Californian red worm biomass increase and its cobalt accumulation under different concentrations of the metal in nutrient medium

Abstract

Californian red worms hybrid biomass is a biologically valuable feed supplement for livestock, poultry and fish. The worm body contains a significant amount of protein, lipids, vitamins and minerals. The chemical composition of worms depends on the nutrient medium in which they were grown. Worms can accumulate minerals from the nutrient medium in the body which called forth conducting research on obtaining worms biomass enriched with Cobalt with the prospect of its further use in fish feeding. It has been found out that the worms quantity and the mass increase depends on the content of Cobalt in the nutrient medium. Adding 20 mg / kg of Cobalt to the nutrient medium contributed to 38.0% and 40.4% increased amount of worms weighing 0.4-0.8 g respectively. The study reveals that the number of immature worms increased by 32.2%. Adding 40 mg / kg of Cobalt to the nutrient medium resulted in worms number and mass increased by 45.9 and 51.1% respectively. Adding 160 mg / kg of Cobalt resulted in 6.5-27.7% smaller amount of worms weighing 0.4-0.8 g as compared with the experimental groups. It has been found out that the number of small worms reduced by 24.0-50.7% compared with the experimental groups under adding 160 mg / kg of Cobalt. The weight reduced by 22.4% and amount of young worms compared with the control has been revealed. We have established the pattern that as Cobalt amount in the nutrient medium increases, its concentration in the worms biomass increases as well. The highest content of Cobalt was found in the biomass dry matter of worms grown in the nutrient medium enriched with the studied metal in the amount of 160 mg / kg. Biomass of worms grown in the nutrient medium with 40 mg / kg of the studied metal added can be used in fish feeding as a protein supplement with a high content of Cobalt.

Cultivation of worms on a substrate containing poultry droppings fermented with addition of biodestructors

“…Problem statement and analysis of recent researche. The dynamic development of poultry farming in most countries of the world leads to the accumulation of significant volumes of litter with and without bedding in limited areas [1,2]. In Ukraine, the issue of the accumulation of poultry droppings in limited areas is also quite relevant.…”

“…Various prepared (composted) organic wastes are used for the cultivation of vermiculture: crop production (straw, chaff, spoiled hay, spoiled hay, silage, etc), livestock production (poultry droppings, animal manure, and waste from slaughterhouses), industrial and food waste [7,9,10,11].…”

“…Water penetration into compacted soils increases. As a result of the action of worms, the mineralization of Nitrogen, Phosphorus and other chemical elements is accelerated, thereby increasing bioavailability for plants [13][14][15][16].…”

Justification of the method for phytoremediation of degraded and contaminated lands by composite vermicompost briquettes

“…In [14], the results of a study of the biomass of worms on a cobalt enriched medium are presented. It is estab lished that the biomass of worms grown in a nutrient medium with the addition of 40 mg/kg cobalt can be used for breeding fish as a protein supplement with a high content of cobalt.…”