## 2 Materials and Methods
### In Vitro Fermentations: Donor Animals and Experimental Procedures  
Samples of the pre-ensiling typha and typha silages were incubated in vitro with ruminal fluid from sheep to determine the gas production kinetics and the main fermentation parameters. In addition, a sample of triplicate hay was included in the in vitro trials for comparative purposes. Four adult rumen-fistulated Lacuane sheep (64.7 \(\pm\) 2.10 kg body weight; female) were used as rumen fluid donors for the in vitro incubations. Sheep handling and ruminal content sampling were performed following the European guidelines for experimental animal protection, and all experimental procedures were approved by the Animal Experimentation Ethics Committee of the Autonomous Community of Madrid (approval number PROEX 035/17). Sheep were housed in pens and fed a mixed diet of alfalfa hay and a commercial concentrate (80:20) at a rate of 48 g DM/kg body weight[75; 76]. The diet was administered twice daily at 09:00 a.m. and 17:00 p.m., and the animals had free access to water and to a mineral-vitamin mixture. For determining the gas production kinetics of the samples, ruminal contents were manually collected from each sheep immediately before the morning feeding, using stainless tweezers (40 cm long) with a shovel on the end. The contents were filtered through 4 layers of cheesecloth into thermal flasks, and immediately transported to the laboratory. The fluid of each individual sheep was mixed with the culture medium of Goering and Van Soest [11] (without including trypticase; 39 \({}^{\circ}\)C) in a 1:4 proportion. The procedure was conducted under CO\({}_{2}\) flushing to minimize air exposure. Then, 200 mg of DM of each sample was accurately weighed into 60 mL glass vials, which were filled with 20 mL of the mixture of rumen fluid and culture medium. The mixture was dosed by means of a peristaltic pump (Watson-Marlow 520 UIP31; Watson-Marlow Fluid Technology Group, Cornwall, UK). The vials were sealed with solid rubber stoppers and incubated at 39 \({}^{\circ}\)C for 120 h. The amount of gas produced was measured at 2, 4, 6, 9, 12, 24, 30, 36, 48, 60, 72, 96, and 120 h of incubation using a pressure transducer (Delta Ohm DTP704-2 BGI, Herter Instruments SL, Barcelona, Spain) and a calibrated syringe. The gas was collected inside a syringe connected to the pressure transducer, until the pressure into the vial was 0. The volume of gas collected in the syringe was then measured, and it was released after each measurement. In addition, 2 bottles with no substrate (blanks) were included for each inoculum (the ruminal fluid from each of the 4 sheep used as donors) for the purpose of correcting the gas production values for the gas released from the endogenous substrates. A single incubation run was performed and replication (n = 4) was achieved using the ruminal fluid of each individual sheep as the inoculum. In order to analyze the main fermentation parameters, immediately after measuring the gas produced after 24 h of incubation, the vials were hand-shaken, a sample of 1 mL was taken from each vial using an insulin syringe (introducing the needle through the rubber cup of the vial) and mixed with 0.40 \(\upmu\)L of 20% H\({}_{2}\)SO\({}_{4}\) to stop fermentation. Samples were frozen at \(-\)20 \({}^{\circ}\)C until the analysis of the VFA and ammonia N (NH\({}_{3}\)-N) content. The potential in vitro DM ruminal degradability (PDMD) was determined by weighing, in duplicate, 300 mg DM of each sample into 30 \(\upmu\)m pore size polyester bags (Ankom Corp F57; Ankom Technology Corp., Fairport, NY, USA), which were placed into 2 jars (1 bag for each sample in each jar) of the Ankom Daisy II incubator (Ankom Technology Corp., Fairport, NY, USA). The ruminal fluids of the 4 sheep were mixed in equal proportion and added to the culture medium of [PERSON] and [PERSON] [11] in a 1:4 proportion. Then, 2 l of the final mixture was filled into each jar, and the jars were immediately placed into the incubator.