Water quality
All living things, from tiny bacteria to giant blue whales, need water to survive.
- Water is a critical nutrient for animal.
- An adequate and safe water supply is essential to the production of healthy animals.
- From transportation to lubrication to temperature regulation, water keeps animal life functioning.
- All chemical reactions in the bodies of animals use water as a medium.
Water has the functions in the animal's body as:
- Temperature regulation: Water acts as a buffer against overheating due to water's high specific heat.
- pH regulation: When the water introduced into an animal's system, it brings the pH closer to a neutral value.
- Hydrolysis and energy production
- Digestion
- Joint lubrication
- Measurements of water quality and quantity are required for effective planning and monitoring of water supplies for livestock.
- If water quality is poor, livestock may drink less than they need or, rarely, may stop drinking.
- When animals drink less, they will eat less and lose condition and if they are lactating, their milk production will reduce.
- Failure to provide proper and sufficient water for livestock not only affects production, it may be an animal welfare offence.
- Mangers must provide enough good quality water to meet the needs of the animal.
Water salinity
- Excessive salinity in livestock drinking water can reduce production.
- High levels of specific ions in water can cause animal health problems and death.
Itai-itai disease
- 1912년 일본 도야마현의 진즈 강 하류에서 발생한 대량의 카드뮴이 사람의 뼈에 축적
| Constituent | Upper limit | Constituent | Upper limit |
|---|---|---|---|
| Aluminum (Al) | 5.0 mg/L | Lead (Pb) | 0.1 mg/L |
| Arsenic (As) | 0.2 mg/L | Manganese (Mn) | no data |
| Beryllium (Be) | no data | Mercury (Hg) | 0.01 mg/L |
| Boron (B) | 5.0 mg/L | Molybdenum (Mo) | no data |
| Cadmium (Cd) | 0.05 mg/L | Nitrate + nitrite (NO3-N + NO2-N) | 100 mg/L |
| Chromium (Cr) | 1.0 mg/L | Nitrite (NO2-N) | 10 mg/L |
| Cobalt (Co) | 1.0 mg/L | Selenium (Se) | 0.05 mg/L |
| Copper (Cu) | 0.5 mg/L | Vanadium (V) | 0.10 mg/L |
| Fluorine (F) | 2.0 mg/L | Zinc (Zn) | 24 mg/L |
| Iron (Fe) | no data | Total dissolved solids (TDS) | 10,000 mg/L |
Microbiological contaminants
Natural toxins originating from cyanobacteria are a primary concern in drinking water for livestock.
Cyanobacteria
- Natural toxins originating from cyanobacteria (blue-green algae) are a primary concern in drinking water for livestock.
- Cyanobacteria is a phylum of bacteria that obtain their energy through photosynthesis.
- Cyanobacteria are known to produce acute hepatotoxins, cytotoxins, neurotoxins, and toxins causing the gastrointestinal diseases.
Cyanobacteria
- However, heavy cyanobacteria growth does not necessarily mean high levels of toxin. The trigger for cyanobacteria to produce toxins is not completely understood.
- If the cyanobacteria growth is not of the Microcystis species, there is a low probability of having high toxin levels.
- It is recommended that water contaminated with cyanobacteria should be avoided until the level of toxins is determined or until the water is treated.
Pathogens
- A variety of microbial pathogens can be transmitted to livestock from drinking water sources contaminated.
- The pathogens of greatest concern in water supplies for farm animals include enteric bacteria such as E. coli, Salmonella and Campylobacter jejuni.
- Other bacterial diseases known to affect livestock that may be transmitted through water supplies include Leptospira, Burkholderia (Pseudomonas) pseudomallei, and Clostridium botulinum.
Pathogens
- The cause of biological contamination of water sources is associated with the animal industry itself.
- For instance, in the situation of intensive livestock operation, the risk of water source contamination with animal waste may be very high.
Water treatment technologies
Water treatment technologies
- Water contaminants can be decreased considerably or even completely eliminated by a variety of treatment methods.
- Some methods are more effective than others, but for treating water for livestock consumption, economics are an important issue.
Activated carbon filters.
Activated carbon filters
- This method is based on passing water through a filter containing activated carbon granules.
- Contaminants attach to the granules and are removed.
- Chlorine, some organic compounds associated with coloration, odour and offtaste of water, mercury, some pesticides and volatile organic compounds can be removed by this method.
- The filters must be inspected and replaced frequently.
- Poor filter maintenance will decrease effectiveness, and may result in bacterial growth on the filter, causing potential contamination of the water with pathogens.
Air stripping
- Air stripping is the transferring of volatile components of a liquid into an air stream.
- It is an environmental engineering technology used for the purification of groundwaters and wastewaters containing volatile compounds.
- Contaminants are transferred from water to air and vented off. This method may be effective in removing hydrogen sulphide, some odours and tastes, and some volatile organic chemicals.
Air-Stripper diagram (Monroe Environmental Corp., 2019).
Biological filters
- Biological filtration is a natural process that takes place in rivers, streams, and oceans.
- Bacteria eat certain compounds, like ammonia, which is broken down into byproducts that are not toxic.
- This method is effective at removing iron, arsenic, and organics.
- A microbiological layer is used to filter and consume contaminants.
A swimming pool which treated chloride.
Chlorination
- This is one of the most common methods in water treatment for pathogen reduction in drinking water for livestock.
- Chlorination is much more effective if it follows a filtration system to remove large particles that can house bacteria.
- In particular, this is an effective and widely used method to kill many kinds of microorganisms in water.
- Chlorine content of the treated water should be monitored because the high concentrations of chlorine released to the animal water system may affect water intake and productivity.
Ozonation
- This method of water treatment is based on application of ozone gas.
- Ozone is a very potent oxidizing agent, and destroys pathogenic microorganisms.
- It can reduce color, improves taste, odor, kills bacteria, viruses, oxidize iron, manganese, cyanide, phenol, benzene, chlorophenol, atrazine, nitrobenzene and other pollutants.
- The equipment typically is quite expensive.
Importance of clean water to mankind
Proportion of population using improved drinking water sources (WHO, 2015).
- Safe and readily available water is important for public health.
- Improved water supply and sanitation, and better management of water resources, can boost countries’ economic growth and can contribute greatly to poverty reduction.
- Billions of people have gained access to water, but huge inequalities remain.
- In 2015, 71% of the global population (5.2 billion people) used a safely managed drinking-water service (available when needed, and free from contamination).
- 89% of the global population (6.5 billion people) used at least a basic service. A basic service is an improved drinking-water source within a round trip of 30 minutes to collect water.
- 844 million people lack even a basic drinking-water service, including 159 million people who are dependent on surface water.
- Globally, at least 2 billion people use a drinking water source contaminated with faeces.
- Contaminated water and poor sanitation are linked to transmission of diseases such as cholera, diarrhoea, dysentery, hepatitis A, typhoid, and polio.
- Inappropriately managed water and sanitation services expose individuals to preventable health risks.
- Some 842,000 people are estimated to die each year from diarrhoea as a result of unsafe drinking-water, sanitation, and hand hygiene.
Who has primary responsibility for collecting water in rural areas? (WHO/Unicef joint monitoring program).
Livestock and sustainable management of water
- Agriculture uses approximately 70% of the available freshwater supply, and roughly 30% of global agricultural water goes on livestock production (Ran et al., 2016).
- The largest proportion is associated with the production of feed.
Water footprint values reported for selected food products (Mekonnen and Hoekstra, 2012).