Simple Summary In the different livestock production systems, forage is the main feed resource. However, the availability and quality of the forage fluctuate throughout the year due to variable environmental conditions, such as temperature, humidity, location, or lack of rainfall. In semiarid regions, this fact is even more critical. The option for forage plants adapted to the semiarid climate, such as cactus cladodes, becomes indispensable for the sustainability of the systems. Nonetheless, it is necessary to combine the cactus with high-fiber-content feeds (silage, hay, and agroindustry residues, among others) to increase fiber contents in the diet to promote ideal rumen conditions. Based on the knowledge that cactus cladodes (Opuntia spp. and Nopalea spp.) are one of the most viable crops in semiarid regions, the association with a by-product rich in NDF proves to be a more feasible alternative in terms of price and availability, with the producer making the final decision. We aimed to evaluate the effect of the cactus cladodes Nopalea cochenillifera (L). Salm-Dyck. (NUB) and cactus cladodes Opuntia stricta (Haw.) Haw. (OUB), both combined with sugarcane bagasse (SB) plus urea, Tifton hay (TH), corn silage (CS), and sorghum silage (SS) plus urea on nutrient intake and digestibility, ruminal dynamics, and parameters. Five male sheep, fistulated in the rumen, were assigned in a 5 x 5 Latin square design. The NUB provided a higher intake of dry matter (DM) and any nutrients than SS. TH provided larger pools of DM and iNDF. The OUB and CS provided a higher DM degradation. CS provided a higher NDF degradation rate. OUB provided a lower ruminal pH. Depending on the collection time, the lowest pH value was estimated at 3.79 h after the morning feeding. There was an interaction between treatments and collection time on VFA concentrations. Due to the high degradation rate, greater energy intake, less change in rumen pH, greater volatile fatty acid production, and feasibility, we recommend using cactus associated with sugarcane bagasse plus urea in sheep diets.