Feeding Value of Dried Fermented and Unfermented Vegetable Based Agro By-Products (VBAP)

Vegetable based agro by-products are unwanted to some farmers in cultivated areas and vegetable markets which considered as wastes, though, these byproducts can be considered as alternative sources of feed for animal production. Recycling of by-product as feedstuffs for animal production is an important factor in waste reduction. The by-product residues can be classified as fruit and vegetable by-products, oil industry by-products and grain-and legume-milling industry by-products. Use of by-products from agro-industry could lessen animal production cost and can resolve waste disposal and environmental pollution problem. Furthermore, production of feedstuffs can be supported with the use of fruit and vegetable by-products as feeds and feed sources (Yang et al., 2021).

Utilization of these byproducts give the needs to identify the nutritional content for feed formulation. Feed quality or nutritional value is an idea that involves many indicators like energy and protein content, chemical composition, consumption and digestibility (Kirilov et al., 2017). Vegetable wastes and by-products such as sugar beet leaves, potato vines, bottle gourd pulp, radish leaves, cabbage leaves, pumpkin oil meal, snow peas among others are good source of energy and crude protein (CP) particularly for ruminant animals which contains more than 20% CP. Other vegetable wastes hold 19% to 10% CPcontents. On the other hand, vegetable waste such as sweetcorn husk, and cob, waste of jackfruit and carrot pulp contains a CPwith less than 10% (Bakshi et al., 2015). Furthermore, fruit seed cakes of passion fruit, soursop and custard apple could be use as feed for animals after industrial process. They contain high amount of dry matter with low moisture content which can become abetter alternative for ruminant feedstuff that may lessen the expenses in animal production (Pinto et al., 2020). Though, agricultural byproducts required preservation for longer shelf life and needs to improve the nutritional value. Fermentation plays important part in food preservation via development organic acid such as formic acid, lactic acid, propionic acid and acetic acid. It includes also the production of reutrin, ethanol, carbon dioxide, bacteriocins and diacetyl. Fermentation could improve food safety, remove toxic compounds, improve the food quality and nutritional value (Ray and Joshi, 2015). Acetic acid produced by LAB strains prevents spoilage and contributes to the aroma. The LAB producing thermostable amylases have potential fermentations of tubers, cereal, and root. The LAB acidifies foods that frequently exert proteolytic and lipolytic activities and produce amino acids upon further bioconversion that contributes to the aroma and flavor of fermented products. LAB could increase nutraceuticals content in fermented foods and increase the quantities of low-calorie polyols in order to lessen amount of sugar. Furthermore, LAB stains may prevent galactose accumulation and lactose intolerance by eliminating the lactose and galactose from fermented milks. Moreover, content of soy that results to intestinal cramps and flatulence can be removed through fermentation (Ray and Joshi, 2015).

Great challenge in feed security is preservation because agricultural byproducts are highly perishable. To preserve these products, drying is an important technique used. Drying of food byproducts is appropriate way for extending shelf life and storage. Moreover, drying favors easy and economical packaging and transport, reduction of greenhouse gas, smaller space for storage and lesser environmental weight (Noori et al., 2022). Drying are used for the long-term storage to preserve raw materials where in, some grains need atleast 9% moisture content depending on the grain and climate (Lyda and Kyosung, 2018). Methods of drying raw materials includes convection/air drying, this is characterized by a method simultaneous movement of mass and heat. Other method is freeze-drying which is the most conventional technique of drying fruits, vegetables and LAB, since the resulting product is of good quality, less effect on nutritional value, aroma, texture and color (Janiszewska-Turak et al., 2021). Other drying methods used for agricultural products, meat products and medicinal plants includes solar drying, ultrasound drying, microwave drying, spray drying, fluidized bed drying and vacuum drying (Noori et al., 2022). Recent researches disclosed that drying agricultural byproducts is important for preservation and significant result of fermentation improved the nutritional value of agricultural byproducts, though published data for the nutritive value of VBAP is limited.

This study aims to determine the chemical composition and mineral content of locally available VBAP and comparing the value of dried unfermented and fermented VBAP.