Frequency of microorganisms isolated at different stages of lactation and milk production loss associated with somatic cell count and to mastitis-causing pathogens

Abstract

The aim of this study was to evaluate the frequency of isolation of agents causing subclinical mastitis in a herd and to estimate production losses associated with SCC> 200,000cells/mL. Three 7-day interval microbiological cultures were performed in all lactating animals from the same farm that was evaluated from June to July. To evaluate the negative and positive isolation frequencies between the lactation phases, a Chi-square test was performed. Simple linear regressions were performed to evaluate the lactation curve of animals grouped by pathogens isolated from negative cows in the microbiological culture and with SCC <200,000cells/mL. To estimate the production losses between the groups, regression coefficients were used. Results found in this experiment were: Culture-negative cows with SCC ≥ 200,000cells/mL, cows testing positive in milk culture, with SCC <200,000cells/mL and cows testing positive in milk culture, with SCC ≥ 200,000cells/mL. Milk production was -3.5; -0.5 and -4.27kg, respectively, when compared to culture-negative cows with SCC <200,000cells/mL. Cows infected with yeast cells, Coagulase-negative staphylococci (CNS), Staphylococcus aureus and environmental streptococci produced -3.42; -0.5; -0.168 and -2.5kg of milk when compared to culture-negative cows with SCC <200,000cells/mL. SCC indicates an inflammatory reaction in the mammary gland and it is directly associated with milk production losses and with presence of microorganisms in the mammary gland.

Qualidade físico-química e microbiológica do leite bovino do Vale do Taquari no Rio Grande do Sul, Brasil

“…A correlação é significativa entre CCS e proteínas e entre CCS e lactose (p<0,05). Segundo Costa et al (28) , CCS acima de 200.000 CS/mL são indicativos de mastite subclínica, causando influência nos componentes do leite. Neste estudo, apenas quatro propriedades (P32, P28, P8, P3), representando 12,12% das amostras, apresentaram CCS abaixo de 200.000 CS/mL.…”

Physicochemical and microbiological quality of bovine milk from Vale do Taquari in Rio Grande do Sul, Brazil

“…The correlation is significant between SCC and proteins and between SCC and lactose (p<0.05). According to Costa et al (28) , SCC above 200,000 SC/mL are indicative of subclinical mastitis, considering influences on milk components. In this study, only four properties (P32, P28, P8, P3), representing 12.12% of the samples, presented SCC below 200,000 SC/mL.…”