Growth Performance and Immune Response Against Newcastle and Avian Influenza Vaccines in Egyptian Chicken Strains

Global Veterinaria 9 (4): 434-440, 2012 ISSN 1992-6197 © IDOSI Publications, 2012 DOI: 10.5829/idosi.gv.2012.9.4.65155 Growth Performance and Immune Response Against Newcastle and Avian Influenza Vaccines in Egyptian Chicken Strains 1 Ayman E. Taha, 2Mohamed A. El-Edel, 3Hany F. El-Lakany and 4Ramadan.S. Shewita Department of Animal Husbandry and Animal Wealth Development, Faculty of Veterinary Medicine, Alexandria University, Edfina, Egypt 2 Department of Animal Husbandry and Animal Wealth Development, Faculty of Veterinary Medicine, Damanhour University, Behira, Egypt 3 Department of Poultry and Fish Diseases, Faculty of Veterinary Medicine, Damanhour University, Behira, Egypt 4 Department of Nutrition and Clinical Nutrition, Faculty of Veterinary Medicine, Alexandria University, Egypt 1 Abstract: 280 one day-old chicks of four Egyptian chicken strains (Mandarah, Inshas, El-Salam and Dokki-4) were used (70 chicks per strain) for successive 12 weeks in order to assess the differences of some growth parameters (body weight, body weight gain (BG), relative growth rate (RGR) and livability percentage) as well as immune response against Newcastle (ND) and avian influenza (AI) vaccine. Results revealed that Mandarah chickens showed the highest body weight among the studied strains at hatch, 2, 4, 6, 8 and 10 weeks of age, while El-Salam strain showed an increase in body weight at 12 week of age. Also, El-Salam chickens recorded higher overall weight gain while the lowest was recorded for Dokki-4 chickens, no differences between four strains for overall RGR, moreover better livability percentage recorded by El-Salam strain. Higher immune response for ND and AI viral vaccines were recorded for Dokki-4 strain that expressed the higher antibody titers for ND vaccine at 14th, 25th, 35th, 45th and 60th days of age and for AI vaccine at 25th, 35th, 45th and 60th days of age. It was concluded that El-Salam strain is the best strain for growth performance parameters, while Dokki-4 strain is the best strain for immune response against ND and AI viral vaccines. Key words: Egypt Chicken Strains Body weight Livability INTRODUCTION Newcastle virus Avian influenza Differences in body weight and growth parameters among breeds and strains were studied by many authors [5- 8]. For several decades Egypt was suffered from repeated attacks of Newcastle disease virus causing high economic losses in poultry industry and vaccination was the only way to decrease the severity of losses from this disease. Recently the avian influenza virus showed the ugly face against poultry industry in Egypt causing higher economic losses in our country in addition to increase the price of another sources for animal protein. Newcastle disease virus is a Paramyxovirus infects domesticated and wild birds throughout the world, while Avian influenza (AI) is an infection of birds caused by a Poultry production plays a major role in providing a large and cheap source of animal protein in Egypt, beside pure Egyptian breeds there were some local developed strains that established for both meat and egg production. In 1966 cross breeding was made between Fayoumi x Barred Plymouth Rock to give Dokki-4 strain [1], while Mandarah strain was produced from a crossing between Alexandria x Dokki-4 [2], Abd El-Gawad et al. [3] made a crossing between Nichols x Maamourah to produce El-Salam strain as well as Inshas strain (a new Egyptian strain of chickens) which was developed by crossing between Sinai and White Plymouth Rock breeds [4]. Corresponding Author: Ayman E. Taha, Department of Animal Husbandry and Animal Wealth Development, Faculty of Veterinary Medicine, Alexandria University, Behira, Rashid, 22758 Edfina, Egypt. 434 Global Veterinaria, 9 (4): 434-440, 2012 single stranded, negative-sense RNA virus in the family Orthomyxoviridae [9]. In addition, Influenza A virus is further categorized by serological reaction of the two surface glycoproteins into 16 different hemagglutinin (H1-16) and 9 different neuraminidase (N1-9) subtypes [10]. Defense against viral infections in poultry consists of natural and adaptive mechanisms. The innate defense is mainly formed by natural killer cells and their secreted products. On the other hand, the adaptive defense can be divided into humeral and cellular immunity [11]. The goals of this study was to determine which one of the four breeds under study (Mandarah, Inshas, El-Salam and Dokki-4) can tolerate and face the infections of NDV and avian influenza virus through measuring antibody titer after immunization of birds as well as measuring some performance parameters. Table 1: Ingredient composition and chemical analysis of the basal diet Starter (0- 4 weeks) % Grower (4 -12 weeks) % Yellow corn, ground Soybean oil meal (44%) Wheat bran Palm oil Di calcium Phosphate Limestone Common Salt Dl- Methionine Lysine Vit and Mineral premix* 62.5 31.28 2.60 ---2.0 0.88 0.38 0.06 --0.30 62.5 17 15.5 1.0 1.70 1.5 0.40 0.05 0.05 0.30 Total 100 100 Chemical analysis C.P ME (Kcal /kg diet) C.F Ca Available phosphorus % Methioine % Meth + Cys % Lysins 19 2825 4.0 0.91 0.51 0.39 0.17 1.08 15.0 2900 3.83 0.97 0.47 0.33 0.59 0.80 Ingredients MATERIALS AND METHODS *Each 3 Kilograms contain: Manganese 100000 mg, Zinc 600000 mg, Iron 30000 mg, Copper 10000 mg, Iodine 1000 mg, Selenium, 200 mg, Cobalt 100 mg, Vitamin A 12000000 iu, Vitamin D3 3000000 iu, Vitamin E 40000 mg, Vitamin K3 3000 mg, Vitamin B1 2000 mg, Vitamin B2 6000 mg, Vitamin B6 5000mg, Vitamin B12 20 mg, Niacin 45000 mg, Biotin 75 mg, Folic acid 2000 mg and Pantothenic acid 12000 mg; 3: Kill cox, Produced by Arabian company for pharmaceutical industries (El-Toba Co. For Premixes and Feed Elsadat City Egypt). Chick Source and Management: This study was conducted on 280 one day-old chicks of four local improved Egyptian chicken strains (Mandarah, Inshas, El-Salam and Dokki-4) as 70 chicks were used from each strain. Chicks were obtained from hatchery lab of department of animal husbandry and animal wealth development, Faculty of Veterinary Medicine, Alexandria University, Egypt. Chicks randomly allocated into four groups of mixed sex according to each strain; group1: Mandarah, group2: Inshas group3: El-Salam, group4: Dokki-4 they were housed in a clean well ventilated room, previously fumigated with formalin and potassium permanganate. The room was provided with heaters to adjust the environmental temperature according to age of the chicks. The room floor was partitioned into four equal compartments (1.5x2 m2 for each one). Chicks were raised in floor pens until 12 weeks of age, composition of the basal diet and chemical analysis was illustrated in Table 1. Diets were provided ad libitum and the birds were provided with continuous lighting. The birds were vaccinated as in the Table 2. Table 2: Vaccination program of birds Age (days) Type of vaccine 7 HitchnerB1 12 14 15 25 35 45 50 60 Eye drops Gumboro Killed ND,1 Reo, Gamboro, IB 2 Killed A.I (H5N2)3 Gumboro & Lasota4 Gumboro & Lasota Gumboro & Lasota Lasota Lasota then biweekly Route of vaccination Eye drops I/M injection I/M injection Eye drops Eye drops Eye drops Eye drops Eye drops 1- ND = Newcastle Disease 2- IB = Infectious Bronchitis 3- Killed Avian Influenza (H5N2) Reg. SAGARPA B-7286-006 4- Lasota = live attenuated Newcastle vaccine (Vet. Ser. and Vacc. Res. Insti. Cairo, Egypt) Immune response measurements, 20 blood samples were collected from each strain at 14th, 25th, 35th, 45th and 60th days of age. Blood samples were collected without anticoagulant for separation of sera to detect the titer of antibodies against Newcastle disease vaccine and avian influenza subtype (H5N2) vaccine using haemagglutination inhibition test according to Takatasy [13]. Log-Geometric mean titer (GMT) was calculated following the method of Brugh [14]. Studied Traits: Body weight was recorded to the nearest gram at hatch, 2nd, 4th, 6th, 8th, 10th and 12th week of age, body weight gain was calculated as the difference between two successive weights, relative growth rate (RGR) was calculated according to Broody [12] as well as calculating mortality and livability percentages. 435 Global Veterinaria, 9 (4): 434-440, 2012 Statistical Analysis: The analysis of variance for the obtained data was performed using SAS [15] software to assess significant differences. Livability and mortality were analyzed using chi-square test to access the significance between different strains using SAS [15] increase in RGR (188.39%), followed by Dokki-4 chickens (188.01%) and Mandarah (187.63%) while Inshas chickens recorded the lowest RGR (187.53 %) these results disagreed with those obtained by Aggrey [21], Taha [22] and Taha [23] who found higher significant differences between quail lines divergently selected for growth and body weight. RESULTS AND DISCUSSION Livability and Mortality Percentages for the Different Strains: Non-significant differences in livability percentages (Table 6 and Figure 2) among the four studied strains, however El-Salam chickens recorded the highest percentage for livability 88.57 % followed by Dokki-4 chickens (84.29 %). 0n the other hand the lowest livability percentage recorded by Mandarah and Inshas chickens (82.86%). Results agreed with those obtained by Olawumi and Dudusola [24] who found that mortality rate not affected by both breed and housing effects while disagreed with those obtained by Awobajo et al. [25] who found that chi-square analysis revealed that there is very high significant different (p<0.001) in the mortality rate of the two different breeds of broilers also, Strain and breed effect were recorded by Tabbaa et al. [26] among different commercial egg type layers Body Weight: Means ± standard errors of body weight from hatch till 12 weeks of age among four strains of Egyptian chickens were listed in Table 3 and Figure 1. Mandarah chickens showed the highest body weight among studied strains at hatch, 2, 4, 6, 8 and 10 weeks of age (38.09, 120.42, 297.84, 487.38, 747.50 and 1008.83 g; respectively), while El-Salam strain showed higher non-significant increase in body weight at 12 week of age (1243.50 g) followed by Mandarah and Inshas chickens (1242.46 and 1207.29 g respectively). on the other hand Dokki-4 chickens recorded significant decrease in body weight at hatch, 4, 6, 8, 10 and 12 weeks of age (34.06, 287.09, 467.70, 698.05, 930.86 and 1144.85 g; respectively). Results agreed with many authors whose recorded breed and strain differences in body weight [5 - 8]. Body Weight Gain: Differences in weight gain between four strains of Egyptian chickens (Table 4) did not take any definite order except for Dokki-4 chickens that recorded the lowest weight gains at BG3, BG4, BG5 and BG6 (179.98, 231.19, 232.81 and 213.98 g; respectively), moreover the overall weight gain from hatch to 12 weeks of age (BG7) showed that the highest weight gain was recorded for El-Salam chickens followed by Mandarah then Inshas, while the lowest weight gain was recorded for Dokki-4 chickens (1207.19, 1204.46, 1169.86 and 1110.76 g; respectively). Tadelle et al. [16] recorded differences in weight gain among different six chicken populations from one day old to 12 weeks of age. Also, many authors recorded differences in weight gain among different breeds and strains [6, 7, 17- 20]. Relative Growth Rate (RGR): Relative growth rate did not showed any definite manner (Table 5) among the four strain during different periods of age, but overall age relative growth rate (RGR7) showed that El-Salam strain recorded the higher non-significant 436 Immune Response for the Different Strains: Dokki-4 chickens found to be significantly higher in antibody titer for NDV vaccine (Table, 7 and Figure 3) at allover periods 14th, 25th, 35th, 45 th and 60 th days of age (1.52, 1.59, 1.45, 1.59 and 1.88; respectively), this higher response in Dokki-4 may be attributed to the genetic potential inherited from the Fayoumi breed (Pure native Egyptian chicken Known global by its high immunity). Lower antibody titers to NDV vaccine were recorded for Mandarah, Inshas and El-Salam chickens. Significant differences between breeding groups for antibody titer responses to Newcastle disease were recorded by [27-31], while Li et al. [32] found no line differences in the antibody responses to Newcastle disease virus vaccine at 1, 2, 3, 4, 5, or 12 wks.’ after vaccination. The results also disagreed with those obtained by Hassan [33] who challenged four native Egyptian breeds (Gimmizah, Sina, Dandrawi and Mandarah) with very virulent IBVD and virulent NDV and found that Mandarah chickens recoded higher genetic resistance for both viral infections. Moreover, Dokki-4 Global Veterinaria, 9 (4): 434-440, 2012 Table 3: Means ± standard errors of body weight from hatch till 12 weeks of age among four Egyptian chicken strains Means of body weights ± standard Errors -------------------------------------------------------------------------------------------------------------------------------------------------------------------------W0 W2 W4 W6 W8 W10 W12 Breed Mandarah Inshas El-Salam Dokki4 38.09±0.36a 37.52±0.41a 36.35±0.35b 34.06±0.35c 120.42±1.56a 117.14±1.58a 106.92±1.45b 109.07±1.34b 297.84±4.79 289.60±4.89 291.00±4.72 287.09±5.10 487.38±10.51 476.71±8.83 482.56±8.30 467.70±8.87 747.50±16.21 a 725.26±16.02 ab 745.16±13.63 a 698.05±15.00 b 1008.83±20.31 a 969.69±20.37 ab 996.34±16.74 a 930.86±18.40 b 1242.46±33.01 a 1207.29±30.34 ab 1243.50±25.52 a 1144.85±28.69 b -Means of the same column bearing different superscripts are significantly different (p < 0.05). W0 = body weight at hatch, W2, W4, W6, W8, W10 and W12 =, body weight at 2, 4, 6, 8, 10 and 12 weeks of age. Table 4: Means ± standard errors of body weight gain from hatch till 12 weeks of age among four Egyptian chicken strains Means of body weight gain ± standard errors ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------BG1 BG2 BG3 BG4 BG5 BG6 BG7 Breed Mandarah Inshas El-Salam Dokki4 82.33±1.66a 79.67± 1.59a 70.58±1.361c 75.01±1.28b 177.42±3.49ab 172.46±3.84b 184.08±3.69a 178.13±4.14ab 185.15±7.04 187.51±5.02 189.19±5.03 179.98±5.02 266.06±7.74 a 247.85±8.33ab 256.24±6.87 a 231.19±7.06 b 257.63±5.20 a 244.43±5.03 ab 251.18±3.89 a 232.81±3.99 b 233.67±13.57 a 237.66±11.22 a 247.19±10.25 a 213.98±10.81 b 1204.46±34.26 a 1169.86±30.28 ab 1207.19±25.43 a 1110.76±28.62 b -Means of the same column bearing different superscripts are significantly different (p < 0.05). BG1, BG2, BG3, BG4, BG5, BG6 and BG7= body weight gain from hatch to 2 weeks of age, body weight gain from 2 weeks to 4 weeks of age, body weight gain from 4 weeks to 6 weeks of age, body weight gain from 6 weeks to 8 weeks of age, body weight gain from 8 weeks to 10 weeks of age, body weight gain from 10 weeks to 12 weeks of age and body weight gain from hatch to 12 weeks of age. Table 5: Means ± standard errors of relative growth rate (RGR) from hatch till 12 weeks of age among four Egyptian chicken strains Means of relative growth rate (RGR) ± standard errors ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------RGR1 RGR2 RGR3 RGR4 RGR5 RGR6 RGR7 Breed Mandarah Inshas El-Salam Dokki4 103.33±1.17a 102.64±1.18a 98.10±1.05b 104.48±0.97a 84.54±0.73c 84.41±0.92c 92.19±0.80a 89.48±0.85b 46.51±1.23 48.74±0.84 48.58±0.92 47.33±0.70 42.84±0.73a 40.75±0.84ab 42.62±0.85a 39.44±0.70b 29.51±0.43 28.96±0.31 29.01±0.32 28.79±0.34 19.84±0.96 21.20±0.68 21.62±0.62 19.86±0.67 187.63±1.26 187.53±1.06 188.39±0.73 188.01±1.07 Means of the same column bearing different superscripts are significantly different (p < 0.05). RGR1, RGR2, RGR3, RGR4, RGR5, RGR6 and RGR7= relative growth rate from hatch to 2 weeks of age, relative growth rate from 2 to 4 weeks of age, relative growth rate from 4 to 6 weeks of age, relative growth rate from 6 to 8 weeks of age, relative growth rate from 8 to 10 weeks of age, relative growth rate from 10 to 12 weeks of age and relative growth rate from hatch to 12 weeks of age. Table 6: Livability and mortality percentages from hatch till 12 weeks of age among four Egyptian chicken strains Breed Livability percentage Mandarah Inshas El-Salam Dokki4 82.86 82.86 88.57 84.29 Chi-square value 3.44 NS Mortality percentage 17.14 17.14 11.43 15.71 NS= non-significant differences (P>0.05). Table 7: Log geometric mean of the antibody titer ± standard deviation (SD) among four Egyptian chicken strains at different periods of age Vaccine Breed ND Mandarah Inshas El-Salam Dokki-4 Mandarah Inshas El-Salam Dokki-4 AI No. of Birds 20 20 20 20 20 20 20 20 Log geometric mean of the antibody titer ± standard deviation (SD) -----------------------------------------------------------------------------------------------------------------------------Day 14 Day 25 Day 35 Day 45 Day 60 1.25 ± 0.27 b 1.17 ± 0.24 b 1.32 ± 0.23 b 1.52 ± 0.20 a 1.39 ± 0.18 1.46 ± 0.23 1.42 ± 0.18 1.37 ± 0.16 1.42 ± 0.24 1.48 ± 0.20 1.49 ± 0.49 1.59 ± 0.33 1.93 ± 0.26 ab 1.89 ± 0.26 ab 1.75 ± 0.30 b 2.00 ± 0.34 a 1.26 ± 0.21 bc 1.13 ± 0.26 c 1.33 ± 0.25 ab 1.45 ± 0.27 a 1.43 ± 0.28 b 1.49 ± 0.27 b 1.75 ± 0.21 a 1.80 ± 0.23 a -Means of the same column within the same vaccine bearing different letters are significantly different (p < 0.05). 437 1.23 ± 0.33 b 1.26 ± 0.25 b 1.25 ± 0.21 b 1.59 ± 0.31 a 1.66 ± 0.30 ab 1.55 ± 0.23 b 1.80 ± 0.21 a 1.79 ± 0.35 a 1.58 ± 0.28 b 1.66 ± 0.25 b 1.60 ± 0.37 b 1.88 ± 0.42 a 2.22 ± 0.26 ab 2.16 ± 0.26 b 2.15 ± 0.36 b 2.37 ± 0.17 a Global Veterinaria, 9 (4): 434-440, 2012 Fig. 1: Mean body weights of four Egyptian chicken strains from hatch to 12 weeks of age. Fig. 2: Livability percentages from hatch till 12 weeks of age among four Egyptian chicken strains Fig. 3: Antibody titer against ND vaccine for four native Egyptian chickens at different periods of age Fig. 4: Antibody titer against AI vaccine for four native Egyptian chickens at different periods of age 438 Global Veterinaria, 9 (4): 434-440, 2012 chickens recorded the highest antibody titer against AI vaccine (Table, 7 and Figure 4) at 25th, 35th, 45th and 60th (2.00, 1.80, 1.79 and 2.37; respectively). On the other hand Inshas chickens recorded the highest nonth significant antibody titer against AI vaccine at 20 days of age (1.46). The results confirmed by those obtained by Chang et al. [34] who found that Local breeds have different immune response to H6N1-LPAIV challenge and subsequent vaccine. 9. 10. 11. CONCLUSION These results suggest that El-Salam chicken strain can be selected for its better growth performance traits compared with others while, Dokki-4 strain can be selected for its higher immune response against ND and AI viral vaccines. 12. 13. REFERENCES 1. 2. 3. 4. 5. 6. 7. 8. 14. El-Itriby, A.A. and I.F. Sayed, 1966. Dokki-4 a new breed of poultry. Agric. Res. Rev. Cairo., 44: 102- 109. Abd EI-Gawad, E.M., 1981. The "Mandarah" a new breed of chickens. Egypt. Poult. Sci., 1: 16-22. Abd El-Gawad, E.M., M.M. Balat, N. Abou El-Ella, M.M. Ali and K.M. Omran, 1983. “El-Salam” a new locally developed strain of chickens. Agric. Res. Rev., 61(6): 147-157. Bakir, A.A.M., T.H. Mahmoud and A.F.M. El-Labban, 2002. A new Egyptian breed of chickens Egyptian Poultry Science, pp: 631. Leeson, S., L. Caston and J.D. Summers, 1997. Layer Performance of Four Strains of Leghorn Pullets Summers Subjected to Various Rearing Programs. Poult. Sci., 76: 1-5. Ajayi, F.O. and O. Ejiofor, 2009. Effects of genotype X sex interaction on growth and some development characteristics of Ross and Anak broiler strains in the high rainforest zone of Nigeria. Asian J. Poult. Sci., 3: 51-56. Enaiat, M.M., A.S. Amina and M.A. Eman, 2010. A comparative study of productive and physiological performance between two local strains of chicks. Egypt Poult. Sci., 30(I): 297-316. Taha, A.E., F.A. Abd El-Ghany and M.M. Sharaf, 2010. Strain and sex effects on productive and slaughter performance of developed local Egyptian and Canadian chicken strains. Egypt. Poult. Sci., 30: 1059-1072. 15. 16. 17. 18. 19. 20. 439 Swayne, D.E., 2009. Avian influenza vaccines and therapies for poultry. Comparative Immunology, Microbiology and Infectious Diseases, 32: 351-363. Swayne, D.E. and D.A. Halvorson, 2003. Influenza. In: Saif YM, Barnes HJ, Fadly AM, Glisson JR, McDougald LR, Swayne DE, editors. Diseases of poultry. Ames, IA: Iowa State University Press, pp: 135-160. Jeurissen, S.H., A.G. Boonstra-Blom, S.O. Al-Garib, L. Hartog and G. Koch, 2000. Defense mechanism against viral infection in poultry: a Review. Vet Q., 22(4): 204-8. Broody, S., 1945. Bioenergetic and growth. Reinhold pub Crop. N.Y. U.S.A. Takatasy, G.Y., 1955. The use of spiral 100 Min Serological and Virologicalmicromethods, Acta, Microbial, Acad. Sci. Hung., 3: 191. Brugh, M.G., 1978. A simple method for recording and analyzing serological data,? Avian Disease. 22: 362-365. SAS, 2004. (Statistical Analysis System) Statistical user’s Guide. INT. Cary, NC. USA. Tadelle, D., C. Kijora and K.J. Peters, 2003. Indigenous Chicken Ecotypes in Ethiopia: Growth and Feed Utilization Potentials. International Journal of Poultry Science, 2(2): 144-152. Rondelli, S., O. Martinez and P.T. Garcia, 2003. Sex effect on productive parameters, carcass and body fat composition of two commercial broilers lines. Rev. Bras. Cienc. Avic., 5(3): 169-173. Zhao, J.P., J.L. Chen, G.P. Zhao, M.Q. Zheng, R.R. Jiang and J. Wen, 2009. Live performance, carcass composition and blood metabolite responses to dietary nutrient density in two distinct broiler breeds of male chickens. Poult. Sci., 88: 2575-2584. Bekele, F., T. Adnoy, H.M. Gjoen, J. Kathle and G. Abebe, 2010. Production Performance of Dual Purpose Crosses of Two Indigenous with Two Exotic Chicken Breeds in Sub-tropical Environment. International Journal of Poultry Science, 9(7): 702-710. Ogbu, C.C., I. Udeh and P.C. Nwakpu, 2012. Comparative performance of two commercial egg strains, the indigenous chickens and their random bred progenies. Livestock Research for Rural Development 24(3) From http://www. lrrd. org/ lrrd 24/3/ ogbu24047.htm. Global Veterinaria, 9 (4): 434-440, 2012 21. Aggrey, S.E., 2003. Dynamics of relative growth rate in Japanese quail lines divergently selected for growth and their control. Growth, Development & Aging. Growth Publishing Co. Inc. Hulls Cove, USA, 67(1): 47-54. 22. Taha, A.E., 2005. Genetic variations among colored varieties of Coturnix. M.V.Sc. Thesis, Fac. of Vet. Med. Alex. Univ. Egypt. 23. Taha, A.E., 2009. Laying performance of Japanese quails divergently selected for body weight under different rearing and lighting systems. Ph.D. Thesis, Fac. of Vet. Med. Alex. Univ. Egypt. 24. Olawumi, S.O. and I. Dudusola, 2010. Effects of Genotype and Housing on Reproductive Performance of Two Strains of Commercial Layers in the Derived Savannah Zone of Nigeria. PAT, 6(1): 102-109. 25. Awobajo, O.K., Y.M. Akintan, A.O. Igbosanu, A.A. Mako and O.T. Olatokunbo, 2007. The Mortality Rate in the Two Breeds of Broiler on Brooding Stage. World Applied Sciences Journal, 2(4): 304-308. 26. Tabbaa, M.J., A.N. Al-Kateb and K.M. Alshawabkeh, 2007. Effect of Breed Strain, Disease, Environmental Conditions and Management on Mortality in Commercial Egg Type Layers. Jordan Journal of Agricultural Sciences, 3(1): 52-65. 27. Peleg, B., N. Ron-kuper and K. Hornstein, 1980. Genetic and phenotypic correlations between immune response to Escherichia coli and to Newcastle disease virus vaccines. Poult. Sci., 59: 49-53. 28. Gyles, N.R., H.F. Moghadam, L.T. Patterson, L.K. Skeeles, G.E. Whitfill and L.W. Johanson, 1986. Genetic aspects of antibody response in chickens to different classes of antigens. Poult. Sci., 65: 223-232. 29. Atta, A.M., 1990. A genetical study on the White Baladi fowl. Ph. D. Thesis, Fac. Of Agric. Cairo Univ. Egypt. 30. Siam, S.M., 1994. Environmental and physiological studies on demostic and local new strains of poultry. Ph.D Thesis, Fac. of Agric. Cairo, Univ. Egypt. 31. El-Gendy, E.A., A.A. Atallah, F.R. Mohamed, A.M. Atta and N.E. Goher, 1995. Strain variation in young chickens in response to chromic heat stress conditions. Egypt. J. Anim. Prod., 32: 237-251. 32. Li, Z., K.E. Nestor, Y.M. Saif, J.W. Anderson and R.A. Patterson, 2001. Effect of Selection for Increased Body Weight in Turkeys on Lymphoid Organ Weights, Phagocytosis and Antibody Responses to Fowl Cholera and Newcastle Disease-Inactivated Vaccines1. Poultry Science, 80: 689-694. 33. Hassan, M.K., M.A. Afify and M.M. Aly, 2004. Genetic Resistance of Egyptian Chickens to Infectious Bursal Disease and Newcastle Disease. Tropical Animal Health and Production, 36(1): 1-9. 34. Chang, C.S., M.T. Boichard, O. Chazara, Y.P. Lee, C.F. Chen, P.C. Chang, J.W. Chen and B.B. Hom, 2011. Different immune responses to three different vaccines following H6N1 low pathogenic avian influenza virus challenge in Taiwanese local chicken breeds. BMC Proceedings 2011, 5(Suppl. 4):S33, From International Symposium on Animal Genomics for Animal Health (AGAH 2010) Paris, France. 31 May 2 June 2010. 440 View publication stats