Genetic Variability in Immunocompetence and Performance Status of Rhode Island Red Chicken Strains and its Crosses

The present investigation envisaged to assess genetic variability in immunocompetence and performance traits in three pure strains of Rhode Island Red (RIR) chicken, viz. RIR S , RIR C & RIR W , and its two crosses, viz. CARI-Sonali and CARI-Debendra. A total of 3232, 1263, 346, 1278 and 1258 eggs of RIR S , RIR C , RIR W , CARI-Sonali and CARI-Debendra, were set in three hatches for performance evaluation. Single hatched out 74, 74, 72, 82 and 81 chicks of corresponding genotypes were investigated for immunocompetence status assessed through haemagglutination (HA) test, Lysoplate Assay and Single Radial Immunodiffusion assay. The data on various immunocompetence and performance traits was recorded and analyzed by least squares analysis of variance. The investigation summarized that pure strains demonstrated better immunocompetence than crosses. RIR W demonstrated highest percent fertility followed by RIR C , RIR S , CARI-Sonali and CARI-Debendra. Highest percent hatchability on total egg set basis was observed in RIR C , whereas CARI-Debendra demonstrated highest percent hatchability on fertile egg set basis. CARI-Debendra demonstrated higher body weights than CARI-Sonali followed by RIR S , RIR W and RIR C strains. CARI-Sonali pullets demonstrated (p<0.05) least AFE than RIR S preceded by RIR W , CARI-Debendra and RIR C . Pullets of crosses had (p<0.05) higher EW28 and EW40 than pure strains. CARI-Sonali pullets had (p<0.05) higher EP40 than RIR S >RIR W =CARI-Debendra>RIR C . There had been significant genotypesex interaction effect on body weights at 2 nd , 8 th week and onwards. At 2 nd week of age, CARI-Debendra-female showed highest body weight but subsequently CARI-Debendra-males were the heaviest. Effects of hatch, sex and chick weightregression on growth traits as well as of hatch and housing weight-regression on layer production traits were significant. Crosses demonstrated least percent mortality than pure strains during brooding but reverse in laying stage.