The effect of the night cooling on milk production milk composition and some physiologic parameters of dairy cows

The present study was conducted to investigate the effects of daytime and night cooling on milk production, milk composition and some physiological parameters of dairy cattle. In the experinend, 28 lactating Holstein dairy cows were divided into 4 groups and were exposed to Control (without cooling), Sprinklers, Sprinklers+Fans, and Fans for daytime (between 10 pm – 5 am) cooling. The cooling was applied between 10 pm – 5 a.m. The experiments were lasted 6 weeks and dairy cows were fed total mixed ration containing corn silage, alfalfa, wheat straw and concantrate (18% crude protein and 2650 kcal/kg metobolizable energy). Milk yield and dry matter intake were measured daily in this experiment. Milk samples were collected 2 times per week and analyzed for components.Body weight and body condition score were recorded weekly. Respiration rate, heart rate, rectal temperature and skin temperature were measured times a day (on 10.30 a.m., 1.30 p.m. and 3.30 p.m.). As a conclusion, whereas night cooling and especially sprinklers treatment increase daily milk yield while worsening of dry matter intake.