Effect of fan and shower cooling systems on dairy cows milk yield, milk components and physiological parameters during the summer months

The objectives of the study were to determine the effect of Fan, Sprinkler and Fan+Sprinkler cooling of dairy cows under a hot and humid climate on intake, milk yield, milk components and some physiological parameters (skin temperature, rectal temperature and respiration rate) in 2 experiments. The experiments were conducted on dairy cows unit located at revolving fund, Faculty of Agriculture, Cukurova University during the months of July and August, 2013. Each experiment lasted three weeks and adaptation period has been considered as the first 10 days. Flow rate of sprinklers of the first experiment were 0.3 L/min, for the second experiment were 0.5 L/min. In both experiment cows used in the study were divided into 4 groups, as no cooling (Control), fan cooling (F), shower cooling (SH) and shower and fan cooling (SH+F). In first experiment, there was significant (P<0.05) effect of treatment and interaction on changes in feed intake (CFI) and changes in body condition score, while there was no significant (P>0.05) treatment effect on the other parameters. However, there were significant effect (P<0.05) of fan and interaction by shower on CFI. Despite the presence of a significant effect (P<0.05) of SH on efficiency of milk production (EMP), there were no significant effect (P> 0.05) of SH, F and interaction on the other parameters. Whereas the results of statistical analisis for physiological parameters on first experiment show that, there were significant effect (P<0.05) of SH on rectal temperature measured at 15:30, there were significant effects (P<0.05) of SH, F and ineraction on skin temperature measured at 15:30. Result of second experiment show that, there were significant effect (P<0.05) of SH on rectal temperature measured at 15:30. There were significant effect (P<0.05) of SH on respiration rate measured at 15:30, in addition to this, the lowest value was found in SH group the highest value was found in F group. Depite of the result of both experiments show that there were no sisgnificant differences between groups in respect of high level of milk yield and milk composition and found level of THI highest then threshold THI for dairy cows were indicate mild and moderate heat stress on cows. In this regard, at the low levels of milk yield of experimental group of animals can be considered as a reason for the lack of a significant effect. In addition, cows used in this study were primiparous and milk yields are given relatively low, implementation of cooling methods can be suggestible for multiparous cows in Cukurova climate conditions. Keywords: dairy cows, heat stress, cooling, physiological parameters