Use of chemical treatments to reduce antinutritional effects of tannins in salseed meal: Effect on performance and digestive enzymes of broilers

Abstract

This study investigated the effects of chemical treatments of salseed ( Shorea robusta) meal (SSM), on intake, growth performance, feed efficiency, and activities of digestive enzymes in broilers. Five experimental iso-nitrogenous and iso-caloric diets, one without SSM (control) and four SSM based, were formulated. The four SSM diets differed in the treatment given to the SSM. The USSM diet contained untreated SSM and the three other diets were contained SSM incubated with (820 ml/ kg of SSM DM) distilled water (pH 5.3), 0.67 M acetic acid (pH 2.4), or 0.67 M sodium hydrogen carbonate (pH 8.2) for 12 h at 37 °C. Inclusion of untreated SSM in the diets markedly depressed the feed intake, growth rate and, feed efficiency in broilers. Treatment of SSM with chemicals partly alleviated these negative effects on the performance of broilers. Growth rate of broilers was significantly higher on alkali and water treated SSM diets than on USSM diet. The broilers on alkali treated SSM diet consumed more feed than those on water or acid-treated SSM diets. Alkali and water treatments of SSM significantly improved the feed efficiency in broilers fed SSM diets however; the effect due to acid treatment was negligible. Inclusion of untreated SSM in diets caused the pancreatic hypertrophy and subsequent depression in the activity of chymotrypsin and α-amylase in pancreatic tissue. Treatment of SSM with alkali and water substantially increased the activity of chymotrypsin in the pancreas. The activities of trypsin, chymotrypsin and α-amylase in the jejunum were depressed with USSM diet. This depression in broilers was partly alleviated with alkali and water treatments to SSM. The activities of dipeptidase, sucrase, and maltase in the jejunal and duodenal mucosa were also depressed with USSM diet. Activity of dipeptidase in the duodenal and jejunal mucosa of the broilers fed treated SSM was improved with alkali treatment. It can be concluded that inclusion of SSM in the diets of broilers markedly depressed the activities of pancreatic and intestinal enzymes, feed consumption, and growth rate. Treatment of SSM with water or alkali improved the digestive enzymatic activity, intake, growth, and subsequently feed efficiency in broilers.