Is it true that adding onion peels can reduce methane emissions from dairy cows?

Authoritative experts have found that adding onion peels to feed can promote the degradation of nutrients and help reduce methane emissions. The following article Kingherbs shares with you.

Onion peels are a sustainable feed ingredient that is widely available and affordable. It is estimated that onion peels account for about 20-30% of the total weight of onions, which means that a large amount of onion peels can be recycled and used in livestock feed. Globally, China ranks first with an annual onion production of 93.23 million tons, followed by India, 19.42 million tons; Egypt, 3.12 million tons; the United States, 3.03 million tons; Iran, 2.35 million tons.

Onion peels are rich in allicin and active substances such as quercetin and other metabolites, which may affect the activity and diversity of rumen microorganisms. Previous reports have shown that the addition of quercetin to beef cattle diets reduces the gas production of beef cattle rumen in vitro fermentation, reduces the content of ammonia nitrogen, increases the content of propionic acid and reduces the production of methane, among which the addition of 1% quercetin is more suitable.

In addition, studies have shown that the addition of garlic extract can improve rumen microorganisms through allicin, such as increasing the relative abundance of Succinivibrionaceae and reducing the relative abundance of strictly anaerobic Methanobacterium. Thus, garlic extract can promote the reduction of intestinal methane emissions through rumen microbial community and propionate ratio.

These speculations were confirmed in a subsequent study. The study showed that the addition of onion extract to a timothy-based diet at a ratio of 1%, 3%, 5%, 7% or 9% did not affect the degradability of dry matter (DM) and linearly reduced methane emissions and acetate concentrations.

The new study compared the possible efficacy of onion peels and their effects on ruminant diets (such as high-fiber or high-concentrate diets). In the study, onion peels were added to two in vitro fermentation systems at a ratio of 2.5% (OP2.5), 5% (OP5), 7.5% (OP7.5) and 10% (OP10). 

The feeds used in the two in vitro fermentation systems were a high-concentrate total mixed diet (HC) and a high-roughage corn silage (HF). 

In addition, the study evaluated total gas production, methane (CH4), carbon dioxide (CO2), ammonia (NH3) and hydrogen sulfide (H2S) concentrations, and nutrient degradability.

The study showed that after 48 hours of in vitro fermentation, the OP7.5 treatment group increased the concentrations of methane, carbon dioxide, ammonia and hydrogen sulfide in the HC feed. At the same time, the OP5 treatment group reduced the production of methane and carbon dioxide in the HF feed.

 The study showed that onion peels can be used to reduce the production of methane and carbon dioxide in animals fed high-roughage. It is well known that high-roughage is more likely to produce methane than high-concentrate feed. 

This finding is conducive to the use of roughage with a higher fiber ratio in ruminant feeding. Relatively speaking, high-fiber roughage will have a more obvious cost advantage and a lower risk of rumen acidosis.

Kingherbs provides high-quality onion extract to meet different customer needs. Don't hesitate any longer, act now. Contact us at info@kingherbs.com to know more about our products and their uses.