Effect of hotly summer in assiut on health status, productivity and behavior of friesian dairy cattle and the evaluation of traditional ways to relef

Abstract EN

Thirty mid-lactation Friesian cows, 178 day post-partum were randomly assigned to three equal groups (N = 10 per group).

All animals were blocked for age (6 year old), stage of milk yield and average body weight.

The experiment was carried out during the months of July and.

August, 2007 in which the first group of the experimented- animal was left in loose box without shade and expressed to heat stress while the second group was left in shaded box (white galvanized metal roof, 4 meters above the ground and covered about 70 % of the yard area).

However the latter group left in a box supported with shade plus fans (fans were installed regularly at height of 2.4 meters above the ground and spaced 1.5 meters along the manger shed).

Our study revealed that provision of shade had no significant effect on temperature-humidity index (THI) while providing shade and fans had significantly lowered THI.

At the same time the shade and fans had a significant effect on daily milk production but shade alone had no significant effect on milk yield.

Milk yield was slightly increased with shade (insignificant) and tended to be greater for shaded and cooled cows (significant) as compare to non-shaded animals.

Also, this study indicated that, forage intake was significantly lower for the experimented cows that housed without shade than for those housed with shade and fans.

Providing dairy cows with access to shade or to shade and fans during summer season was effective in reducing mean rectal temperature and respiratory rate.

Moreover, this study revealed some statistically significant differences in certain behavioral patterns of cows.

That.

Housed without shade under the prevalent hot weather and those housed either under shade only or under shade and fans (pO.Ol).

Moreover, leucocytic series of the experimented cows was not significantly affected by any of the studied housing conditions however Cortisol and glucose levels were significantly higher (pO.Ol) in the serum of the experimented cows that housed without shade than in those housed either with shade only or with shade and fans.