Thesis (M.Sc.)-Cairo University, 2022.

Bibliography: pages 64-78.

Local and indigenous chicken breeds play important roles in rural development and
sustainability, and thus, evaluating and improving local breeds is essential. Growth traits are
affected by both genotype and sex, as well as genotype-by-sex interaction. Genotype-by-sex
interaction refers to the interaction of genetic architecture with male or female performance. The
current study aimed to evaluate the differences between a fully-feathered local chicken line and
a naked-neck local chicken line. The analysis of the phenotypic data revealed significant G × S
interactions for body weights at 4 and 10 weeks of age. The line effects on body weight traits
were significant and consistent except for 2-wk body weight. Also, significant sex effects were
shown for body weights at all ages. The effect of sex on biweekly body weight gains and growth
rates was significant for the traits from 0 to 4, 6 to 8, and 12 to 14 weeks of age. The line effect
was significant for 0-2 and 2-4 growth rates, and 0-2 and 6-8 body-weight gains. Growth rates in
males were significantly higher than females at early ages. The comparisons between different
lines in the genomic information generated by different loci showed that the lowest allele
numbers were 0 and 4 alleles detected at loci LEI0094 and MCW217, respectively, and the
highest allele number was 10 detected at MCW328 and ADL299 loci, with an overall mean of
6.69 alleles/locus. The levels of heterozygosity were relatively high and were higher for the
naked-neck line (CE4) than for the fully-feathered line (CE2), as expected. The genetic distance
between males and females of line CE2 was shorter (0.018) than that between males and females
of line CE4 (0.104), and the opposite was observed for genetic identity. Also, ΦPT values were
0.088 (p < 0.001), and 0.080 (p < 0.01) for line CE2 and line CE4, respectively. The association
between alleles and body weights revealed different alleles of microsatellites MCW217,
MCW328, MCW193, ADL299, and MCW064 were contributed significantly to body weight
variance at different ages

تم تقييم الاختلافات بين خطين من الدجاج المحلي أحدهما كامل الترييش والأخر عاري الرقبة. وجد تفاعل معنوي بين الجنس G والتركيب الوراثي S لصفة وزن الجسم في اعمار 4 و10 أسابيع وكانت تأثيرات التركيب الوراثي على صفات وزن الجسم معنوية. أكبر عدد للأليلات كان10 أليلات في موقع MCW328 وADL299، بمتوسط إجمالي 6.69 أليلات / موقع. كانت مستويات الـ heterozygosity مرتفعة نسبيًا وكانت أعلى في التركيب الوراثي (CE4) عنه في التركيب الوراثي (CE2)، وكما هو متوقع كانت المسافة الوراثية بين الذكور والإناث للتركيب الوراثي CE2 أقصر (0.018) من تلك التي بين الذكور والإناث للتركيب الوراثي CE4 (0.104)، ولوحظ العكس بالنسبة للهوية الجينية.. أظهر الارتباط بين الأليلات وأوزان الجسم أليلات مختلفة من المايكروساتلايت MCW217 وMCW328 وMCW193 وADL299 وMCW064 ساهمت بشكل كبير في تباين وزن الجسم في مختلف الأعمار.

Issues also as CD.

Text in English and abstract in Arabic & English.