Author: c001os

Exploring organic or natural feed additives has recently gained more attention. One category of these recommended feed additives is phytogenic feed additives, which are rich in secondary metabolites.

A study, published in the journal Animals, by the researchers of North Carolina Agricultural and Technical State University reveals that onion peel, a by-product of the onion processing industry, is showing promise as a natural feed additive and the potential to reduce methane emissions. 

Onion peel, often discarded as agricultural byproducts, has garnered increasing attention as a potential feed additive. Additionally, onion peel is a sustainable, cost-effective feed ingredient, as it is widely available and typically underutilized. It is estimated that about 20–30% of the total weight of onions consists of outer skins, which translates to a significant volume of onion peel that could be repurposed for livestock feed. In the United States, approximately 3 million tons of onions are produced annually, leading to a substantial amount of onion peel waste.

The study evaluated different inclusion levels of onion peel at 2.5% (OP2.5), 5% (OP5), 7.5% (OP7.5), and 10% (OP10) on the in vitro fermentation of 2 diets: a total mixed ration referred to as high concentrate (HC), and corn silage referred to as high forage (HF).

In addition, total gas production, methane (CH₄), carbon dioxide (CO₂), ammonia (NH₃), and hydrogen sulfide (H₂S) concentrations, as well as nutrient degradability, were assessed.

The HC diet produced more gas but less CH₄, CO₂, NH₃, and H₂S compared to the HF diet. The onion peel at all levels increased CH₄, CO₂, NH₃, and H₂S concentrations in the HF diet.

The OP2.5 treatment had the lowest degradable dry matter in the HC diet, while the onion peel linearly increased degradable acid detergent fibre (ADF) in both diets.

The lowest total volatile fatty acids (VFA) and acetate were observed with the OP5 treatment in the HC diet, while OP5, OP7.5, and OP10 had lower total volatile fatty acids concentration in the HC diet.

The OP7.5 treatment increased gas production and CH₄ and CO₂ production in the HC diet. However, the OP5 treatment had the lowest CH₄ production in the HF diet. Incorporating 5% of onion peel in the HF diet is recommended as the optimal inclusion level to decrease ruminal methane production and improve nutrient degradability.

The study concluded that onion peel supplementation is more suitable for HF diets than HC diets. The results suggest that the adding onion peel indicates a promising strategy for improving ruminal fermentation efficiency, and reducing CH4 production in HF diets compared to HC diets.

The recommended levels of onion peel are not very clear; however, onion peel at 5–10% to the HF diet enhanced nutrient degradability and reduced CH₄ production, and increased total volatile fatty acids, acetate, and propionate. Although this figure is not given in the conclusion, in the summary of the study the authors claim that incorporating 5% of OP in the forage-based diet is recommended as the optimal inclusion level to decrease ruminal methane production and improve nutrient degradability.

The authors emphasise that additional in vitro and in vivo studies are needed to clarify the underlying mechanisms of action, evaluate the long-term effects of onion peel on animal performance and environmental sustainability, and address potential challenges in translating these findings into practical feeding strategies.

Foot-and-mouth disease outbreaks recorded in 2025 in a number of European countries are associated with the genetic lines of the virus that previously circulated in Turkey and Pakistan. This was announced by representatives of the European Commission at a webinar with the participation of experts from the Rosselkhoznadzor and the Federal State Budgetary Institution VNIIZH.

According to information provided by European experts, the virus detected in Germany belongs to the O/ME-SA/SA-2018 lineage, which was previously widespread in Turkey. Isolates from Slovakia and Hungary belong to the O/ME-SA/Panasia2/ANT-10 subline, which circulated in Pakistan in 2017-2018. This indicates various channels for the introduction of the disease into the territory of the EU.

At the webinar, the countries with reported outbreaks – Germany, Hungary and Slovakia – presented reviews of the current epizootic situation. Germany has mostly regained its FMD-free status, with the exception of the restricted area near Berlin. In Slovakia and Hungary, standard measures have been applied: surveillance zones have been established, emergency vaccination of susceptible animals in foci, subsequent slaughter and restrictions on the movement of live livestock.

Additionally, the EU has decided to expand the restriction zones beyond the standard 3 and 10 km. The new zone will cover all ten identified foci and will be classified as a containment zone in accordance with Chapter 8.8 of the World Organization for Animal Health (WHOH) Terrestrial Animal Health Code.

Milk fever, or hypocalcaemia, in lactating cows has a significant economic impact on the dairy industry, with losses amounting to thousands of dollars per farm annually.

Farmers find it challenging to identify asymptomatic subclinical hypocalcaemia (SCH) in transition dairy cows, although monitoring SCH in milk samples can expedite treatment and improve the health, productivity and welfare of dairy cows.

SCH occurs when calcium levels in the blood fall below normal, and it can affect nearly half of mature dairy cows and a quarter of first-time calvers. The condition compromises muscle and nerve function, leading to reduce feed intake, lower milk production and increased susceptibility to other diseases.

Current diagnostic tools rely on blood sampling and lab-based analysis, which are costly, time-intensive and impractical for routine farm use. Researchers at the School of Animal Sciences at Virginia Tech in the US wanted to develop an attomolar-sensitive sensor using extrusion 3D-printed sensing structures to detect the ratio of ionised calcium to phosphate levels in milk samples.

The 3D-printed sensor features intricate microstructures and a unique wrinkled surface creating using a solid-contact ion-to-electron transducer. These design elements enhance the surface area, enabling rapid and highly accurate detection of milk ions.

The diagnostic device can identify SCH in as little as 10 seconds with attomolar-sensitivity and, unlike bulky and expensive lab equipment, the sensor produced at Virginia Tech, with a solid-state feature, is portable and can be integrated with milking machines or farm pipelines. Farmers can now test milk samples on-site, eliminating the need for invasive blood tests or transporting samples to labs.

Lead researcher at Virginia Tech, assistant professor Azahar Ali, said the innovation bridges a long-standing gap in dairy diagnostics.

“Farmers have traditionally relied on either expensive commercial analysers or subjective assessments based on visible symptoms like weakness or difficulty standing. Neither approach is sufficient for detecting SCH early enough to prevents its cascade of complications. Our 3D-printed sensor not only makes early detection feasible, but also democratises access to advanced diagnostics,” said Ali.