New challenges for efficient usage of Sargassum fusiforme for ruminant production.

Sargassum fusiforme, which is a type of brown algae, can provide fiber and minerals to ruminant diets. In this study, dried S. fusiforme was tested in vitro at four different doses 1, 3, 5, and 10% of the total ration for its effect on ruminal fermentation characteristics, and gas profiles when incubated for 72 h. At a level of 1 and 10%, S. fusiforme supplementation augmented total volatile fatty acid (VFA) concentrations compared to that with 0% supplementation. In addition, total gas, methane, and carbon dioxide emissions significantly decreased at 3 and 24 h of incubation at this dose. An in situ trial was performed for 72 h with S. fusiforme to evaluate it as a potential feed ingredient by comparing its degradation parameters with timothy hay (Phleum pretense). 1H nuclear magnetic resonance spectroscopy profiling was used to identify and quantify metabolites of S. fusiforme. Mannitol, guanidoacetate and ethylene glycol were largely accumulated in S. fusiforme. Moreover, nutritious minerals for feed ingredients were present in S. fusiforme. Whereas a high concentration of arsenic was found in S. fusiforme, it was within the allowable limit for ruminants. Our results suggest that S. fusiforme could represent an alternative, renewable feed ingredient for ruminant diets, with nutritional, as well as environmental, benefits.

Effects of the Appropriate Addition of Antioxidants from Pinus densiflora and Mentha canadensis Extracts on Methane Emission and Rumen Fermentation.

This study aimed to investigate the optimal addition of terpene-based Pinus densiflora and Mentha canadensis extracts, with antioxidant and methane reduction effects, as feed supplements to ruminants. Two cannulated steers (450 ± 30 kg), consuming Timothy Hay and a commercial concentrate (60:40, w/w) twice daily (at 09:00 and 17:30) at 2% of body weight, with free access to water and a mineral block, were used as rumen fluid donors. In vitro fermentation experiments, with Timothy Hay as the substrate, were conducted with P. densiflora and M. canadensis extracts as supplements to achieve concentrations of 30, 50, and 70 mg/L on a Timothy Hay basis. Fibrobacter succinogenes decreased in proportion upon P. densiflora and M. canadensis extract supplementation at 50 mg/L, while the dry matter degradability of the feed was not significantly different (p < 0.05). Methane emission was significantly lower in the 50 and 70 mg/L treatment groups, for both extracts, at 12 h (p < 0.05). Based on methane production and antioxidant activity, our study suggests that 30 mg/L addition is the most appropriate level of supplementation.