Egg, a biological structure intended by nature for reproduction, protects and provides a complete diet for the developing embryo and serves as the principal source of food for the first few days of the chick’s life. This study aims to assess the quality of eggs used for incubation, which to a very large extent determines fertility and hatchability recorded in hatchery operations. An initial total of 2000 eggs from three different breeds (Local, Imported and their Cross) of turkey hens, all between the ages of 51 – 60 weeks were collected over a period of thirty days. Hens were raised on litter floor and pen-mated using commercially accepted management practices. The eggs were tagged at the sharp end indicating breed and egg number. All eggs were measured soon after lay and stored prior to incubation. Measurements included egg weight, egg length, egg width, vertical and horizontal circumferences. The weight loss at 25
thday of incubation and shape index of each egg were also computed. All statistical analyses (Exploratory, Descriptive, General Linear Model (GLM) and Tukey Honestly Significant Difference Post Hoc Comparisons) were done with Minitab 17® Statistical Software. Data was scrutinized for normality and outlier values for all variables across the three breeds were eliminated, resulting in only 1930 eggs included in the final analyses. With the exception of horizontal circumference, breed had significant (P<0.05) influence on all other variables studied. The Imported breed consistently had higher values on all variables except incubation weight-loss and shape index (Table 1). However, the performance of the crossbred was below expectation as it did not reflect any improvement on the values obtained in the Local breed, and mostly less than the mid-parental average. This study revealed that crossbreeding the Imported with the Local breed did not yield any significant improvement in the performance of the crossbred. Thus, selecting higher performing local birds for breeding purposes will lead to faster genetic gain than crossbreeding the local with the imported breed.
Table 1: Descriptive Statistics of Variables Studied
Breed
|
N
|
Egg Weight (g)
|
Egg Length (mm)
|
Egg Width (mm)
|
Vertical Circumference (mm)
|
Horizontal Circumference (mm)
|
Weight Difference (g)
|
Shape Index (%)
|
Local
|
780
|
67.27±0.61b
|
63.06±0.32a
|
44.80±0.12b
|
170.10±0.66a
|
139.54±0.41
|
8.72±0.23a
|
71.14±0.31b
|
Imported
|
670
|
69.18±0.70a
|
63.78±0.32a
|
45.32±0.14a
|
171.18±0.70a
|
140.49±0.40
|
8.45±0.28ab
|
71.14±0.31b
|
Crossbred
|
480
|
66.97±0.65b
|
61.29±0.31b
|
45.05±0.13ab
|
166.50±0.73b
|
139.63±0.51
|
7.75±0.30b
|
73.57±0.32a
|
Combined
|
1930
|
67.86±0.39
|
62.87±0.20
|
45.04±0.08
|
169.58±0.42
|
139.89±0.25
|
8.38±0.15
|
71.75±0.20
|
Means with different superscript within the same column differs significantly (P<0.05)
