Tropical Plant Phytonutrient Improves the Use of Insect Protein for Ruminant Feed

Abstract

This work aimed to examine the effects of binding proteins from Gryllus bimaculatus with Sesbania grandiflora phytonutrient on gas dynamics, in vitro digestibility, and ruminal fermentation characteristics. For rumen fluid sources, two dairy bulls with permanent cannulas were used as donors. G. bimaculatus and S. grandiflora powder were combined in the following ratios: 100:0, 99:1, 98:2, 97:3, 96:4, 95:5, 94:6, and 93:7. As 7% of S. grandiflora and 3% of G. bimaculatus were combined, the rumen undegradable protein increased by 45.8% when compared to the control group (p < 0.05). All gas kinetics were not substantially different across treatments, except for cumulative gas output during 96 h of incubation (p < 0.05). Comparing the G. bimaculatus powder to S. grandiflora at a ratio of 95:5 to 93:7 revealed an increase in cumulative gas production (p < 0.05), compared to the other groups. Reduction of G. bimaculatus resulted in a linear increase of in vitro dry matter digestibility (IVDMD) and in vitro organic matter digestibility (IVOMD) at 24 h after incubation. The lowest level of G. bimaculatus—93% with 7% S. grandiflora—showed the greatest IVDMD and IVOMD (p < 0.05) when compared with the control group. Ruminal pH in all treatments remained constant after 4 and 8 h of in vitro incubation (p > 0.05). However, as the quantity of S. grandiflora in the sample increased, the concentration of ammonia-nitrogen (NH3-N) linearly decreased (p < 0.05). Compared to the control group, the NH3-N concentration at 4 h of incubation was decreased by 47% when 7% S. grandiflora and 93% G. bimaculatus were mixed. The alteration in the G. bimaculatus to S. grandiflora ratio did not affect the levels of acetic acid or butyric acid. However, when 93% of G. bimaculatus was combined with 7% of S. grandiflora at hour 4 of incubation, propionic acid concentration was moderately increased (p < 0.01) by 6.58 mmol/L. In conclusion, combining 93% G. bimaculatus with 7% S. grandiflora powder enhanced protein utilization, in vitro digestibility, propionate concentration, and cumulative gas production.