Analysis of behavior and milk yield of cows raised in different climatization systems and bedding in the summer

摘要

A study was carried out in summer season (from May to September) 2002 with 380 Italian Freisian cows raised in a freestall barn located in the Po Valley in Italy. The animals were divided in to 3 groups. Each pen of cows was provided with a feeding area, a freestall area and an external paddock. A group was placed in a pen with fans plus misting in the feeding area and fans with straw in the cubicles (VN); the group (VP) in a pen with fans in the feeding area and fans with straw in the cubicles and the last group was placed in a pen with fans in the feeding area and fans with sand in the cubicles (VS). The groups were similar in milk yield and days of lactation. Microclimatic parameters, milk yield and behavior were recorded. The summer 2002 was not very hot; the maximum temperature was above 35°C only in August. The minimum temperature was always high in the hottest period it was higher than 22°C.The better climatic conditions in the hottest period of the summer were found in the pen with fans and sand in the cubicles (VS). Then there was the section with fans and straw in the cubicles (VP) and then the VN group. During the hottest period the cows belonging to the VS groups showed a high presence time in the cubicles (66%) in comparison with VP (54%) and VN (42%). During the hottest period we had a milk yield reduction; in this period we recorded these milk yield values: 29.0 kg in VP pen, 30.2 in VS pen and 27.5 in VN pen. The results confirm that the sand in the cubicles provides a more comfortable resting area. The sand also allow s a better efficiency of the climatization systems.