Effects of feeding 3-nitro-4-hydroxyphenylarsonic acid on Growing-FinishingPigs

The effect of a dietary supplement of 3-nitro-4-hydroxyphenylarsonic acid (3-nitro) on the performance, tissue arsenic residues and intestinal lesions was determined using a total of 60 crossbred growing-finishing pigs. None of the dietary levels (0, 25, 50, 100 and 150 mg kg −1 ) significantly (P > 0.05) increased weight gain or feed efficiency. There was a sex effect (barrows vs. gilts), independent of treatment, for average daily gain and average feed intake, but not for gain-to-feed ratio. Total arsenic residues increased with increasing dosage level and were highest in the liver, lower in kidneys and lowest in muscle. Arsenic residues in liver declined rapidly during the first 5 d of a 10-d withdrawal period. Feeding 3-nitro did not cause thinning of the intestinal wall, and there were no lesions in the intestinal tract sufficient to cause clinical signs. This study concludes that supplementation of 3-nitro in the diet does not have beneficial effects on performance. Key words: Pigs, 3-nitro-4-hydroxyphenylarsonic acid, arsenic residues