Table 2.
Effects of dietary supplementation of PFAs on growth performance of laying hens.
| Feed Additive | Major Components | Dose (mg/kg Diet) | Diet | Line and Age | Main Findings | References |
|---|---|---|---|---|---|---|
| Non-Challenging Conditions | ||||||
| Mentha arvensis (MA) and Geranium thunbergii (GT) extracts | MA: menthol, isomenthol, neomenthol, p-cymene, d-menthone, eugenol, and cineol GT: citronellol, isomenthone, and geraniin |
100, 500 and 1000 | Corn-wheat- soybean meal based diet |
Hy-Line Brown layers (28–44 weeks) | ↑ FI, egg production and egg weight | [89] |
| Fermented pine (Pinus densiflora) needle extract | α-pinene, caryophyllene, beta-pinene and bisbenzene, camphene, borneol, phellandrene, quercetin, kaempferol, and terpene | 2.5 and 5 | Corn-soybean meal-based diet | Hy-Line Brown laying hens (40–46 weeks) | ↑ FI, egg production and egg mass | [90] |
| Fermented Schisandra chinensis pomace (SC), fermented Pinus densiflora (PD) needle extract, and Allium tuberosum (AT) powder | SC: lignin PD: phenolics, flavonoids, and tannins AT: organosulfur compounds, polyphenols, and saponins |
1000 and 3000 | Corn-soybean meal-based diet | Hy-line brown laying hens (48–54 weeks) | -=Egg production, daily egg mass and FCR. -↑ FI |
[91] |
| Dry leaf extract of peppermint (Mentha piperita L.) | Menthol | 0, 74, 148, 222, and 296 | Corn-soybean meal-based diet | Bovans Brown laying hens (32–44 weeks) | ↑ FI, egg production, egg weight and egg mass | [48] |
| Citrullus lanatus EOs | Phenolics (1.57 mg/100 g) Sterols (600.56 mg/100 g) Flavonoids (163.5 mg RE/kg) |
1000 and 2000 | Corn-soybean meal-based diet | White Leghorn laying hens (18–26 weeks) | ↑ Weight gain, ADFI, ADG and egg mass; ↓ FCR | [46] |
| Tea tree (Melaleuca alternifolia) EO | Terpinen-4-ol (40.0%), γ-Terpinene (23.0%) and α-Terpinene (10.4%) | 40 and 80 | NM | Lohmann Brown hens (55–58 weeks) | ↑ Daily egg production and ↓ FCR | [47] |
| Thyme (Thymbra spicata) and Rosemary (Rosemarinus officinalis) | -Thyme: Carvacrol (87.81%), thymol (9.58%), L-Linalool (0.86%), borneol (0.74%) -Rosemary: 1.8 cineole (34.08%), camphor (27.95%), alpha-Pinene (14.50%), borneol l(8.65%), alpha-Terpineol (7.39%), alpha-Thujone (1.09%), camphene (0.55%) |
1000 for each source | Corn-soybean meal-based diet | Bovans-White (48–56 weeks) | -No effects on FCR -↓ Egg production and egg weight |
[92] |
| Cumin (Cuminum cyminum L.) seed oil | Cuminol, cuminique alcohol, cuminaldehyde, cymine, phellandrene, carvone, cymol, terpenes, α-pinene… | 500 | Corn-soybean meal-based diet | Boven hens (24–30 weeks) | =Egg production rate, egg mass and FI ↓ FCR and ↑ egg weight |
[93] |
| Eucalyptus leaves | Polyphenols | 500, 800 and 1200 | Corn-soybean meal-based diet | Yueqinhuang laying hens (35–44 weeks) | ↑ Egg production and egg mass | [94] |
| Fennel seeds (F), black cumin (BC) seeds and hot red pepper (RP) | F: trans-anethole BC: thymoquinone, anethole, carvacrol and 4-terpinol RP: Capsaicin |
5000 for each | Corn-soybean meal-based diet | Lohmann Brown Lite laying hens (32–40 weeks) | ↑ Egg weight, egg production, egg mass and ↓ FCR by F and RP | [53] |
| Green tea | Polyphenols | 200 | Corn-soybean meal-based diet | Hy-line Brown (65–74 weeks) | ↑ Egg production and ↓ FCR | [95] |
| EOs | Thymol (13.5%) and cinnamaldehyde (4.5%) | 50, 100 and 150 | Corn-wheat-soybean meal based diet | Lohmann White (54–65 weeks) | =Egg production, egg weight, egg quality, FI and FCR | [65] |
| Echinacea purpurea powder | Caffeic acid and alkamids, phenolic acids, polyacetylenes | 2500, 5000, 7500 and 10,000 | Corn-soybean meal-based diet | Leghorn laying hens (43–53 weeks) | ↑ Egg production and egg mass | [96] |
| Peppermint EO Thyme EO |
-Menthol and menthone -Thymol, γ-Terpinen and ρ-Cymene |
1000 | Corn-soybean meal-based diet | Lohmann LSL-lite (40–48 weeks) | ↑ Egg production and egg mass ↓ FCR |
[97] |
| Dried grape pomace | Polyphenols | 40,000 and 60,000 | Corn-soybean meal-based diet | Bovans laying hens (80–92 weeks) | =Live weight, feed intake, egg production and feed efficiency | [98] |
| Fennel (F) and thyme (T) extracts | F: anethole, limonene T:-Thymol, γ-Terpinen and ρ-Cymene |
40 | Corn-soybean meal-based diet | Hy-Line White (26–38 weeks) | ↑ Egg weight and egg mass | [99] |
| Cold stress + Escherichia coli | ||||||
| Curcuma longa | Curcumin | 200 | Corn-soybean meal-based diet | Hy-Line Brown laying hens (84–90) | =Egg production, egg mass, feed intake and FCR | [100] |
| Cold stress | ||||||
| Oregano EO | Carvacrol and thymol | 50, 100, 150 and 200 | Corn-soybean meal-based diet | Semi-heavy laying hens (59–71 weeks) | =FCR, egg production and egg mass | [73] |
| Heat stress | ||||||
| Grape pomace flour | Polyphenols | 10,000, 20,000 and 30,000 | Corn-soybean meal-based diet | Hy-Line lineage (74–79 weeks) | ↑ FI | [101] |
ADG: Average Daily Gain; ADFI: Average Daily Feed Intake; FI: Feed Intake; FCR: Feed Conversion Ratio; ↑: increased; ↓: decreased; =: equal.