Citric acid and fumaric acid as food additives for early-weaned piglets

Abstract
The effects of diet acidification on the growth performance of piglets were assessed in two experiments. In the first, 167 piglets were weaned at 10 days of age and penned in litter-mate groups (seven groups per treatment) which were allocated to one of three diets, with either citric acid (30 g/kg; C), fumaric acid (15 g/kg; F) or no additional organic acid (N); pigs were fed ad libitum for 25 days. The rate of live-weight gain was significantly higher for treatment C than for treatments F or N (216 (s.e. 10), 170 (s.e. 7) and 189 (s.e. 6) g/day respectively; P < 0·05). The voluntary food intake on treatment C also tended to be higher than on the other two diets (220 (s.e. 24), 182 (s.e. 18) and 189 (s.e. 7) g/day for treatments C, F and N respectively).In experiment 2, 30 crossbred piglets were penned in single-sex groups of three and weaned at 10 days of age. The same diets were used as in experiment 1 but all three diets were available ad libitum to each group of piglets for 25 days. When dietary choice was allowed, piglets consumed significantly greater quantities of the control diet than of the acidified diets (1381, 1422, 2972 (s.e. 132) g/day for diets C, F and N respectively; P < 0·01). When the relative intake of each diet was correlated with live-weight gain, only diet C showed a significant positive correlation (r = +0·74; P < 0·05). Correlations of F and N intakes with live-weight gain were negative. It is concluded that citric acid (30 g/kg) in the diet of early-weaned piglets promotes live-weight gain, although acidification of the diet may decrease palatability.