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

Abstract

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.

Impacts of vitamin C and E injections on ovarian structures and fertility in Holstein cows under heat stress conditions

“…However, in chickens (26), rabbits (27), and rats (20) under heat stress, supplementation of these vitamins improved reproductive performance.…”

Technical Note: Design of a large variable temperature chamber for heat stress studies in rabbits.

“…One of the major constraining factors for rabbit production is the environmental conditions (Fernández-Carmona and Cervera, 2010), especially high temperatures, which negatively affect reproduction and growth performance (Maertens and De Groote, 1990;Chiericato et al, 1992;Fernández-Carmona et al, 2003;Yassein et al, 2008;Oseni and Ajayi, 2010). For this reason, several works have focused on evaluating heat stress effects and possible solutions to alleviate their impact on rabbit performance.…”

Exploring the genetics of the efficiency of fertile AI dose production in rabbits

“…Exposure to heat stress before insemination could have a negative effect on female reproductive performance due to higher embryonic degeneration compared to non-stressful conditions (Cheng et al, 1999). A reduction in the development of mature follicles and in the number of developing oocytes has been observed in rabbits during summer heat stress (Yassein et al, 2008). It has also been reported in cattle and goats that heat stress affects follicular dynamics, ovulation rate, steroid secretion and gene expression (Doney et al, 1973;Roth et al, 2001;Argov et al, 2005;.…”

“…The detrimental effects of heat stress on conception rate and litter size have been described by several authors in rabbits, especially in countries with hot climate conditions (Sittmann et al, 1964;Marai et al, 2006;Yassein et al, 2008). For example, litter size at birth was about 1 kits/litter higher for does kept at an average temperature of about 20ºC than for does kept at constant 30ºC (Papp and Rafai, 1988;Fernández-Carmona et al, 1995).…”

“…Chapter five Effect of temperature on male and on female fertility (Marai et al, 2006;Yassein et al, 2008). In rabbit, the number of functional sweat glands is scarce and its fur does not allow a great perspiration.…”