Influence de la fréquence d’alimentation sur la performance alimentaire des crevettes Penaeus monodon en saison froide Cas de la société OSO® Farming – Ambilobe

Abstract

Feed management is a complex task during shrimp production, which often leads in overfeeding
and the generation of large amounts of waste in the rearing tanks. It plays a major role in the
economical and environmental status of shrimp farms which involves basic aspects such as
when, where and how much to feed? This study is conducted during february to september 2020
to evaluate the effect of feeding frequency on water quality, consumption, growth, survival rate,
and consequently on the IC of Penaeus monodon juveniles during 6 weeks in hothouse and 10
weeks in tank using cages. Four feeding treatments were then tested in tanks (in greenhouse)
with 3, 4 and 5 times the distribution frequency at an equitable quantity and at a different
quantity at each feeding hour for a distribution frequency of 4 times a day (control). Two other
feeding treatments with 4 feeding frequencies were also tested in cages, one with a fair amount
and the other with a different amount at each feeding time. Although shrimp fed for the 5 times
per day feeding treatment [(experiment in hothouse: 1,82±1,20g.shrimp-1) and control
(experiment in tank using cages: 6,30±0,23g. shrimp-1)] showed the best final growth, at harvest
no statistical differences were detected at this level and for feed conversion ratio between the 4
feeding treatments tested in the hothouse: 6,63±1,91 to 11,66±4,56) and control and test cages
in the earthen pond (7,68±3,60 and 12,96±9,55) nor survival (p > 0,05). There was no
significant change in shrimp consumption in 6 weeks of rearing between hothouse treatments
(p > 0,05). Nevertheless, it was higher in the last feeding for the 4 feeding treatments tested and
the best daily consumption rate was observed in the 5 times a day feeding frequency (80%).
Temperature, salinity and dissolved oxygen (DO) values showed no significant difference
between greenhouse treatments (p > 0.05) with respective daily mean values of 28,6±1.26°C,
27±1,49‰ and 6,55±0,16mg.l-1 for all experimental frequencies combined. All the values of
the parameters studied fit perfectly within the tolerance range for rearing Penaeus monodon
except salinity, which was low at the start of the greenhouse experiment