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This study aimed to evaluate the effects of calcium salts of fatty acids (CSFA) from soybean oil in diets with different levels of rumen degradable protein (RDP) on bio-hydrogenation extent, and fatty acid (FA) profile intake, omasal digesta, rumen bacteria, and milk fat. Eight Holstein lactating cows were used in a replicated 4 × 4 Latin square design. Treatments were arranged in a 2 × 2 factorial design with two CSFA levels (0 or 33.2 g/kg DM of CSFA) and two RDP levels (98.0 or 110 g/kg DM). There was RDP and CSFA interaction effect on the omasal flow of total FA and some specific FA. Only in -CSFA diets, the higher RDP level increased omasal flow of total FA. Dietary RDP levels did not affect the FA profile of bacteria and milk fat. Feeding CSFA reduced or tended to reduce the bacterial proportion of C15:0, C16:0, C16:1, C17:0, and C18:0 FA and decreased the concentrations of short- and medium-chain FA (<18C) and increased the concentrations of unsaturated and long-chain FA (≥18C) in milk fat. Feeding CSFA of soybean oil increases the intake and omasal flow of FA and augments unsaturated FA content in bacteria pellets and milk fat.

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This research paper analyzes the stability of raw cow milk in the alcohol test and seeks to understand to know the factors that influence milk stability and the occurrence of unstable non-acid milk. Milk samples were collected from the cooling tanks of rural farmers in the state of Paraná twice in summer and twice in winter. The farms were classified according to the production system: pasture with supplementation and feedlot. The following variables were analyzed: stability in the alcohol test, titratable acidity, ionized calcium concentration (iCa), chemical composition of milk, somatic cell count and standard plate count. The results showed that milk stability was greater in winter vs. summer, when the milk contained higher iCa, and in the feedlot vs. pasture system. The Pearson Correlation between variables (ethanol stability, milk composition, iCa, cooling tank temperature, milk volume, number of milking, number of cows milked, fat/protein ratio, distance and travel time) were analyzed. Stability was negatively correlated with iCa concentration and positively with lactose content. Logistic regression of the risk of unstable non-acid milk at 72% alcohol (UNAM72) showed that only iCa and lactose were determinants, while evaluation of the same risk at 78% alcohol revealed iCa, titratable acidity, lactose and milk urea nitrogen as risk factors. Under the dairy farming conditions of Paraná state, the frequency of UNAM72 was low (12.16%) and was higher in summer and in pasture systems with supplementation. In conclusion, in dairy herds bred with high technological level, with adequate nutritional and health management, the frequency of UNAM is low and is related to nutritional management abnd, perhaps, heat stress, factors that alter iCa and lactose levels.

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Este estudo objetivou avaliar aspectos que exercem influência sobre a contagem bacteriana total (CBT) e a contagem de células somáticas (CCS) do leite e avaliar a adequação das amostras do produto à Instrução Normativa nº 76, de 26 de novembro de 2018, do Ministério da Agricultura e Pecuária do Brasil (IN 76). A pesquisa foi realizada em propriedades rurais da microrregião de Birigui, São Paulo, Brasil, e se baseou em coleta de dados, por entrevista estruturada, e coletas de leite nas propriedades. Foi realizada amostragem por conveniência, sendo escolhidos 15 produtores de cada estrato (de acordo com a produção diária de leite: pequeno - até 100 L; médio - 101 a 300 L; grande - mais de 300 L), totalizando 45 produtores de leite. Participaram da pesquisa somente propriedades com base da alimentação volumosa em sistema de pastejo ou em semiconfinamento. Para avaliar a influência de diferentes fatores sobre a contagem bacteriana total (CBT) e a contagem de células somáticas (CCS), separadamente, realizou-se regressão multivariada. Ainda, foi determinado o coeficiente de correlação entre variáveis desta pesquisa. As variáveis resposta foram transformadas em logaritmo para normalização dos dados. Foi feita comparação entre os resultados da pesquisa e os parâmetros da IN 76 para verificar o cumprimento das normas pelos produtores. Foram encontrados valores médios de 6.986.977,818.961.790,7 UFC/mL para CBT e de 608.911,1 ± 414.802,9 CS/mL para CCS. A utilização de tanque de resfriamento individual mostrou-se favorável à baixa CBT, em comparação com não uso de tanque ou uso de tanque comunitário, conforme o esperado, pois quanto mais tempo leva para resfriar o leite, maior é a proliferação de bactérias no produto. Foi verificado que o leite de produtores que realizam o California Mastitis Test (CMT) com maior frequência apresentou CCS mais elevada, o que não era esperado. As análises físico-químicas médias foram densidade 1,031 g/mL a 15°C, índice crioscópico -0,538 °H, teor de proteína 3,58%, teor de gordura 4,06%, extrato seco total 12,75%, extrato seco desengordurado 8,69%, acidez titulável 16,2 °D e estabilidade ao álcool (Alizarol 72%) 100%. Em 13,3% (6/45) das amostras foi detectada presença de antibióticos. Considerando a IN 76, o leite de somente 8,9% (4/45) dos produtores apresentou-se adequado simultaneamente para todos os parâmetros analisados (CBT, CCS, densidade, índice crioscópico, proteína, gordura, extrato seco total, extrato seco desengordurado, acidez titulável, estabilidade ao alizarol e pesquisa de antibióticos). A utilização de tanque de resfriamento individual e a realização de CMT favoreceram menor CBT e maior CCS, respectivamente.

This study aimed to evaluate aspects that exerts influence on the total bacterial count (TBC) and somatic cell count (SCC) of milk and evaluate the conformity of the samples to the Normative Instruction no. 76, from November 26, 2018, of the Brazilian Agriculture and Livestock Ministry (NI 76). The research was done in farms around Birigui micro-region, São Paulo State, Brazil, and was based on data collection obtained by structured interviews and milk collection in the farms. Convenience sampling was carried out from 15 producers of each stratum (according to daily milk production: small - up to 100 L; medium - 101 to 300 L; large - more than 300 L), totalizing 45 milk producers. Only farms with grazing or semi-feedlot system for roughage feeding base were included. To evaluate the influence of different factors on Total Bacterial Count (TBC) and Somatic Cell Count (SCC), separately, a multivariate regression was done. Moreover, the correlation coefficient among variables was determined. The response variables were transformed into logarithms for the normalization of the data. A comparison between results and NI 76 parameters was done to verify the standard compliance by producers. Mean TBC was 6.986.977,8 ± 18.961.790,7 CFU/mL and mean SCC was 608.911,1414.802,9 cells/mL. The use of individual cooler tank was favorable to lower TBC, compared with the non-use of the tank or with the use of the communitarian tank, as expected, since the longer it takes to cool the milk, the higher the proliferation of bacteria in the product. It was verified that milk from farmers that more frequently perform California Mastitis Test (CMT) showed higher SCC, which was not expected. The average physicochemical analyzes were density 1.031 g/mL at 15°C, cryoscopic index -0.538 °H, protein content 3.58%, fat content 4.06%, total dry extract 12.75%, dry extract defatted 8.69%, titratable acidity 16.2 °D and alcohol stability (Alizarol 72%) 100%. The presence of antibiotics was detected in 13.3% (6/45) of the samples. Considering NI 76, milk from only 8.9% (4/45) farmers were proper simultaneously for all the parameters analyzed (TBC, SCC, density, cryoscopic index, protein, fat, total dry extract, defatted dry extract, titratable acidity, alizarol stability and antibiotics). The use of individual cooling tank and the CMT performance support lower TBC and higher SCC respectively.

Este estudio tuvo como objetivo evaluar los aspectos que influyen en el contaje bacteriano total (CBT) y el contaje de células somáticas (CCS) de la leche y evaluar la adecuación de las muestras del producto a la Instrucción Normativa nº 76, de 26 de noviembre de 2018, del Ministerio de Agricultura y Ganadería en Brasil (IN 76). La investigación se llevó a cabo en propiedades rurales en la microrregión de Birigui, São Paulo, Brasil, y se basó en la recolección de datos, a través de entrevistas estructuradas, y colectas de leche en las propiedades. Se realizó un muestreo por conveniencia, escogiendo 15 productores de cada estrato (de acuerdo con la producción diaria de leche: pequeño - hasta 100 L; medio - 101 hasta 300 L; grande ­ más de 300 L), totalizando 45 productores de leche. Participaron de la investigación únicamente propiedades basadas en alimentación voluminosa en sistema de pastoreo o, a lo sumo, en semiconfinamiento. Para evaluar la influencia de diferentes factores sobre el contaje bacteriano total (CBT) y el contaje de células somáticas (CCS), por separado, se realizó una regresión multivariada. Asimismo, se determinó el coeficiente de correlación entre las variables de esta investigación. Las variables de respuesta se transformaron en logaritmos para la normalización de datos. Se realizó una comparación entre los resultados de la investigación y los parámetros de la IN 76 para verificar el cumplimiento de las normas por parte de los productores. Se encontraron valores medios de 6.986.977,818.961.790,7 UFC/mL para CBT y de 608.911,1 +414.802,9 CS/mL para CCS. El uso de un tanque de enfriamiento individual se ha mostrado favorable a la baja CBT, en comparación con no usar un tanque o usar un tanque comunitario, conforme lo esperado, ya que cuanto más se tarda en enfriar la leche, mayor es la proliferación de bacterias en el producto. Se verificó que la leche de los productores que realizan el California Mastitis Test (CMT) con mayor frecuencia presentó CCS más alto, lo cual no se esperaba. Los análisis fisicoquímicos promedio fueron densidad 1,031 g/mL a 15°C, índice crioscópico -0,538 °H, contenido de proteína 3,58%, contenido de grasa 4,06%, extracto seco total 12,75%, extracto seco desgrasado 8,69%, acidez titulable 16,2°D y estabilidad del alcohol (Alizarol 72%) 100%. En el 13,3% (6/45) de las muestras se detectó la presencia de antibióticos. Considerando la IN 76, la leche de solo el 8,9% (4/45) de los productores se presentó adecuado simultáneamente para todos los parámetros analizados (CBT, CCS, densidad, índice crioscópico, proteína, grasa, extracto seco total, extracto seco desgrasado, acidez titulable, estabilidad al alizarol e investigación de antibióticos). El uso de un tanque de enfriamiento individual y la realización de CMT favorecieron un CBT más bajo y un CCS más alto respectivamente.

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The primary objective of this study was to investigate the association between the bulk tank somatic cell count (SCC) and dairy farmers' knowledge about milk quality, mastitis control, and their socioeconomic characteristics. Additionally, we estimated the association between the bulk tank SCC and bulk tank milk hygienic quality in dairy herds. Bulk tank milk samples from 120 dairy herds enrolled in the milk quality payment program were collected for the determination of the SCC, the total bacterial count (TBC), the preliminary incubation count (PIC), the laboratory pasteurization count (PC), and the coliform count (CC). Based on the bulk tank SCC results, 63 herds were selected and categorized into three groups: (a) low SCC: ≤250,000 cells/mL (n = 16); (b) medium SCC: >250,000 ≤ 400,000 cells/mL (n = 24); and (c) high SCC: >400,000 cells/mL (n = 23). Socioeconomic profiles, attitudes, and knowledge of somatic cell count and milk quality were assessed using previously tested questionnaires, which were used to interview the herd managers of the 63 selected dairy herds. Among the findings, 87.0% of the dairy herds had an SCC < 400 × 103 cells/mL, and presented milk production as the main economic activity of the farm, whereas only 47.0% of dairy herds with an SCC > 400 × 103 cells/mL had milk production as the main economic activity of the farm (p < 0.031). In a total of 95% of the selected herds (n = 60), milking machines were used, with pipeline milking machines being more predominant, accounting for 70.8% in herds with a medium somatic cell count (SCC) and 78.3% in herds with a high SCC, as opposed to herds with a low SCC at 50% (p < 0.031). The frequency of dairy producers' awareness of the maximum legal requirements for the bulk tank SCC and TBC was higher in herds with a higher SCC than in herds with a medium SCC. In conclusion, the results of this study indicate a significant association between the bulk tank somatic cell count (SCC) and dairy farmers' knowledge about milk quality, mastitis control, and socioeconomic characteristics. These findings emphasize the importance of knowledge and the socioeconomic profiles of dairy farms in maintaining and enhancing milk quality in dairy herds.

RESUMO

Among the milk contaminating microorganisms, those which are able to form heat-resistant spores are concerning, especially for dairy companies that use ultra-high temperature (UHT) technology. These spores, throughout storage, can germinate and produce hydrolytic enzymes that compromise the quality of the final product. This study evaluated 184 UHT milk samples from different batches collected from seven Brazilian dairy companies with a possible microbial contamination problem. The bacteria were isolated, phenotypically characterized, clustered by REP-PCR, and identified through 16S rDNA sequencing. The presence of Bacillus sporothermodurans was verified using biochemical tests (Gram staining, catalase and oxidase test, glucose fermentation, esculin hydrolysis, nitrate reduction, and urease test). According to these tests, none of the isolates presented typical characteristics of B. sporothermodurans. In sequence, the isolates, that presented rod-shapes, were submitted to molecular analyses in order to determine the microbial biodiversity existing among them. The isolates obtained were grouped into 16 clusters, four of which were composed of only one individual. A phylogenetic tree was constructed using the sequences obtained from the 16S rDNA sequencing and some reference strains of species close to those found using BLAST search in the NCBI nucleotide database. Through this tree, it was possible to verify the division of the isolates into two large groups, the Bacillus subtilis and the Bacillus cereus groups. Furthermore, most isolates are phylogenetically closely related, which makes it even more difficult to identify them at the species level. In conclusion, it was possible to assess, in general, the groups of sporulated contaminants in Brazilian UHT milk produced in the regions evaluated. In addition, it was also possible to determine the biodiversity of spore-forming bacteria found in UHT milk samples, thus opening up a range of possible research topics regarding the effects of the presence of these microorganisms on milk quality.

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The present study described the chemical composition and somatic cell score (SCS) of samples of refrigerated raw milk collected from commercial farms in the state of Rio Grande do Sul in order to better understand the behavior of constituents present in non-fatty solids (NFS) in milk according to the season of the year. Means were used to describe statistical data. To estimate the probability of NFS levels meeting IN 76 (BRAZIL, 2018), binary logistic regression was used. It was reported that 18.2% (233.817) of analytical results showed NFS below 8.4%, representing the minimum required by IN 76. The highest average NFS level observed in the five-year period was registered in the micro-region of Passo Fundo (8.70%) in winter. The microregion with the lowest results was Porto Alegre (8.53%); however, it still demonstrated levels within the limits established by IN 76. The study indicates that milk constituents show differences between seasons. In autumn and winter, the constituents remained equal to or higher than those required by current legislation, while spring and summer were the periods with the lowest NFS values. The SCS was also influenced by the seasons, with the highest rates in spring, summer, and autumn.

O presente estudo teve como objetivo descrever os resultados de composição química e escore de células somáticas (ECS) de amostras de leite cru refrigerado coletado em fazendas comerciais no estado do Rio Grande do Sul, para melhor entendimento do comportamento dos constituintes presentes nos sólidos não gordurosos (SNG) no leite de acordo com as estações do ano. As médias foram estudadas para descrever as estatísticas dos dados. Para estimar a probabilidade de os teores de SNG atenderem à IN 76 de 2018, foi utilizada a regressão logística binária. Foi constatado que 18,2% (233.817) dos resultados analíticos apresentaram SNG abaixo de 8,4%, que representa o mínimo exigido pela IN 76 (BRASIL, 2018). A maior média de SNG observada no período de cinco anos foi registrada na microrregião de Passo Fundo (8,70%), no inverno. A microrregião com menores resultados foi a de Porto Alegre (8,53%), no entanto com teores dentro do estabelecido pela IN 76/2018. O estudo demonstrou que os constituintes do leite apresentaram diferenças entre as estações do ano. O outono e inverno foram os períodos em que os constituintes se mantiveram iguais ou superiores aos exigidos pela legislação vigente, enquanto que a primavera e o verão foram os períodos com os menores valores de SNG. O ECS também foi influenciado pelas estações do ano. Na primavera, verão e outono ocorreram os maiores índices.

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ABSTRACT: The present study described the chemical composition and somatic cell score (SCS) of samples of refrigerated raw milk collected from commercial farms in the state of Rio Grande do Sul in order to better understand the behavior of constituents present in non-fatty solids (NFS) in milk according to the season of the year. Means were used to describe statistical data. To estimate the probability of NFS levels meeting IN 76 (BRAZIL, 2018), binary logistic regression was used. It was reported that 18.2% (233.817) of analytical results showed NFS below 8.4%, representing the minimum required by IN 76. The highest average NFS level observed in the five-year period was registered in the micro-region of Passo Fundo (8.70%) in winter. The microregion with the lowest results was Porto Alegre (8.53%); however, it still demonstrated levels within the limits established by IN 76. The study indicates that milk constituents show differences between seasons. In autumn and winter, the constituents remained equal to or higher than those required by current legislation, while spring and summer were the periods with the lowest NFS values. The SCS was also influenced by the seasons, with the highest rates in spring, summer, and autumn.

RESUMO: O presente estudo teve como objetivo descrever os resultados de composição química e escore de células somáticas (ECS) de amostras de leite cru refrigerado coletado em fazendas comerciais no estado do Rio Grande do Sul, para melhor entendimento do comportamento dos constituintes presentes nos sólidos não gordurosos (SNG) no leite de acordo com as estações do ano. As médias foram estudadas para descrever as estatísticas dos dados. Para estimar a probabilidade de os teores de SNG atenderem à IN 76 de 2018, foi utilizada a regressão logística binária. Foi constatado que 18,2% (233.817) dos resultados analíticos apresentaram SNG abaixo de 8,4%, que representa o mínimo exigido pela IN 76 (BRASIL, 2018). A maior média de SNG observada no período de cinco anos foi registrada na microrregião de Passo Fundo (8,70%), no inverno. A microrregião com menores resultados foi a de Porto Alegre (8,53%), no entanto com teores dentro do estabelecido pela IN 76/2018. O estudo demonstrou que os constituintes do leite apresentaram diferenças entre as estações do ano. O outono e inverno foram os períodos em que os constituintes se mantiveram iguais ou superiores aos exigidos pela legislação vigente, enquanto que a primavera e o verão foram os períodos com os menores valores de SNG. O ECS também foi influenciado pelas estações do ano. Na primavera, verão e outono ocorreram os maiores índices.

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The study aimed to evaluate the use of the azidiol® preservative for psychrotrophic microorganism count (PMC) in cooled raw milk. Two studies were carried out, one under controlled conditions (experiment 1) and the other under field conditions (experiment 2), in which samples of raw milk were taken with and without the use of the azidiol® preservative and analyzed at predefined times (0, 6, 12 and 24 hours -experiment 1) and at varying times (experiment 2). Analysis of variance and regression analysis using SAS were applied for data statistical analysis. Milk samples without azidiol®showed higher PMC with increasing time between sampling and analysis, while in samples preserved with azidiol®, this count remained constant. Samples of cooled raw milk intended for PMC should be collected in flasks containing the azidiol®preservative.(AU)

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This study aimed to describe the epidemiological indexes of mastitis, milk quality and udder hygiene in the Compost Barn system, as well as to search for associations between isolated pathogens from milk with compost characteristics. Three dairy herds participated in the study, and the samples were collected during different periods on each farm. Individual milk samples were collected in duplicate for SCC analysis and microbiological culture. Environmental pathogens caused most cases of clinical mastitis on farm 2, and contagious pathogens caused the most cases on farm 1. Bed moisture was not associated with the incidence of environmental pathogens. Most of the animals remained in good udder hygiene during the study. Poor udder hygiene contributed to the increased incidence of environmental pathogens in one of the farms. A higher number of animals with a hygiene score of ≥ 2 were observed during the warmer and rainfall periods. There was no association between hygiene scores and somatic cell counts. The results suggest that pathogens isolated from milk in animals confined in Compost Barn under tropical climate are like other confinement systems adopted elsewhere. The year period influenced the udder hygiene score, reinforcing the importance of bed management throughout the year.

O objetivo deste estudo foi descrever os índices epidemiológicos da mastite, da qualidade do leite e da higiene do úbere em animais confinados no sistema Compost Barn, bem como buscar associações entre patógenos isolados do leite e características do composto. Três rebanhos leiteiros participaram do estudo e as amostras foram coletadas em diferentes períodos em cada fazenda. Amostras individuais de leite foram coletadas em duplicata para análise de CCS e cultura microbiológica. Patógenos ambientais causaram a maioria dos casos de mastite clínica na fazenda 2, e na fazenda 1 a maioria dos casos foi em decorrência de patógenos contagiosos. Amostras de material da cama foram coletadas em duas fazendas para análise da densidade bacteriana e da umidade. A umidade da cama permaneceu dentro da faixa de controle durante o estudo e não foi associada à incidência de patógenos ambientais. A maioria dos animais permaneceu com boa higiene de úbere durante o estudo. A falta de higiene do úbere contribuiu para o aumento da incidência de patógenos ambientais em uma das fazendas. Durante o período mais quente e mais chuvoso, um número maior de animais com escore de sujidade ≥2 foi observado em todos os rebanhos. Não houve associação entre escore de sujidade e contagem de células somáticas em qualquer uma das três fazendas. Os resultados indicam que o perfil de patógenos isolados do leite em animais confinados em Compost Barn sob clima tropical é semelhante a outros sistemas de confinamento adotados em outros lugares. O período do ano influenciou o escore de higiene do úbere, o que reforça a importância do manejo da cama ao longo do ano.

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The aimed of the study was to evaluate the quality of raw milk from some suppliers in rural and urban areas and to test the hypothesis that it is unsafe for direct consumption. The study was conducted with suppliers in rural and urban areas in Presidente Médici municipality, Rondônia state. The method of the Ministério da Agricultura, Pecuária e Abastecimento (MAPA), was used, which consists of titrating a portion of the sample with a sodium hydroxide solution of known concentration, using phenolphthalein as an indicator. According to Brazilian legislation and literature, stability of Alizarol, foreign substances, Chloride, Hypochlorite, Hydrogen Peroxide and Colostrum were analyzed. Microbiological analysis, standard plate count (SPC) and quantification of thermotolerant coliforms were also performed using the most probable number (MPN) technique. Values above the limits established by legislation were found, mainly for temperature and titleable acidity, in addition to stability results against Alizarol and the presence of colostrum. There were high microbial contents with regard to SPC, and, in this case, the presence of pathogenic microorganisms cannot be disregarded. The presence of thermotolerant coliforms may indicate probable contact of milk with feces. Therefore, it is considered that the samples analyzed here are not safe for ingestion in the raw form.(AU)

O objetivo do estudo foi avaliar a qualidade do leite cru de alguns fornecedores da zona rural e urbana e tes-tar a hipótese de que não são seguros para o consumo direto. O estudo foi conduzido em fornecedores da zona rural e urbana do município de Presidente Médici, estado de Rondônia. Empregou-se o método do Ministério da Agricultura Pecuária e Abastecimento (MAPA), que consiste na titulação de uma porção da amostra por uma solução hidróxido de sódio de concentração conhecida, utilizando como indicador a fenolftaleína. Conforme a legislação brasileira e a lite-ratura, foram analisados estabilidade do Alizarol, substâncias estranhas, Cloreto, Hipoclorito, peróxido de Hidrogênio e Colostro. Foram realizadas também análises microbiológicas, contagem Padrão em Placa (CPP) e quantificação dos coliformes termotolerantes através da técnica do número mais provável (NMP). Foram encontrados valores acima dos limites estabelecidos pela legislação, principalmente para temperatura e acidez titulável, além dos resultados de estabili-dade frente ao Alizarol e da presença de colostro. Houve altos teores microbianos no que se refere à CPP, e, nesse caso, a presença de microrganismos patogênicos não pode ser desconsiderada. A presença de coliformes termotolerantes pode indicar provável contato do leite com fezes. Portanto, considera-se que as amostras aqui analisadas não são seguras para ingestão na forma crua.(AU)

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