Effect of zinc oxide on liveweight, reproductive organ dimensions and spermatozoa production of Archachatina marginata during dry season

Abstract

Abstract Demand for Giant African Land Snail in Nigeria is so high such that it is very difficult to meet up with the supply as a protein source. However, during dry season, production at intensive level is often challenged with decline in growth and reproduction despite interventions to boost production. This study therefore evaluates the effect of zinc oxide on liveweight, reproductive organ dimensions and spermatozoa production of Giant African Land Snail (Archachatina marginata) during dry season. Thirty-two (32) snails with an average weight of 100 – 180 g were used for this experiment. The snails were allotted to four different feeding treatments which included concentrate diet only, concentrate +10 mg/kg of zinc oxide, concentrate +15 mg/kg of zinc oxide and concentrate +20 mg/kg of zinc oxide, respectively. Each treatment contained eight replicates. After nine weeks, five snails were selected from each treatment and dissected. Variables monitored were: weekly weight gain, shell circumference, shell length and shell diameter. Other reproductive data collected after dissections were: organ weight, reproductive tract weight, albumen weight, ovo-testis weight, gonado-somatic index (GSI) and spermatozoa concentration. The result showed that dietary zinc oxide significantly (P < 0.001) influenced feed intake, shell parameters, organ weight ovo-testis weight, albumen weight, gonado-somatic index, reproductive tract weight and spermatozoa concentration. Snailsfed zinc oxide supplemented diet had better shell measurements, organ weight, ovo-testis weight, albumen weight, gonadosomatic index and reproductive tract weight. Considering spermatozoa concentration, 10 mg/kg of zinc oxide inclusion into concentrate diet gave the highest concentration. The results of the present study showed that dietary zinc oxide positively influenced feed intake, shell measurements, organ weight, ovo-testis and albumen weight. Similarly, gonado-somatic index and spermatozoa production were also positively influenced. Therefore, 10 mg/kg inclusion of zinc oxide is recommended for better reproductive tract development, and spermatozoa production at the desirable economic level during the dry season production of Archachatina marginata.