SUCROSE AS AN ENERGY-SOURCE FOR GROWING PIGS - DIGESTIBLE ENERGY CONTENT AND ENERGY-UTILIZATION

Two experiments were conducted to determine the effect of including sucrose in diets on energy utilization by growing pigs. In the first experiment, the digestible energy (DE) content of sucrose was determined as 15·6 MJ/kg, indicating that gross energy was 0·96 digested. In the second experiment, iso-energetic diets were used to determine the effects of sucrose on growth and nutrient utilization. Sucrose was used to replace wheat gradually in four iso-energetic diets (15 MJ DE, 0·75 g lysine per MJ DE for pigs from 20 to 50 kg live weight and 15·1 MJ DE, 0·67 g lysine per MJ DE for pigs from 50 to 80 kg live weight). Pigs were fed ad libitum. Food intake (P < 0·01) and carcass daily gain (P < 0·05) increased with sucrose inclusion, independently of the level of sucrose in the diet. Food conversion ratio of male (boar) pigs on a carcass basis was unaffected by sucrose inclusion but increased with female pigs (P < 0·01). Killing-out proportion increased linearly with sucrose inclusion (P < 0·01). Sucrose inclusion improved energy retention (P < 0·05) and increased fat deposition (P < 0·05) but protein deposition was not affected. The weight of the full viscera (P < 0·01), empty digestive tract (P < 0·05), stomach (P < 0·01) and large intestine (P < 0·05) decreased with increasing sucrose inclusion. Sucrose did not affect blood triglycerides or cholesterol concentration (P > 0·05). Sucrose inclusion decreased the crude fibre and crude protein content of the diet and energy utilization was improved. Differences in gut fill indicated that sucrose-based diets were rapidly digested and absorbed. © 1990, British Society of Animal Science. All rights reserved.