TABLE 7.
Evaluation of essential oils (EO) and herbal betaine on final body weight (g) and carcass yields (%) of broiler chickens exposed to cyclic heat stress at day 43a.
| Thermoneutral | Heat stress | Heat stress + EO1 | Heat stress + EO2 | |
|---|---|---|---|---|
| Live weight | 3,310.73 ± 30.02a | 2,468.60 ± 26.85c | 2,718.54 ± 26.85b | 2,673.10 ± 26.85b |
| Fat yield (%) | 1.11 ± 0.05 | 1.05 ± 0.04 | 1.04 ± 0.04 | 1.01 ± 0.04 |
| Hot carcass yield (%) | 74.73 ± 0.21 | 74.66 ± 0.18 | 74.26 ± 0.18 | 74.22 ± 0.18 |
| Chilled carcass yield (%) | 79.37 ± 0.36 | 79.06 ± 0.32 | 78.81 ± 0.32 | 79.22 ± 0.32 |
| Wing yield (%) | 8.08 ± 0.08b | 8.70 ± 0.07a | 8.30 ± 0.07b | 8.61 ± 0.07a |
| Breast yield (%) | 20.46 ± 0.20a | 17.50 ± 0.18b | 18.09 ± 0.18b | 18.10 ± 0.18b |
| Tender yield (%) | 4.03 ± 0.07 | 4.03 ± 0.06 | 4.00 ± 0.06 | 4.14 ± 0.06 |
| Leg yield (%) | 23.96 ± 0.19b | 25.75 ± 0.17a | 25.32 ± 0.17a | 25.36 ± 0.17a |
| Rack yield (%) | 21.67 ± 0.18 | 22.03 ± 0.16 | 21.84 ± 0.16 | 21.72 ± 0.16 |
a
Data are expressed as the mean ± SE.
abc Indicates significant differences between the treatments within the rows (p < 0.05). Cyclic heat stress started at day 10. EO1: essential oil of Lippia origanoides, thymol chemotype (45 ppm) and herbal betaine (150 ppm). Administration dose: 350 g/Ton food. EO2: essential oil of Lippia origanoides, phellandrene chemotype (45 ppm) and herbal betaine (150 ppm). Administration dose: 350 g/Ton food.