ENERGY-METABOLISM IN RELATION TO PHYSICAL-ACTIVITY IN GROWING PIGS ASAFFECTED BY TYPE OF DIETARY CARBOHYDRATE

The effect of dietary carbohydrate source on physical activity in rela tion to metabolic rate in pigs was studied. Six groups of 12 pigs (50- kg, castrated males) were fed one of two diets: a starch diet or a non -starch polysaccharide (NSP) diet. Both diets had a similar calculated net energy content. The starch diet contained 13% tapioca, and the NS P diet contained 17% sugar beet pulp silage. Pigs were housed in group s and fed at approximately two times maintenance (approximately 900 kJ ME . kg(-.75). d(-1)). Nitrogen and energy balances were measured per group during a 7-d experimental period, which was preceded by a 2-wk adaptation period. Heat production and physical activity were measured during successive discrete 9-min intervals. Metabolizability of gross energy was 79.4% and 78.2% for the starch-fed and NSP-fed pigs, respe ctively (P < .10). Activity differed between treatments. Activity-rela ted heat production tended to be higher for the starch-fed pigs than f or those fed the NSP diet (P < .10); 118 and 90 k.J . kg(-.75). d(-1), respectively. During the dark phase of the day (from 2000 to 0800) ac tivity-related heat production was 8 kJ.kg(-.75). d(-1) higher for the starch-fed pigs than for those fed the NSP diet (P > .1), whereas dur ing the light phase, this difference was 48 kJ . kg(-.75). d(-1) (P < .10). Retained energy was similar for both treatments. These results s how that dietary composition can change physical activity of pigs and thereby affect their energy utilization.