اثر جايگزيني كاه ماش (Vigna radiate) با كاه گندم يا سيلاژ ذرت كم‌دانه بر قابليت هضم و برخي فراسنجه‌هاي خوني و شكمبه‌اي بره ميش‌هاي عربي

Effect of replacement of the mung bean straw (Vigna radiate) with wheat straw or low grain-corn silage on digestibility and some blood and ruminal parameters in Arabi lambs

زمينه مطالعاتي: به منظور كاهش هزينه خوراك مي‌توان از بقاياي حاصل از مزارع كشاورزي نظير كاه ماش در تغذيه دام استفاده كرد. هدف: آزمايش حاضر به منظور بررسي اثر جايگزيني كاه ماش با كاه گندم يا سيلاژ ذرت بر قابليت هضم، تخمير و جمعيت پروتوزوآي شكمبه در بره ­هاي نژاد عربي انجام گرفت. روش كار: پس از تعيين سطح مناسب جايگزيني كاه ماش با كاه گندم و سيلاژ ذرت با استفاده از آزمون توليد گاز، تعداد 16 بره ميش با جيره‌هاي آزمايشي برگزيده از مرحله اول شامل جيره فاقد كاه ماش (شاهد)، 100 درصد جايگزيني كاه ماش بجاي كاه گندم (جيره 1)، 25 درصد جايگزيني كاه ماش بجاي سيلاژ ذرت (جيره 2) و 50 درصد جايگزيني كاه ماش بجاي سيلاژ ذرت (جيره 3) در قالب طرح كاملا تصادفي تغذيه شدند. جهت برآورد فراسنجه‌هاي خوني، تخميري و شمارش جمعيت پروتوزآهاي شكمبه، سه و چهار ساعت پس از خوراك‌دهي صبح از بره‌ها به ترتيب مايع شكمبه و خون‌ گرفته شد. نتايج: در آزمايش تعيين سطح، با جايگزيني كاه‌ماش با كاه‌گندم در جيره، براي تمام سطوح (25 تا 100 درصد) پتانسيل توليد گاز نسبت به شاهد افزايش يافت (0/05>P). مقدار 25 درصد جايگزيني كاه ماش بجاي سيلاژ ذرت نسبت به جيره شاهد توليد گاز را افزايش و 100 درصد جايگزيني آن را كاهش داد (0/05>P). بازده توليد توده ميكروبي در تمام جيره­هاي حاوي كاه ماش جايگزين شده با سيلاژ ذرت نسبت به جيره شاهد بيشتر بود (0/05>P). نتايج حاصل از آزمايش روي دام نشان داد كه بيشترين مصرف خوراك و قابليت هضم مواد مغذي مربوط به جيره 1 بود (0/05

18 مهرام ي ر ي ، چاج ي ... و نشريه پژوهش هاي علوم دامي/ جلد 2 7 شماره 3 / سال 1396 Effect of replacement of the mung bean straw ( Vigna radiate ) with wheat straw or low grain - corn silage on digestibility and some blood and ruminal parameters in Arabi lambs I Mehramiri 1 , M Chaji 2* , S Tabatabai Vakili 2 , T Mo hammadabadi 2 and M Sari 2 Received: 24 December 201 5 Accepted: 17 September 201 6 1 MSc Graduated Student, Department of Animal Science, Faculty of Animal Sciences and food industries, Ramin Agriculture and National Resources University of Khouzest an, Molasani, Ahvaz, Iran 2 Associate Professors, Department of Animal Science, Faculty of Animal Sciences and food industries, Ramin Agriculture and National Resources University of Khuzestan, Ahvaz, Iran * Corresponding author: Email: chaji@ramin.ac.ir In troduction : The dry and semi - arid climates and the deficiency of rainfall in Iran have led to increasing the nutrition cost, which will be affected the incomes of animal farm er s. In recent decades, demand for livestock products (like meat and milk) has gro wn because of population growth and economic progress. In order to reduce feed costs, in ma ny countries, crop residues are used as agricultural by - product in feeding of farm animal, includ ing mung bean straw. Mung bean is a plant that has been cultivated i n the arid and semi - arid regions of Iran and elsewhere in the Middle East. This plant is important because of the ability to stabilize nitrogen in the soil, to strengthen and prevent its erosion. Most of the nutrition studies that have been done in relatio n to mung beans have been more focused on mushy seed, but few studies have been conducted on mung bean straw. Therefore, t he present experiment was conducted to study the effects of replacing mung be a n straw with wheat straw or corn silage on digestibility , rumen fermentation and protozoa population in Arabic lambs. Material and methods: The present experiment was conducted in two steps. The first step was to determine the appropriate level of replacing the mung bean straw with wheat straw or corn silage i n the diet using a gas production te chnique . In the second step, by examining the results of the first stage of the experiment, some levels of replacing mung bean straw instead of wheat straw and corn silage were selected and digestion and metabolism of di ets were investigated. After determining the appropriate level of replacing mung bean straw with wheat straw and corn silage in diet, 16 lambs fed with selected diets from first step . The experimental diets included: diet without mung bean straw (control r ation ), 100% replacing of mung bean straw with wheat straw (ration 1) , 25 and 50 % replacing of mung bean straw instead of corn silage ( rations 2 and 3 respectively ) were fed in a completely randomized design. In order to estimate blood and rum i n al fermenta tion parameters, and protozoa population count at the end of the experiment, rumen fluid and blood was taken from the lambs 3 and 4 h after the morning feeding , respectively . R esults and discussion : Mung bean straw had a higher crude protein and crude fa ts than wheat straw and more crude fat than corn silage. While the crude protein content of corn silage was higher than mung bean straw. Although no statistical analysis was performed, protein content, NDF, ADF, ME mung bean and corn silage had a slight di fference, but differences were considerable with wheat straw. Wheat straw had the highest amount of NDF, ADF and lignin and the lowest amount of crude fat and ME. Mung bean straw had the highest amount of fat . In one experiment, mung bean straw had 88.20% dry matter, 9.70% crude protein, 26.56% crude fiber, 2.39% crude fat and 11.43% ash in dry matter base (Khatik et al. 2007), the data of present experiment was closely same with them . Based on the results of chemical analysis, wheat straw or corn silage we re detected as a suitable replacement for mung bean straw in diet. In the first step of study, replacing mung bean straw with wheat straw in the diets, for all levels (25 to 100%) increased the potential of gas production (GP) compared to control ( P<0.05 ). T he diet contains 25% of replacing mung bean straw instead of corn silage increased and 100% replac ement decreased GP (P <0.05 ). Microbial bio mass production efficiency in all mung bean straw replaced with corn silage diets were higher compared to control ( P<0.05 ). The reason for the reduction of gas production in diet contain 100% mung bean straw replaced with corn silage , may be attributed to higher amounts of NDF (52.2%) and ADF (52.2%) in mung bean straw than corn silage. The researchers reported that t here is a significant negative correlation between NDF and ADF and the volume of produced gas (Haddi et al. 2003), and the negative effect of cell wall (cellulose, hemicellulose and lignin) on gas production can be due to decreased microbial activity. Howe ver, the data in Table 2 on the chemical composition of these products showed that there was difference for amount of lignin and fat between mung bean straw and the corn silage. Therefore , the reason for the decrease in gas production can be attributed to these factors. Fats, especially unsaturated oils, have a negative effect on fiber digestion by covering surface of fibers or cellulolytic bacteria . The results of in vivo study showed that ration 1 had the highest feed intake and nutrient digestibility (P< 0.05). The re was not difference for rumen ammonia nitrogen and blood parameters between diets (P >0.05 ). Only the rumen fluid pH in the diet 3 had significant difference with control and was the lowest amount (P<0.05). Rumen protozoan population was lower i n diets containing corn silage (rations 2 and 3) , as compared to control (P<0.05). C onclusion : Therefore, due to proper price and abundance of mung bean straw in some regions of the Iran included Khuzestan province , we can recommend using it as replacemen t for wheat straw or low - grain corn silage in feeding of sheep.