Hostname: page-component-cd9895bd7-dzt6s Total loading time: 0 Render date: 2024-12-23T23:46:47.719Z Has data issue: false hasContentIssue false
  • English
  • Français

Naked neck and frizzle genes for improving chickens raised under high ambient temperature: I. Growth performance and egg production

Published online by Cambridge University Press:  13 December 2013

M.M. FATHI ,
A. GALAL ,
S. EL-SAFTY  and
M. MAHROUS
M.M. FATHI*
Affiliation:
Dept. of Animal Production and Breeding, Qassim University, Buraydah, Saudi Arabia
A. GALAL
Affiliation:
Dept. of Poultry Production, Ain Shams University, Cairo, Egypt
S. EL-SAFTY
Affiliation:
Dept. of Poultry Production, Ain Shams University, Cairo, Egypt
M. MAHROUS
Affiliation:
Dept. of Poultry Production, Ain Shams University, Cairo, Egypt
*
Corresponding author: [email protected]
Get access

Abstract

High ambient temperatures in tropical and subtropical regions adversely affect the growth and egg productive performance of both broiler and laying chickens. Relative humidity and ventilation rate influences bird's performance, particularly when they are reared in open sided poultry houses. Genetic approaches that aid in reducing or altering the extent of plumage cover has, as a result, been adopted in many hot regions. Fortunately, there are some major and marker genes can reduce the deleterious effects of heat stress, naked neck (Na) and frizzle (F) genes being the most notable ones. The bulk of relevant literature has shown that their favourable effects on growth and laying performance are well established. Therefore, the naked neck and frizzle genes can be a viable alternative for broiler and layer production particularly, in the tropical countries where summer temperatures are very high.

Keywords

naked neckfrizzleheat stressgrowthproductive performance
Type
Review Article
Information
World's Poultry Science Journal , Volume 69 , Issue 4 , December 2013 , pp. 813 - 832
Copyright
Copyright © World's Poultry Science Association 2013 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

ABDEL-RAHMAN, A.M. (1990) Significance of some major genes in relation to the productive adaptability of four German Sub-lines compared with local Egyptian chickens under Assiut subtropical conditions. Ph.D. Thesis, Assiut University, Egypt.Google Scholar
ADEYINKA, I.A., ONI, O.O., NWAGU, B.I. and ADEYINKA, F.D. (2006) Genetic parameter estimates of body weights of naked neck broiler chickens. International Journal of Poultry Science 5: 589-592.Google Scholar
AJAYI, F.O., AGAVIEZOR, B.O. and AJUOGU, P.K. (2011) Semen characteristics of three strains of local cockerels in the humid tropical environment of Nigeria. International Journal of Animal and Veterinary Advances 3 (3): 125-127.Google Scholar
ALMEIDA, A.M. and ZUBER, U. (2010) The effect of the Naked Neck genotype (Nana), feeding and outdoor rearing on growth and carcass characteristics of free range broilers in a hot climate. Tropical Animal Health and Production 42: 99-107.CrossRefGoogle Scholar
BAIN, M.M. (1990) Eggshell strength: a mechanical/ultrastructural evaluation. Ph.D. Thesis, University of Glasgow, UK.Google Scholar
BAIN, M.M. (1992) Eggshell strength: A relationship between the mechanism of failure and the ultrastructural organisation of the mammillary layer. British Poultry Science 33: 303-319.CrossRefGoogle Scholar
BARUA, A., HOWLIDER, M.A.R and YOSHIMURA, M. (1998) Indigenous naked neck fowl of Bangladesh. World's Poultry Science Journal 54: 279-286.CrossRefGoogle Scholar
BARUA, A. and HOWLIDER, M.A. (1991) Meat yield of free-range naked neck and full feathered Bangladeshi chicken. Indian Journal of Animal Science 15: 1776-1783.Google Scholar
BORDAS, A. and MÉRAT, P. (1984) Effects of the naked-neck gene on traits associated with egg laying in dwarf stock at two temperatures. British Poultry Science 25: 195-207.CrossRefGoogle Scholar
BORDAS, A. and MÉRAT, P. (1992) Egg production performances of hens of the NaNa (homozygous naked neck), Nana+ (heterozygous) and Na+Na+ (normal plumage) genotype from a brown-egg dwarf (dw) line submitted to high constant temperature or to high temperature with periodic fluctuations. Archiv für Geflügelkunde 56: 22-27.Google Scholar
BORDAS, A., MÉRAT, P., SERGENT, D. and RICARD, F.H. (1978) Influence due gene Na (cou nu) sur la crossance la consomation alimentaire et al composition corporelle du poulet selon la temperature ambiente. Annales de Genetique et Selection Animale 10: 209-331.CrossRefGoogle Scholar
BORDAS, A., MONNET, L.E. and MÉRAT, P. (1980) Gene counu, performances ponte et efficacite alimentaire selon la temperature chez la poule. Annals Genetics Selection Animal 12 (4): 343-361.Google Scholar
BUYSE, J., SIMONS, P.C.M., BOSHUWERS, F.M.G. and DECUYPERE, E. (1994) Effect of intermittent lighting, light intensity and source on the performance and welfare of broilers. World's Poultry Science Journal 52: 121-130.CrossRefGoogle Scholar
CAHANER, A., AJUH, J.A., SIEGMUND-SCHULTZE, M., AZOULAY, Y., DRUYAN, S. and VALLE ZÁRATE, A. (2008) Effects of the Genetically Reduced Feather Coverage in Naked Neck and Featherless Broilers on Their Performance Under Hot Conditions. Poultry Science 87: 2517-2527.CrossRefGoogle ScholarPubMed
CAHANER, A., DEEB, N. and GUTMAN, M. (1993) Effects of the plumage-reducing naked neck (Na) geneon the performance of fast-growing broilers at normal and high ambient temperatures. Poultry Science 72: 767-775.CrossRefGoogle Scholar
CAHANER, A., YUNIS, R. and DEEB, N. (1994) Genetics of feathering and heat tolerance in broilers. Pages 67-70 in: Proceedings of the 9th European Poultry Conference. Vol. 2. Glasgow, UK.Google Scholar
CHEN, C.F., BORDAS, A., GOURICHON, D. and TIXIER-BOICHARD, A. (2004) Effect of high ambient temperature and naked nick genotype on performance of dwarf brown-egg layers selected for improved clutch length. British Poultry Science 45: 346-354.CrossRefGoogle Scholar
CHEN, C.F., GOURICHON, D., HUANG, N.Z., LEE, Y.P., BORDAS, A. and TIXIER-BOICHARD, M. (2009) Performance comparison of dwarf laying hens segregating for the naked neck gene in temperate and subtropical environments. Genetics Selection Evolution 41: 13.CrossRefGoogle ScholarPubMed
CHEN, C.F., BORDAS, A. and TIXIER-BOICHARD, M. (2002) Effect of high ambient temperature and naked neck genotype on egg production in purebred and crossbred dwarf brown-egg layers selected for improved clutch length. Proceedings of the 7th World Congress on Genetics Applied to Livestock Production, August 19-23, Montpellier, France.Google Scholar
CRAWFORD, R.D. (1977) Naked Neck locus in domestic fowl. A balanced polymorphism. Poultry Science 57: 1131.Google Scholar
DECUYPERE, E., BUYSE, J., MÉRAT, P., ZOONS, J. and VLOEBERGHS, I. (1993) Growth, abdominal fat content, heat production and plasma hormone levels of naked-neck and control broiler chickens. Animal Production 57: 483-490.Google Scholar
DEEB, N. and CAHANER, A. (1994) Genotype-environment interaction and heat tolerance of naked neck broilers. Pages 65-68 in: Proceeding of the 5th World Congress on Genetics Applied to Livestock Production. Vol. 20 Guelph, on, Canada.Google Scholar
DEEB, N. and CAHANER, A. (1999) The effect of naked neck genotypes, ambient temperature and feeding status and their interaction on body temperature and performance of broilers. Poultry Science 78: 1341-1346.CrossRefGoogle ScholarPubMed
DEEB, N. and CAHANER, A. (2001) Genotype-by-environment interaction with broiler genotypes differing in growth rate. 1. The effects of high ambient temperature and naked-neck genotype on lines differing in genetic background. Poultry Science 80: 695-702.CrossRefGoogle ScholarPubMed
EL-ATTAR, A.H. and FATHI, M.M. (1995) Incorporating naked neck gene, Na, to increase breast meat yield of dressed chickens. Egyptian Poultry Science 15: 285-297.Google Scholar
EL-ATTAR, A.H., SHEHATA, M.A. and ABDEL-RAHMAN, S. (1986) Effect of naked neck (Na) gene on growth and carcass measurements of Fayoumi cross strain in relation to dietary protein level. Annals of Agricultural Sciences 31: 1663-1677.Google Scholar
EL-SAFTY, S.A. (2006) Influence of naked neck, frizzle, crest genes and their triple segregation on productivity of layer chickens under hot environmental conditions. Egyptian Poultry Science 26: 1253-1267.Google Scholar
EL-SAFTY, S.A. and FATHI, M.M. (2004) Impact of frizzle, crest genes and their interaction on some phenotypic and genetic parameters of male chickens under winter conditions of Egypt. Proceedings of 9th Conference of Agricultural and Developmental Researches, Ain Shams University, Cairo, Egypt.Google Scholar
EL-SAFTY, S.A., ALI, U.M. and FATHI, M.M. (2006) Immunological parameters and laying performance of naked neck and normally feathered genotypes of chickens under winter conditions of Egypt. International Journal of Poultry Science 5: 780-785.Google Scholar
EL-WARDANY, I. and ZEIN EL-DEIN, A. (1995) Testis histology and semen quality of naked neck cockerels as affected by vitamin E and selenium supplementation. Journal of Agricultural Sciences, Mansoura University 20: 2853-2861.Google Scholar
EMMANS, G.C. and KYRIAZAKIS, I. (2000) Issues arising from genetic selection for growth and body composition characteristics in poultry and pigs. Pages 39–53 in The Challenge of Genetic Change in Animal Production. Occasional Publication No. 27.CrossRefGoogle Scholar
EZEKWE, A.G. and MACHEBE, S. (2004) Effect of dry season on the ejaculate characteristics of three genotypes of local cockerels in the humid tropics. Proceedings of the 9th Annual Conference of the Animal science Association of Nigeria (ASAN), Ebonyi State University, Abakiliki, Nigeria. pp: 239-241.Google Scholar
FATHI, M.M. (1987) Effect of naked neck gene on some quantitative characters in chickens. M.Sc. Thesis, Ain Shams University, Egypt.Google Scholar
FATHI, M.M. and GALAL, A. (2001) Assessing the combined effects of naked neck and crest genes on growth performance and meat yield of chicken under high ambient temperature. Egyptian Poultry Science 21: 319-338.Google Scholar
FATHI, M.M., EL-ATTAR, A.H., ALI, U.M. and NAZMI, A. (2008) Effect of naked neck gene on carcase composition and immunocompetence in chicken. British Poultry Science 49 (2): 103-110.CrossRefGoogle Scholar
FATHI, M.M., EL-WARDANY, I.E., EL-HOMMOSANY, M., ALI, U.M., GAD, A.G. and ZEIN EL-DEIN, A. (1998) Some hematological and semen quality aspects of naked neck and frizzle genotypes. Egyptian Poultry Science 18: 199-216.Google Scholar
FATHI, M.M., GALAL, A., EL-SAFTY, S.A. and ABDEL-FATTAH, S.A. (2005) Impact of naked neck and frizzle genes on cell-mediated immunity of chickens. Egyptian Poultry Science 25: 1055-1067.Google Scholar
FATHI, M.M., ZEIN EL-DEIN, A., EL-ATTAR, A.H. and AYOUB, H. (1993) Association of naked neck gene with carcass measurements in New-Hampshire chicken. Proceedings of Fourth Conference of Agricultural Development Research, 13-18 Feb., Cairo, Egypt, pp. 659-668.Google Scholar
FATHI, M.M., ZEIN EL-DEIN, A., EL-ATTAR, A.H. and AYOUB, H. (1994) Relationship between egg production and blood minerals in naked neck and normal laying hens under elevated temperature. Journal of Agricultural Sciences, Mansoura University 19 (8): 958-964.Google Scholar
GALAL, A. (1995) Effect of naked neck gene on growth and other productive traits of chicken under hot climatic conditions. M.Sc. Thesis, Ain shams University.Google Scholar
GALAL, A. (2000) Pleiotropic effects of naked neck, frizzled and double segregation genes on some phenotypic and genetic parameters of chickens under hot environmental conditions. Egyptian Poultry Science 20 (4): 945-960.Google Scholar
GALAL, A. (2007) Predicting semen attributes of naked neck and normally feathered male chickens from live performance parameters. International Journal of Poultry Science 6: 36-42.Google Scholar
GALAL, A., ALI, U.M., GAMAL EL-DEIN, N.M, EL-MEDANY, N.M., AL-AFIFI, S.H. (2000) Semen quality, body weight, food intake of naked neck, normally feathered cockerels as influenced by dietary protein. Journal of Agricultural Sciences and Mansoura University 9: 5227-5239.Google Scholar
GALAL, A., EL-SAFTY, S.A. and ALI, U.M. (2007) Incorporating some marker genes in Dandarawi chicken to improve.1. Growth performance and carcass characters. 4th World's Poultry Conference, Sharm El-Sheikh, March, 27-30, pp. 59-74.Google Scholar
GALAL, A. and FATHI, M.M. (2001) Improving carcass yield of chicken by introducing naked neck and frizzle genes under hot prevailing conditions. Egyptian Poultry Science 21: 339-362.Google Scholar
GALAL, A. and FATHI, M.M. (2002) Introducing crest gene to enhance productive performance of naked neck chickens under moderate ambient temperatures. Egyptian Poultry Science 22: 611-628.Google Scholar
GALAL, A. and YOUNIS, H.H. (2006) Minimising residual feed intake by introducing dwarf and naked neck genes in laying chicken. Egyptian Poultry Science 25: 677-694.Google Scholar
GARCES, A., CASEY, N.H. and HORST, P. (2001) Productive performance of naked neck, frizzle and dwarf laying hens under various natural climates and two nutritional treatments. South African Journal of Animal Science 30: 105-110.Google Scholar
GOWE, R.S. and FAIRFULL, R.W. (1995) Breeding for resistance to heat stress. In: DAGHIR, N.J. (Ed.) Poultry Production in Hot Climates, pp. 11-29 (CAB International, UK).Google Scholar
HORST, P. (1980) Genetically perspectives for poultry breeding on improved productive ability to tropical conditions. Proceedings of the 2nd World's Congress of Genetics Applied to livestock Production 8: 887-892.Google Scholar
HORST, P. (1982) Genetical perspective for poultry breeding on improved productive ability to tropical conditions. Proc. 2nd World Congress Genetics Applied Livestock Production 8: 887-892.Google Scholar
HORST, P. and MATHUR, P.K. (1994) Feathering and adaptation to tropical climates. Proceedings of the 9th European Poultry Conference, Glasgow, Vol. II, pp. 79-82.Google Scholar
HUTT, F.B. (1949) Genetics of the Fowl. McGraw Hill Book Company, New York, USA.Google Scholar
ISLAM, M.A., BULBUL, S.M., SEELAND, G. and ISLAM, A.B. (2001) Egg quality of different chicken genotypes in summer and winter. Pakistan Journal of Biological Science 4: 1411-1414.Google Scholar
LOU, M.L., QUOI, O.K. and SMITH, W.K. (1992) Effects of naked neck gene and feather growth rate on broiler in two temperatures. p. 62 in: Proceedings 19th world's Poultry Congress. 2. Amsterdam, the Netherlands.Google Scholar
LUGER, Y.D., CAHANER, A., DOTAN, M., RUSAL, M. and HURWITZ, S. (1998) Thermoregulation in naked neck chickens subjected to different ambient temperatures. British Poultry Science 39: 133-138.Google Scholar
MACLEOD, M.G. and HOCKING, P.M. (1993) Thermoregulation at high ambient temperatures in genetically fat lean broiler hens fed adlibitum or on controlled feeding regime. British Poultry Science 34: 589-596.CrossRefGoogle Scholar
MAGOTHE, T.M., MUHUYI, W.B. and KAHI, A.K. (2010) Influence of major genes for crested-head, frizzled-feather and necked-neck on body weights and growth patterns of indigenous chickens reared intensively in Kenya. Tropical Animal Health and Production 42: 173-183.CrossRefGoogle Scholar
MAHROUS, M.Y. (2008) Effect of interaction between some major and marker genes on immune response and productive performance of chickens. Ph.D. Thesis, Ain Shams University, Egypt.Google Scholar
MAHROUS, M.Y. (2012) Eggshell ultrastructure of naked neck, frizzle and normally feathered genotype chickens. Egyptian Journal of Animal Production 48: 69-78.Google Scholar
MAHROUS, M.Y. and EL-DLEBSHANY, A.M. (2011) Reduction of the cholesterol content of eggs by introducing naked neck (Na) and frizzle genes in laying hens. Egyptian Poultry Science 31: 817-824.Google Scholar
MAHROUS, M.Y. and GALAL, A. (2011) Eggshell ultrastructure of naked neck, frizzle and normally feathered genotype chickens. Proceedings of 100th Poultry Science Annual Meeting, America's Center, St. Louis, Missouri, USA, Poultry Science 90 (Suppl. 1).Google Scholar
MAHROUS, M.Y., GALAL, A., FATHI, M.M. and ZEIN EL-DEIN, A. (2003) Improving productivity of layer chickens in hot environmental condition by introducing naked neck and frizzled genes. Egyptian Poultry Science 23: 393-408.Google Scholar
MAHROUS, M.Y., GALAL, A., FATHI, M.M. and ZEIN EL-DEIN, A. (2008) Impact of naked neck (Na) and frizzle (F) genes on growth performance and immunocompetence in chickens. International Journal of Poultry Science 7: 45-54.CrossRefGoogle Scholar
MATTHEW, A.A., SUNDAY, O.O., MICHAEL, O.N., CHRISTIAN, I., ADEYEMI, M.B. and OLUFUNMILAYO, A.A. (2011) Effect of crossbreeding on fertility, hatchability and embryonic mortality of Nigerian local chickens. Tropical Animal Health and Production 44 (3): 505-510.Google Scholar
MÉRAT, P. (1986) Potential usefulness of the Na (naked neck) gene in poultry production. World's Poultry Science Journal 42: 124-142.CrossRefGoogle Scholar
MÉRAT, P. (1990) Pleiotropic and Associated Effects of Major Genes, in: CRAWFORD, R.D (Ed.) Poultry Breeding and Genetics, pp. 429-467 (Elsevier, Amsterdam, The Netherlands).Google Scholar
MONNET, L.E., BORDAS, A. and MÉRAT, P. (1979) Gene cou nu et performances de croissance selon la temperature cher le poulet. Annals Genetics Selection Animal 11 (4): 397-412.Google Scholar
NASCIMENTO, V.P., CRANSTOUN, S. and SOLOMON, S.E. (1992) Relationship between shell structure and movement of Salmonella Enteritidis across the eggshell wall. British Poultry Science 33: 37-48.CrossRefGoogle ScholarPubMed
NWACHUKWU, E.N., IBE, S.N. and AMADI, U. (2006a) Effect of genotype and frequency of semen collection on semen characteristics of local chicken cockerels in the humid tropics. Journal of Animal and Veterinary Advances 5 (7): 562-565.Google Scholar
NWACHUKWU, E.N., IBE, S.N. and EJEKWU, K. (2006b) Short term egg production and egg quality characteristics of main and reciprocal crossbred normal local, naked-neck and frizzle chicken X exotic broiler breeder stock in a humid tropical environment. Journal of Animal and Veterinary Advances 5 (7): 547-551.Google Scholar
OKE, U.K. and IHEMESON, C. (2010) Effect of genotype on the morphometric differentiation of the reproductive organs and sperm reserves in the Nigerian local chicken. Livestock Research for Rural Development 22 (3): Available online: http://www.lrrd.org/lrrd22/3/cont2203.htm.Google Scholar
PATRA, B.N., BAIS, R.K.S., PRASAD, R.B. and SINGH, B.P. (2002) Performance of naked neck versus normally feathered coloured broilers for growth, carcass traits and blood biochemical parameters in tropical climate. Asian-Australasian Journal of Animal Science 15: 1776-1783.CrossRefGoogle Scholar
PEREZ, P., FRAGA, I.M. and FEBLES, M. (1993) Effect of decreasing the level of crude protein in naked neck broilers. 2. Carcass indices. Cuban Journal of Agricultural Science 27: 57-62.Google Scholar
PETERS, S.O. (2005) Variation in semen quality, reproductive performance and growth of artificially inseminated strains of pure and crossbred chickens. Ph.D. Thesis, University of Agriculture, Nigeria, PP: 213.Google Scholar
PETERS, S.O., SHOYEBO, O.D., IIORI, B.M., OZOJE, M.O., IKEOBI, C.O.N. and ADEBAMBO, O.A. (2008) Semen quality traits of seven strains of chickens raised in the humid tropics. International Journal of Poultry Science 7 (10): 949-953.CrossRefGoogle Scholar
RAJKUMAR, U., RAJARAVINDRA, K.S., NIRANJAN, M., REDDY, B.L.N., BHATTACHARYA, T.K., CHATTERJEE, R.N. and SHARMA, R.P. (2010) Evaluation of naked neck broiler genotypes under tropical environment. Indian Journal of Animal Science 80: 463-466.Google Scholar
RAJKUMAR, U., REDDY, M.R., RAMA RAO, S.V., RADHIKA, K. and SHANMUGAM, M. (2011) Evaluation of growth, carcass, immune response and stress parameters in naked neck chicken and their normal siblings under tropical winter and summer temperatures. Australasian Journal of Animal Science 24: 509-516.CrossRefGoogle Scholar
RAJU, M.V., SUNDER, G.S., CHAWAK, M.M., RAMA RAO, S.V. and SADAGOPAN, V.R. (2004) Response of naked neck (Nana) and normal (nana) broiler chickens to dietary energy levels in a subtropical climate. British Poultry Science 45: 186-193.CrossRefGoogle Scholar
RAUEN, H.W. (1985) Auswirkungen des Gens fur Befiederungsreduckton und nackthalsigkeit (Na- Gen) auf das productive Adaptationsvermogen von Legehennen an hohec umwelhemperaturen. Ph.D. Thesis, Berlin Univ., pp: 155.Google Scholar
REDDY, B.L.N., SHARMA, R.P., NIRANJAN, M. and CHATTERJEE, R.N. (2008) Evaluation of performance of Naked neck (Na/Na,Na/Na) and dwarf (dw/dw, dw/-) gene lines under low selection intensity. Indian Journal of Animal Science 78: 975-979.Google Scholar
SANDERCOCK, D.A., MITCHELL, M.A. and MACLEOD, M.G. (1995) Metabolic heat production in fast and slow growing broiler chickens during acute heat stress. British Poultry Science 36: 868 (Abstract).Google Scholar
SHARIFI, A.R. and SIMIANER, H. (2007) Effects of naked neck gene (Na) on egg quality of broiler breeder dams under high and temperate ambient temperature. XVIII European Symposium on the Quality of Poultry Meat and XII European Symposium on the Quality of Eggs and Egg Product, Prague.Google Scholar
SHARIFI, A.R., HORST, P. and SIMIANER, H. (2010a) The effect of naked neck gene and ambient temperature and their interaction on reproductive traits of heavy broiler dams. Poultry Science 89: 1360-1371.CrossRefGoogle ScholarPubMed
SHARIFI, A.R., HORST, P. and SIMIANER, H. (2010b) The effect of frizzle gene and dwarf gene on reproductive performance of broiler breeder dams under high and normal ambient temperatures. Poultry Science 89: 2356-2369.CrossRefGoogle ScholarPubMed
SINGH, B., SINGH, B.P., SINGH, S., CHAUDHARY, D. and MALIK, C. (1998) Naked neck; a noble gene for broiler production in tropical climate. Journal of Applied Animal Research 13: 37-48.CrossRefGoogle Scholar
SINGH, C.V., KUMMER, D. and SINGH, Y.P. (2001) Potential usefulness of the plumage reducing Naked Neck (Na) gene in poultry production at normal and high ambient temperatures. World's Poultry Science Journal 57: 139-156.CrossRefGoogle Scholar
SOLOMON, S.E. (1999) An egg ist ein ei, es un huevo, est un oeuf. British Poultry Science 40: 5-11.CrossRefGoogle ScholarPubMed
SOMES, R.G. (1988) International registry of poultry genetic stocks. Bulletin 476, Storrs Agricultural Experimental Station, University of Connecticut, Storrs.Google Scholar
SOMES, R.G. and JOHNSON, S. (1982) The effect of the scaleless gene, sc, on growth performance and carcass composition of broilers. Poultry Science 61 (3): 414-23.CrossRefGoogle Scholar
STEVENS, L. (1991) Genetics and Evolution of the Domestic Fowl, CABI Publishing.CrossRefGoogle Scholar
THIRUVENKADAN, A.K., PANNEERSELVAM, S. and PRABAKARAN, R. (2010) Layer breeding strategies: an overview. World's Poultry Science Journal 66: 477-501.CrossRefGoogle Scholar
VAN MARLE-KÖSTER, E. and WEBB, E.C. (2000) Carcass characteristics of South African native chicken lines. South African Journal Animal Science 30: 53-56.CrossRefGoogle Scholar
YAHAV, S., LUGER, D., CAHANER, A., DOTAN, M., RUSAL, M. and HURWITZ, S. (1998) Thermoregulation in naked neck chickens subjected to different ambient temperatures. British Poultry Science 39: 133-138.CrossRefGoogle ScholarPubMed
YALCIN, S., BILGEN, G., OKTAY, G., AÇIKGÖZ, Z. and BILGILI, S.F. (1998) Effect of season and dietary energy concentration on composition and strength of skin in naked neck fowl. British Poultry Science 39: 627-632.CrossRefGoogle ScholarPubMed
YALCIN, S., OZKAN, S., ACIKGOZ, Z. and OZKAN, K. (1999) Effect of dietary methionin on performance, carcass characteristics and breast meat composition of heterozygous naked neck (Na/Na+) birds under spring and summer conditions. British Poultry Science 40: 688-694.CrossRefGoogle Scholar
YALCIN, S., TESTIK, A., OZKAN, S., SETTAR, P., CELEN, F. and CAHANER, A. (1997) Performance of naked neck and normal broilers in hot, warm, and temperate climates. Poultry Science 76: 930-937.CrossRefGoogle ScholarPubMed
YUNIS, R. and CAHANER, A. (1999) The effects of the naked neck (Na) and frizzle (F) genes on growth and meat yield of broilers and their interactions with ambient temperatures and potential growth rate. Poultry Science 78: 1347-1352.CrossRefGoogle ScholarPubMed
ZEIN EL-DEIN, A. ZEINY, M. and AYOUB, H. (1981) Carcass measurements of naked neck and normal chicks. Annals Genetics Selection Animal 13: 435440.Google ScholarPubMed
ZEIN EL-DEIN, A., MÉRAT, P. and BOARDS, A. (1984) Body composition of naked neck and normal chicks on different dietary protein concentrations. Genetics Selection Evolution 16: 491-501.Google Scholar