عنوان مقاله [English]
Introduction: The use of agricultural and food industry by-products in animal feed leads to a reduction in breeding costs and on the other hand, the use of agricultural waste in poultry feed also reduces the environmentally harmful effects (Persia et al., 2003). One of these by-products is pistachio green peel, which is produced in food industries. Common pistachio (common pistachio in the market) with the scientific name Pistacia vera is a plant of the genus Anacardiaceae. Iran is the world's largest pistachio producer with 58% of the world's pistachio production. Research has shown that about four hundred thousand tons of pistachio by-products are produced annually in Iran and large volumes in the harvest season and high humidity of these products cause environmental pollution and pistachio orchards (Bohloli Ghaen et al., 2010). Pistachio green peel has a parenchymal and fibrous structure and contains water, sugars, proteins, fats, minerals, vitamins, color compounds and terpenes (Vahmani et al., 2006). Green pistachio skin contains 4425.45 Kcal/kg of gross energy, 32.64% of dry matter, 11.24% of crude protein, 15.38% of crude fiber, 13.13% of ash, 5.79% of ether extract, 1.08 of calcium, 0.11% of phosphorus, 0.31% of magnesium, 4.44% of potassium. The concentrations of iron, manganese, copper and zinc in pistachio green peel are 660.68, 23.6, 16.23 and 5.27 mg/kg, respectively. There are significant amounts of alpha-pinene, alpha-terpinolene, flavonoids and phenolic compounds (Chahed et al., 2007; Alizadeh & Rostaazad, 2003). Food sources rich in phenolic compounds have a set of physiological properties including antioxidant (Rajaei et al., 2010), antimicrobial (Periera et al., 2007), anti-mutagenicity (Duarte et al., 1999), lipoprotein oxidation inhibitor and have platelet aggregation (Kay, 2002), anti-inflammatory activity (Wang et al., 1999) and strengthen the immune response (Tangestani et al., 2011). The use of pistachio green peel extract improved the growth performance of broiler chickens, blood lipids and abdominal fat (Yousefi et al., 2018). The use of pistachio green skin extract in the diet of broiler infected with Staphylococcus aureus improved growth performance, increased antibody titer against sheep erythrocytes, decreased blood lipids and microbial population of the gastrointestinal tract of broilers (Hosseini Vashan et al., 2020). Therefore the aim of this research was to investigate the effect of Green Pistacia of kallequchi and its processed with urea on growth performance, blood indices, immune response and jejunum morphology of broiler chickens.
Material and methods: A total of 280 male broilers were randomly distributed in 28 experimental units including 7 treatments, 4 replicates and 10 chicks each. The experimental diets consisted of the levels of 0, 1.5, 3, and 5% of the raw and processed green hull of kallequchi pistachio. The broilers were fed with three dietary programs including starter (1-10 days), grower (11-24 days), and finisher (25-42 days). At the end of each period, the body weight gain and feed consumption were recorded and the feed conversion ratio was calculated. Two birds of each replicate were slaughtered and their blood was gathered to analyze the biochemical blood indices at 42 days of age. The data were analyzed with SAS software and the mean was compared with the Tukey test at 0.05.
Results and Discussion: The addition of green hull of pistachio and its processed to diets cause a decrease in the feed conversion ratio during the starter and the whole period of the experiment (P≤0.05). In the starter period, adding 3% of the green hull of the pistachio increased the body weight gain compared to the control (P <0.05). The pistachio green hull increased total antibody and immunoglobulin G antibody titer against sheep red blood cells compared to control (P≤0.05). Experimental diets decreased serum cholesterol and LDL concentrations compare to control (P≤0.05). The green hull of kallequchi pistachio and its processed increased the villus height and decreased villus width and the ratio of height to crypt depth compared to the control (P≤0.05). Different levels of kallequchi pistachio green hull and its processed increased relative weight of the breast, heart, burs fabricius and decreased abdominal fat compared to control (P≤0.05). The same findings were reported by researchers that pistachio green hull extract decreased blood lipids and increased the immune response of broiler chickens (Yousefi et al., 2018; Hosseini Vashan et al., 2020).
Conclusion: It is concluded that adding green hull of kallequchi pistachio up to 5% into broiler diets may improve growth performance, however, the addition of 3% could reduce cholesterol, FCR and improve the immune response of broiler chickens.