EFFECT OF SUPPLEMENTARY FAT ON GROWTH AND CARCASS QUALITY OF SHEEP FED RATIONS CONTAINING DIFFERENT ROUGHAGE LEVELS

Abstract

This study was carried

out at the Agriculture Experimental

Station, Faculty of

Agriculture, Cairo University and the Animal

Production Department, National Research Center. The objective of the present work was to study the effect of supplemental protected fat and roughage level on growth performance and carcass characteristics of growing lambs. Two levels (10 %and 30 %) ofberseem hay and three levels of calcium soaps of palm oil (0, 4 and 8 %) were fed to

sixty male Barki lambs (aging

8 months and averaging 27.5 kg body

weight) in six treatment groups for 70 days. Ether extract contents were 2.90, 6.37 and 9.84% for low roughage diets and 2.65, 6.12 and 9.59 % for high roughage diets containing 0,4 and 8% protected fat, respectively. The average final body weights ranged from 41.6 to 44.3 kg. Eighteen male Barki lambs were slaughtered at the end ofthe experimental period. Increasing fat level up to 8 % and decreasing

roughage level to (10 % hay)

increased energy density and energy

intake. Water intake increased with increasing dietary fat level to 8%

and roughage level to 30 %.

Nutrient digestibilities improved by

feeding diet containing 4 % fat and CF digestibility was higher for sheep fed high roughage diets. Dietary treatments had no significant effect on nitrogen balance. Rumen fermentation was not significantly affected by fat inclusion but rumen pH increased as dietary roughage

increased. Blood plasma lipids

increased by fat feeding. Generally,

lamb performance improved by feeding 8 % protected fat or low roughage diets (10 % hay). The highest net revenue was reported for lambs fed high fat - low roughage diet. Protected fat containing diets had no significant effect on carcass characteristics and meat quality. It could be concluded that the effect of adding protected fat to

fattening diets of lambs was calcium soaps allowed using

limited. However, incorporation of 8 % ration higher in roughage than usually

used for growing lambs with no adverse effects on the performance.