Defining the tolerable level of ergot in the diet of weaned pigs

The present study investigated the effect of ergot alkaloids on performance and clinical symptoms in weaned pigs. Wheat ergot sclerotia (1880 mg alkaloid kg-1; ergocristine, ergotamine, ergosine, ergocryptine, and ergocornine constituting 40, 36, 11, 7, and 6% of the total, respectively) were added on a weight basis to a basal diet at 0.00 (control), 0.05, 0.10, 0.25, 0.50, and 1.00% and fed to 192 weaned pigs (20.4 ± 3.4 d; 6.9 ± 1.3 kg; mean ± SD) for 28 d, beginning 7 d post-weaning. Pigs fed the 1.00% diet gained 82 and 38% less than the control (P < 0.001, 211 vs. 39 g d-1, wk 1 and 432 vs. 269 g d-1, wk 2) and body weight on day 28 was reduced quadratically by alkaloids (P < 0.005). Ergot alkaloids decreased average daily feed intake (ADFI) quadratically (P < 0.04) and feed efficiency linearly (P < 0.03) (0.62 vs. 0.44; control vs. 1.00%) over the entire period, but ADFI was not affected during the initial 14 d (P > 0.20). Ergot alkaloids decreased serum prolactin quadratically (P < 0.002) and urea nitrogen concentrations (P < 0.05). The maximum tolerable ergot level in the diet was 0.10 and 0.05% based on average daily gain (ADG) and ADFI, respectively, corresponding to 2.07 mg and 1.04 mg alkaloid kg-1 diet. Key words: Pig, ergot, alkaloid, toxicity, performance, prolactin