Table 6.
Summary of THY residue dynamics in food-producing animals.
| Species | THY source/ administration | Sample matrices | Findings | Key conclusions | References | Year |
|---|---|---|---|---|---|---|
| Dairy cattle | Intramammary | Milk, liver, kidney | Residues are detected in milk up to 36 h, liver up to 96 h | THY persists longer in liver, a key organ for metabolism | (63) | 2016 |
| Intramammary | Liver | Prolonged clearance is observed in liver; liver is recommended as a primary testing site | Liver acts as a principal residue storage site | (64) | 2017 | |
| Feed. THEO | Milk | The recommended milk withdrawal period is 72 h | Ensures consumer safety by reducing residue exposure | (66) | 2022 | |
| Feed. THEO (21 days) | Milk | Minimal THY levels are detected | Minimal residue risk in milk | (67) | 2023 | |
| Feed. THY-CAR blend | Feces | Low residual levels are found in feces, suggesting minimal environmental impact | Low risk of environmental contamination post-supplementation | (53) | ||
| Pigs | Encapsulated and free THY (oral) | Liver, lungs, kidneys, gastrointestinal contents | Low residues are found in organs; higher concentrations in gastrointestinal contents | Limited systemic deposition; effective metabolic processing | (61) | 2014 |
| Broiler chickens | Feed. THEO | Duodenum, Jejunum, Liver | Highest concentrations are observed in duodenum and jejunum; low levels are found in liver | Efficient metabolism and clearance in tissues | (57) | 2013 |
| Feed. THY | Duodenum | Biotransformation occurs into sulfate and glucuronide metabolites; highest levels are found in duodenum | Supports safe THY use due to efficient metabolism | (68) | 2017 | |
| Feed. THY | Muscle | Only trace residues are detected in muscle | Low risk of residue in edible muscle tissue | (69) | ||
| Feed. THY | Muscle | Trace concentrations are detected after extended feeding | Minimal tissue residue risk | (59) | 2019 | |
| Feed. THEO | Duodenum to Caecum, Plasma | A concentration gradient is observed from duodenum to caecum; plasma levels correlate with gut concentration | THY is absorbed systemically with minimal tissue residues | (70) | ||
| Quails | Feed. THY | Egg yolk, Droppings | Dose-dependent increases are observed in egg yolk THY levels; levels decrease upon withdrawal | THY is deposited in eggs and decreases after withdrawal | (71) | 2019 |