Effect of Dietary Rumen-Degradable Starch to Rumen-Degradable Protein Ratio on In Vitro Rumen Fermentation Characteristics and Microbial Protein Synthesis

Abstract

The objective of this study was to investigate the effects of dietary rumen-degradable starch (RDS, g/kg of DM) to rumen-degradable protein (RDP, g/kg of DM) ratios (SPR) on in vitro rumen fermentation characteristics and microbial protein synthesis (MCPS). Treatments were eight diets with SPR of 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5 and 2.6 and were formulated to be isoenergetic, isonitrogenous, and isostarch. Substrates were anaerobically incubated in sealed culture vials (100 mL) for 6, 24 or 48 h. Three incubation runs were conducted within two consecutive weeks. With the increase of the dietary SPR, the gas production (GP), in vitro dry matter disappearance (IVDMD) and concentration of MCPS and total volatile fatty acids (TVFA) linearly increased after 6 h of incubation (p ≤ 0.01), whereas they quadratically increased and peaked at the SPR of 2.3 after 24 and 48 h of incubation (p < 0.05). In response to dietary SPR increasing, the in vitro neutral detergent fiber disappearance (IVNDFD) quadratically increased (p < 0.01), and the ammonia nitrogen (NH3-N) concentration linearly decreased (p < 0.01) after 6, 24 and 48 h of incubation. Based on the presented results, an SPR of 2.3 is recommended for formulating a diet due to its greatest IVDMD, IVNDFD, GP, TVFA and MCPS. However, as the results obtained are strictly dependent on the in vitro conditions, further in vivo studies are needed to verify our findings.

Comparison of Cassava Chips and Winged Bean Tubers with Various Starch Modifications on Chemical Composition, the Kinetics of Gas, Ruminal Degradation, and Ruminal Fermentation Characteristics Using an In Situ Nylon Bag and an In Vitro Gas Production Technique

“…In this study, the NH 3 -N values were within the normal range [10,52]. It has been reported that the optimal level is 15-30 mg/dL to support microbial protein synthesis and optimize ruminal feed digestibility.…”

Effects of dietary wheat supplementation levels on growth performance, rumen bacterial community and fermentation parameters in Chinese Tibetan Sheep

“…Schwab et al (2005) reported a greater ruminal NH 3 ‐N concentration was required if more rapidly fermentable carbohydrates were supplied. Compared with corn‐based diet, the wheat‐based diet contains more rumen degradable starch, which will increase in demand for NH 3 ‐N and the ability to capture N by rumen microbes (Chen et al, 2022; Nadia et al, 2022).…”

“…Compared with corn-based diet, the wheat-based diet contains more rumen degradable starch, which will increase in demand for NH 3 -N and the ability to capture N by rumen microbes (Chen et al, 2022;Nadia et al, 2022).…”

Nutrición animal: Texto de formación universitaria

“…El nivel de energía de la dieta promueve mejora la productividad energética del microbioma ruminal y mejora la síntesis de PM, por lo que el suministro de energía a los microorganismos del rumen es un factor importante que afecta la cantidad de nitrógeno proteico incorporado en la PM (Lu et al, 2019). El sincronismo del suministro de energía y RDP en rumen es una estrategia que mejora la digestibilidad de la materia seca, puesto que existe un fuerte vínculo entre la eficiencia de la fermentación ruminal y la viabilidad microbiana que maximiza el crecimiento y la actividad de los microorganismos, potencia la eficiencia de la fermentación del rumen y la síntesis de proteína microbiana y la disponibilidad de aminoácidos esenciales, mejorando la utilización de N en vacas lecheras (Chen et al, 2022).…”