ABSTRACT
Four types of macroalgae, i.e., Ulva spp., Chaetamorpha spp., Sargassum spp., and Enteromorpha spp. collected from Gunungkidul D.I. Yogyakarta coastal were evaluated for degradation in the rumen using the in-situ technique. Approximately 5 g of each sample was put in a nylon bag and incubated on the rumen of two male PO cows for 6, 12, 24, 48, and 72 hours. The results of degradation observations were fitting using non-linear regression equations. The response variables calculated were dry matter degradation (DMD), organic matter degradation (OMD), effective degradation of dry matter (EDDM), effective degradation of organic matter (EDOM), and the kinetic degradation profile of each material. The experimental design used a randomized completely block design (RCBD). The cows as a host were not significantly different (p>0.05). The DMD at 72 h incubation value was different between types of algae (P<0.05) with Ulva spp. having the highest value of 81.58%, and the lowest was Sargassum spp. with 39.46%. Relatively similar results occur in OMD and EDOM values. The highest OMD value was obtained from Ulva spp., and the lowest from Sargassum spp. with values 74.28% and 24.62%, respectively, while the highest EDOM value was obtained from Enteromorpha spp. = 49.48% and the lowest was obtained from Sargassum spp. = 19.24%. The highest EDDM value was obtained from Ulva spp. 97.32% and the lowest value was obtained from Sargassum spp. = 35.25%. The results 96showed that the macroalgae being collected had different degradation under rumen fermentation conditions.
