Effects of limited feeding of aflatoxin B1 contaminated feed on the performance of broilers.

The forty-two days long experiment was conducted on a total of 1000 Arbor Acres broilers, divided into two groups. Both groups of broilers were fed with a commercial feed mixture which consisted of standard feedstuffs and contained enough nutrients regarding the requirements. During the first three weeks of the trial, corn naturally contaminated with AFB1 0.0445 ppm per kg dry matter was used in the amount of 20% in the experimental group, while AFB1 free corn was given to birds in the control group. After the period of toxin administration until the end of the trial, broilers from both groups were normally fed another 5 weeks with uncontaminated feed.In the first phase of the trial, broilers in the control groups had an average daily gain (ADG) of 31 g, average daily feed intake (ADFI) of 45 g and a feed: gain ratio (FCR) of 1.42. In the same time, experimental broilers achieved an ADG of 25 g, ADFI of 35 g and a FCR of 1.39. During the whole period of the trial, control and experimental broilers achieved 49.12 g, 95.24 g and 1.94 and 39.71 g, 86.90 g and 2.19, respectively.For the experimental group, the end of the trial was delayed due to lower performances till weighing standard body weight. The trial lasted two weeks longer but overall performances were unsatisfying (ADG 37 g, ADFI 121 g and FCR 3.27).After the period of using contaminated feed, the liver of treated broilers was enlarged, dark yellow colored and tender in consistence. In some cases punctoforme and maculose extravasations could be seen. In all liver samples residues of AFB1 were detected in amounts of 0.63±0.12 ppb.AFB1 had negative effects on performances of broilers even in small amounts. The removal of contaminated feed could alleviate its adverse effects only to a certain extent.