Review of literature
Body weights
Body size is of special importance to broiler breeders because it presents a ceiling on growth at a specific time. Body size is commonly measured by weighing birds which determines both bone size and flesh including muscle and fat. Hence nutrition and hygiene have a lesser effect on bone size than on flesh, bone size is more highly heritable, shank length therefore should be a better measure of body size than body weight (Nordskog ,1974).
Hassan et al. (1976) reported that body weight is generally agreed to be highly heritable and the degree of inheritance of rate of growth appears to be nearly as that to body weight and body conformation.
With respect to the effect of crossing on body weight, Coligado et al. (1985) found that crossing of Philippine native female chickens to pure breed males generally resulted in better performance of the F1 grade compared to the native chickens.
Amin et al. (1992) found that body weight of crossbred birds was higher than the pure Bangladesh local breeds.
Body weight of pure breed.
Sharara (1974) found that the average body weights of Fayoumi chicks at hatch time, 4, 8, 12, 16 and 24 wk of age were 29.3, 84.6, 203.2, 382.1, 628 and 1050.4 g, respectively. The average body weights of Dandarawi chicks were 27.9, 97.9, 233.5, 419, 635.9 and 944 g at the same order. This study was carried out under upper Egypt condition.
Hassan et al. (1976) reported that the effect of breed (Dandarawi, Fayoumi, and Dokki-4) on body weights at hatch time, 4, 8, 12, and 24 wk but not at 16 wk of age was highly significant. Generally, the effect of breed on body weights is decreasing with advanced of age. There were no significant differences between sex at hatching time but the differences became significant from 4 up to 24 wk of age.
Rath et al. (1980) reported that average body weights of White Leghorn chicks at one day, and 2, 3, 6, 10, 12, 16, and 20 wk of age were 37.5, 93.4, 174.6, 257.9, 463.4, 621.9, 1240.1, and 1515.8 g, respectively.
Rathor et al. (1980) found that body weights of White Leghorn at 1, 2, 3, 4, and 5 months of age were 149.57, 301.72, 563.49, 870.06, and 1085.82, respectively.
Sabri (1993) reported that body weights at hatch time of two standard breeds, White Leghorn and New Hampshire, and a selected Fayoumi strain for heavy body weight at 8 wk of age, were 41.2, 37.9, and 31.2 g, respectively, while they were 324, 376, and 316 g at 6 wk of age, respectively, and were 802, 979, and 903 g at 12 wk of age at the same order .
Abd El-Ghany (1995) found that average of body weights for Rhode Island Red males were 190.96, 637.66, 1033.12, and 1512.14 g at 4, 8, 12, and 16 wk of age, respectively, and 192.93, 543.05, 904.56, and 1259.32 g for females at the same age, respectively. For White Leghorn, males body weights were 187.45, 549.94, 884.10, and 1305.16 g, and for females 169.47, 406.78, 703.40, and 991.35 g at the same age respectively. Body weights of Fayoumi males were 228.10, 561.14, 1102.52, and 1436.49 g, and for females 210.27, 482.21, 870.98, and 1050.81 g at the same age, respectively. The average of Sinai male body weights were 212.79, 518.51, 903.26, and 1272.87 g and for females 200.39, 443.82, 763.87, and 1031.68 g at the same age, respectively. For Dandarawi males the body weights were 181.42, 449.72, 835.92, and 1139.44 g, and for females were 156.87, 411.57, 628.08, and 859.39 g at the same age, respectively.
Body weight of some crosses.
Hassan (1973) found that two-way reciprocal crosses of Fayoumi, Single Comb White Leghorn and Rhode Island Red gave heavier day-old chicks than that of the Fayoumi. The day-old chicks weight was heavier when Fayoumi was used as a male in the reciprocal cross. These may be due to the maternal effect, hence Fayoumi recorded the smallest egg size among the three breeds.
Sabri (1979) studied the effect of Genotype on body weights of Fayoumi strains which were selected for high body weight at 8 wk of age (GG), selected for high egg number (PP), Random bred control (RR), (GP), and (PG) crosses. The hatch weights were 29.85, 25.9, 27.15, 31.25, and 30.95 g for GG, PP, GP, PG, and RR, respectively, while body weights at 12 wk of age were 1026.75, 846.1, 928.85, 991.6, and 919.55 g for the five genotypes, respectively. No significant differences were observed between GG and PG males in body weight. However, significant differences were found between GG and PG females at 8, 10, 12, and 14 wk of age.
Verma et al.(1980 a) and Verma et al.(1980 b) Studied the effect of breed [Rhode Island Red (R), Australorp (A), White Plymouth Rock (W), White Cornish (C), and their three and four-way crosses] on body weights. For three-way crosses at 1-day of age A(C*W) had the highest body weight (39.41g) while A(W*R ) had the lowest body weight (37.66 g). At 2 wk of age C(A*R) had the lowest body weight than all crosses (105.35 g) while R(C*A) had the highest body weight (131.93 g). At 4 wk body weight A(W*R) had the lowest body weight (236.63 g) while A(C*W) had the highest body weight (283.00 g). At 6 wk of age W(A*R) had the lowest body weight (438.21 g) while A(C*W) had the highest body weight (531.50 g). At 8 wk of age (C*A) had the lowest body weight (675.16 g) while A(C*W) had the highest body weight (775.58 g). At 10 wk of age R(C*A) had the lowest body weight (936.86 g) while R(C*W) had the highest body weight (989.21 g). Generally, these crosses were 7.34% higher than pure breeds at 10 wk of age. They also reported that there were significantly differences between pure breeds and four-way crosses in body weights at hatch and 2 wk of age, but the differences were not significant at 4, 6, 8 and 10 wk of age.
El-Turky (1981) showed that body weights of some local crosses [Alexandria (A), Silver Montazah (S), Gimmizah (G), Bandara (B)] and their reciprocal crosses including (AS), (AG), (AB), (SA), (SG) , (SB), (GA), (GS), (GB), (BA), (BS), and (BG) at 12 wk of age were 816, 808, 825, 836, 833, 879, 870, 834, 902, 865, 890, 875, 773, 844, 833, and 830 g for males, respectively, and were 752, 701, 706, 724, 754, 733, 686, 725, 718, 735, 739, 716, 654, 719, 705, and 671 g for females at the same order.
Abd El-Glil (1993) found significant differences in body weights of LSL, Bandara, Golden Montazah, Gimmizah, Dokki-4, Fayoumi, and Dandarawi strains during all studied growing age intervals. Bandara chicks were heavier, while Dandarawi chicks were lower in body weight at all studied periods.
Mossad (1994) found that average of body weights at 4 wk of age for Bandara, Gimmizah, Mamourah and El-salam were 207, 211, 191, and 202 g, respectively, while body weigths at 8 wk were 517, 511, 530, and 495 g for the same breeds, respectively. At 12 wk of age the average of body weights were 810, 898, 965, and 875 g, while at 16 wk of age body weights were 1146, 1216, 1311, and 1189 g for the four breeds, respectively. Highly significant differences found among the breeds and sexes of body weight at 4, 8, 12, and 16 wk of age. The effect of interaction between breeds and sexes was highly significant for body weight at 4 and 8 wk of age while it was significant (p £ 0.05) at 12 and 16 wk of age.
Ali (1994) found that the average body weights at hatching were 41.9, 30.2, and 40.2 g for Rhode Island Red (R), Fayoumi (F) and R*F chicks, respectively.
Abd El-Ghany (1995) estimates body weights at 12 wk of two-way crosses produced by reciprocal crosses of five pure breeds [Rhode Island Red (RIR), White Leghorn (WL), Fayoumi (FA), Sinai (SA) and Dandarawi (DA)]. The estimated value of body weights were 679.92 g (RIR*WL), 757.60 g (RIR*FA), 701.57 g (RIR*SA), 689.99 g (RIR*DA), 721.25 g (WL*RIR), 702.62 g (WL*FA), 680.08 g (WL*SA), 627.2 g (WL*DA), 777.57 g (FA*RIR), 733.41 g (FA*WL), 728.38 g (FA*SA), 664.49 g (FA*DA), 723.63 g (SA*RIR), 681.00 g (SA*WL), 717.94 g (SA*FA), 647.11 g (SA*DA), 693.01 g (DA*RIR), 681.79 g (DA*WL), 676.37 g (DA*FA), and 653.43 g (DA*SA).
Correlation estimates for body weights at different ages.
Merritt (1966) reported that the genetic correlations between body weights at different ages were positive and high.
El-Hossari et al. (1970) found that the genetic correlations of body weights at 8 wk of age and both 4 and 12 wk of age were 0.92 and 0.86, respectively
Sabri (1979) found that the genetic correlation (rg) between hatch weight and 4, 8, 10, 12, 14, and 16 wk of age for Fayoumi strains which were selected for high body weight at 8 wk of age ( GG ), selected for high egg number ( PP ), Random bred control ( RR ), ( GP ), and ( PG ) crosses, were 1.00, 0.32, 0.32, 0.23, 0.42, and 0.19, respectively for (RR) males and were 0.59, 0.40, 0.27, 0.30, 0.30, and 0.32 for ( RR ) females at the same order. And rg were -0.03, 0.29, 0.17, 0.14, 0.21, and 0.26 for (PP) males, respectively and were -0.06, 0.20, 0.26, 0.20, 0.26, and 0.22 for ( PP ) females, respectively. The rg were 0.56, 0.45, 0.45, 0.56, 0.62, and 0.59 for ( PG ) males, respectively and were 0.22, -0.06, 0.12, 0.23, 0.21 and 0.46 for ( PG ) females at the same order. The rg were -0.45, -0.29, -0.09, -0.38, -0.40, and -0.20 for GP males, respectivelly. The rg were -0.03, -0.37, -0.32, -0.34, -0.34, and -0.30 for GP females, and were 0.64, 0.71, 0.78, 0.73, 0.60, and 0.53 for GG males, respectively and 0.12, 0.40, 0.29, 0.35, 0.32, and 0.44 for GG females at the same order. Generally, phenotypic correlation in males was higher than that in females for all groups.
Ezzeldin (1991) found that most phenotypic correlations between body weights at different ages were positive, highly significant, and of high magnitude. His estimated value was ranged from 0.42 to 0.91. The phenotypic correlations between 2 wk and 4, 6, 8, 16, and 20 wk of age were 0.73, 0.67, 0.66, 0.64, 0.48, and 0.42, respectively, while between 4 wk and 6, 8, 12, 16 and 20 wk of age were 0.81, 0.78, 0.73, 0.54, and 0.50, respectively. The phenotypic correlations were 0.90, 0.83, 0.63, and 0.59 between 6 wk and 8, 12, 16, and 20 wk of age, respectively, while between 8 wk and 12, 16, and 20 wk of age the phenotypic correlations were 0.91, 0.67 and 0.65, respectively. Between 12 wk and both 16 and 20 wk of age the phenotypic correlations were 0.75 and 0.73, respectively. The phenotypic correlation was 0.62 between 16 and 20 wk of age.
Balat et al. (1993) found that the phenotypic correlations between 8 wk and both 16 and 20 wk of age for turkey males were 0.42 and 0.425 and the genetic correlations were 1.00 and 1.00, respectively. The phenotypic correlation was 0.867 and the genetic correlation was 0.965 between 16 and 20 wk of age, respectively. On the other hand in females the phenotypic correlations were 0.437 and 0.366 and the genetic correlations were 0.76 and 0.763 between 8 wk and 16 and 20 wk of age, respectively, the phenotypic correlation was 0.626 and the genetic correlation was 0.984 between 16 and 20 wk of age, respectively.
Sabri (1993) reported that the genetic correlations (rg) between hatch body weight and 4, 8 and 12 wk of age for two standard breeds, White Leghorn and New Hampshire, and a local Fayoumi strain selected for heavy body weight at 8 wk of age were 0.63, 0.32, and 0.12, respectively for White Leghorn, while they were 0.38, 0.24, and 0.14 for New Hampshire, respectively and were - 0.11, 0.57 and 0.47 for Fayoumi strain at the same order. The (rg) between body weights at 4 wk and both 8 and 12 wk of age were 0.47 and 0.57 for White Leghorn, 1.00 and 0.61 for New Hampshire and 0.85 and 0.45 for Fayoumi, respectively. The (rg) between 8 and 12 wk of age were 0.96, 0.77, and 0.55 for the three strains, respectively. The phenotypic correlations among hatch body weight and 4, 8, and 12 wk of age were 0.29, 0.20, and 0.16, respectively for White Leghorn, while they were 0.25, 0.17, and 0.09 for New Hampshire and were 0.1, 0.12 and 0.12 for Fayoumi, respectively. The phenotypic correlations between 4 and 8 and 12 wk of age were 0.55 and 0.43 for White Leghorn, 0.7 and 0.47 for New Hampshire and .66 and 0.46 for Fayoumi, respectively. The phenotypic correlation among 8 and 12 wk of age were 0.54, 0.53 and 0.68 for the three breeds, respectively.
Heritability estimates for body weights
Abd El-Gawad (1971) found that heritability estimates for body weight were 0.14, 1.00 and 0.79 for White Leghorn from sire, dam and sire+dam components, respectively at 8 wk of age and were 0.25, 1.00 and 0.72 at the same order for Fayoumi.
Rishel et al. (1973) found that heritability estimates from sire component were higher than that estimates from dam component. In contrast, Shalash (1977) found that heritability which estimates for body weight from dam component were higher than that which estimates from sire component.
Sabri (1979) found that heritability estimates from sire component [for Fayoumi strains which were selected for high body weight at 8 wk of age ( GG ), selected for high egg number ( PP ), Random bred control ( RR ), ( GP ), and ( PG ) crosses] were higher than those from dam component for GG and GP males while the heritability estimates from dam component were higher than estimates from sire component for PP and RR males, the GG females and both sexes of the PG crosses. Heritability estimates for hatch weight for GG, GP, PG, PP, and RR males from sire+dam components were 1.34, 0.84, 0.73, 1.13, and 1.28, respectively and were 1.51, 1.20, 0.77, 1.24, and 1.47 for females at the same order. At 12 wk of age they were 0.28, 0.27, 0.65, 0.37, and 0.34 for males, respectively and were 0.40, 0.51, 0.81, 1.02, and 0.31 for females at the same order.
Eid (1979) found that heritability estimates from sire component for Fayoumi strain (F) and two lines of Alexandria strains selected for high (H) and low (L) 8 wk body weight were 0.34, 0.14 and 0.17 at hatching time, respectively for H, L and F. The estimates were 0.64, 0.51 and 0.01 at 4 wk of age for the three genotypes at the same order.
Hataba (1980) found that the heritability estimates at 8 wk of age of Fayoumi were 0.12, 0.65, and 0.38 from sire, dam and sire+dam components, respectively.
El-Full (1989) found that heritability estimates from sire+dam components for 4, 8, 12, and mature body weight were 0.60, 0.43, 0.51, and 0.47, respectively for Fayoumi breed.
Aly (1993) found that the estimate of heritability from sire (s) and dam (d) components decreased with advanced of age. Heritability estimates from dam component tended to be higher than that from sire component, probably due to maternal effect. The results showed that the heritability estimates from sire, dam and sire+dam components, for Fayoumi males at 4 wk of age were 0.228, 0.493, and 0.361, respectively while estimates were 0.172, 0.431, and 0.302 at 8 wk, 0.195, 0.375 and 0.285 at 12 wk, and 0.077, 0.282 and 0.180 at 20 wk, at the same order. For females at 4 wk the estimates were 0.263, 0.363 and 0.313, while estimates were 0.179, 0.444 and 0.312 at 8 wk, 0.224, 0.398 and 0.311 at 12 wk, and 0.174, 0.368 and 0.305 at 20 wk from from sire, dam and sire+dam components, respectively.
Abd El-Gany (1995) found that heritabilities of body weight at 4 wk of age from sire component of Rhode Island Red, White Leghorn, Fayoumi, Sinai, and Dandarawi, were 0.044, 0.484, -, -, and 0.076, respectively. The estimates at 12 wk of age were 0.282, 0.222, 0.687, 0.305, and 0.644 at the same order. The heritability values at 16 wk of age were 0.214, -, 0.198, 0.500, and 1.00, respectively. The results showed breed differeces in heritability for body weight.
Sexual maturity traits
Age and body weight at sexual maturity:
Cross breeding of poultry for egg production is practiced as an efficient method for a quick increase in egg production of market eggs. Hassan (1973) found that age at sexual maturity for Fayoumi (F), White Leghorn (L), Rhode Island Red (RIR), and their crosses F*L, L*F, F*R, R*F, L*R, and R*L were 196.1, 225.7, 240.6, 228.8, 207.4, 239.7, 224.7, 245.9, and 229.1 days, and body weights at sexual maturity were 1168.4, 1807.0, 2022.1, 1914.0, 1152.8, 1941.3, 1219.9, 1966.0, and 1093.0 g, respectively.
Shrara (1974) reported that age at sexual maturity was earlier in Dandarawi (218.5 days) compared with the Fayoumi (223.8 days) and the Dokki (226.8 days). However, the analysis of variance showed that the differences among the three breeds were not statistically significant. Means of body weight at sexual maturity were 1177, 1273, and 1465 g for Dandarawi, Fayoumi, and Dokki, respectively. The difference among breeds for body weight at sexual maturity was highly significant.
Abd El-Latif (1977) found that Dandarwi (D) had the lightest body weight ,while Rhode Island Red (RIR) had the heaviest one. The cross RIR*D had higher body weight at sexual maturity than D*RIR. There were highly significant differences between genotypes in body weight at sexual maturity. The dandarawi began laying comparatively earlier than the Rhode Island Red. However, the crossbreeds between RIR*D and D*RIR matured at intermediate ages. He found that both flocks of pure breeds take longer time to be completely matured than the two crosses. In other words, the pure breeds had wider variation in the age of sexual maturity than the crossbreeds. Age at which the laying commenced was 165, 170, 163 and 162 days in Dandarawi, Rhode Island Red, D*R and R*D, respectively, while the age at which 50% of the females matured was 212, 243, 218 and 212 days in Dandarawi, Rhode Island Red, D*R, and R*D, respectively. However, all pullets matured (100%) at 285, 300, 262 and 272 days in Dandarawi, Rhode Island Red, D*R, and R*D, respectively.
Smith et al. (1977) found no significant differences in the age at sexual maturity between different breeds of Necked Neck.
Hassan et al.(1981) found that Fayoumi chickens reached their sexual maturity at 170.7 days of age and their body weight at sexual maturity was 1066.5 g
Elham et al.(1981) found that the age at sexual maturity was 181 and 190.4 days for Mandarah and Dokki-4, respectively while the average of body weights at sexual maturity 1710 and 1445 for the two breeds, respectively.
El-Turky (1981) found that the age at sexual maturity for Alexandria, Silver Montazah, Gimizah, and Bandara were 187, 210, 226, and 2233 days, respectively. The average of body weights at sexual maturity were 1801, 1775, 2094, and 2102 for the same breeds, respectively.
Stino (1983) reported that Fayoumi hens reached sexual maturity significantly (p£0.01) earlier than the White Baladi hens.
Neg (1984) found that Fayoumi pullets took from 7 to 8 days longer to lay first egg than Ross Tint.
Verma (1987) showed that the average of age at sexual maturity (days) for four strains of Single Comb White Leghorn (L33, L55, L77 and L99) and their crosses (L35, L37, L39, L53, L57, L59, L73, L75, L79, L93, L95 and L97) was 150.7, 154.59, 163.23, 157.27, 149.22, 156.28, 151.33, 157.72, 158.44, 150.44, 153.14, 154.62, 154.34, 151.16, 148.74, and 151.75, respectively.
El-Bogdady et al. (1993) on a study on Fayoumi and LSL found that within breed there was significant differences in age at sexual maturity. Data indicated that LSL reached sexual maturity significantly 11 days earlier than Fayoumi. The age at sexual maturity for Fayoumi was 154.83 days, while for LSL was 143.07 days.
Ali (1994) reported that age at sexual maturity for Rhode Island Red, Fayoumi and their crosses did not differ significantly among genotypes.
Ali (1994) found that ages at sexual maturity for Necked Neck and Dandarawi were 167.4 and 164.9, respectively, while body weights at sexual maturity were 1366 and 1108. For different plumage color group of Necked Neck, ages at sexual maturity were 169.74 , 167.54 and 163.52 for Red, White and Black, respectively. Body weights at sexual maturity were 1350, 1350, and 1440 at the same order.
El-Wardany et al. (1994) found that body weights at sexual maturity were 1496 ± 32.5 and 1510 ± 44.2 for Gimmizah and Mamourah breeds, respectively
Abd El-Ghany (1995) found that the averages of body weights at sexual maturity were 1719.9, 1438.78, 1364.41, 1296.4, and 1078.19 for Rhode Island Red, White Leghorn, Fayoumi, Sinai, and Dandarawi, respectively. While the averages of age at sexual maturity were 150.9, 158.9, 153.1, 149.8, and 153.8.
Body measurements at sexual maturity.
Abd El-Gawad et al. 1979 and Sabra 1990, found significant differences among breed groups in shank length.
Sabri (1979) found highly significant differences in shank lengths among Fayoumi strains, GG selected for high body weight at 8 wk of age, PP selected for high egg number, their crosses (GP&PG) and Random bred control (RR). The genotype GG had the longer shank than those of the PP. The cross PG males were similar to those of GG strain. On the other hand, there were highly significant differences among strains in keel length. The keel lengths of the control RR and the crosses GP and PG were intermediate between the two pure strains GG and PP.
Renden et al. (1986) found that age at sexual maturity was inversely related to body weight for the hens which were produced from random breeding within lines of dwarf White Leghorn that had been divergently selected for four generations for 20 wk body weight. Throughout the experiment, body weight increased with age in all lines, and shank reached a maximum length 8 wk after sexual maturity. A negative correlation existed between shank length and age at sexual maturity.
Shanawany et al. (1992) found that body weight was linearly related to shank length at 8, 12 and 16 wk of age of 240 females of chicken.
Shinde et al. (1993) showed that females which had longer shank had higher average body weight, egg production, and egg weight than those with shorter shanks.
Sabri (1993) reported that Least Square Means (LSM) for lengths of shank , keel , wattle, and comb and comb hightt were 73.4, 67.3, 8.4, 33.4, and 14.9 (mm.) for females of White Leghorn, 79.2, 68.7, 8.1, 27.6, and 9.2 for females of New Hampshire and 76.6, 68.0, 8.5, 31.5, and 12.1 for females of Fayoumi, respectively. The differences among breed groups were significant for shank length, Comb hightt, comb length and keel length, but not in wattle length.
El-Sayiad et al. (1994) reported that the Fayoumi females had body weight of 1278.79 (g), shank length 81.38 (mm), and wattle length 21.33 (mm) at sexual maturity, respectively.
El-Wardany et al. (1994), reported that the means of shank length of Gimmizah and Mamourah breeds were 9.35 and 9.50 cm at 20 wk of age, respectively while the means of keel length were 11.52 and 11.29 cm at the same order.
Egg production traits:
Egg weight and number:
El-Itrbi et al. (1963) found that the range of egg number for dandarawi breed ranged from 126 to 145 egg/year.
Hassan et al. (1976) under upper Egypt conditions found that the first 90 days of egg production for Dandarawi (D), Rhode Island Red ( R ) and their reciprocal crosses D*R and R*D were 35, 39, 39, and 43. The averages of egg weight were 40.2 , 44.4 , 44.8 and 45.9 for DD, RR, DR, and RD, respectively. Abd El-Llatif (1977) found that 90 days egg number were 35.8, 32.7, 42.4 and 42.1 eggs for DD, RR, D*R and R*D, respectively.
Hassan et al. (1981) Found that Fayoumi chicks were reached sexual maturity at 170.7 days of age and egg number in the first 90 days of laying was 21.9 and average egg weight was 35.3 g
El-Turky (1981) found that egg weights for Alexandria (A), Silver Montazah (S), Gimmizah (G) and Bandara (B) were 48.8, 49.8, 53.4, and 54.1 g, respectively and the average of percent egg production ( egg / hen / month ) were 51.7, 56.3, 45.6, and 47.2 % at the same order. Egg mass were 2289.4, 2362.6, 2228.7, and 2086.6 g, respectively. The average of egg number for A, S, G, B and their reciprocal crosses ( AS, AG, AB, SA, SG, SB, GA, GS, GB, BA, BS and BG ) pullets up to 500 days of age were 93, 113, 105, 95, 131, 113, 109, 60, 126, 95, 150, 85, 108, 109, 132, and 120 eggs, respectively. Egg weights were 49, 48, 51, 51, 49, 51, 51, 53, 51, 51, 50, 55, 51, 50, 52, and 51 g at the same order . There were significant differences among breeds in both egg number and egg weight .
Elham et al. (1981) reported that the annual egg production was 180 for Mandarah and 172.4 for Dokki-4, respectively, while averages of egg weight were 50.4 and 50.1 g for for Mandarah and Dokki-4, respectively.
Atalla et al. (1983) found that the average of egg production until 40 wk, 44 wk, 48 wk, 52 wk, and 70 wk of age were 26.8, 38.3, 50.2, 62.6, and 96.3 eggs, respectively for Fayoumi chickens.
Poggenpoel et al. (1988) found that age at sexual maturity was 148.3 days and egg number to 273 days was 98.7 eggs, while egg number was 243.4 eggs to 497 days for White Leghorn.
Yoo et al. (1981) found that age at sexual maturity was 150.3 days and egg number from 18 to 43 wk of age was 125.8 eggs, while it was 232.5 eggs from 18 to 65 wk of age for White Leghorn.
Shebel (1991) reported that the average of age and body weight at sexual maturity were 180.94 days and 2007.00 g. The 90 day egg number and egg mass were 48.47 eggs, and 1545.59 g, respectively, for Alexandria chickens.
Aly (1993) using three years data of a Fayoumi strain reported that the average of egg number for sixty days production and 90 days production of the first year were 29.7 and 43.59 eggs, respectively, and egg weights were 35.59 and 36.61 for the two periods, respectively. Egg numbers for the second year were 27.88 and 41.77 and egg weights were 37.3 and 39.93 for the two periods, respectively. In third year egg numbers were 28.53 and 43.79 and egg weights were 38.51 and 39.52 for 60 and 90 days of egg production, respectively.
Merat (1994) on a study of the effect of genotype on heterosis in crosses between White Leghorn (L) and a Brown egg (B) line, found that the egg numbers for normal line were 151.2, 175.6, 173.58, and 173.8 for L, L*B, B*L, and B, respectively and egg weights were 52.16, 16.14, 57.09, and 55.98, at the same order.
Correlation estimates for sexual maturity and egg production traits.
Sharara (1974) stated that the phenotypic correlations between biological year egg production (BY) and age at sexual maturity (SA) for Dandarawi, Dokki-4, and Fayoumi were -0.278, -0.113, and -0.353. Between (BY) and body weight at sexual maturity (SW) were 0.143, 0.120, and -0.047, and between (BY) and 90 day production were 0.269, 0.452, and 0.401 for the three strains, respectively. The phenotypic correlations between egg weight and (SA) were 0.105, 0.349, and 0.098, between (EW) and (SW) were 0.293, 0.450, and 0.342, and between age and body weight at sexual maturity were 0.219, 0.561, and 0.271 for the three strains, respectively.
El-Turky (1981) reported that the phenotypic correlations between 16 wk body weight and shank length were 0.576, 0.599, 0.442, and 0.454 for females of Alexandria, Silver Montazah, Gimizah, and Bandara. The phenotypic correlation between 16 wk body weight and keel length were 0.673, 0.608, 0.603, and 0.660 for the four strains, respectively.
Poggenpoel et al. (1988) found that the genetic and phenotypic correlations between age at first egg and 37 wk egg weight were 0.07 and 0.02, respectively, while they were -0.60 and -0.41 between age at first egg and egg production to 273 days at the same order for White Leghorn.
Yoo et al. (1988) showed that the genetic correlations between age at first egg and egg number from 18 to 43 wk of age and egg weight at 31and 34 wk of age were -0.85 and 0.10, respectively. The phenotypic correlations were -0.56 and 0.04 at the same order for White Leghorn.
Sheble (1991) showed that the genetic correlation between age at sexual maturity and 90 day egg number, egg mass and body weight at sexual maturity were -0.84, -0.63 and 0.27, respectively. The phenotypic correlations were -0.49, -0.40 and 0.18 between these traits, respectively for Alexandria chickens.
Sabri (1993) reported that the genetic correlations between shank, keel, wattle, and comb lengths and comb hightt [for two standard breeds, White Leghorn and New Hampshire; and a local Fayoumi strain selected for heavier body weight at 8 wk of age] were 1.00, 0.85, 0.4 and 0.20 for White Leghorn, while they were 0.67, 0.69, 0.63 and 0.46 for New Hampshire and were 0.01, -1.0, -1.0 and -1.0 for Fayoumi, respectively.
Aly (1993) found that the genetic and phenotypic correlations between shank length and wattle length at maturity for Fayoumi strain were 0.304 and 0.122, while they were 0.240 and 0.103 between shank length and 60 days egg weight and were 0.312 and 0.124 between shank length and 90 days egg weight respectively. The genetic and phenotypic correlations between shank length and 60 days egg number were -- and 0.059, while they were -0.327 and -0.043 between shank length and 90 days egg number at the same order. The genetic and phenotypic correlations between wattle length and 60 days egg weight were 0.362 and 0.099, while they were 0.451 and 0.138 between wattle length and 60 days egg weight and were -0.162 and 0.034 between wattle length andd 60 days egg number. The genetic and phenotypic correlations between wattle length and 90 days egg number were - 0.229 and -0.028, while they were -0.775 and 0.089 between 60 days egg number and 60 days egg weight and were -0.546 and -0.011 between 60 days egg number and 90 days egg weight, respectively. The genetic and phenotypic correlations between 90 days egg number and 60 days egg weight were -0.152 and 0.057 and were 0.006 and 0.045 between 90 days egg number and 90 days egg weight.
Heritability estimates for sexual maturity and egg production traits.
Hossari (1966) Estimated the heritability of age at sexual maturity for Fayoumi. The values were 0.20, 0.35 and 0.28 from sire, dam and sire+dam components, respectively.
Abd El-Gawad (1971) found that heritability estimate for age at sexual maturity was 0.31, 0.86 and 0.59 for White Leghorn from sire, dam and sire+dam components, respectively, 0.85, 0.63 and 0.74 for Rhode Island Red and -0.03, -0.07, and -0.05 for Fayoumi at the same order. ;
Mohapara and Ahuja (1971) Found that heritability estimate for age at sexual maturity was 0.75, -0.07, and 0.34 for White Leghorn from sire, dam and sire+dam components, respectively.
Abd El-Gawad (1975) found that h 2 for age at sexual maturity was 0.31, 0.44 and 0.38 for Dokki-4 from sire, dam and sire+dam components, respectively and was 0.46, 0.52 and 0.49 for egg weight at the same order.
Poggenpoel et al. (1988) found that the h2 estimates of age at first egg for White Leghorn were 0.18, 0.47, and 0.32 from sire, dam and sire+dam components, respectively, and they were 0.19, 0.03, and 0.11 for egg production to 273 days at the same order.
Yoo et al. (1988) found that heritability estimates for White Leghorn for age at first egg were 0.69, 0.64 and 0.58 from sire, dam and sire+dam components, respectively, and for number of egg laid from 18-43 wk of age they were 0.32, 0.39, and 0.24 at the same order, and for egg weight at 32-34 wk of age they were 0.63, 0.70, and 0.63 at the same order.
El-Ibiary (1971) reported that the heritability estimate for body weight at sexual maturity for Rhode Island Red was -0.03, -0.31, and -0.17 from sire, dam and sire+dam components, respectively. El-Full (1989) estimates was 0.90, 0.06, and 0.47, respectively for Fayoumi strain, while for the same strain Dourgham (1980) estimate was 0.24, 0.58, and 0.41, respectively.
For some body measurement at sexual maturity Abd El-Warith et al. (1979) found that heritability for wattle length of Fayoumi females were 0.81, 0.14 and 0.48 from sire, dam and sire+dam components, respectively. Dourgham (1980) reported that heritability estimates for wattle length for Fayoumi strain were 0.50, 0.35, and 0.43 from sire, dam and sire+dam components, respectively. El-Full (1989) estimates for wattle length were -0.10, 1.00, and 0.50 at the same order for the same breed. For shank length at sexual maturity were 0.45, 0.43 and 0.44 for Fayoumi females from sire, dam and sire+dam components, respectively.
Aly (1993) found that the heritability estimates for body weight at sexual maturity of Fayoumi females were 0.42, 0.40 and 0.41 from sire, dam and sire+dam components, respectively. For shank length were 0.56, 0.19, and 0.29 at the same order, while for wattle length heritability were 0.57, 0.38, and 0.48, respectively. Heritability for age at sexual maturity, 60 day egg number, and 90 day egg number were 0.334, --, and -- from sire component, 0.307, 241, and 0.180 from dam component and were 0.325, 0.121, and 0.09 from sire+dam components at the same order. For 60 day egg weight they were 0.205, 0.337 and 0.271 from sire, dam and sire+dam components, respectively, and were 0.309, 0.412 and 0.360 for 90 day egg weight at the same order.
Sabri (1993) estimated h2 for shank, keel, wattle, comb lengths and comb hight for different breed to be 0.33, 0.05, 0.12, 0.37, and 0.27for White Leghorn, respectively, 0.35, 0.30, 0.33, 0.36, and 0.26for New Hampshire at the same order and were 0.08, 0.13, 0.01, 0.15, and 0.06 for selected Fayoumi at the same order from sire+dam components, respectively.
Heritability estimates for egg number were reported by many investigator, Hossari (1966) estimated heritability for the first 50 and 250 day egg production. The estimates were 0.04 and 0.50 from sire, 0.04 and 0.24 from dam and 0.04 and 0.15 from sire+dam components, respectively. Singh (1972) found that heritability for 90 day egg production was 0.64, 0.70 and 0.67, from sire, dam and sire+dam components, respectively for White Leghorn, and Abd El-Gawad (1977) estimated were 0.06, 0.20, and 0.13 respectively for Fayoumi strain.
For egg weight Lerner and Grudan (1951) found that heritability was 0.60, 0.40, and 0.50 from sire, dam and sire+dam components, respectively for White Leghorn. El-Ibiary (1971) estimated was 0.26, -0.15, and 0.25, respectively for the same breed and was 0.52, -0.24, and 0.40 for Rhode Island Red at the same order.