Effect of feeding a pellet diet containing high sulphur with fresh cassava root supplementation on feed use efficiency, ruminal characteristics and blood metabolites in Thai native beef cattle.

Abstract

The objective of this experiment was to study the effect of feeding pellet containing high sulphur (PELFUR) diet and fresh cassava root (FCR) to Thai native beef cattle on feed use efficiency, ruminal characteristics and blood metabolites. Four male purebred Thai native beef cattle (1.5-2.0years old) with initial body weight (BW) of 150±15.0kg were allocated with a 2×2 factorial arrangement in a 4×4 Latin square design. Factor A was FCR supplementation at 15 and 20g/kg of BW. Factor B was the sulphur level in the PELFUR ration at 15 and 30g/kg of dry matter (DM). No interaction effect was found among FCR supplementation and PELFUR in terms of feed intake and nutrient intake (p>0.05). Cyanide intake was significantly increased based on FCR supplementation (p<0.05), whereas sulphur intake was increased by level addition of PELFUR levels (p<0.05). There were interaction effects among FCR supplementation and PELFUR on digestibility coefficients of DM and organic matter (OM) (p<0.05). FCR supplementation at 20g/kg BW with PELFUR 30g/kg demonstrated the highest digestibility of DM and OM. Moreover, interactions were observed between FCR and PELFUR for bacterial populations (p<0.01). The populations of bacteria were highest in FCR supplementation at 20g/kg BW with PELFUR 30g/kg at various feeding times. An interaction effect from among feeding FCR with PELFUR was found on blood thiocyanate concentrations at various feeding times (p<0.01). The highest mean values of blood thiocyanate were observed when feeding FCR at 20g/kg BW with PELFUR at 30g/kg. No interaction effect was found between FCR and PELFUR on total volatile fatty acids (VFA) and their profiles (p>0.05). However, the proportions of the total VFA at 0 and 4h post-feeding were increased when FCR at 20g/kg BW was supplemented (p<0.01). FCR at 20g/kg BW could enhance propionate (C3) at 4h post-feeding when compared with FCR at 15g/kg BW (p<0.01). Moreover, supplementation of PELFUR at 30g/kg increased the total VFA at 0 and 4h post-feeding, whereas the concentration of C3 at 4h post-feeding was enhanced (p<0.05). However, no significant changes were found for any parameters among treatments and between the main effect of FCR and PELFUR supplementation (p>0.05). In conclusion, feeding of two combinations (FCR 20g/kg BW with PELFUR 30g/kg) could promote the nutrient digestibility, the bacterial populations and the rate of disappearance of cyanide without having any adverse effect on rumen fermentation.