چكيده لاتين :
Introduction Vermicomposting is the process of composting organic materials using various worms to decomposing vegetable, food waste, bedding materials and many organic waste materials. Many wastes and residues have been used to produce vermicompost. Using variety of left over products such as vegetable cuttings, food wastes and manure from cattle and chickens for vermicomposting can inhibit environmental pollution while producing valuable vermicompost. However, worms require specific conditions for activity and composting. Vermicast (worm manure) is the end product of the breakdown of organic matter by earthworms which usually applies as an organic and natural fertilizer. Due to appropriate protein and organic matter of vermicast or vermicompost, it is maybe possible to use vermicompost as a feedstuff in ruminant animals such as low producing cattle, sheep and goats. Then, the aim of the current research was to investigate the possibility of using rumen content which has been enriched with organic wastes (fruits and vegetables waste, oyster mushroom wastes) as a decomposing material for worms and nutritive value of the produced vermicompost for ruminants.
Materials and Methods Experimental treatments were T1: rumen contents (control), T2: 60% rumen contents + 40% fruits & vegetables wastes, T3: 60% rumen contents + 40% oyster mushroom wastes, T4: 60% rumen contents + 20% fruits & vegetables wastes + 20% oyster mushroom wastes. Three boxes (65×35×30 cm) were made for each treatment and 8 kg of materials and 80 grams of worms (200 worms) were added to one of them. The boxes were kept for 75 days in a room with 25oC temperature and 65-70% of relative humidity. After 75 d, a sample of each replicated was chosen for pH and dry matter analysis. Another sample from each replicated was grounded and analyzed for chemical composition (crude protein, ash, crude fiber, neutral detergent fiber, acid detergent fiber) and gas production measurement. Gas volume was recorded at 2, 4, 6, 8, 12, 16, 24, 36, 48, 72 and 96 h of incubation. The kinetics of in situ was estimated using model: P=a+b (1-e-ct). The effective degradability of dry matter and crude protein to feed was calculated by the following equation ED = a+bc/(c+k). Rumen rate of passage k which to calculated effective degradability of this study, from rate of 2, 5 and 8 percent per hour was used.
Results and Discussion Vermicomposting efficiency was lower in T4 and higher in T2 and T3 treatments when compared with T1. The highest and lowest vermicomposting efficiency was in T3 and T4 treatments, respectively. Moreover, T3 treatment showed the highest crude protein and crude fat concentrations among the treatments. T3 treatment also had the lowest ash, crude fiber, neutral detergent fiber and acid detergent fiber concentrations among the treatments. The values of pH after 75 days were 6.76, 6.15, 7.55 and 7.02, respectively. The concentrations of crude protein for T1 to T4 were 16.50, 17.44, 17.05 and 18.45%, respectively. Also, the concentrations of neutral detergent fiber for T1 to T4 were 41.5, 40.18, 41.42 and 38.87%, respectively. Moreover, the concentrations of acid detergent fiber for T1 to T4 were 27.33, 26.11, 28.64 and 26%, respectively. The results of effective degradability of dry matter with a pass rate 0.02, 0.05 and 0.08 with the highest in the T4, 62.90, 46.45 and 38.10 percent respectively, and reported effective degradability of crude protein, with same pass rate, 62.37, 41.25 and 35.12 percentage respectively (P<0.01). The results showed that by mixing appropriate amounts of organic wastes (cellulosic resources) with the contents of the rumen to produce vermicompost with good nutritional value (energy and high protein) can be used as animal feed.
Conclusion The results of this study show that using up to 20% fruits & vegetables wastes + 20% oyster mushroom wastes in vermicomposting rumen content can produce vermicompost with great nutritive value (higher protein and lower fiber concentration) and high digestibility and energy content, which can be used in ruminants nutrition.
