Effects of plant extracts on in-vitro gas production kinetics and ruminal fermentation of four fibrous feeds: Thought sustainable animal diets

Abstract

This study was conducted to investigate the effects of increasing doses: 0 (control), 6 (low), 12 (medium), and 18 (high) ml/g DM of plant extracts (Moringa, Thyme, and Rosemary) on in-vitro gas production (IVGP) of four fibrous feeds (Penisetum clandestium, Alfalfa hay, Oat hay, and corn stover). IVGP were assessed using three fistulated goats and incubation of samples at specified times. At the end of incubation, the dry matter degradability (DMd), gas yield (GY24), metabolizable energy (ME), short chain fatty acids (SCFA), and microbial crude protein production (MCP) were determined. The results showed that the increasing extract dose had neither linear nor quadratic effect (P > 0.05) on gas production (GP) of all fibrous feeds. Addition of plant extract also increased (P ≤ 0.05) GP at all incubation times being higher for Thyme. Addition of Moringa, Thyme, and Rosemary extracts altered ruminal fermentation parameters including ME, MCP, SCFA, the partitioning factor at 72 h of incubation (PF72), and DMd being higher for Thyme followed by Rosemary and Moringa. As a conclusion, the inclusion of Thyme increases GP, ME, MCP, SCFA, PF72, and DMd compared with Rosemary and Moringa plant extracts. However, additional in-vivo studies should be conducted to confirm these effects.