Abstract: This experiment was conducted to study the effect of light music on milk yield and serum hormone levels of dairy cows.Thirty two healthy Holstein dairy cows with similar milk yield,age,parity and lactation were randomly divided into two treatments and 16 cows in each treatment.Playing light music for 2 h at every feeding time in experimental group,20 classical piano (Richard Clayderman) of light music was selected,the control group was routine feeding.The pre-test period lasted for 7 days and the trial period lasted for 60 days.The milk yield and blood samples were determined every 10 d.The results showed that the milk yield in experimental group was significantly higher than that in control group at 10 and 40 days (P<0.05),the milk yield in experimental group was higher than that in control group at 20,30,50 and 60 days,but the difference was not significant (P>0.05).In the whole experiment period,the milk yield in experimental group was extremely significantly high than those in control group (P<0.01),which increased by 1.72 kg.In the whole experiment period,light music could increase the serum γ-aminobutyric acid,growth hormone levels,and reduce the serum cortisol,serotonin levels,but the difference was not significant (P>0.05).In conclusion,light music could reduce stress and improve milk yield of dairy cows through increase the serum γ-aminobutyric acid level,promote the growth homone secretion and reduce the serum cortisol and serotonin levels.

Key words: light music; dairy cows; milk yield; serum hormone levels