USING PATH ANALYSIS TO PARTITION THE VARIABILITY IN GROWTH AND CARCASS TRAITS IN THREE LINES OF JAPANESE QUAIL. | ||
| Fayoum Journal of Agricultural Research and Development | ||
| Article 5, Volume 20, Issue 2, July 2006, Pages 38-54 PDF (579.36 K) | ||
| Document Type: Research articles. | ||
| DOI: 10.21608/fjard.2006.197585 | ||
| Authors | ||
| Ensaf A. El Full; E. M. Omar | ||
| Poult. Prod. Dept., Fac. Agric., Fayoum Univ., Egypt. | ||
| Abstract | ||
| Chicks of two selected lines of Japanese quail for high six weekbody weight and high 1-6 week growth rate (HBW6 and HGR0-6) over three generations were used to partition the variability of growth and carcass traits. A randombred control line (RC) was kept in order to facilitate comparison between lines. The RC had the lowest boneless meat% (BLM), fat% and live body weight at slaughter (LBW6) being 48.13%, 16.09% and 184.65g, respectively. Although HGR had the highest BLM% and dressing%, birds of this line had significantly poorer feed conversion (FC) and performance index (PI) than other lines. On the other hand, birds of the HBW line had the highest LBW6 and PI but had higher carcass' fat% (200.25g, 3.55 and 20.51%, respectively). Sex significantly affected BLM%, carcass %, dressing%, LBW6, FC and PI. Although males had significantly higher carcass%, their PI were poorer than females, this may be due to the superiority of females growth than males at different ages of growth and this difference may be attributed primarily to the relatively large ovaries, liver and intestines of the females. When these parts were excluded, lower carcass% for female was obtained. Except triglycerides (TG), line significantly affected all plasma constituents. The RC line had the highest growth hormone (GH) and the lowest albumin (Alb), total lipids (TL), total protein (TP), triiodothyronine (T3) and ratio of T3 to thyroxine (T3/T4). Whereas, HGR had the lowest GH and the highest Alb, TP, T3 and T4. Females had significantly higher Alb, TP and T3/T4 than males, however, males had higher T3 than females. The results of path analyses revealed that the studied plasma constituents measured at three weeks of age in both sexes could be used to predict carcass traits and growth productive performance in Japanese quail. Each of GH, TG, TL, Alb, TP and T3/T4 was the first contributors of studied productive traits in line by sex groups indicating direct effects which ranged from 0.530 to 0.763, 0.504 to 0.945, 0.887 to 0.906, 0.513 to 0.990 and 0.609 to 0.892, respectively. Plasma constituents showed higher indirect coefficients of determination for their effects on all studied productive traits than their direct effects. This suggests that a part of the variations in these traits could be attributed to a trait or more, not handled in this study and may diminish the random error variation when considered. | ||
| Keywords | ||
| Path analyses; variability; growth; carcass traits; Japanese quail | ||
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