Prospects for using alfalfa flour as part of feed for Australian red-claw crayfish (Cherax quadricarinatus)

Abstract

The possibility of partial replacement of fish meal with alfalfa flour in feeds for the Australian red-clawed crayfish (Cherax quadricarinatus) has been investigated. Crayfish were kept in aquariums with a volume of 150 liters at a temperature of 24-26.5 °C. The control group was fed with granular feed intended for sturgeon fish. In experimental feeds, fish meal was partially replaced with alfalfa flour. An enzyme preparation, natuzyme, was added to one of the feed options. The duration of the experiment was 45 days. Feeding was carried out manually 2 times a day in the morning and evening hours. The feed was introduced in portions, monitoring the digestibility. The feeding rate was 2-4% of body weight. Morphometric, linear-weight and biochemical parameters of Cherax quadricarinatus and hemocyte formula are analyzed. It was found that the growth of crayfish on feeds with high and low animal protein content occurred almost equally, which indicates a good prospect of using alfalfa flour in feed in order to reduce their cost by reducing the amount of fish meal. At the same time, for better assimilation of the plant components of the feed, it is recommended to add the complex enzyme preparation natuzyme to the feed. The positive effect of feed with the addition of alfalfa flour on biochemical parameters and hemocyte formula of the Australian red-clawed crayfish was noted. Experimental feeds provided sufficient content of total protein, lipids, glucose, phosphorus and calcium in the hemolymph. A decrease in urea content was found.