser humano. Para tanto, se faz necessário monitorar os suplementos minerais disponíveis no amplo mercado bovino pecuário, investigando os componentes e suas respectivas relações. Nesta finalidade, a presente pesquisa quantificou os elementos fósforo e flúor em formulações minerais comercializadas na cidade de Londrina, estado do Paraná, onde há expressivo comércio de insumos para a pecuária. Em oito importantes marcas comerciais, os autores encontraram algumas formulações com níveis elevados de flúor, promovendo alteração na relação com o elemento fósforo, caracterizando produtos com padrões fora das normas brasileiras vigentes.(AU)

A quality mineral formulation for cattle must be free of toxic metals in their composition and have the correct ratio of phosphorus and fluoride. As well as complying with the Brazilian law, it is important to strive for the purity of the raw materials that make up any mineral supplement, so that the food chain has no vulnerability to the consumption of meat and milk by humans. Therefore, it is necessary to monitor mineral supplements available on the large livestock cattle market, investigating the components and their relationships. With this purpose, the present study quantified phosphorus and fluoride found in mineral formulations marketed in the city of Londrina, Parana, where there is significant trade of inputs for livestock. In eight important brands, the authors found some formulations with high levels of fluoride, promoting change in relation to phosphorus, featuring products with patterns that are not compliant with the current Brazilian standards.(AU)

Una formulación mineral de calidad para bovinos necesita ser exenta de metales tóxicos y tener en su composición la correcta relación de los elementos fósforo y flúor. Además de obediencia a la legislación brasileña, es importante preciar por la pureza de las materias primas que componen cualquier suplemento mineral, para que en la cadena trófica alimentar no haya vulnerabilidad al consumo de carne y leche por el ser humano. Por lo tanto, se hace necesario monitorear los suplementos minerales disponibles en el amplio mercado bovino pecuario, investigando los componentes y sus respectivas relaciones. Así, esa investigación cuantificó los elementos fósforo y flúor en formulaciones minerales comercializadas en la ciudad de Londrina, estado de Paraná, donde hay expresivo comercio de insumos para la ganadería. En ocho marcas comerciales importantes, los autores encontraron algunas formulaciones con niveles elevados de flúor, promoviendo alteración en la relación con el elemento fósforo, caracterizando productos con estándares fuera de las normas brasileñas vigentes.(AU)

Assuntos

RESUMO

Com o objetivo de identificar as principais falhas no sistema de produção que limitam a pecuária em Santarém, Pará, foram entrevistados, ao acaso, 21 pecuaristas (90,5 por cento de corte - cria, recria e engorda; 9,5 por cento de leite), proprietários de 10 por cento da população de bovinos do município. 71,4 por cento das propriedades tinham currais para manejo do gado, entretanto apenas 38,1 por cento possuíam balança e 23,8 por cento tronco de contenção. A Brachiaria brizantha estava presente em todas as fazendas, sendo usada exclusivamente em 42,9 por cento das propriedades. A disseminação de plantas invasoras (61,9 por cento) foi considerada a principal dificuldade no manejo das pastagens. Constatou-se que 76,2 por cento dos pecuaristas utilizam misturas minerais com macro e micro-elementos, geralmente de formulações comerciais, enquanto que 19 por cento utilizam apenas sal comum, enriquecido com micro-elementos. A concentração de fósforo (P) na mistura mineral estava abaixo do recomendado para bovinos de corte em 76,9 por cento das propriedades e apenas 19 por cento das propriedades possuía cochos para suplementação mineral adequada.

With the objective of identifying the main problems of cattle nutrition in the production systems of Santarém, Pará, Brazil, ranchers in different regions of the municipality and who owned 10 percent of the municipality's animals were interviewed at random. The ranchers raised mostly beef cattle; only 9.5 percent had dairy cattle. The infrastructure conditions are inappropriate; only 23.8 percent of the ranches have adequate facilities for beef cattle management and 61.9 percent of the ranchers do not consider weight control. Weed invasion was considered the main problem of the pastures (61.9 percent). The most common forage was Brachiaria brizantha, used exclusively in 42.9 percent of the ranches. 76.2 percent of the ranchers used a complete mineral supplement, with macro and micro elements, while 19 percent used only salt (NaCl) with micro elements; the other 5 percent did not use mineral supplements at all. The phosphorus concentration in the mineral supplement at 76.9 percent of the ranches was less than the minimum level suggested for beef cattle and only 19 percent of the ranches had appropriate mineral feeders.

Assuntos

RESUMO

With the objective of identifying the main problems of cattle nutrition in the production systems of Santarém, Pará, Brazil, ranchers in different regions of the municipality and who owned 10% of the municipality's animals were interviewed at random. The ranchers raised mostly beef cattle; only 9.5% had dairy cattle. The infrastructure conditions are inappropriate; only 23.8% of the ranches have adequate facilities for beef cattle management and 61.9% of the ranchers do not consider weight control. Weed invasion was considered the main problem of the pastures (61.9%). The most common forage was Brachiaria brizantha, used exclusively in 42.9% of the ranches. 76.2% of the ranchers used a complete mineral supplement, with macro and micro elements, while 19% used only salt (NaCl) with micro elements; the other 5% did not use mineral supplements at all. The phosphorus concentration in the mineral supplement at 76.9% of the ranches was less than the minimum level suggested for beef cattle and only 19% of the ranches had appropriate mineral feeders.

Com o objetivo de identificar as principais falhas no sistema de produção que limitam a pecuária em Santarém, Pará, foram entrevistados, ao acaso, 21 pecuaristas (90,5% de corte - cria, recria e engorda; 9,5% de leite), proprietários de 10% da população de bovinos do município. 71,4% das propriedades tinham currais para manejo do gado, entretanto apenas 38,1% possuíam balança e 23,8% tronco de contenção. A Brachiaria brizantha estava presente em todas as fazendas, sendo usada exclusivamente em 42,9% das propriedades. A disseminação de plantas invasoras (61,9%) foi considerada a principal dificuldade no manejo das pastagens. Constatou-se que 76,2% dos pecuaristas utilizam misturas minerais com macro e micro-elementos, geralmente de formulações comerciais, enquanto que 19% utilizam apenas sal comum, enriquecido com micro-elementos. A concentração de fósforo (P) na mistura mineral estava abaixo do recomendado para bovinos de corte em 76,9% das propriedades e apenas 19% das propriedades possuía cochos para suplementação mineral adequada.

RESUMO

We measured lead and cadmium concentrations in samples of mineral mixtures commercialized in Londrina city. Lead and cadmium content were determined by inductively coupled plasma atomic emission spectrometry. Considering maximum concentrations recommended by National Research Council (1996) and Association of American Feed Control Officials Incorporated (2001), of the 10 analyzed samples, 06 had values greater than 30 ppm of lead and all of them had values greater than 0.5 ppm of cadmium. These findings show the necessity for careful industrial monitoring because some mineral mixtures contain sufficient lead and cadmium to cause bovine toxicity.

Para se proceder a uma investigação em misturas minerais, foi realizada uma pesquisa quantificando os elementos chumbo e cádmio em diferentes formulações, comercializadas na cidade de Londrina. Os metais pesados foram determinados pela técnica de espectrofotometria de absorção atômica por plasma de indução acoplada. Considerando como parâmetro de comparação às referências do National Research Council (1996) e a Association of American Feed Control Officials Incorporated (2001), em 10 diferentes marcas analisadas, seis apresentaram níveis de chumbo inorgânico superiores ao limite máximo aceitável que é de 30 ppm. Contudo, em todas as amostras o nível de cádmio encontrado superou o limite de 0,5 ppm, que é o valor máximo aceitável. Os resultados demonstram a urgente necessidade de monitoramento junto aos fabricantes e/ou revendedores, pois algumas misturas minerais podem ser eminentemente perigosas, possibilitando efeitos cumulativos tóxicos de chumbo e cádmio inorgânico aos bovinos.

RESUMO

Effects of temporary calf removal and phosphorus supplementation on conception rate in a 60 or 120 day breeding season period was observed in several trials conducted over three years on Nelore cows. Experiment I involved 47 acyclic Nelore cows with suckling calves ranging in age from 55 to 70 days. Calves were temporarily removed from their dams for 48 h at the beginning of the trial or stayed with the dams throughout the trial. The proportion of cows that cycled during the breeding season was 5 out of 25 (20%) in the control group and I5 out of 22 (68%) in the group whose calves had been removed (p 0.05). In Experiment II, 66 acyclic Nelore cows, averaging 60 ± 0.57 (x ± SE) days post-partum were allocated at random in three groups as follows: A, calves temporarily removed from their dams for 48 h on the first day of the breeding season; B, similar to Group A, except that calves were removed for 72 h and C, control group (no calf removal). The percentage of pregnant cows at the end of the breeding season was 54.6 in control cows compared with 50.0 in the 48 h removal group and 63.6 in the 72 h removal group. In Experiment III, 75 pregnant cows were selected in the final trimester of gestation. Cows were allocated at random in four groups: Group A, the cows received a free choice mineral mixture with 12% p during three months before and three months after the calving season

Estudou-se o efeito da desmama temporária e a suplementação de fósforo sobre a taxa de concepção aos 60 e 120 dias da estação de monta. A avaliação foi feita mediante diversos ensaios levados a cabo durante três anos utilizando vacas Nelore. O Experimento I incluiu 47 vacas Nelore acíclicas com bezerro ao pé e com idades que flutuavam entre 55 e 70 dias. Um grupo de bezerros foi separado de suas mães por 48 h no início do experimento e outro permaneceu com suas mães durante todo o período experimental. A proporção de vacas que ciclaram durante a estação de monta foi de 5 sobre 25 vacas (20%) no grupo controle e de 15 sobre 22 (68%) no grupo em que o bezerro foi separado (p 0,05). No Experimento II, 66 vacas Nelore acíclicas com média de 60 ± 0,57 dias (x ± EP) pós-parto foram distribuídas ao acaso nos três grupos seguintes: Grupo A, bezerros separados de suas mães por 48 h no primeiro dia da estação de monta; Grupo B, similar ao grupo A, mas os bezerros foram separados por 72 h; e Grupo C, grupo controle (o bezerro não foi separado). As porcentagens de vacas gestantes no final da estação de monta foram de 54,6 no grupo controle, de 50,0 no grupo de 48 h de separação e de 63,6 no grupo de 72 h de separação. No Experimento II, 75 vacas gestantes foram selecionadas no terço final da gestação. As vacas foram distribuídas ao acaso em quatro grupos: Grupo A, as vacas receberam uma