Assessing M. japonica as a Solution for Methane Reduction in Beef Cattle

A study conducted at the Beef Cattle Metabolism Facility of Agriculture and Agri-Food Canada, Lethbridge Research and Development Centre (Lethbridge, AB), aimed to investigate the effects of incorporating Mazzaella japonica, a red seaweed, in beef cattle diets. Six mature heifers were subjected to a double 3 × 3 Latin square design over 35-day periods. Dietary treatments included 0% (control), 1%, and 2% M. japonica inclusion on a dry matter basis.

Results

An increase in dry matter intake (DMI) was observed with M. japonica inclusion, with heifers consuming 1% exhibiting significantly higher intake compared to controls. However, apparent total-tract digestibility of dry matter decreased linearly with M. japonica inclusion, attributed to its relatively high inorganic fraction. While nitrogen intake and fecal nitrogen excretion increased with M. japonica supplementation, nitrogen utilization and retention did not improve. Rumen fermentation parameters remained unaffected, but a decrease in methane production was observed, although CH4 yield per unit of DMI did not differ significantly among treatments.

Discussion

Supplementing forage-based diets with M. japonica failed to mitigate enteric CH4 yield in beef cattle, despite a slight decrease in daily CH4 production at higher inclusion rates. This highlights the importance of further research into alternative seaweeds for methane mitigation and emphasizes the complex interactions between dietary components and methane production in ruminants.

Conclusions

While M. japonica can contribute to meeting cattle’s protein requirements, its high inorganic fraction, particularly elevated sulfur content, may limit inclusion rates. Thus, at levels up to 2% of the diet, M. japonica cannot be recommended as a CH4 inhibitor for beef cattle fed high-forage diets.

Source: “Abbott D. W., Aasen I. M., Beauchemin K. A., Grondahl F., Gruninger R., Hayes M., et al. (2020). Seaweed and seaweed bioactives for mitigation of enteric methane: challenges and opportunities. Animals 10, 2432. doi: 10.3390/ani10122432″