Raw Cow Milk Protein Stability under Natural and Technological Conditions of Environment by Analysis of Variance

Abstract

Heat stability (HS) is substantial technology property of raw milk. Analysis of sources of HS variation and its regular monitoring can contribute to creating higher added value in the dairy industry. The goal of this analysis was to assess the practice sources of raw cow milk HS variability on the results of an extensive data set of bulk tank milk samples. There was implemented neither a compositional technology modification nor acidity adjustment of milk, just original raw milk was used for the analysis. A total 2634 HS analyses were performed, including other milk indicators, during three years of an experimental period. The log HS mean and standard deviation were 1.273654 ± 0.144189, equal to the HS geometric mean of 18.8 min. Explanation of the HS variability through the linear model used was 41.1% (p < 0.0001). According to the results of the variance analysis, the milk HS was influenced (p = 0.0033 and mostly <0.0001) by all the farm factors such as year; season; calendar month; altitude; total annual rainfall; herd size by the number of cows; milk yield; cow breed; type of milking; litter type in the stable; summer grazing application; farm effect. During the calendar months (p < 0.0001), milk HS values suggest similar seasonal dynamics with the somatic cell count, total count of mesophilic microorganisms, coli bacteria count and urea and lactose concentration and opposite configuration pattern to fat, crude protein, solids-not-fat and total solids content and milk freezing point depression. Here performed quantification of these effects by analyzing the variance may allow efficient raw milk selection to be processed into specific dairy products.

CSN1S1 and LALBA Polymorphisms and Other Factors Influencing Yield, Composition, Somatic Cell Score, and Technological Properties of Cow’s Milk

“…The lactation stage (days in milk) influenced milk fermentation ability and SCS; non-fat solids influenced renneting. Hanuš et al [ 47 ] carried out, within three years, an analysis of 2634 raw milk samples. The thermostability was, on average, 18.8 min and was affected by all 12 evaluated factors, e.g., year, season, milk yield, breed, milking, and summer grazing.…”

Interrelationships Between Milk Constituents, Protein Profile, Genotypes of Kappa-Casein Gene and Ethanol Stability of Cow's Milk

“…Somatic cell count and TBC were reported to be both health and hygiene indicators for dairy cows (Hanuš et al, 2021). In discussing the difference between ethanol stable and unstable milk with SCC and TBC in this study, a significant increase in both SCC and TBC in the unstable milk was observed, as shown in table (1).…”

“…Also, the results of Oliveira et al (2013) suggested that the high SCC may be involved as a causal factor for the high incidence of ethanol unstable milk as the last showed higher SCC as well as lower casein contents which approved our results. Lately, Hanuš et al (2021) cleared that, milk stability values suggested similar seasonal dynamics with the SCC and TBC and opposed composition patterns to crude protein, fat, SNF, and TS content.…”

Seasonal Variation in Raw Milk VOC Profile within Intensive Feeding Systems

“…Such changes in forage chemical composition could affect either cows' feeding behaviour or the metabolism of carbohydrates and protein in the rumen. This could be the origin of the different native macro-and micro-compounds detected in the milk in winter compared to summer [47]. Moreover, evidence has been reported of a strong impact of raw milk's indigenous microbial community on the development of its VOC profile, but indoor milk is more likely to have higher proportions of host/gut-associated microbes [48].…”