IN OVO AND TEMPERATURE DEPENDENT SEX REVERSAL TECHNIQUE IN CHICKENS

Abstract

ABSTRACT Sex reversal techniques offer an innovative solution to improve poultry production and achieve mono-sexing in poultry. This study investigated sex reversal techniques and their influence on hatching parameters, sex ratio and post-hatch performance of egg and meat-type chickens. The study was divided into three experiments. Experiment I considered effects of temperature dependent sex reversal techniques and oral administration of oestradiol on egg-type chickens Experiment II investigated the role of temperature dependent sex reversal techniques and oral administration of letrozole on meat-type chicken and experiment III consider in ovo injection of oestradiol and letrozole on performance of broiler chicken Data collected in the course of three experiments were respectively subjected to one-way Analysis of Variance. In experiment I, hatching parameters and sex ratio were not significantly (p>0.05) affected by higher incubation temperature (38.1℃), while in experiment two, higher chick weights (45.21, 45.24 and 45.31 g) were observed in birds resulting from positive control as well as those administered letrozole orally at 0.5 and 1 ml per bird respectively. . Furthermore, sex ratio also was influenced as more male chicks were observed in birds from the positive control 0.5 and 1 ml orally administered letrozole. In experiment three, in ovo injection of letrozole increased percentage chick yield (73.68%) and resulted in significantly (p<0.05) higher percentage of male chicks (87.71%), while hatchability was reduced significantly (p<0.05) as a result of in ovo injection of oestradiol (45.00%). In experiment one, post-hatch administration of oestradiol at 1ml significantly (p<0.05) increased the progesterone level (82.55ng/g) and also increased the number of ova (8.50) and ova weight (18.05g) of 16 weeks old egg-type chicken. Administration of letrozole post hatch in experiment two and in ovo injection of letrozole in experiment three resulted in significantly (p<0.05) improved post hatch performance in term of body weight (2121.40g and 2196.70g), daily weight gain (56.97g and 49.05g), feed conversion ratio (1.68 and 1.63), body linear measurement and carcass characteristics. The study concluded that while higher incubation temperature (38.1℃) cannot be used as a sex reversal technique in egg-type chicken, it is an effective sex reversal method in meat-type chicken. Furthermore, in ovo injection of eggs with letrozole is an effective sex reversal method and can aid higher number of male population in broiler production with improved post-hatch performance.