title: Effect of climatic variables on production and reproduction traits of colored broiler breeder poultry.
abstract: OBJECTIVE
  The present study was conducted to investigate the important climatic variables affecting production and reproduction in a broiler breeder flock.
  
  
  METHODS
  The experiment was conducted for a period of 1 year on colored synthetic female line male and female poultry birds. 630 female progeny and 194 male progenies from 69 sires and 552 dams produced in four consecutive hatches at an interval of 10 days were used for the present study. Each of the seven, body weight and reproduction traits were regressed with nine environmental variables. Initially, the data were subjected to hatch effect and sire effect corrections through best linear unbiased estimator (BLUE) method and, then, multiple linear regressions of environmental variables on each trait were applied.
  
  
  RESULTS
  The overall regression was significant (p<0.01) in all traits except 20 week age body weight of females. The R(2) value ranged from 0.12 to 0.90 for the traits. Regression coefficient values (b values) for maximum temperature and minimum temperature were significant (p<0.05) on 5(th) week age body weight of males. Similarly, evaporation and morning relative humidity (RH) was significant (p<0.05) for 5(th) week age body weight of females. Almost all b values were significant (p<0.05) for egg production up to 40 week age. The b values representing rainfall, morning RH, afternoon RH, sunshine hours, and rainy days were significant (p<0.05) on bodyweight at 20 week age. All environmental variables except maximum temperature and minimum temperature were significant (p<0.05) on body weight of females at 20 weeks of age. Age at sexual maturity was regressed significantly (p<0.05) with evaporation, afternoon RH whereas, egg shape index was regressed significantly (p<0.05) with a maximum temperature, evaporation and afternoon RH.
  
  
  CONCLUSIONS
  The result indicated that various environmental variables play a significant role in production and reproduction of breeder broiler poultry. Controlling these variables in adverse weathers may increase production.
authors.affiliation: Department of Animal Breeding and Genetics, College of Veterinary Science and Animal Husbandry, Orissa University of Agriculture & Technology, Bhubaneswar - 751 003, Odisha, India.
authors.forename: G D
authors.initials: GD
authors.lastname: Nayak
authors.affiliation: Department of Poultry Science, College of Veterinary Science and Animal Husbandry, Orissa University of Agriculture & Technology, Bhubaneswar - 751 003, Odisha, India.
authors.forename: N C
authors.initials: NC
authors.lastname: Behura
authors.affiliation: Department of Pharmacology & Toxicology, College of Veterinary Science and Animal Husbandry, Orissa University of Agriculture & Technology, Bhubaneswar - 751 003, Odisha, India.
authors.forename: K K
authors.initials: KK
authors.lastname: Sardar
authors.affiliation: Department of Poultry Science, College of Veterinary Science and Animal Husbandry, Orissa University of Agriculture & Technology, Bhubaneswar - 751 003, Odisha, India.
authors.forename: P K
authors.initials: PK
authors.lastname: Mishra
keywords: Best linear unbiased estimator; climatic variables; colored breeder; multiple regressions; production; reproduction