The Nutritive Value of Wastewater Grown Barley and its Utilization in Fish Feed

Abstract

Abstract:The feasibility of using wastewater grown barley plants as a component of fish feed was evaluated. The barley plants were grown in a hydroponics system on wastewater from a recirculating aquaculture facility. The effects of wastewater application rate on plant growth and pollution potential reduction were investigated. At the end of the experiment, the average crop heights and yields were 31.0 and 36.0 cm and 59 and 83 t ha -1 at wastewater application rates of 690 and 1380 mL compartment -1 day -1 , respectively. The hydroponics system reduced the TS, COD, NH 4 + -N, NO 2 --N, NO 3 --N and PO 4 -3 -P of the aquaculture wastewater by 51. 5-52.9, 72.3-72.3, 81.8-82.3, 97.9-98.2, 78.9-79.7 and 84.7-86.3%, respectively. The aquaculture wastewater grown barley met the energy, fat, Ca, Mg, P, Na, S and Mn dietary requirements of aquatic animals. It exceeded the carbohydrate, crude fiber, Cl, K, Cu, Fe, Se and Zn dietary requirements of fish and shellfish. It did not contain sufficient amounts of protein. The aquaculture wastewater grown barley could potential be used as a component in fish feed, but will require supplementation with a high protein source that contains low concentrations of carbohydrate, crude fiber, Cl, K, Cu, Fe, Se and Zn. Common protein sources that could be used for supplementation included fishmeal, bone meal and blood meal.

Drying of Poultry Manure for Use as Animal Feed

“…Providing the optimum energy level in the diet is important for the healthy development of animals. Excess dietary energy may result in high fat deposition, decreased feed intake and reduced weight gain, while a diet low in energy content may result in reduced weight gain as the animal utilize nutrients for energy provision rather than for the synthesis of new tissues and growth (Snow and Ghaly, 2007;NRC, 1984). The dried poultry manure had an energy content of 181.0 MJ/kg which meets the energy requirements of animals (32-37 MJ/kg).…”

“…They consist of amino acids joined by peptide bonds and are composed of 50-55% carbon, 15-18% nitrogen, 20-23% oxygen, 6-8% hydrogen and 0-4% sulphur. Protein is required in the diet to provide essential amino acids and nitrogen for the synthesis of non-essential amino acids and other nitrogen containing compounds (Snow and Ghaly, 2007;NRC, 1984). Protein is typically the largest and most expensive component of an animal diet.…”

An Effective Passive Solar Dryer for Thin Layer Drying of Poultry Manure

“…Protein provides the essential amino acids and nitrogen for the synthesis of non-essential amino acids and other nitrogen containing compounds (Snow and Ghaly, 2007;NRC, 1984). The dried poultry manure had a protein content of 422 g/kg which exceeds the recommended dietary intake of animals (7.3-7.8 g/kg) reported by the NRC (1984).…”