Effects of periodic feeding of diets containing ochratoxin A on the performance and clinical chemistry of pigs from 15 to 50 kg body weight
Diets containing zero (0), low (L) or high (H) concentrations of ochratoxin A (OA), 0.0, 0.5 and 2.5 mg kg−1 diet, respectively, were fed to barrows of initial body weight 14.8 kg (SD = 1.49) over three successive periods, each of 21-d duration. The four treatment combinations (TC1 to TC4) were the feeding of diets that differed in OA content in Periods 1 and 2, respectively, 0 and 0 diets for TC1, 0 and H diets for TC2, L and 0 diets for TC3, and L and H diets for TC4. An OA-free diet (0) was fed to all animals in Period 3. Average daily gain was lower with L (P < 0.05) and H (P < 0.01) diets compared to the 0 diet. Feed intake was lower (P < 0.05) and feed efficiency was poorer (P < 0.01) with the H compared to the 0 diet. A change in kidney function was indicated with OA in both L and H diets: (1) hyperproteinemia (P < 0.05, L and H diets), without (P > 0.05) a change in serum albumin; and (2) azotemia, a higher serum urea (P < 0.05, L diet) and creatinine (P < 0.01, L and H diets). Hypocholesterolemia and hypercalcemia were noted (P < 0.01) with the H compared to the 0 diet. The TC2 pigs recovered with a higher than normal average daily gain in Period 3 after 21 d of dietary OA in Period 2; however, the requirement for Zn and (or) P may differ after this exposure to OA. For TC4 pigs, a low serum albumin after Period 3 was indicative of a residual kidney damage after 42 d of dietary OA in Periods 1 and 2. The results suggest that pigs weighing 15 to 24 kg did not adapt to OA when a sequence of L diet followed by H diet was fed during successive 21-d periods. Key words: Pigs, ochratoxin A, growth, serum chemistry