ABSTRACT. 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.

ABSTRACT. Technical regulations that determine milk quality standards in Brazil establish the minimum criteria that the processing industry's raw material must present. These rules can challenge the logistics sector (transport) to maintain adequate milk conservation levels. We aimed to evaluate the influence of bulk transport and storage conditions on refrigerated raw milk quality. The experiment was carried out in a dairy industry in Santa Catarina State. Information and samples of refrigerated raw milk were collected from dairy farms, from isothermal compartments of milk trucks, and from the industry's storage silo. These samples were submitted to microbiological analysis, somatic cell count (SCC), and physicochemical analysis. The results were evaluated by ANOVA and multivariate analysis (factor analysis). The transport of raw milk in bulk and the transfer of raw material to the industrial silo worsened the milk's microbiological quality (p < 0.0001) for standard plate count (SPC) and psychrotrophic microorganism count (PMC), without affecting, the physicochemical characteristics of the milk (p > 0.05). Poor hygienic conditions in milk storage rooms, in the refrigeration bulk tanks of the dairy farms, and during the transport, as well as the transport on longer routes, were related to higher SPC and psychrotrophic count while receiving milk by the dairy industry with higher temperatures was only associated with higher SPC.

RESUMO: A cultura de leite na fazenda (do inglês On farm culturing) é uma tecnologia em franca expansão no Brasil. Fundamenta-se no diagnóstico microbiológico de amostras de leite colhidas de casos clínicos de mastite bovina, na própria fazenda onde são manejados os animais, de forma rápida, simples e com custo acessível. Com este recurso, após 24 horas de incubação, os micro-organismos isolados são classificados em Gram-positivos ou Gram-negativos, auxiliando na tomada de decisões quanto à terapia dos animais. Considerando a relevância da região meio oeste catarinense no cenário nacional de produção leiteira, o objetivo do presente estudo foi promover a capacitação técnica dos produtores em três propriedades localizadas em Treze Tílias-SC, e auxiliar na implementação e avaliação da cultura de leite na fazenda como recurso tecnológico voltado ao uso reduzido de antimicrobianos nos rebanhos. Além da rápida aceitação pelos produtores e eficiente capacitação dos mesmos, verificou-se, com o emprego da tecnologia, redução de 45% a 50% do uso de antimicrobianos nos rebanhos. Este resultado, além de demonstrar significativo impacto em saúde animal, determinou importante redução de custos aos produtores, como apresentado detalhadamente no presente artigo.

ABSTRACT: On-farm culturing is a technology booming in Brazil. It is based on the microbiological diagnosis of milk samples collected from clinical cases of bovine mastitis, on the farm where the animals are handled, quickly, simply, and at an affordable cost. With this resource, after 24 h of incubation, the isolated microorganisms are classified as gram positive or gram negative, helping to make decisions regarding the therapy of the animals. Considering the relevance of the Midwestern region of Santa Catarina State in the national dairy production scenario, the objectives of the study were: 1) to promote the technical training of the farmers in three dairy farms located in Treze Tílias-SC, 2) to assist in the implementation and evaluation of on-farm culturing as technological resource viewing the reduced use of antimicrobials in herds. In addition to the rapid acceptance by the farmers and their efficient training, with the use of the technology, there was a 45-50% reduction in the use of antimicrobials in dairy herds. This result demonstrated a significant effect on animal health, and determines an important cost reduction for farmers, as presented in detail in this manuscript.

ABSTRACT We aimed to determine the relationship of milk yield, milk composition, and somatic cell score (SCS) with functional traits (lameness score, udder cleanliness score, udder depth, and teat end hyperkeratosis score) and physiological status (parity and days in milk (DIM) of cows housed in compost bedded pack barn system (CBP) using multivariate analysis. Data were collected in September and October of 2017 and evaluated using factor and cluster analysis. Four factors were formed, with the first factor showing the traits responsible for altering the lactose content in milk, the second factor comprising the effect of DIM, the third factor representing the teat end hyperkeratosis score, and the fourth factor demonstrating the udder cleanliness. The cluster analysis formed three clusters. Clusters 2 and 3 differed for protein and lactose content, SCS, parity, DIM, lameness score, and udder depth. Cluster 1 differed from the others, especially due to the high milk yield. Cow conformation traits and physiological status affected milk yield and composition in CBP. There is an association between udder depth, parity, and SCS with negative impact on lactose content. Parity is also associated with higher milk yield and teat end hyperkeratosis score. Cows with lower lameness score presented dirtier udders due to increased movements on the feed parlor and water troughs areas. Special attention to the improvement of the udder conformation traits, as well as management practices that reduce hyperkeratosis, are necessary to keep high yielding, healthy, and cows with higher longevity. The cleanliness in the feed parlor and water troughs area is very important to preserve milk quality and healthy cows.

Resumo O teste do álcool é amplamente utilizado na recepção dos laticínios para a verificação da estabilidade do leite cru. O leite que não é estável no teste e não apresenta acidez elevada é definido como leite instável não ácido (LINA). A sua ocorrência tem característica multifatorial e pode estar relacionada ao manejo nutricional inadequado. Este estudo objetivou avaliar a influência da infraestrutura da propriedade e da alimentação dos animais sobre a ocorrência de LINA. A infraestrutura foi caracterizada através de questionário guia semiestruturado. Analisou-se a composição centesimal do leite das propriedades, resistência ao teste do álcool, acidez titulável e o pH. Foram consideradas LINA as amostras que precipitaram em concentração de álcool menor ou igual a 72%, com acidez e pH normais. Nos alimentos coletados, determinou-se o teor de fibra em detergente neutro. Os dados foram avaliados através de análise fatorial e de agrupamento utilizando o pacote estatístico SAS. O uso de suplementos alimentares volumosos e concentrados, com consequente melhoria da produtividade animal e maior teor de lactose no leite foi relacionado com menor ocorrência de LINA nas condições estudadas. A ocorrência de LINA apresentou pouca relação com a infraestrutura das propriedades e com a estação do ano.

Abstract The alcohol test is largely used in the dairy reception platform in order to verify raw milk stability. Milk that is not stable in the test and does not present high acidity is defined as unstable non-acid milk (UNAM). Its occurrence has a multifactorial characteristic and may be related to inadequate nutritional management. This study aimed to evaluate the influence of farm structure and animal feed on the occurrence of UNAM. The farm structure was characterized by means of a semi-structured questionnaire guide. Milk composition of the farms, resistance to alcohol test, titratable acidity and pH were analyzed. UNAM samples were those that precipitated at alcohol concentration less than or equal to 72%, with normal acidity and pH. Neutral detergent fiber was determined in the feed collected. Data were evaluated using factor and cluster analysis by using SAS statistical package. The use of roughages and concentrated food supplements with consequent improvement of animal productivity and higher lactose content in milk were associated with lower occurrence of UNAM under the studied conditions. The occurrence of UNAM had little relation with the farm structure and with the season of the year.