Synergistic effect of perennial ryegrass mixtures with clover on ruminal degradability

Livestock nutrition is based on pastures with diverse levels of quality, species, and maturity. The objective of this research was to evaluate the synergistic effect of mixtures of Lolium perenne with Trifolium rapens or T. pratense on the kinetics of dry matter and crude protein rumen degradability. The research was conducted in the province of Pichincha, Ecuador; in the cantons of Mejía (forage mixture), Quito (laboratory analysis), and Rumiñahui (in situ degradability), between December 2022 and June 2023. Two experiments were proposed: the first one being a mixture of ryegrass (R) and white clover (Wc) [(90:10, 80:20, 70:30), 100 % R and 100% Wc], and the second mixture of ryegrass (R) and red clover (Rc) [(90:10, 80:20, 70:30), 100% R and 100% Rc]. Three repetitions per treatment were considered. Each treatment was evaluated at the following incubation times: 0, 4, 8, 12, 16, 24, 36, 48 and 72 hours. The effective degradability and the degradability rate were evaluated. The variables studied were rumen degradability of dry matter (DM) and crude protein (CP). A completely randomized design and Tukey test for mean separation were used. The results indicate that adding clover to the mixtures with perennial ryegrass modifies the chemical composition, increases the concentration of CP, and decreases the NDF and ADF. Differences were observed (p < 0.05) for the degradability of DM and CP, being, in both experiments, the mixture with 70% ryegrass and 30% clover had a potential degradability of 90% and 96%, respectively. The addition of clovers to the mixture with ryegrass improves the joint degradability of the mixture. However, the risk of foamy swelling in ruminants is a risk with higher clovers percentages. Finally, no significant differences were found between the incorporation of white clover and red clover.