Yes, moldy hay is unequivocally harmful to livestock and should not be fed. The presence of mold indicates a deterioration in hay quality that can lead to serious health issues for animals, including horses, cattle, sheep, and goats.
Why Moldy Hay Poses a Risk to Livestock
High moisture content in hay creates an ideal environment for the proliferation of various bacteria, molds, and fungi. These microorganisms can produce substances that are dangerous when ingested or inhaled by animals.
The Danger of Mycotoxins
One of the primary concerns with moldy hay is the potential for the production of mycotoxins. These are toxic compounds produced by certain fungi that grow on forages. Ingesting mycotoxins can lead to a range of severe health problems, collectively known as mycotoxicosis, which can affect multiple organ systems.
Common effects of mycotoxins in livestock include:
- Neurological issues: Tremors, incoordination, and paralysis.
- Liver damage: Reduced liver function, jaundice.
- Kidney damage: Impaired kidney function.
- Digestive problems: Colic, diarrhea, reduced appetite, weight loss.
- Immune suppression: Making animals more susceptible to other diseases.
- Reproductive issues: Infertility, abortion, or birth defects.
Respiratory Illnesses
Even without mycotoxins, inhaling mold spores from dusty, moldy hay can cause significant respiratory problems in animals, particularly horses. Conditions like Recurrent Airway Obstruction (RAO), commonly known as "heaves," are often triggered or worsened by mold exposure. Symptoms include:
- Chronic cough
- Nasal discharge
- Difficulty breathing (flared nostrils, heave line)
- Reduced exercise tolerance
Digestive Upset and Nutritional Deficiencies
Consuming moldy hay can also lead to direct digestive upset. Molds can irritate the gastrointestinal tract, leading to colic, diarrhea, and general discomfort. Furthermore, moldy hay often has reduced palatability, meaning animals may eat less, leading to inadequate nutrient intake and poor overall health or performance. The mold itself consumes nutrients, lowering the actual nutritional value of the hay.
Identifying Moldy Hay
Identifying mold in hay is crucial for preventing harm. Here are some common indicators:
| Characteristic | Description |
|---|---|
| Appearance | Visible white, gray, green, or black patches; dusty, clumpy, or matted sections. |
| Odor | Musty, sour, or earthy smell, distinct from fresh hay. |
| Feel | Often feels damp, warm, or spongy when squeezed, indicating ongoing microbial activity. |
| Dustiness | Excessive dustiness when shaken, indicating a high concentration of mold spores. |
Preventing Mold in Hay
Preventing mold growth is key to ensuring safe hay for your animals.
- Proper Curing: Hay must be adequately dried to a moisture content of 15% or less before baling. High moisture content (above 15-20%) is the primary cause of mold.
- Storage: Store hay in a dry, well-ventilated area, off the ground, to prevent moisture absorption. Using pallets or old tires can help with air circulation.
- Protection from Elements: Protect hay from rain, snow, and condensation.
- Timely Baling: Bale hay promptly after cutting, taking advantage of good drying weather.
What to Do if Hay is Moldy
If hay is moldy, the most important action is to not feed it to any livestock.
- Dispose Safely: Dispose of moldy hay away from animals. It can sometimes be used as compost if mold types are known to be non-pathogenic, but caution is advised.
- Consider Testing: For valuable hay or if health issues are suspected, some forage laboratories offer testing for the presence of mold and mycotoxins. This can help confirm the extent of the problem and identify specific toxins.
- Clean Storage Areas: Thoroughly clean any areas where moldy hay was stored to prevent contamination of new hay.
- Inspect Remaining Hay: Carefully inspect the rest of your hay supply for any signs of mold. Mold can spread, so a small patch of moldy hay might indicate a larger issue in the bale or stack.
Prioritizing hay quality is essential for maintaining the health and productivity of your livestock.
