Hot climate effects and their amelioration on some productive and reproductive traits in rabbit does

Abstract

[EN] This study aimed to improve productive and reproductive performance of female rabbit does during the summer season hot climate using vitamin C or cooled water in combination with equine chorionic gonadotropin (eCG) treatment. Sixty New Zealand White rabbit does were assigned to three groups, according to drinking-water treatment: 1) fresh tap water without any supplementation (control, C), 2) cooled drinking water (10-15ºC) (CW), and 3) fresh tap water supplemented daily with added ascorbic acid (1 g/L) (vitamin C). Twenty four hours before mating, does of each group were randomly divided into two subgroups; H does were intravenously injected with 40 IU/doe eCG, while NH does did not receive any hormonal treatment. Productive and reproductive performance were signifi cantly (P<0.05) improved in the treated groups. Kit weights at kindling and weaning were greater (P<0.05) in both vitamin C and cooled water groups than in the control regardless of hormonal treatment. It is worthy noticed that conception rate and litter size at birth were adversely affected by eCG, especially in does drinking vitamin C. The percentage of mature oocytes was lower (P<0.01) in control than in treated groups. The oocyte maturation rate improved after treatment with vitamin C to reach 80% compared to 66% in control group. In conclusion, cool drinking water or vitamin C is recommended for alleviating heat stress during summer in rabbits.