Suchergebnisse

O resfriamento do leite após a ordenha em todas as dimensões dos tanques de expansão deve preservar as características do leite. Portanto, o objetivo do trabalho foi verificar a temperatura do leite cru mensurada por termostato e termômetro em pontos superficiais e do fundo de 33 tanques de expansão no Vale do Rio Doce (MG). Os dados foram relacionados com a qualidade do leite e conhecimento dos produtores quanto à refrigeração do leite. A temperatura média mensurada pelo termostato do tanque de refrigeração foi inferior (p<0,05) às temperaturas médias mensuradas pelos termômetros, mas estas foram iguais (p>0,05) em pontos diferentes no interior do tanque. A contagem bacteriana do leite foi maior (p<0,05) em tanques com alta temperatura de armazenamento, o que causou desconformidade de 42,4% de amostras quanto a legislação. A falta de informação dos produtores a respeito da refrigeração correta do leite e a refrigeração inadequada de tanques comprometeram a qualidade e conformidade de 10% de amostras quanto à legislação. A manutenção e inspeção de tanques devem ser efetivadas de forma constante.

The process of teat disinfection is a widely accepted component of successful mastitis control programs by reducing the number of bacteria on the teat skin and healing teat lesions. For contagious pathogens such as Staphylococcus aureus, post-milking teat disinfection remains a simple, effective and economical practice for prevention of new intramammary infections (IMIs) of lactating dairy cows. Despite the universal acceptance of teat dipping as a method of mastitis control, variations in the susceptibility and resistance profile of mastitis pathogens among antiseptics have been described. Thus, here we sought to explore the in vitro efficacy of the followings antiseptics against S. aureus isolated from IMIs: chlorhexidine (2.0%), chlorine (2.5%), quarternary ammonium (4.0%), lactic acid (2.0%) and iodine (0.6%). We used 50 S. aureus strains isolated from bovine IMIs from 50 dairy herds located at Minas Gerais, São Paulo, Paraná and Rio Grande do Sul States (Brazil). The antiseptics were evaluated at four different specific intervals (15, 30, 60 and 300 s). We found a higher activity for quarternary ammonium and chlorhexidine against S. aureus at all time-points, followed by iodine and then chlorine. Lactic acid treatment produced the worst results for all time-points and strains. Due to variations in the sensitivity and resistance profile of antiseptics against S. aureus isolated from IMIs, the effectiveness of the antiseptics against the major mastitis pathogens should be periodically evaluated in dairy farms in an attempt to reduce the rate of new IMIs in the herd.

Fermented milk beverage is a product containing milk, whey and/or other ingredients, fermented by specific microorganisms and/or added with fermented milks. Fat determination in this product is important to quality control and inspection. The Gerber method is used worldwide as a simple and rapid method for fat content analysis in raw and processed milks. In Brazil, Roese-Gottlieb is the official method for analysis of fat content in milk beverages. However, the use of Gerber method for fat content determination in fermented milk beverages is widespread throughout the industry in the country. Several authors have tested the use of Gerber method for some dairy products, but there is no report on this evaluation for fermented milk beverages. In this context, the objectives of this work were to determine the fat content of fermented milk beverages by the Gerber method and evaluate the performance of this test, using Roese-Gottlieb as a reference method. Thirty samples of fermented milk beverages were analyzed by both methods. The fat contents ranged from 1.25 to 2.40% by the Gerber method and from 1.24 to 2.50% by the Roese-Gottlieb method. There was no difference (p > 0.05) between the methods. The Gerber method can be used to determine the fat content of fermented milk beverages, without prejudice to the results obtained.