Season influence on milk physico-chemical and microbiological aspects in Western Santa Catarina

Abstract

The objective of this study was to analyze the influence of seasonal changes on milk quality in Western Santa Catarina, Brazil. Dairy farms (799) had raw milk samples (9144) collected and analyzed for fat, protein, SCC (somatic cell count) and TBC (total bacterial count). Samples were collected from cooling tanks on the farm during the months of October 2009 to September 2010 and grouped into four seasons (summer, autumn, winter, and spring). The data were classified according to the normative instructions 51 and 62 the Ministry of Agriculture, Livestock and Food Supply, and also according to a quality pay system adopted by the dairy industry in the region of the study. The results revealed differences between groups (P<0.05), where fat content was higher in autumn, protein and TBC were higher in winter and SCC showed the highest rates in the summer. According to the criteria established by legislation, the main quality problem was the TBC, with higher counts in the winter, and in the summer we observed the highest percentage of non-compliant samples. For the quality payment system, chemical composition resulted on better prices to be paid to producers, while TBC was primarily responsible lower price. Key words: Milk quality, payment based on quality, seasonality ResumoO objetivo do trabalho foi analisar as variações sazonais da qualidade do leite no oeste de Santa Catarina de acordo com as estações do ano. Utilizaram-se dados de 799 produtores de leite de uma cooperativa do Oeste Catarinense, considerando os teores de gordura, proteína, CCS (contagem de células somáticas) e CBT (contagem bacteriana total) de 9144 amostras de leite cru, coletadas diretamente dos tanques de resfriamento do produtor, durante os meses de outubro de 2009 a setembro de 2010. Os dados foram agrupados em quatro estações do ano (verão, outono, inverno e primavera). Para as quatro estações do ano, os dados também foram classificados segundo as instruções normativas IN 51 e IN 62 do Ministério da Agricultura, Pecuária e Abastecimento, como também de acordo com um sistema de remuneração ao produtor adotado por laticínios na região do estudo. Os resultados revelaram diferença entre os grupos (P<0.05), sendo que o teor de gordura foi maior no outono, a proteína e CBT foram maiores no inverno e CCS apresentou os maiores índices no verão. Conforme os critérios estabelecidos pela legislação, o principal problema observado foi associado a CBT, sendo que no inverno foram observadas as maiores contagens e, no verão, a maior porcentagem de amostras fora do padrão preconizado pela legislação. Com base na remuneração por qualidade, a composição centesimal resultou para a maioria dos produtores em bonificação no preço do leite pago ao produtor, e a CBT foi a principal responsável pela diminuição do preço final. Palavras-chave: Qualidade do leite, remuneração por qualidade, sazonalidade

Effects of some environmental factors on somatic cell count and milk chemical composition in cow bulk tank milk

“…Significantly higher protein content was observed in spring and winter compared with autumn and summer (P<0.05). Similar to present study, Simioni et al (2014) determined that the autumn season had the highest fat content, while the winter season showed the highest protein content. Similar finding was also reported by Maciuc et al (2017) who determined that protein and fat in milk were higher during cold months.…”

“…LogSCC was the highest in summer and the lowest in winter (Table 3), which is consistent with previous studies (El-Tahawy and El-Far, 2010;Pavel and Gavan, 2011;Maciuc et al, 2017). The authors attributed the higher average in the summer to stress due to high temperatures and humidity exposing animals to a greater number of pathogens and increasing susceptibility to infections and occurrence of mastitis (Simioni et al, 2014;Ribas et al, 2014). Also, according to Harmon (1994) some stressors, especially heat, may increase SCC in milk.…”

“…This was probably due to lower intake of feed energy with in-door feeding and may reflect the feeding regime used for herds (Maha et al, 2016). Another factor that could explain the lower concentration of fat and protein content in the summer would be the presence of lipases leukocyte metabolizing fatty acids in milk and leukocyte proteases that could cause a significant reduction on casein (Simioni et al, 2014). Besides, spring grass or pasturing may have a specific transient and beneficial effect on milk protein (Agabriel et al, 1993).…”

Modelling relationships between raw milk quality parameters and climatic conditions - the case study of a 3-years survey in Serbia

“…Since the elevation of SCC is a response to an insult to the mammary gland and is modulated by inflammatory mediators, Harmon (1994) points that the major factor influencing SCC is infection status and that few factors other than infection status may have a significant impact on milk SCC. Several authors emphasize seasonal variation of SCC (Bernabucci et al, 2015;Paula, Ribas, Monardes, Arce, & Andrade, 2004;Roma Júnior, Montoya, T. Martins, Cassoli, & Machado, 2009;Simioni et al, 2014).…”

Conformity of Refrigerated Raw Milk From Family Production Units of Southern Espírito Santo

“…Considering that the great majority of dairy farmers in Brazil found difficult to comply with the legislation, in 2011, the Federal Government approved the Normative Instruction number 62 that extended the deadlines for compliance for standard plate count and somatic cell count (4) . Even currently, studies have shown that producers still find difficult to meet such standards (5,6) .…”