The present study was carried out at the Department of Poultry and Fish Production, Faculty of Agriculture at Shibin El-Kom, Menoufia University. The aim of the present study was to determine the concentrations of maternal antibody (IgY) in blood serum of layers and hatched chicks, in addition to egg yolk of three, control, high and low IgY antibody lines of Sinai and Silver Montazah local strains of chickens as a genetic marker to improve fertility, hatchability and livability percentages.
The results were summarized as follows:
1. Sinai strain had significantly higher IgY antibody concentration than Silver Montazah strain of chickens, being 4.68 vs 4.22 mg/ml in hen blood serum, 4.11 vs 3.46 mg/ml in egg yolk, 3.09 vs 2.66 mg/ml in hatched chicks serum and 48.00 vs 38.41 mg/egg yolk total, respectively.
2. Highly significant differences (P<0.01) among lines, the high (LH) lines harvested the highest IgY level and control line (CL) occupied intermediate level, whereas the low lines (LL) had the lowest IgY level in both strains of chickens. The means of IgY concentrations were 3.74, 6.15 and 2.44 mg/ml in Silver Montazah strain, where the corresponding values in Sinai strain were 4.63, 6.65 and 2.47 mg/ml for control, HL and LL lines, respectively.
3. The high IgY antibody lines had significant (P < 0.05) higher percentages of fertility than the control and low IgY antibody lines. The averages of fertility percentages were 76.97 vs 77.21 for control lines, 85.29 vs 88.19 for high lines and 68.38 vs 68.81 for low lines of Silver Montazah and Sinai strains of chickens, respectively.
4. The means of hatchability percentages of fertile eggs were 72.32% vs 77.60% for Silver Montazah and Sinai chickens, respectively. Also, means of hatchability percentages were 89.18 vs 91.89% for high lines, 75.11 vs 77.65% for control lines and 57.07 vs 61.33% for low lines of Silver Montazah and Sinai strains of chickens, respectively.
5. Sinai chickens had significantly (P < 0.5) higher livability (%) as compared to Silver Montazah chickens (80.65 vs 75.14%) due to the direct action of maternal antibody (IgY) transferred from layers to newly hatched chicks.
6. High IgY lines had significantly (P < 0.5) higher percentages of livability at 28d. The means of livability (%) were 75.83 vs 80.91 (%) for control lines, 87.92 vs 93.49 (%) for high lines, and 65.29 vs 65.79 (%) for low lines of Silver Montazah and Sinai strains of chickens, respectively.
7. Since the high IgY antibody improved fertility, hatchability and viability, So that, the IgY can be used as a genetic marker to improve some productive traits in chickens.