تأثيرجيره‌هاي حاوي فرآورده هاي فرعي پسته¬ي تيمار شده با بيم الكترون، سود و پلي¬اتيلن گلايكول بر قابليت هضم و عملكرد بره¬هاي پرواري زندي

The effect of diets containing pistachio by products treated with electron irradiation, NaOH, and PEG on nutrients digestibility and performance of finishing Zandi lambs

به منظور بررسی تأثیر فرآورده های فرعی پسته¬ی تیمار شده با بیم الكترون، پلی¬اتیلن¬گلایكول و هیدروكسید سدیم بر عملكرد و قابلیت هضم بره‌های پرواری، آزمایشی در قالب طرح كاملاً تصادفی با استفاده از 20 رأس بره نر زندی (52/1±21 كیلوگرم) به مدت 70 روز انجام شد. جیره¬های آزمایشی شامل جیره شاهد (حاوی 22 درصد فرآورده های فرعی پسته، تیمار 1) و جیره حاوی فرآورده های فرعی پسته¬ی تیمار شده با بیم الكترون (دز 30 كیلوگرم، تیمار 2)، هیدروكسید سدیم (چهار درصد، تیمار 3) و پلی¬اتیلن¬گلایكول (15 گرم در كیلوگرم، تیمار 4) بود. میانگین افزایش وزن و خوراك روزانه مصرفی جیره حاوی فرآورده های فرعی پرتوتابی شده بیشتر از سایر تیمارها بود. ضریب تبدیل بهتر در تیمار سود و پرتوتابی مشاهده شد. بیشترین مقدار قابلیت هضم ماده آلی در تیمار پرتوتابی شده (18/81 درصد ماده خشك) و كم¬ترین در تیمار سود (22/72 درصد ماده خشك) مشاهده شد. استفاده از پرتوتابی و پلی¬اتیلن¬گلایكول سبب افزایش قابلیت هضم پروتئین خام شد. قابلیت هضم الیاف نامحلول در شوینده خنثی در تیمار پرتوتابی شده نسبت به سایر تیمارها بیشتر بود. نتایج این آزمایش نشان داد كه استفاده از فرآورده های فرعی پسته تیمار شده با بیم الكترون باعث بهبود عملكرد و قابلیت هضم در بره¬های پرواری زندی می شود.

Introduction It has been estimated that PBP production based on fresh weight in Iran is over 400,000 MT annually. Pistachio by-products consist of 53.50% external hull (epicarp) with the remaining composed of leaves, mesocarp and kernel. The results of few studies showed feeding of low levels of PBP had no effects on sheep, dairy cow and goat performance. Ensiled of PBP with PEG, NaOH and urea then treated by electron irradiation could be caused to better nutrition value via deactivation of tannins. The aim of this study was to survey the effect of diets containing pistachio by products treated by electron irradiation, NaOH, and PEG on nutrients digestibility and performance of finishing Zandi lambs. Materials and methods Twenty male Zandi lambs with the initial average body weight of 21±1.52 kg were housed in individual pens and were allocated to four dietary treatments in a completely randomized design for 70 days. The basal diet consisted of 220 g/kg DM PBP, 130 g/kg DM wheat straw and 650 g/kg DM barley based concentrate. The four dietary treatments included control diet (Treatment 1; basal diet containing 22% PB), ER-PBP (Treatment 2; containing 22% electron irradiated PBP), NaOH-PBP (Treatment 3; containing 22% NaOH treated PBP) and PEG-PBP (Treatment 4; PEG added to basal diet as 15 g/kg of diets DM). Throughout the 70 d experiment, body weight was measured weekly. Feed intake and ort of lambs were recorded and sampled daily for determination of nutrient intake of DM, CP (N × 6.25), EE and NDF as describes before. Apparent total digestibility of nutrients was estimated by the marker ratio technique using acid insoluble ash (AIA) as an internal marker. Blood samples (10 ml) were taken from jugular vein of lambs before morning feeding on d 70 of experiment. The serum concentrations of total protein (TP), albumin, creatinine, glucose and urea were determined using commercial laboratory kits (Pars Azmun Laboratory, Tehran, Iran) and an auto analyzer. The data were analyzed as completely randomized design. Duncan’s multiple range tests were used to determine the differences amongst treatments. Significant levels were defined as those with probabilities of 0.05 or less. Results and Discussion Nothing as the effects of dietary treatments were observed on FBW. Feeding ER-PBP diet to lambs tended to increase DMI and also increased (P < 0.01) weight gain and average daily gain compared to other treatments and control group. Inclusion of ER-PBP into the diets of lambs decreased (P < 0.01) FCR compared to control and other diets. Irradiation of PBP increased (P < 0.01) digestion of diets DM and CP compared to the control group. Digestion of EE and NDF was increased (P < 0.01) in ER-PBP and NaOH-PBP diets. Serum levels of true protein (TP) was increased (P < 0.01) in lambs fed PEG-PBP diets compared to other groups. Conclusion It can be concluded that irradiation of pistachio by-product is a useful treatment to improve nutritional value of pistachio by-product as a feed ingredient for sheep. Further studies are necessary to evaluate the effects of other physicochemical treatments of PBP on lamb performance and to evaluate the economic value of including PBP in ruminant diets.