Neco Model Questions Vol1 2021 Agricultural Science Question 7

A 0.5 ha pond (average depth 1.2 m) is stocked with catfish fingerlings at a density of 5 000 fingerlings per ha. Thus 2 500 fingerlings are introduced. Survival after six months is given by \(S = 0.9 - 0.02\,(FCR - 1.5)\), where \(FCR\) is the feed conversion ratio. The farmer can choose between Feed A (\(FCR = 1.6\), cost \(\text{₦}150\) per kg) and Feed B (\(FCR = 1.4\), cost \(\text{₦}200\) per kg). Each surviving fish receives 0.02 kg feed per day. The culture period is 180 days and the market price of live fish at harvest is \(\text{₦}500\) per kg. Fish reach an average weight of 0.8 kg at harvest if survival exceeds 70 %; otherwise the average weight falls proportionally to the survival percentage. Determine which feed gives the higher profit and state that profit (in Naira).