The effect of a shade structure on the feed intake, water intake, milk production and milk composition of Dutch-type Friesian cows in a temperate climate was determined over three summer seasons. The shade structure reduced (P < 0.01) radiation as was indicated by lower black globe temperatures. Feed intake of shade cows was higher (P < 0.05 during 1984/85 and P < 0.01 during 1985/86) than that of no-shade cows. Regression analysis suggested that day-time feed intake was significantly (P < 0.05 for shade cows and P < 0.01 for no-shade cows) affected by increasing maximum ambient temperatures. No-shade cows had higher (P < 0.01) free-water intakes than shade cows (114 vs. 97 1/day). Regression of total daily free-water intake of cows on daily maximum ambient temperatures indicated significant (P < 0.01) increases in water intake of the no-shade cows with increasing ambient temperatures, although the relationship was not suitable for prediction (R2 = 0.085). The overall milk production of shade cows was 5.5% higher (P < 0.05) than that of no-shade cows. High day-time ambient temperature did not affect (P > 0.05) average daily milk production of cows in either treatment. No significant difference was found in milk composition of shade vs. no-shade cows. At prevailing prices and costs the improvement in milk production resulted in a nett return of 42% per annum on the capital outlay of the shade structure.
Effect of shade on various parameters of Friesian cows in a Mediterranean climate in South Africa. 1. Feed and water intake, mil
Author: C.J.C. Muller, J.A. Botha and W.A. Smith
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