Determination of the Nutritional Value of Tomato Shoot Silage in Ruminant Nutrition by In Vitro Techniques

Background: Developing countries, especially with dry weather conditions, are facing the problem of lack of animal feed.Thus, agricultural by-products, which are often processed for feeding in ruminants, can be used as an alternative or part of the diet; it also reduces animal feed costs.The reuse of agricultural waste in ruminant nutrition is a method for managing agricultural waste, which also reduces the risks of environmental pollution.Tomato shoot obtained from tomato plant pruning in the greenhouses for growing and producing this valuable product is one of the major agricultural wastes, which can be considered a part of ruminant feed due to its high volume of production.This study aimed to investigate the nutrient value of tomato shoot silage by in vitro techniqes as a substitute for a part of hay in ruminant feeding and to determine the effect of bacterial additives on the quality of silage.Methods: Pruned tomato shoots in a greenhouse, which are part of agricultural waste, were collected from the industrial greenhouses of the East Azerbaijan region, cut into 3-5 cm pieces, and ensiled in a mini-silo.Microbial additives and amounts used in this experiment were 1bacterial additive with the SiloLact brand, a product of the Fardis Roshd Mehrgan Company of Iran, containing Lactobacillus plantarium, Bacillus acidophilus, and dextrose monohydrate bacteria (10 6 colony-forming units (CFU) were added per gram of fodder), 2-enzymatic additive with the brand name enzymatic-SiloLact, produced by the Fardis Roshd Mehrgan Company of Iran, containing L. plantarium, L. acidophilus, cellulase enzyme, xylase, and dextrose monohydrate (10 6 CFU were added per gram of fodder), and 3-SilOne additive containing L. buccaneri, L. plantarum, Enterococcus faecium, L. acidophilus, and Pediococcus acidi lactici, at the rate of 10 10 CFU/g along with multi-enzyme, which was mixed with water based on the amounts recommended by the manufacturer and added as a spray on chopped fodder.The experimental treatments were 1-pruned tomato shoot silage without additive, 2-pruned tomato shoot silage with enzymatic-siloLact additive, 3-pruned tomato shoot silage with non-enzymatic-SiloLact additive, and 4-pruned tomato shoot silage with SilOne additive.It is necessary to explain that in the preparation of silage, three replications were considered for each treatment.The measured chemical compounds included dry matter, crude protein, ash, crude fat, neutral detergent fibers, acid detergent fiber, and fermentation parameters including pH, volatile fatty acids, lactic acid, ammonia nitrogen, and soluble carbohydrates.Besides, gas production and digestibility were measured by in vitro Holden's method.This research was conducted in the form of a completely randomized design, and the resulting data were analyzed with SAS software.Results: The results obtained in the investigation of pruned tomato shoot silage showed that the microbial additive SilOne and enzymatic-SiloLact significantly affected the pH of the silage compared to the control treatment.The pruned tomato shoot ensiled with SilOne additive contained more dry matter and crude protein than the control treatment.the enzymatic-SiloLact and silovan additives reduced ADF compared to the control treatment.The amount of total volatile fatty acids and lactic acid increased in silage treatments with bacterial additive compared to the control treatment, but no significant difference was observed in this increase.Microbial addition of enzymatic-SiloLact and SilOne decreased the amount of ammonia nitrogen in silage compared to the control treatment.The highest volume of gas production was recorded in the treatments ensiled with enzymatic-SiloLact and SilOne at the final hours of the incubation with a significant difference (P < 0.05).By examining metabolizable energy, net energy for lactation, digestible organic matter, and short-chain fatty acids of untreated and treated tomato shoot silage, it was found that processing by microbial additives did not affect metabolizable energy, but net energy for lactation, digestible organic matter, and short-chain fatty acids were affected