Reducing Cattle Pollution: Strategies For A Greener Future

Cattle are the largest agricultural source of methane, a greenhouse gas with 28 times the planet-warming potential of carbon dioxide. Cattle produce 4% of global greenhouse gas emissions, and 40% of agricultural emissions.

Cattle emit methane through belching and droppings. Methane is produced as a byproduct of the digestive process, with over 90% of methane from cattle emitted through burping.

There are several ways to reduce pollution from cattle, including:

- Feeding cattle based on their nutrient needs

- Using feed additives to lower methane production from belching

- Using compost to reduce methane emissions from manure

- Using surface covers to reduce methane emissions from stored manure

- Capturing methane from manure and using it as an energy source

Feed seaweed to cattle

Feeding seaweed to cattle is a promising approach to reducing methane emissions from beef and dairy cows. Seaweed contains a compound called bromoform, which reduces gut microorganisms that emit methane. This can lead to an up to 80% reduction in methane emissions from cattle.

Benefits of Feeding Seaweed to Cattle

• Reduces methane emissions by up to 80%
• Does not negatively impact the taste of beef or milk
• May improve the growth and dairy production of cattle
• May be a relatively inexpensive solution for reducing emissions

Challenges and Considerations

• Current global seaweed production is not sufficient for mass adoption in cattle diets
• Large-scale cultivation of seaweed for cattle feed will be required
• Environmental concerns related to seaweed farming in oceans
• Processing and distribution of seaweed is challenging due to its weight and shelf life
• More research is needed to understand the impact of feeding seaweed on cow biology
• Bromoform, a compound in seaweed, is suspected to cause cancer and may be present in milk from cows fed seaweed
• Financial incentives may be needed to encourage the adoption of seaweed in cattle feed

Use feed additives to reduce methane production

Using Feed Additives to Reduce Methane Production from Cattle

Feed additives are supplements that can be added to cattle feed to improve the quality of the feed and reduce methane production. They can be categorised into two types: methane inhibitors and rumen fermentation modifiers.

Methane Inhibitors

Methane inhibitors are feed additives that block the formation of methane by changing the structure or function of key drivers of methane formation. Some examples of methane inhibitors include:

• 3-nitrooxypropanol (3NOP): This synthetic additive is designed to specifically block one key event necessary for methane production and has been shown to decrease methane yield by up to 36% in dairy cattle and 50% in beef cattle.
• Bromoform: This is a natural compound found in red seaweed (Asparagopsis taxiformis) that prevents the binding of a vitamin B12 cofactor with an enzyme, inhibiting methane formation.

Rumen Fermentation Modifiers

Rumen fermentation modifiers lead to favourable changes in the rumen environment, improving animal productivity, health, and efficiency. They can also increase the availability of dietary protein for the animal by protecting it from being used by undesirable microbes. Some examples of rumen fermentation modifiers include:

• Ionophores: These are antibiotics that modify ruminal fermentation patterns to improve feed efficiency and performance. They can decrease methane production by up to 31%.
• Tannins: These are plant metabolites that have the ability to bind to and denature proteins, reducing protein breakdown in the rumen by microbes. They have been shown to reduce methane emissions by 13-16% in dairy cattle.
• Essential oils: These have antioxidant and antimicrobial properties and have been shown to reduce methane emissions and improve animal health and performance.

Other Feed Additives

In addition to the above, other feed additives have also been explored for their potential to reduce methane production in cattle:

• Red seaweed (Asparagopsis taxiformis): This has been described by scientists as "unprecedented" in its ability to reduce beef cattle emissions, with some studies showing a reduction of up to 98% in methane emissions.
• Green tea and oregano: A 2018 study found that a mix of green tea and oregano had "few and small additive effects" on methane reduction.
• Ozone: A study found that adding ozone to cattle drinking water led to a reduction of slightly more than 20% in methane emissions.

Challenges and Future Directions

While feed additives show promising results in reducing methane production, there are some challenges and considerations to keep in mind:

• Cost and scalability: The cost of feed additives needs to be considered for widespread adoption by farmers. Additionally, producing enough of these additives, especially for those derived from natural sources like seaweed, can be a challenge.
• Safety and sustainability: The safety of feeding certain additives to livestock, such as seaweed containing bromoform, needs further research. Additionally, the sustainability of harvesting and producing these additives should also be considered.
• Effect on animal health and performance: While some feed additives have shown positive effects on animal health and productivity, others may have negative impacts, such as reduced feed intake and lower animal performance.
• Regulatory policy and economic impact: More research is needed to understand the regulatory policies and economic impacts of implementing these feed additives for dairy and beef producers.

Feed additives offer a promising strategy to reduce methane production from cattle, with some additives showing significant reductions in methane emissions. However, further research and development are needed to address the challenges and optimise the use of these additives to make cattle farming more sustainable.

Improve breeding, feeding and health programs

Breeding programs in cattle reproduction may use artificial insemination (AI) or rely on natural service. Modern AI methods were developed in the 1930s and 1940s and are used widely in dairy cattle but much less in beef cattle due to handling and labor costs. AI offers bulls with known genetic potential and less risk of disease transmission than with the introduction of new bulls. When nutrition and heat detection are properly managed, and semen quality is adequate, satisfactory results are obtained.

To improve breeding programs, it is important to monitor body condition scores. Cows should be managed to calve at a target body condition of 5–6 on a 1–9 scale, where 1 is emaciated and 9 is morbidly obese. This increases their likelihood of rebreeding within a defined calving season and calving once per calendar year. Evaluating body condition at set points throughout the year enables adjustments to feeding programs.

Optimizing nutritional management of forage-based cow-calf production systems requires synchrony between nutrient requirements and nutrient supply. Cows should be bred to calve and be rebred during times of greatest forage abundance and nutrient supply because this is when their nutrient requirements are the greatest.

Supplementation programs should be based primarily on nutrient need and supplement value. It is recommended to consult with a beef cattle nutritionist to develop an optimal supplementation program.

A health management program is extremely important for ensuring animal well-being and biosecurity. A solid health care plan can also improve a farm’s efficiency and profitability by reducing treatment costs and increasing animal performance. Every health program should be centered around three main aspects: prevention, diagnosis, and treatment. Management strategies that producers should consider include monitoring nitrate intake and feed consumption, minimizing stress for the herd, and establishing a vaccination schedule.

Compost manure

Composting cattle manure is an effective way to manage cattle waste and produce high-quality fertilizer for almost all types of plants. However, storing and managing cow manure can be challenging, and incomplete decomposition can harm crops and the environment.

Aerobic Digestion

Anaerobic digestion is a simple process that takes place in a sealed, oxygen-free environment. Bacteria break down the organic components of cow waste inside a digester and turn them into a series of elements. Through this process, you can obtain:

• Biogas in liquid form, which can be used for cooking or heating.
• Liquid fertilizer (also known as digestate), which improves soil quality and boosts crop growth.
• Other residues in small quantities.

Hot Cow Manure Composting

Hot composting is a biological process where microorganisms break down raw organic waste and transform it into nutrient-rich organic matter. To obtain high-quality fertilizer, cattle waste must be mixed with other organic materials, such as hay, grass clippings, certain types of food waste, or even sawdust. This process takes longer, and you have less control over the results. It occurs at high temperatures generated by the microorganisms that break down the organic matter. As a result, weed seeds and other harmful pathogens are killed. However, to make this happen, you need to have a large pile so that enough microorganisms can grow inside and reach a minimum temperature of 55 degrees Celsius (130 degrees Fahrenheit) for several consecutive days.

Vermicomposting

Vermicomposting uses various types of earthworms (the most common is Eisenia foetida, or red worm) to treat livestock organic wastes. In this process, earthworms consume fresh cow manure and transform it into vermicompost. According to studies, the fertilizer resulting from this process has a different composition from the one produced through traditional composting methods, but it's still excellent for boosting crops. Depending on the amount of waste and the number of earthworms, the process can take anywhere from a few weeks to several months.

Important Considerations

When creating fertilizer from cow manure, it's essential to watch the biobed because earthworms will reproduce during the process. Additionally, cow manure includes high quantities of water, making it easy for this fertilizer to balance soil pH levels and temperature, positively impacting plant root growth and the overall biological activity in the soil.

Cow manure is also rich in ammonia and, sometimes, can contain dangerous pathogens and bacteria, such as E. coli. Therefore, an aging or decomposition process is necessary to break down the organic matter and eliminate harmful substances before applying the manure to fields.

Use manure storage covers

Using manure storage covers is an effective way to reduce methane emissions from cattle. Manure management is a critical aspect of reducing environmental pollution from the livestock sector, particularly ammonia emissions, which are released during the breakdown of animal manure containing carbon and nitrogen.

There are several manure management practices that can reduce methane emissions, and one of them is using manure storage covers. Manure storage covers can be semi-permeable or natural/induced crusts, which help to enclose open manure storage. These covers can be made from materials like geo-textile, straw, wood chips, or other natural materials that form a crust over the manure. The use of covers helps to reduce methane, ammonia, and odor emissions from manure storage.

When selecting a manure management practice, it is important to consider its impact on other greenhouse gas emissions, such as nitrous oxide, and on carbon sequestration. In general, liquid manure management systems lead to anaerobic conditions, which increase methane production. Therefore, switching to practices that manage manure in drier, aerobic conditions is essential for reducing methane emissions.

The effectiveness of manure storage covers in reducing methane emissions depends on the type of manure, the climate, and the management system. Covered storage is more commonly used for pig and cattle slurry than for solid manure. For example, covered storage accounts for 45% of cattle slurry and only 27% of solid poultry manure. Additionally, the use of covers may vary depending on the geographical location and the size of the farm.

It is worth noting that the use of manure storage covers may have trade-offs with other environmental impacts. While covers can reduce methane emissions, they may increase nitrous oxide emissions. Therefore, a lifecycle analysis may be necessary to fully understand the net greenhouse gas emission reductions from using manure storage covers.

Overall, the use of manure storage covers is a viable strategy for reducing methane emissions from cattle, but it should be considered as part of a comprehensive approach to manure management and pollution reduction.

Frequently asked questions