Influence of Temperature-Humidity Relations During Years on Milk Production and Quality

The aim of this study was to evaluate influence of climatic conditions represented by daily air temperature and relative air humidity on indicators of Holstein cows’ milk quality and production. The first dataset represented individual milk production in day of milk performance recording (milk kg, fat %, protein %, and somatic cells count thous./ml). The second dataset represented total daily milk characteristics of herd (milk kg, fat %, protein % and somatic cells count thous./ml). A total of 654 Holstein cows were observed and evaluated. Both datasets were evaluated in relation to selected external influences (year, month, average daily air temperature, and average daily relatively air humidity). Statistical analysis was performed using SAS 9.3, and UNIVARIATE, REG and GLM procedure. Three groups of daily air temeperature (less than 4.4 degC; 4.4 - 13.2 degC; more than 13.2 degC), and daily relative air humidity (less tan 65.3 %; 65.3 - 80.4 %; more than 80.4 %) were conducted for evaluation. Significant (P less than 0.05) linear regressions were computed among daily air temperature and all milk production indicators, except of somatic cells count attribute. The highest individual daily milk production (35.94 kg, P less than 0.01), and protein content (3.41 %, P less than 0.01) were achieved with the highest average daily air temperature. Opposite results were observed for milk yield of herd as well as protein content. Average daily relative air humidity had lower influence on individual and bulk milk samples. The better results were achieved for both datasets (individual and bulk samples) in groups (65.3 - 80.4 %; more than 80.4 %) of average daily relative air humidity. Obtained results point out importance of outdoor climatic parameters monitoring and preventive measures of climatic conditions in the stable.