Influence of the storage period on the nutritional and microbiological value of sun-dried brewer's grains / Influencia del período de almacenamiento sobre el valor nutricional y microbiológico de los granos de cervecería secados al sol / Influência do período de estocagem sobre o valor nutricional e microbiológico de grãos de cervejaria secos ao sol

Abstract Background: Brewer's grains, a by-product of the brewery industry, can be included in the diet of ruminants. However, its high humidity makes it difficult to store and preserve. Objective: To evaluate the efficiency of sun dehydration of wet brewer's grains (WBG) and the effect of storage period on its nutritional and microbiological quality. Methods: A completely randomized experimental design was used to evaluate WBG dehydration efficiency, with treatments corresponding to 0, 1, 2, 4, 6, 8, 10, 12, 14 and 16 hours of sun exposure. A second experiment was carried out using also a completely randomizeddesign to evaluated the effect of storage with the following treatments: 0, 10, 20, 30, 60, 90, 120, 150 and 180 days of storage of the dry by-product. Results: Dry matter (DM) content linearly increased with dehydration period. The chemical composition of the dried brewer's grains had no effect as a function of storage period. Indigestible protein (C fraction) increased linearly but did not compromise the cumulative gas production and the in vitro digestibility of DM and protein. Storage time had no effect on fungus population. The maximum aflatoxin value was 45.5 μg/kg, and remained within acceptable limits for bovine feed. Conclusion: Dehydration of WBG in the sun is efficient to guarantee conservation and makes it possible to store the by- product. The storage of the dry by-product for 180 days does not compromise its nutritional or microbiological quality.

Resumen Antecedentes: Los granos de cervecería son un subproducto de la industria cervecera que puede ser incluido en la dieta de rumiantes; sin embargo, su alta húmedad dificulta el almacenamiento y conservación de ese producto. Objetivo: Evaluar la eficiencia de la deshidratación al sol de los granos húmedos de cervecería (WBG) y el efecto del período de almacenamiento sobre su calidad nutricional y microbiológica. Métodos: Para evaluar la eficiencia de la deshidratación de los WBG se utilizó un diseño experimental completamente al azar, con tiempos de tratamiento de 0, 1, 2, 4, 6, 8, 10, 12, 14, y 16 horas de exposición al sol. En un segundo experimento, también con diseño experimental completamente al azar, se evaluó el efecto del almacenamiento comparando los siguientes tratamientos: 0, 10, 20, 30, 60, 90, 120, 150 y 180 días de almacenamiento del subproducto seco. Resultados: La materia seca (DM) del WBG presentó un efecto lineal creciente con el proceso de deshidratación. La composición química de los granos secos de cervecería no tuvo efecto en función de los tiempos de almacenamiento. La proteína no digestible (fracción C) aumentó linealmente; sin embargo, no comprometió la producción acumulativa de gas y la digestibilidad in vitro de la DM y de la proteína. El tiempo de almacenamiento no tuvo efecto sobre la población de hongos. El valor máximo de aflatoxina obtenido fue de 45,5 μg/kg y permaneció dentro de los limites aceptables para alimentación de bovinos. Conclusión: La deshidratación de WBG al sol es eficiente para garantizar la conservación del material y viabilizar su almacenamiento. El almacenamiento por 180 días de este subproducto seco no compromete su calidad nutricional y microbiológica.

Resumo Antecedentes: Os grãos de cervejaria são um subproduto que podem ser incluídos na dieta de ruminantes, no entanto sua forma úmida dificulta o armazenamento e a conservação desse produto. Objetivo: Avaliar a eficiência de desidratação ao sol dos grãos úmidos de cervejaria (WBG) e o efeito do período de armazenamento sobre a qualidade nutricional e microbiológica. Métodos: Para avaliar a desidratação do WBG, utilizou-se um delineamento experimental inteiramente casualizado, sendo os tratamentos os tempos de 0 e 1, 2, 4, 6, 8, 10, 12, 14 e 16 horas de exposição ao sol. Um segundo experimento foi realizado em delineamento inteiramente casualizado. Os tratamentos foram 0, 10, 20, 30, 60, 90, 120, 150 e 180 dias de armazenamento do subproduto seco. Resultados: A matéria seca (DM) do WBG apresentou efeito linear crescente com o processo de desidratação. A composição química dos grãos secos de cervejaria não apresentou efeito em função dos tempos de armazenagem. A proteína indigestível (Fração C) aumentou linearmente, no entanto não comprometeu a produção cumulativa de gás e a digestibilidade in vitro da DM e da proteína. A população de fungos não apresentou efeito com o tempo de armazenamento. O valor máximo de aflatoxina obtido foi de 45,5 μg/kg e permaneceu dentro dos limites aceitáveis para a alimentação de bovinos. Conclusão: A desidratação do WBG ao sol foi eficiente em garantir a conservação do material e viabilizar o seu armazenamento. A estocagem desse subproduto seco por 180 dias não comprometeu a sua qualidade nutricional e microbiológica.

Effects of Black Wattle (Acacia mearnsii) Condensed Tannins on Intake, Protozoa Population, Ruminal Fermentation, and Nutrient Digestibility in Jersey Steers.

The objective of this study was to evaluate the effect of inclusion of condensed tannins (CT) from black wattle (Acacia mearnsii) on feed intake, ruminal protozoa population, ruminal fermentation, and nutrient digestibility in Jersey steers. Five ruminally-cannulated steers were used in a 5x5 Latin square design, with five periods of 20 days each (14 days for diet adaptation and six days for sample collection per period). Treatments were composed of dietary inclusion levels of condensed tannins at 0, 5, 10, 15, and 20 g/kg of diet dry matter. Intakes of dry matter, organic matter, ether extract, crude protein, neutral detergent fiber, and total digestible nutrients were not affected by condensed tannins. The ruminal pH was reduced linearly with tannin levels. Ruminal ammonia nitrogen concentration was not affected by tannins. Tannins reduced the molar proportion of acetate and did not affect the ruminal protozoal population, which might be related to the low doses used. Digestibilities of dry matter, organic matter, and neutral detergent fiber were not altered; however, there was a linear reduction in crude protein digestibility. Based on these results, CT extracts from black wattle are not recommended for improving nutrient utilization in steers at the tested levels.

Black Wattle (Acacia mearnsii) Condensed Tannins as Feed Additives to Lactating Dairy Cows.

The objective of this study was to evaluate the effects of five levels of condensed tannins (CT) from black wattle (Acacia mearnsii) in the diets of lactating dairy cows on intake, nutrient digestibility, ruminal microbial protein synthesis, milk production, composition, oxidative profile, and blood metabolites. Five Holstein cows (88 ± 26.8 days in milk) were allocated in a 5 x 5 Latin square design for a period of 20 days (14 days of diet adaptation and six for sampling). Treatments were the inclusion levels of CT at 0, 5, 10, 15 and 20 g/kg of dry matter (DM) in the diet. There was no effect of CT on DM intake. The digestibility of DM and neutral detergent fiber changed quadratically, with the maximum values at 12.2 and 11.4 g/kg of DM, respectively. There was no effect on ruminal microbial protein synthesis and milk production; however, milk casein concentration was reduced linearly. There was no effect on the milk oxidative profile. Inclusion of CT at levels up to 20 g/kg of DM did not affect intake or microbial protein synthesis; however, added CT depressed the production of energy corrected milk and milk casein concentration.

Tipologia de manejo de ordenha: análise de fatores de risco para a mastite subclínica / Typology of milking management: analysis of risk factors for subclinical mastitis

Apesar do volume de leite produzido, a qualidade da matéria-prima é um dos maiores entraves ao desenvolvimento tecnológico e à consolidação da indústria de laticínios no Brasil. Dentre os entraves, toma destaque a contagem de células somáticas do leite, que é o indicador mais usado em programas de controle e prevenção da mastite em todo o mundo. Com objetivo de identificar características no manejo de ordenha e quantificar fatores de risco que elevam a mastite subclínica e seus principais agentes causadores, realizou-se coleta de dados in loco em propriedades leiteiras na região Oeste do Paraná, coletas que consistiam na aplicação de dois questionários guia semi-estruturados, acompanhamento de uma ordenha e coleta de leite de três vacas que apresentassem o teste de CMT positivo. Com a utilização do método estatístico de análise de correspondência múltipla (ACM) chegou-se a um montante de 12 variáveis a serem estudadas e a formação das dimensões 1 e 2 com 28,54% e 21,06% da variância explicada respectivamente. Com a análise de classificação hierárquica ascendente permitiu reduzir o universo inicial de 112 vacas para quatro grupos homogêneos de produção (G1, G2, G3, G4). As características de manejo de ordenha: tipo de ordenha, secagem dos tetos antes da ordenha, tratamento para casos de mastite clínica, higiene das mãos do ordenhador e treinamento dos ordenadores foram identificados como fatores de risco para mastite subclínica com isolamento do agente Staphylococcus coagulase negativo, o qual foi o agente mais prevalente nos isolamentos microbiológicos das amostras de leite com mastite subclínica.(AU)

Despite the produced milk volume, its quality is one of the barriers for technological development and consolidation of the dairy industry in Brazil. Among the barriers is the milk somatic cell count, which is the indicator used in most control programs and prevention of mastitis. In order to identify characteristics in the management of milking and to quantify risk factors that increase subclinical mastitis and its main bacterial agents, data were collected in situ on dairy farms in western Paraná. The data collection consisted in the application of two questionnaires, in accompanying a milking procedure, and in collection of CMT positive milk samples from three cows. Using the statistical method of multiple correspondence analysis (MCA) we came to a total of 12 variables to be studied, and to the formation of dimension 1 and 2 with respectively 28.54% and 21.06% of the explained variance. With the hierarchical ascending classification analysis it was possible to reduce the initial population of 112 cows to produce four homogeneous groups (G1, G2, G3, G4). The milking handling characteristics, as type of milking, drying teats before milking, treatment for cases of clinical mastitis, milker's hand hygiene and as training of officers, were identified as risk factors for subclinical mastitis with isolation of a coagulase negative Staphylococcus, which was the most prevalent agent in milk samples of subclinical mastitis.(AU)

Use of dried waste of cassava starch extraction for feeding lactating cows.

The aim of this study was to determine the best level of utilization of dried waste of cassava starch extraction (WCSEd) as a substitute for corn for lactating cows. Four lactating cows were fed diets with increasing levels (0%, 33%, 66% and 100%) of WCSEd as a substitute for corn. The intake and digestibility of dry matter and nutrients, milk production and composition, blood parameters of glucose and urea and microbial synthesis of the diets were evaluated. There was a reduction in dry matter intake, organic matter, ether extract and total carbohydrate, and increased intake of acid detergent fiber. Nutrient digestibility was not affected while the synthesis of microbial protein increased. These changes resulted in reduced milk production, without altering the efficiency of production or the constituents of milk, with a decreasing effect on daily production of lactose, solids and minerals. Metabolic parameters, glucose and urea nitrogen in plasma, remained within appropriate levels. The dried residue from the extraction of cassava starch can be used as feed for dairy cows to replace up to 100% of the corn ration. However, its use promotes a reduction in intake of dry matter and nutrients as well as a reduction in the production of milk, with impacts on the profitability of the product.