In situ ruminal digestibility and degradability of Macrocystis pyrifera and Sargassum spp. in bovine livestock

An alternative for the use of macroalgae as forage was explored since the technology for its processing is simple and accessible. In this study we determined the chemical composition, energy contribution, in situ degradability and ruminal digestibility of Macrocystis pyrifera and Sargassum spp. Both algae are considered fodder with low energy contribution. The disappearance of dry matter in the rumen in a time lapse of 96 h yielded an 85% digestibility estimate for M. pyrifera and 54.83% for Sargassum spp., with an estimated rate of degradability of 0.03 and 0.05, respectively. Crude protein analysis indicated that the 8.40% estimated for M. pyrifera and 5.99% for Sargassum spp. are not degraded in the rumen (P < 0.01). In vitro analysis suggests that these proteins may function as bypass proteins to be digested in the abomasum. Mineral analysis confirmed a high yield by these macroalgae. The overall analysis supports the use of these species as a complementary meal for ruminants and M. pyrifera as a better choice because of its higher nutritional value.