Evaporative cooling for Holstein dairy cows under grazing conditions.
Twenty-four grazing Holstein cows in mid and late lactation were randomly assigned to two treatment groups: control and cooled. The trial was performed at the Experimental Dairy Unit, Rafaela Agricultural Experimental Station (INTA), Argentina. The objective was to evaluate the effects of sprinkler and fan cooling before milkings on milk production and composition. The effects of the cooling system on rectal temperature and respiration rate were also evaluated. Cooled cows showed higher milk production (1.04 l cow(-1) day(-1)). The concentration and yield of milk fat and protein increased in response to cooling treatment. The cooling system also reduced rectal temperature and respiration rate. No effects were observed on body condition. It was concluded that evaporative cooling, which is efficient for housed animals, is also appropriate to improve yields and animal well-being under grazing systems. These results are impressive since the cooling system was utilized only before milkings, in a system where environmental control is very difficult to achieve. This trial was performed during a mild summer. The results would probably be magnified during hotter weather.
Valtorta
Silvia E
SE
National Council for Scientific and Technical Research (CONICET), Rafaela Agricultural Experimental Station, National Institute of Agricultural Technology (INTA), Ruta 34 km 227, (2300) Rafaela, Santa Fe Argentina. svaltorta@rafaela.inta.gov.ar
Gallardo
Miriam R
MR
D000822:Animal Husbandry; D000827:Animal Welfare; D000818:Animals; D001831:Body Temperature; D001833:Body Temperature Regulation; D002417:Cattle / Q000502:physiology*; D005247:Feeding Behavior; D005260:Female; D006799:Housing, Animal; D007774:Lactation; D011897:Random Allocation; D012119:Respiration; D014835:Volatilization