In-vitro evaluation of processed castor cake

The present experiment was carried out to study the effect of different physical and chemical treatments on in vitro OM digestibility (IVOMD) of castor cake. Physical treatments, soaking (2, 6 and 12h), boiling at 100°C (30 and 60 min), autoclaving at 15 psi (30 and 60 min) and heating (at 100, 120 and 140°C for 30, 25 and 20 min, respectively) were employed, while the chemical treatments comprised of ammonia (2.5 and 5.0%), formaldehyde (0.5, 1.0 and 1.5%), lime (2, 4, 6 and 8%), sodium chloride (0.25, 0.50, 1 and 2%), tannic acid (1, 2, 4 and 8%) and sodium hydroxide (0.25 and 0.50%). The results showed that of all the methods tried, only heating (100°C for 30 minutes) could improve (p<0.05) IVOMD, while ammonia at 5% level and autoclaving did not effect the IVOMD of the cake and the rest of the treatments reduced the IVOMD of the cake to varying extent. The observed IVOMD values in different processed cakes did not reflect the changes in the ricin content.