Efeito de boas práticas agropecuárias sobre qualidade do leite em rebanhos mestiços

Abstract

The effect of milking routines on milk quality parameters was evaluated using data from crossbred herds located in the cities of Janaúba, Porteirinha, Serranópolis de Minas, São João da Lagoa and Jaíba, north of Minas Gerais state.The data collection period ranged from january 2002 to december 2012. Milk samples were collected in order to evaluate somatic cells coint (CCS) and the total bacterial count (CBT). California Mastitis Test (CMT) eas also performed. Questionnaires about milking management were applied in order to know mastitis's control and prevention procedures adopted at the proprieties. Description analisys for all the studied variables (CCS, CBT and CMT) by propriety, year, season and month were done. Multiple correspondence analisys was performed in an attempt to establish an association between climatic, herd, milking routines and milk quality traits. The risk factors for determination of the probability odf milk samples have somatic cell counts (CCS)>400,00 cells mL-1and total bacterial count (CBT)>100,00 cfu mL-1, that implies in milk price penalty, were inferred by means of logistic regression considering the milking routines as explanatory variables. The probabiility of milk samples to have CCS>400,00 mL-1 cells was 16.42 times greater when milking order was not adopted. The risk of CBT being greater than 100,000 cfu mL-1 was 12.59 times greater when paper towels were not used to dry teats before milking. The milking practices adopted along the seasons ove the years were efficient to maintain milk quality even in high rainfall periods. Milking routines as, milking line, milking environment and utilization of disposable material to clean cow teats pre milking, should be adopted in order to avoid the increase of CCS and CBT in milk samples.