The influence of temperature, relative air humidity and temperature humid index on the quality of cow milk

Abstract

Centuries long experience has shown, and decades-long measurements have confirmed that there was no significant
difference in the quality of milk on the farm during the year. These variations are correlated with a number of
factors. Some of them are biological (are related to characteristics of breeds and individual cows), but a large number of groups are abiotic (Ambient conditions). With regard to biological factors difficult and slow to change, the aim of this study was to investigate the influence of environment conditions on the quality of milk on selected farms. The farm "Stari Tamis" near Belgrade was chosen. There are daily milked 200 cows to 220. About 95% of cows are the Holstein-Friesian and Simmental remained. Over 35% of cows in first lactation, and less than 5% had previously five lactations. Studies were performed using standard methods for determining the total amount of: fat, protein and dry matter. Analyzing the obtained results, it was found that with increasing temperature of the wet index values, there is
a decrease in the quantity of dry matter in milk. Thus, at the lowest interval index of up to 74, the percentage of dry
matter in milk was 12.26%, while the highest interval index of over 84, the percentage of dry matter was reduced to
11.81%. The increase of the index will result in declining of the amount of fat. In the days when it was the lowest
interval when heat stress was hardly any, the amount of milk fat was 3.45%, while on days with extremely strong and heat stress the index value was over 84, fat dropped to 3,18%. The increase of the index humid temperature value, led to a decline in the amount of protein in milk. Thus, at the lowest interval index of up to 74, the amount of protein in milk was 3.30%, while the highest interval index of over 84, the amount of protein was reduced to 3.21%.