一, The Hazards of Moldy Feed
Moldy feed can destroy the nutrients within the feed, leading to a decline in its nutritional value. Furthermore, it generates numerous mycotoxins, resulting in reduced palatability, feed intake, and digestibility in broilers, as well as decreased growth rates and feed conversion efficiency; in severe cases, it can even cause poisoning. Certain mycotoxins—such as aflatoxin—also possess specific toxic properties, including carcinogenic, mutagenic, and teratogenic effects.
二, Control of Moldy Feed
(1) Severely moldy feed must be discarded and under no circumstances be utilized.
(2) Feed that is only slightly moldy or deteriorated should undergo the following treatments:
A. **Physical Treatment Methods:** Moldy particles can be manually, mechanically, or electronically sorted out and removed. Processing the feed by rolling or milling to remove the bran and hulls can also significantly reduce toxin levels. Additionally, mixing moldy feed with non-moldy feed can dilute the overall concentration of mycotoxins within the total feed batch. According to my country's feed hygiene standards, the permissible limit for Aflatoxin B1 in compound feed for chicks is ≤ 0.01 mg/kg.
B. **Chemical Treatment Methods:** These methods are suitable for moldy grains and seeds (e.g., corn, wheat). One approach involves soaking the feed in a 5% lime solution for 3 to 5 hours, followed by thorough rinsing with clean water; this method can achieve a detoxification rate of over 90%. Alternatively, exposing moldy feed to ultraviolet (UV) radiation from a high-pressure mercury lamp—or simply sun-drying it—can effectively eliminate mold. Other chemical treatments involve using substances such as ammonia, sodium hydroxide, or sodium bicarbonate to treat the moldy feed. Furthermore, oxidizing agents—such as hydrogen peroxide, sodium hypochlorite, or chlorine gas—can be applied to reduce or neutralize the activity of the mold.
C. **Microbial Fermentation Treatment:** Subjecting moldy feed to fermentation processing can either destroy mycotoxins or convert them into substances with lower toxicity. Compared to chemical methods, this approach results in minimal loss of the feed's nutritional components; however, it has not yet been widely implemented in commercial production settings.
D. **Mineral Treatment Methods:** Since activated carbon, bentonite, fluorite, and similar substances possess strong adsorption capabilities—in addition to being chemically stable, generally insoluble in water, and not readily absorbed by animals—incorporating them into animal feed allows for the adsorption of mycotoxins present in the feed, thereby mitigating the adverse effects of these toxins on the animals.
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