Effects of Thunbergia laurifolia Linn. on nutrient digestibility, antioxidant enzyme activity and liver function of broiler fed mycotoxin-contaminated feed

Abstract

The objectives of this experiment were to study the effects of Thunbergia laurifolia Linn. (TL) on nutrient digestibility, antioxidant enzyme activity and liver function of broiler fed mycotoxin-contaminated feed. In a preliminary study, the effects of TL on growth performance, blood glucose and heterophil:lymphocyte (H:L) ratio were examined. One hundred and fifty, one day old, male, Arbor Acre broilers were divided into 3 treatment groups: T1, basal diet (control group), T2 and T3, basal diet supplemented with 2 and 4% TL, respectively. Body weight gain, feed intake, feed conversion ratio (FCR), blood glucose and H:L ratio were measured at day 21 and 42. The results showed that 2% TL was appropriate to be used in the experiment. In the experiment, 450 one day old, male, Arbor Acre broilers were divided into 6 treatment groups: T1, control corn-soybean diet; T2, control diet supplemented with 1% yeast glucomannan (GCM); T3, diet with mixed mycotoxins (aflatoxin, fumonisins and tricothecene) contaminated corn; T4, diet as in T3 supplemented with 1% GCM; T5, diet as T3 supplemented with 2% TL; T6, diet as T3 supplemented with 2% TL and 1% GCM. Body weight gain, feed intake, mortality rate, nutrient digestibility, antioxidant enzyme activity, serum enzyme activity in relation to liver function were measured at day 21 and 42. The results showed that broilers in T5 and T6 groups had significantly (p<0.05) higher nutrient digestibility than other groups at day 42. Broilers in T4 groups had significantly (p<0.05) higher maltase activity than other groups. However, broilers in T3 groups had significantly lower (p<0.05) maltase activity than other groups on day 21. Broilers in T4, T5 and T6 groups had significantly higher (p<0.05) glutathione peroxidase activity than other groups on day 21 and 42. In conclusion, TL reduced blood glucose concentrations in normal broilers. Mixed mycotoxins contamination in feed reduced growth performance of broilers during day 21-42 of age. TL and TL plus GCM helped to ameliorate the adverse effect of mixed mycotoxin with improving nutrient digestibility and increasing antioxidant enzyme (glotathione peroxidase) activity. The level of mixed mycotoxins in this study slightly affected serum enzyme activity and histopathological changes.