Table 4.
Effects of in ovo feeding of γ-aminobutyric acid and embryonic thermal manipulation on growth, feed intake, and feed conversion ratio in broiler chickens
| Parameters | Treatment1) | SEM | p-value | |||
|---|---|---|---|---|---|---|
|
| ||||||
| CON | G10 | TM | G10+TM | |||
| BW (g) | ||||||
| Day old | 40.3 | 40.2 | 39.9 | 40.0 | 0.07 | 0.149 |
| 7 d | 155.1 | 154.3 | 152.2 | 167 | 0.10 | 0.161 |
| 21 d | 909.1 | 901.7 | 879.8 | 881.7 | 8.10 | 0.528 |
| 28 d | 1,450.2 | 1,493.8 | 1,431.3 | 1,419 | 18.3 | 0.526 |
| ADWG (g) | ||||||
| 1 to 7 d | 16.4 | 16.2 | 16.1 | 18.2 | 0.37 | 0.151 |
| 8 to 21 d | 53.8 | 53.4 | 52 | 51.1 | 0.52 | 0.211 |
| 22 to 28 d | 77.3 | 84.6 | 78.8 | 76.8 | 2.31 | 0.649 |
| 1 to 28 d | 49.1 | 51.4 | 48.9 | 48.6 | 1.40 | 0.628 |
| ADFI (g) | ||||||
| 1 to 7 d | 15.4 | 14.8 | 14.6 | 16.9 | 0.35 | 0.084 |
| 8 to 21 d | 67.6 | 69.1 | 66.1 | 67.3 | 0.58 | 0.337 |
| 22 to 28 d | 116 | 125.8 | 119.9 | 112.1 | 1.96 | 0.067 |
| 1 to 28 d | 66.3 | 69.9 | 66.8 | 65.4 | 1.20 | 0.095 |
| FCR (g/g) | ||||||
| 1 to 7 d | 0.94 | 0.91 | 0.91 | 0.92 | 0.01 | 0.585 |
| 8 to 21 d | 1.25b | 1.28ab | 1.26ab | 1.30a | 0.02 | 0.018 |
| 22 to 28 d | 1.51 | 1.49 | 1.52 | 1.51 | 0.03 | 0.984 |
| 1 to 28 d | 1.23 | 1.23 | 1.23 | 1.25 | 0.02 | 0.873 |
Values were obtained from n = 5 repetitions per treatment.
SEM, standard error of the mean; BW, body weight; ADWG, average daily weight gain; ADFI, average daily feed intake; FCR, feed conversion ratio.
The treatments are described as follows: CON, control eggs without in ovo injection and incubated at standard temperature; G10, eggs injected at 17.5 days of incubation with 0.6 mL of 10% γ-aminobutyric acid dissolved in distilled water; TM, thermally manipulated eggs exposed to 39.6°C for 6 h daily from embryonic day 10 to 18; G10+TM, eggs that received both previous treatments during incubation. Chicks obtained were grown for 28 days.
Means in a row that possess different superscripts differ significantly (p<0.05).