Fayoumi Research Articles

Differentiation of Exotic Chicken Breeds based on Egg Quality Traits using Classification Tree Algorithm

This study aimed to evaluate the effect of breed on egg quality traits and to discriminate chicken breeds (i.e., Bovan Brouwn (BV), Fayoumi (FM) and Sasso (SS)) based on egg quality traits using classification tree algorithm (CTA). For this purpose, a total of 1696 eggs were utilized and the traits egg weight, albumen height, albumen weight, egg length, egg width, egg weight, shell weight, shell thickness, yolk colour, yolk height and yolk weight, were recorded. Significant differences (P<0.05) were found in egg weight, albumen height, albumen weight, and egg width, with Bovans exhibiting the highest LSM values, indicating superior egg quality

Evaluation of reciprocal F1 crosses of Fayoumi with two exotic chicken breeds 2: additive and non-additive effects on egg quality traits

The current study evaluates additive and non-additive genetic variances for egg quality traits in six genotypes generated through pure mating and reciprocal crossing of Fayoumi (FM) with Koekoek (KK) and White Leghorn (WL). For each genotype, measurements were taken on 30 eggs randomly sampled at 32, 36, and 40 weeks of age to evaluate both external and internal egg quality parameters. The results revealed significant differences (P < 0.001) among the genotypes in all external quality traits and most internal quality traits, including yolk weight (YW), albumen weight (AW), and yolk height (YH). The results also showed that variations due to purebred effect (PE), general combining ability (GCA), maternal effect (ME), and specific combining ability (SCA) were significant in most traits, which reflects that both additive and non-additive variances are important for the inheritances of the parameters investigated. In most of the traits, the ME and PE were higher in KK and WL, while GCA was higher in KK and FM. The FM x WL had higher SCA than FM x KK. The results suggest the likelihood of genetic improvement in these genotypes through selection and crossbreeding strategies and/or a combination of the two.

Estimation of crossbreeding parameters for growth and feed efficiency traits in exotic chicken breed crosses with Fayoumi under reciprocal mating

A better understanding of genetic parameters is required to evaluate the combining abilities of different genotypes. The current experiment aimed to estimate crossbreeding parameters for body weight (BW), body weight gain (BWG), and feed conversion ratio (FCR) in genetic groups generated through reciprocal mating between Fayoumi (FM) and three other exotic breeds, namely, Koekoek (KK), Sasso (SS), and White Leghorn (WL) at different growth stages. Birds were weighed individually at hatch and every four weeks until 20 weeks, and BWG was determined. The FCR was estimated based on the feed intake of each genetic group. Purebred effect (PE), general combining ability (GCA), maternal effect (ME), specific combining ability (SCA), and heterosis were highly significant for BW, BWG, and FCR at different ages. Purebred SS had the highest PE and GCA for BW and BWG but the lowest estimate for FCR; in some instances, KK showed values slightly closer to SS's. Closely followed by KK, purebred SS had the highest ME for BW. Crosses of FM with WL and KK exhibited the highest SCA for BW and BWG and the lowest value for FCR, whereas reciprocal crosses between FM and KK had positive heterosis for BW and BWG but negative heterosis for FCR. The results generally suggest the importance of additive (PE, GCA, and ME) and non-additive (SCA and heterosis) genetic effects for the inheritance of growth and feed efficiency traits. In crossbreeding programs involving these genetic groups, synthetic breeds with different breed combinations could be developed using genotypes showing the highest additive effects (SS and KK) as male parents and those having the highest non-additive effects (FM x KK, KK x FM, and FM x WL) as female parents.

Effect of Incorporating Early Feather Restriction Gene (KS) From Native Chicken to Purebred Chicken

Fast growing chicken suffers more in a hot humid condition than a slow growing one. The slow feathering affects the insulation mechanism of the chicken, thus enhance birds ability to dissipate heat during heat stress to a greater extent. As a consequence, slow feathered birds are more adaptive to hot humid environmental conditions. This study was undertaken to investigate the effect of incorporating early feather restriction gene (KS) in exotic population. A total of 34 slow feathered (SF) native chicks with KS gene of 28-day-old were collected from different villages and markets and were reared up to sexual maturity. After attaining sexual maturity, 2 males and 8 females of SF native chicken were randomly chosen to make a di-allelic cross with rapid feathered (RF) Rhode Island Red (RIR) and Fayoumi (FY). The crossbred progeny of each cross were reared up to 105 days to assess growth, survivability, heat tolerance and carcass yield under hot humid Bangladeshi condition. The collected data were arranged in a 3(genotype)×2(feather pattern)×9(age) factorial experiment in a Completely Randomized Design (CRD) and analyzed by SAS. Among genotypes, the highest survivability was obtained in Desi×Fayoumi (96.7%) and in SF chicks (96.1%) and the lowest in Desi×RIR (91.5%) and in RF chicks (90.5%). The SF chicks exhibited an average 8% heavier live weight than that of their RF counterparts. The cloacal temperature varied among genotypes and between feathering patterns (FP); being highest in Desi×RIR (430C) and in RF chicks (41.60C) and lowest in RIR×Desi (400C) and in SF chicks (41.40C). In case of Desi×RIR, RIR×Desi and Desi×Fayoumi, cloacal temperature increased linearly by 0.047, 0.044 and 0.0320C for each gram of live weight increase. Further, the cloacal temperature increased linearly by 0.036 and 0.0440C for the increase of each gram of live weight gain in case of RF and SF chicks, respectively. There was no significant (P&gt;0.05) difference of dressing percentage for the effect of either genotype or FP (55.4% for SF vs. 46.6% for RF birds). Genotype and FP had significant effects (P&lt;0.05; P&lt;0.01) on total meat yield; being highest in Desi×RIR (24.6%) and in SF birds (26.2%) and lowest in Desi×Fayoumi (21.4%) and in RF birds (20.6%). Breast meat yield of SF birds (9.2%) was significantly (P&lt;0.01) higher than that of RF birds (7.1%). The highest thigh meat yield was obtained in Desi×RIR (7.6%) and in SF birds (8.3%) and the lowest in Desi×Fayoumi (6.7%) and in RF counterparts (6.0%). The highest drumstick meat yield was obtained in RIR×Desi (5.6%) and in SF birds (5.9%) and the lowest in Desi×Fayoumi (5.0%) and in RF birds (4.8%). Genotype and FP had significant interaction effect on total meat yield as well as fractional meat yields. The study revealed that incorporation of ‘Ks’ gene in the exotic one by crossing with native chicken and rearing under hot humid environment may be a means of improving growth, survivability, heat tolerance and carcass yield.

Assessment of genetic diversity among Egyptian and Saudi chicken ecotypes and local Egyptian chicken breeds using microsatellite markers

Aim: To assess genetic diversity of two chicken ecotypes from Egypt and Saudi Arabia and compare these ecotypes to six local Egyptian and two exotic pure chicken breeds using 14 microsatellite markers. Methodology: Dataset consisted of two subsets. First subset represented two ecotypes from Saudi Arabia and Egypt. Second dataset consisted birds six Egyptian native chicken strains: Fayoumi (FAY), Dandarawy (DAN), Baladi (BAL), Sinai (Sini), El-Salam (Els) and Golden Montazah (GG), and two commercial strains: White Leghorn (WL) and Rhode Island Red (RIR). fourteen microsatellites markers were utilized to assess DNA polymorphism. Data analyses of the results were carried out using R statistical environment. Results: The obtained results indicated that number of alleles per locus averaged 11.4 ± 5.0. Polymorphic information content was informative (&gt; 50%) for the local breeds, but not for two ecotypes. The observed and expected heterozygosity averaged 0.46 and 0.75, both ecotypes had the lowest estimates. All breeds showed significant deviation from Hardy–Weinberg equilibrium expectation. The average population differentiation index (FST) was 0.143, overall heterozygosity deficiency (FIT) was 0.156, and global inbreeding of individuals within breeds (FIS) was 0.319. Interpretation: This study revealed that both Egyptian and Saudi ecotypes have an endangered status. Lower genetic distances and lower FST values were reported for the Egyptian indigenous breeds. Phylogenetic and principle components showed that both ecotypes were genetically closer to each other when compared with other breeds. It also showed that the Dandarawy native Egyptian chicken breed was genetically the closest breed to both the Egyptian and Saudi ecotypes. Key words: Chicken, Ecotypes, Genetic diversity, Microsatellites, Phylogenetics

Teratogenic Effect of Sodium Phenytoin on Limb Development in Chick Embryos is Time-Mediated as Evident by Stereomicroscope

Background: Women suffering from seizure-related illnesses are prescribed phenytoin during pregnancy if the benefits outweigh the risks. But the teratogenic effect of this drug on limb development needs exploration. This study was designed to investigate the time-mediated teratogenic effect of sodium phenytoin on limb development of chick embryos on days 04 and 09 of development using the stereomicroscope and at the time of hatching. Material and Methods: This randomized control trial comprised of two main groups of fertilized chicken eggs (Egyptian Fayoumi breed), control group A and experimental group B, each having 90 eggs. Each experimental egg was injected with sodium phenytoin (3.5 mg, teratogenic dose) just before incubation. Both the groups were divided into three subgroups each A1, A2, &amp; A3/B1, B2 &amp; B3. Stereomicroscope was used to observe the limb buds and cartilaginous elements in subgroups 1 and 2 on days 04 and 09 of development respectively. The embryos of subgroups 3 were assessed for gross limb deformities on hatching. Survival was noted in all the subgroups.Results: The difference in limb bud size between experimental and controls was statistically insignificant. There was no variation or deformity in the bones. The experimental group 3 had gross limb defects on hatching and the difference in survival was also statistically significant in subgroups 3.Conclusion: Prenatal administration of sodium phenytoin induces limb defects in chick embryos as evident after hatching but limb anomalies are not observed on days 04 and 09 of development as investigated by stereomicroscope. We conclude that the teratogenic effect of phenytoin is time-mediated.

Assessment of date palm pollen supplementation on productivity, digestibility, immune response, and intestinal and hepatic morphology of Egyptian fayoumi laying Hens

Assessment of date palm pollen supplementation on productivity, digestibility, immune response, and intestinal and hepatic morphology of Egyptian fayoumi laying Hens

Quantitative Analysis of the Area of the Apical Ectodermal Ridge in Chick Appendages Using Image-J.

To determine the effect of sodium phenytoin on the apical ectodermal ridges (AER) of chick wing buds by using the software program Image-J. An experimental study. Department of Anatomy, Regional Center, College of Physicians and Surgeons Pakistan (CPSP), Islamabad, from January 2014 to January 2015. Sixty fertilised chicken eggs of 'Egyptian fayoumi' breed were selected and separated into experimental (B) and control (A) groups, each having 30 eggs. A single dose of 3.5 mg sodium phenytoin was injected into each egg of the experimental group. The controls were injected with the same volume of normal saline. Developing embryos were extracted 96 hours (day 4) after incubation and histological sections were cut at 5 μm thickness. These sections were stained with Feulgen Nuclear and Light Green. The area of apical ectodermal ridges of chick wing buds was calculated by employing Image-J and subjected to statistical analysis. The difference between the mean values of the area of apical ectodermal ridges of experimental and control groups, as calculated by Image-J, was found to be statistically insignificant. Change in the area of the apical ectodermal ridges in experimental chicks, following phenytoin exposure, was insignificant as proven on the basis of quantification by Image-J.

P4060 Runs of homozygosity reveal natural selection footprints of some African chicken breeds and village ecotypes

The earliest evidence of domestic chicken (Gallus gallus) introduction into Africa was in Egypt in the New Kingdom, 19th Dynasty (1307–1196 BC) through the ancient cinnamon trade. Chickens were introduced in Eastern Africa (EA) later via Egypt or direct introduction via Indian Ocean trading. With the absence of genetic improvement schemes and breeding associations, EA rural chicken populations are likely under natural selection, and most are considered as ecotypes, not breeds. A few populations, e.g., Egyptian Fayoumi have fixed criteria and are registered as a breed. The current study aims to assess probable co-ancestry among six African chicken populations, in comparison with a highly inbred US Fayoumi line, to investigate the inter-population genomic variation due to natural selective pressure and to determine functional variants associated with Runs of Homozygosity (ROH). The populations studied included three indigenous African ecotypes from Uganda (UGN), Rwanda (RWN) and Egyptian naked-neck (ENN); two Egyptian registered breeds; Fayoumi (FEG) and Dandarawi (DEG), one hybrid developed in India and sampled in Uganda, Kuroiler (KRL), and a highly inbred US Fayoumi (FUS). A total of 290 birds were randomly sampled from villagers in Egypt, Rwanda, and Uganda, representing indigenous populations, and 6 birds were sampled from the inbred FUS flock. Birds were genotyped using the Affymetrix 600K Axiom® Genome-Wide Chicken Genotyping Array. ROH were defined using PLINK v1.9, for a minimum ROH length of 500kb, with no more than one missing SNP and one heterozygous SNP genotype per window. A total number of 15,277 ROH were detected across the studied populations. ROH length ranged between 500kb to around 50Mb. ROH were classified into three length categories; short (500kb to < 1Mb, n = 9970; 65.3%); medium (1Mb to < 5Mb, n = 4960; 32.5%) and long (≥ 5Mb, n = 347; 2.3%). The average number of ROH per bird was highest for the inbred FUS (240.7), and the least for the DAN (19.9) indicating outbreeding. Intra-breed regions with a high occurrence of ROH were identified on several chromosomes indicating ROH landscaping, where several genes involved in survivability and tolerance (i.e., reproduction, metabolism, muscle formation, ion-exchange, and heat and oxidative stresses tolerance) were detected. This study illustrates the distribution of ROH and functional variants within ROH in some African breeds and ecotypes. Detecting genomic regions involved in traits under natural selection contributes to our understanding of regions of importance for selection and distribution of functional variants in the chicken genome.

A comparative study on quality, proximate composition and cholesterol content of eggs and meat in Fayoumi and commercial White Leghorn chickens

AbstractThe present study was conducted at Poultry Research Institute, Rawalpindi (Pakistan) with the objective of evaluating egg quality, proximate composition and cholesterol content of eggs and meat in Fayoumi (FAY) and commercial (Nick chick) White Leghorn (WLH) breeds of chickens. For this purpose, 64 adult (40 weeks-old) laying hens, 32 each of FAY and WLH breeds were maintained on littered floor in two separate pens under optimal management conditions. The birds were fed ad libitum a balanced layers ration. They had free access to clean and fresh drinking water and were kept under 16 h daily lighting schedule. Egg quality parameters, proximate composition and cholesterol content of eggs were studied for 6 weeks by randomly collecting 3 eggs daily from each breed. Thigh and breast meat samples were obtained from randomly selecting two birds from each breed by slaughtering them at the termination of experiment for determination of proximate composition and cholesterol content. The results show signif...

Haematological and biochemical profiles of Gallus indigenous, exotic and hybrid chicken breeds (Gallus domesticus l.) from Rajshahi, Bangladesh

A comparative account of haemato-biochemical profiles of an indigenus (IND) and five chicken breeds: viz. Cobb 500 (COB), cockerel (COC), Fayoumi (FAY), Rhode Island Red (RIR), and Sonali (SON, derived from RIR cock × FAY hen), has been presented. The haematological profile included total counts (TC) of RBC, WBC, platelets, haemoglobin (Hb%) and ESR and differential counts (DC) of WBC included neutrophils, eosinophils, lymphocytes, monocytes and basophils. All the haematological parameters except WBC, ESR and basophils showed significant difference among the breeds (P &lt; 0.01). Vital biochemical parameters from blood sera such as calcium, cholesterol, creatinine, glucose and urea also showed significant difference among the chicken breeds (P &lt; 0.05). The haematobiochemical parameters, however, were not significantly correlated (P &gt; 0.05) with each other among the chicken breeds. Except for cholesterol vs. urea in IND, none of the correlations tested for haemato-biochemical profiles of the experimental chickens was found significant. Relevance of this study in relation to health, clinico-pathology and improved breeding strategies of the poultry species in the country has been discussed.Bangladesh J. Zool. 41(2): 135-144, 2013

Management Practices, Disease Incidence, Uses of Indigenous Knowledge, and Conditions and Problems of the Poultry Farmers in Rajshahi, Bangladesh

Data on management practices, incidences of common diseases, uses of indigenous knowledge (IK) and conditions and problems of the poultry farmers in some selected areas of Rajshahi, Bangladesh, were investigated. Data from small, medium and large poultry enterprises situated in the urban, semi-urban and rural areas at six Upozillas of Rajshahi District viz., Boalia, Godagari, Motihar, Mohonpur, Poba and Rajpara were collected. An indigenous (IND), four exotic (EXO) viz. Cob 500 breed of broiler, Cockerel, Fayoumi (FAY), and Rhode Island Red (RIR), and a crossbred (CRO) called Sonali (derived from RIR cock × FAY hen) chicken breeds were included in the study. Eighteen parameters on management practices, 13 diseases, 20 indigenous knowledge (IK) items, 3 major conditions, 11 problems encountered and top 10 opinions of the poultry farmers were identified. Satisfactory to good management practices were recorded for IND in Godagari and that for EXO and CRO in Rajpara. All the remaining farms practiced moderate to unacceptable management practices. Bacillary white diarrhoea (39.56%), omphalitis (57.40%) and hypervitaminosis (55.56%) were the most frequent diseases whereas common cold (10.16%), bacillary white diarrhoea (32.82%) and bacillary white diarrhoea (27.62%) were the least frequent diseases for IND, EXO and CRO chickens, respectively. However, no incidence of bird flu (avian influenza) was recorded during the survey period. Uses of broody hens (82.25%), changing of waterier (62.45) and vaccination (49.19) were found to be the prevalent IK items for IND, EXO and CRO birds. Separating healthy versus diseased respectively, chicks (26.45%), feeding maize grain (52.45%) and feeding molasses (49.10%) were healthcare IK items for the chicken breeds, respectively. Majority of the poultry farmers of IND, EXO and CRO breeds had respectively primary (50.08%), graduate (47.18%) and higher secondary (45.77%) education levels. Agriculture (60.71%), miscellaneous (46.14%) and miscellaneous (35.50%) were dominant occupations among the three categories of poultry farmers. IND farmers predominantly had cultivable land (50.16%) in comparison with the cultivable landholdings by the EXO (21.69%) and homestead landholdings by their CRO (31.16%) counterparts. Poor housing (44.86%), disorganized and unreliable marketing system (52.05%) and lack of institutional credit facilities (47.89%) were identified to be the major problems for the IND, EXO and CRO farmers respectively, who opined strongly in favour of improved native breeds (30.04%), proper breeding facilities (49.90%) and government co-operation (48.01%). The impacts of these findings on the poultry enterprise in Rajshahi have been discussed. DOI: http://dx.doi.org/10.3329/jles.v7i0.20120 J. Life Earth Sci., Vol. 7: 43-49, 2012

Evaluation of egg quality traits among different breeds/strains of chicken locally available in Pakistan.

Appreciated for their versatile nutritive value and functionalproperties, eggs are considered as an important item in human diet. Eggs areone of the most common foods available worldwide as they play an important rolein human diet by providing humans with protein, lipids, minerals and vitaminsin an adequate amount. Chicken breeds differ in physical and biochemicalcontents in terms of eggs and meat yield. The objective of this study was toevaluate the egg quality traits among different breeds/varieties of chickenavailable in Pakistan. For this purpose a total of 105 eggs were collected from7 different breeds/strains of poultry namely, Aseel Lakha, Aseel Mianwali,Aseel Peshawari, Naked neck (Ganji), Fayoumi, Rhode Island Red (RIR) and WhiteLeg Horn (WLH) and used to evaluate the egg quality traits. Statisticalanalysis of data was carried out through one way ANOVA, and comparison of meanswith DMR test (SAS, 9.1). Analysis revealed significant differences amongbreeds in egg weight, egg width, albumen height, yolk height, and Haugh unitwhile non-significant differences in egg length and shape index at (P<0.05).

Effects of autosomal dwarf gene on growth and shank length of chicken

A partial diallel crossing of Rhode Island Red (RIR), White Leghorn (WLH), Fayoumi (FO), Desi normal (DN) and Desi dwarf (DD) produced RIR, WLH, FO, DN, DD, RIR x DD, WLH x DD and FO x DD offspring. A total 709 chicks, 75 RIR, 130 WLH, 100 FO, 70 DN, 66 DD, 80 RIR x DD, 80 WLH x DD and 108 FO x DD were reared for studying growth performance up to 18 weeks of age. At 19 weeks, the crossbreds RIR x DD, WLH x DD and FO x DD were separated into normal and dwarf genetic groups on the basis of shank length and thus 11 genetic groups, RIR, WLH, FO, DN, DD, RIR x DD normal, RIR x DD dwarf, WLH x DD normal, WLH x DD dwarf, FO x DD normal and FO x DD dwarf were obtained. Day-old weight differed significantly (P&lt;0.05) between genotypes. When crossed with Desi dwarf, the day-old weight of RIR, WLH and FO decreased by 7.0, 8.7 and 15.3%. DD chicks had 9.2% lower day-old weight than DN. All DD and DD crossbred chicks had lower feed intake (P&lt;0.01) at all stages of growth. There were no significant differences in daily weight gain, feed conversion ratio and mortality between genotypes (P&gt;0.05). The shank length differed significantly between genotypes at all ages regardless of sex (P&lt;0.01) and differences between genotypes increased at older ages. Shank length of pure breeds and normal crossbreds were similar and much longer than in dwarf crossbreds DOI: http://dx.doi.org/10.3329/bvet.v30i1.16282 Bangl. vet. 2013. Vol. 30, No. 1, 25-32

Effect of Introgressing Dwarf Gene from Bangladeshi Indigenous to Exotic Breeds on Egg Production

An experiment was conducted to assess the effect of introgressing autosomal recessive dwarf gene (adw) from Bangladeshi indigenous (deshi) dwarf (DD) chicken to Rhode Island Red (RIR), White Leghorn (WLH) and Fayoumi (FO) on body weight and egg production. Deshi normal (DN), DD, RIR, WLH and FO were used in crossings to produce 8 genotypes; RIR, WLH, FO, DN, DD, RIR x DD, WLH x DD and FO x D D. At 19 weeks of age, for separation of crossbreds into normal and dwarf on the basis of shank length, altogether gave 11 genetic groups; RIR, WLH, FO, DN, DD, RIR x DD normal, WLH x DD normal, FO x DD normal, RIR x DD dwarf, WLH x DD dwarf and FO x DD dwarf. At 19 weeks of age, 154 pullets; 14 from each genetic group were individually caged up to 42 weeks of age to compare egg production performance. Introgression of adw gene significantly reduced mature body weight and feed intake and adw pullets utilized feed more efficiently into egg mass in comparison with their normal size counterparts. Conservation and improvement of deshi adw chicken is suggested for their future use in breeding for egg production.

Association of MHC class I and class II gene polymorphisms with vaccine or challenge response to Salmonella enteritidis in young chicks.

Salmonella enteritidis (SE) is a worldwide source of salmonellosis in humans, caused mainly by consumption of contaminated poultry products. The major histocompatibility complex (MHC) class I and class II molecules, which function as antigen-presentation structures, are involved in both macrophage and dendritic cell immune response to Salmonella and may, therefore, play an important role in host resistance to infections. The chicken MHC class I and class II were investigated as candidate genes for immune response to SE. We characterized the complete MHC class I cDNA sequences for an outbred broiler line and four diverse highly inbred lines: two MHC-congenic Leghorn (G-B2 and G-B1), one Egyptian Fayoumi (M15.2), and one Spanish (Sp21.1), to define the allelic sequences within these lines, so that we might study the association between particular MHC polymorphisms and response to SE. The F1 offspring of outbred broiler sires crossed with three inbred lines (G-B1, G-B2, and Fayoumi) were evaluated as young chicks for either bacterial load in spleen and cecum after pathogenic SE inoculation or antibody level after SE vaccination. Alleles defined by a Lys(148)-->Met(148) polymorphism in the MHC class I alpha(2) domain were associated with spleen bacterial load after SE challenge. These results suggest that particular MHC haplotypes may contribute to control of responses to SE, and that particular polymorphisms may serve as markers for genetic resistance to SE in the chicken.

Effect of Different Molting Programs on Productive and Some Physiological in Norfa and Fayoumi hens

Effect of Different Molting Programs on Productive and Some Physiological in Norfa and Fayoumi hens

Endogenous Viral Genes in Thirteen Highly Inbred Chicken Lines and in Lines Selected for Immune Response Traits

Thirteen highly inbred lines of chickens of Leghorn, Spanish, and Egyptian Fayoumi origin, four partly inbred Leghorn lines selected for MHC alleles and immune response to GAT (Ir-GAT), and two replicated, noninbred Leghorn lines divergently selected for multiple immune response traits were subjected to molecular genotyping for endogenous viral (ev) gene sequences. In all highly inbred lines of Leghorn origin, ev 1 alone or both ev 1 and ev 2 were observed. The Spanish and Fayoumi lines had three and five ev genes, respectively, most of which were not readily identifiable with standard Leghorn ev gene loci. The Leghorn lines selected for MHC and Ir-GAT had ev 1 fixed in the population. Differences in ev 3 and ev 5 gene frequency were associated with Ir-GAT in the B1 haplotype, but not in the B19 haplotype. In the noninbred lines, which were divergently selected for multiple traits of immune responsiveness, ev 6 and ev 9 differed in frequency between lines, and both were in lower frequency in the lines selected for high immunoresponsiveness. These two ev genes are the only ones known in White Leghorns that have the gs– chf+ phenotype [expressing chicken helper factor (chf) but not expressing group-specific antigen (gs)].

Genetic influences on growth and partition of fat between depots and its distribution in fowl carcasses

Thirty-two Hubbard and 40 Egyptian Fayoumi (dual-purpose) chickens were slaughtered in series at 2-wk intervals between 2-8 wk and 2-10 wk of age, respectively. Genetic differences in the allometric fat growth equation constants were studied. Relative to total body fat (TBF), the breeds did not differ significantly in relative growth of non-carcass fat. The Fayoumi tended to lay down carcass fat at a faster rate than the Hubbard. As TBF increased, the proportion of non-carcass fat increased and that of carcass fat decreased in the Hubbard; these depots tended to grow at the same rate as TBF in the Fayoumi. The Hubbard had significantly higher relative rates of fat deposition in the thigh, drumstick, breast and lower rates of fat deposition in the wing and neck than the Fayoumi. As the Hubbard matured, their growth coefficients of carcass fat tended to decrease anteriorly from breast to neck and also from leg to wing. The specific growth rates in almost all parts of the Fayoumi did not differ significantly from that of the total carcass fat. The present study shows for the Hubbard, as compared to Fayoumi, distinct patterns of fat partitioning (higher non-carcass fat: carcass fat; higher intermuscular fat: subcutaneous fat) and distinct patterns of fat distribution (higher proportion of the total depot occurring in the prime cuts). The study also gives some indications of different fat deposition patterns in poultry as compared to ruminants (cattle and sheep).

Heterosis in Fayoumi strain incrossing

Heterosis in Fayoumi strain incrossing