Evaluation of different traits from day-old to age at first eggs of Fayoumi and White leghorn chickens and their reciprocal crossbreeds

Evaluation of reciprocal F1 crosses of Fayoumi with two exotic chicken breeds 1: additive and non-additive effects on egg production traits

The present study estimates additive and non-additive effects on egg production traits in genotypes generated through pure mating and reciprocal crossing of Fayoumi (FM) with Koekoek (KK) and White Leghorn (WL). Age at first egg (AFE) and body weight at first egg (BWAFE) were determined when the first bird in the pen laid its first egg, and egg weight at first egg (EWAFE) was the average weight of eggs laid consecutively during the first 10 days. Egg number (EN) and egg weight (EW) were recorded daily from AFE to 40 weeks of age. Egg mass (EM) was the product of EN and EW. EN of hens initially housed and hens alive during the experiment were used to calculate hen-housed egg production (HHEP) and hen-day egg production (HDEP), respectively. All the traits showed statistically significant differences among the genotypes. The results revealed the importance of additive and non-additive effects, where purebred effect (PE), general combining ability (GCA), maternal effect (ME), specific combining ability (SCA), and residual reciprocal effect (RRE) significantly affected most of the traits. The KK and WL had a higher PE, and GCA was highest in KK, with FM and WL showing a higher ME. The FM x WL had higher SCA and RRE. The KK x FM and FM x WL outperformed their main and reciprocal crosses, respectively, and purebred contemporaries. Therefore, a synthetic breeding program involving KK as a sire and FM, WL, FM x WL, and KK x FM as a dam would be feasible.

Estimation of genetic parameters of eggshell translucency and production traits in different genotypes of laying hens

The translucency of eggshells is a ubiquitous appearance problem caused by moisture translocation and the accumulation of egg contents into the eggshell ultrastructure. Previous studies have mainly investigated the causes of eggshell translucency from nutritional and environmental perspectives. However, little is known of the effect of genetics the causes of eggshell translucency on hen production performance. To evaluate the genetic parameters of eggshell translucency and other production performance indicators, we performed an experiment on 3 pure hen lines: 624 Dwarf Layer-White, 1,612 Rhode Island Red, and 813 Rhode Island Red-White. We collected eggs from each hen over 5 d and measured eggshell translucent level (TL) using the grading method. Additionally we measured indicators of each hen during the laying period, including age at laying of the first egg (AFE), body weight at laying of the first egg (BWFE), weight of the first egg (FEW), body weight at 40 wk (BW40), egg weight at 40 wk (EW40), egg production up to 40 wk of age (EN), and calculated the genetic parameters among the indicators. The results showed that the estimated heritability of TL in the 3 genotypes were 0.30, 0.24, and 0.20, respectively, suggesting a low or moderate level of heritability. We found a positive correlation between TL and AFE, with genetic correlation coefficients 0.19 to 0.41, and negative genetic correlation between TL and EN, with correlation coefficient -0.36 to -0.19. Additionally, we observed positive correlation exists between AFE and FEW, BWFE and FEW, and BW40 and EW40; and negative correlation between AFE and EN in the 3 pure lines. These results enriched the research on heritability of eggshell translucency in different hen breeds and demonstrated moderate or low heritability of the indicator. Furthermore, eggshell translucency was negatively affected by AFE and EN. Our results provide a valuable reference for predicting selection response of eggshell translucency and production performance in brood hens, and locating the genes regulating eggshell translucency.

Growth performance, mortality, and carcass yield evaluation of pure and reciprocal crosses between Sasso and Wassache chickens

The indigenous chicken production has become an integral part of smallholder farming systems in Africa. Their products are preferred due to their taste and flavor; crossbreeding using exotic breeds can improve the productivity of these chickens without sacrificing their genetic merits. This study was aimed at improving the Wassache chicken. F1 generations of the crosses between the Wassache and Sasso chickens were simultaneously evaluated for growth traits, mortality, and carcass yield in a pure and reciprocal cross design. Data on body weight, performance, and mortality were collected on 451 birds (Sasso × Sasso [SS] = 110; Wassache × Wassache [WW] = 113; Sasso × Wassache [SW] = 113 and Wassache × Sasso [WS] = 115) for 12 weeks. On the 12th week of the study, 20 birds from each genotype were dissected to determine carcass yield. All data collected were analyzed using Minitab 19. The results showed significantly higher (P < 0.05) values reported for the SS genotype in all parameters studied. Likewise, the reciprocal crosses showed higher performance in growth and carcass traits next to pure Sasso. However, the feed conversion ratio and dressing percentage of the hybrids did not differ (P < 0.05) from those of the SS and WW genotypes. Within the reciprocal crosses, there was no significant difference (P > 0.05) in all parameters measured except for hatch weight where the WS showed a higher (P < 0.05) hatch weight compared to the SW cross. The study encourages the crossbreeding of the Wassache and Sasso chickens for improved meat production in this region.