Evaluation of the compositional, microbiological and sanitary quality of raw milk in the second third of lactation in dairy cows

Introduction: One of the most important parameters associated with the production of milk and its transformation, is to have adequate hygienic-sanitary conditions in terms of milk quality that allow improving the conditions of the producer and processing companies and therefore provide a food safety to the consumer guaranteeing their well-being and health. Objetive: Compositional, microbiological and sanitary characteristics of raw milk were evaluated during its second third of lactation in dairy cows. Materials and methods: Milk samples were taken every 10 days in duplicate to 7 dairy cows during their second third of lactation. For this, the following tests were carried out: Compositional analysis, adulterants, presence of antibiotics, somatic cell count (RCS / mL), identification of Staphylococcus aureus and antibiogram by the Kirby-Bauer method. Results: The presence of Staphylococcus aureus was evidenced in 66.2% of the samples and 4.6% of them were positive for Listeria sp. There was no presence of antibiotics, peroxides and starches. Positive samples were found for chlorides and neutralizers, and it was determined that for each kilogram of milk, 30, 25 and 84 grams of protein, casein and non-fatty solids (SNG) were obtained, with 83% of the protein representing casein. In the case of RCS / mL, values higher than one million RCS / mL were found. Conclusions: The compositional, sanitary and microbiological quality of raw milk in the second third of lactation in dairy cows is not adequate, because values that surpass some guidelines of the Colombian technical standard 399 of 2002, in which account is established of mesophiles and somatic cell counts (SCR / mL) maximum of 700000 / ml of raw milk, therefore they do not allow the consumption of milk and its transformation.
Introducción: uno de los parámetros más importantes asociados a la producción de leche y su transformación es contar con condiciones higiénico-sanitarias adecuadas en cuanto a calidad de la leche que permitan mejorar las condiciones del productor y empresas transformadoras y, por ende, proporcionar inocuidad alimentaria al consumidor garantizando su bienestar y salud. Objetivo: se evaluaron características composicionales, microbiológicas y sanitarias de leche cruda durante el segundo tercio de lactancia en vacas lecheras. Materiales y métodos: se tomaron muestras de leche por duplicado cada 10 días a siete vacas lecheras durante su segundo tercio de lactancia. Posteriormente, se realizaron las siguientes pruebas: análisis composicional, adulterantes, presencia de antibióticos, recuento de células somáticas (RCS/mL), identificación de Staphylococcus aureus y antibiograma por el método de Kirby-Bauer. Resultados: se detectó la presencia de Staphylococcus aureus en el 66,2% de las muestras y 4,6% resultaron positivas para Listeria sp. No hubo presencia de antibióticos, peróxidos y almidones. Se evidenciaron muestras positivas para cloruros y neutralizantes, además se determinó que por cada kilogramo de leche se obtiene 30, 25 y 84 g de proteína, caseína y sólidos no grasos (SNG), respectivamente; donde la caseína representó el 83% de la proteína. Para el caso del RCS/mL se encontraron valores superiores a un millón de RCS/mL. Conclusiones: para el caso estudiado la calidad composicional, sanitaria y microbiológica de la leche cruda en el segundo tercio de lactancia en vacas lecheras no es adecuada debido a que se presentaron valores que sobrepasan algunos lineamientos de la Norma Técnica Colombiana (NTC) 399 de 2002, en la cual se establece un conteo de mesófilos y de células somáticas (RCS/mL) máximo de 700.000/ml de leche cruda, a partir del cual se debe descartar el consumo de leche o su transformación.