كليدواژه :
بره , روي پروتئينات , روي سولفات , روي گلايسينات , روي متيونين
چكيده فارسي :
آزمايشي به منظور بررسي اثر منابع مختلف مكمل هاي آلي و معدني روي بر عملكرد رشد، فراسنجه هاي هماتولوژي، پروفيل مواد معدني و ليپيدي خون در بره هاي پرواري به صورت طرح كاملاً تصادفي انجام شد. تعداد 30 رأس بره نر با سن 5-4 ماه و ميانگين وزن بدن 2/8 ± 30/8، به طور تصادفي به 5 گروه تقسيم شدند. تيمارها شامل: 1- جيره غذايي پايه بدون مكمل روي (حاوي 19/72 ميلي گرم روي در كيلوگرم ماده خشك)؛ 2- جيره پايه بعلاوه 30 ميلي گرم روي به ازاء هر كيلو گرم ماده خشك به شكل روي متيونين؛ 3- جيره پايه بعلاوه 30 ميلي گرم روي به ازاء هر كيلوگرم ماده خشك به شكل روي پروتئينات؛ 4- جيره پايه بعلاوه 30 ميلي گرم روي به ازاء هر كيلو گرم ماده خشك به شكل روي گلايسينات و 5- جيره پايه بعلاوه 30 ميلي گرم روي به ازاء هر كيلو گرم ماده خشك به شكل روي سولفات بودند. اين آزمايش 70 روز به طول انجاميد. ميزان ماده خشك مصرفي روزانه، افزايش وزن روزانه و ضريب تبديل خوراك تعيين گرديد. ميانگين افزايش وزن روزانه و ماده خشك مصرفي براي همه گروه هاي تغذيه شده با مكمل روي بالاتر از گروه شاهد بود و ضريب تبديل نيز بهبود پيدا كرد. علاوه بر اين، فراسنجه‌هاي خوني در روزهاي صفر، 35 و 70 آزمايش مورد ارزيابي قرار گرفت. غلظت روي و هموگلوبين و تعداد گلبول هاي قرمز و سفيد خون با افزودن روي به جيره بطور معني داري افزايش يافت، اما در بين تيمار هاي دريافت كننده مكمل اختلاف معني داري وجود نداشت. غلظت آهن پلاسما به طور معني داري در بره هاي دريافت كننده سولفات روي نسبت به گروه شاهد كاهش يافت. در بين تيمار ها از نظر غلظت پلاسمايي مس، كلسيم، فسفر، تري گليسيريد، كلسترول و ليپوپروتئين ها (شامل HDL، LDL و VLDL) اختلاف معني داري وجود نداشت. به طور كلي مي توان نتيجه گرفت كه استفاده از مقدار 30 ميلي گرم روي در كيلوگرم ماده خشك از منابع روي متيونين، روي پروتئينات، روي گلايسينات و روي سولفات سبب بهبود عملكرد رشد، ميزان روي پلاسما و فراسنجه هاي هماتولوژي در بره هاي پرواري تغذيه شده با جيره پايه حاوي 19/72 ميلي گرم روي در كيلوگرم ماده خشك شد.
چكيده لاتين :
Introduction 1 The role of trace minerals in animal production is an area of strong interest for producers, feed
manufactures, veterinarians and scientists. Zn (Zn) is one of the most important elements that has been
recognized as an essential catalytic factor for more than 300 enzymes enzyme. Zinc also has an essential role
in metabolism of nucleic acids, proteins, lipids, and carbohydrates. The National Research Council (1985
and 2007) recommended about 30 mg/kg zinc for ewes and growing lambs. However, the soil status and zinc
concentration in native plants are also affected. In many regions of Iran, the Zn content of soil and plants is
commonly low (less than 0.8 mg/kg). As a result, health and performance of animals reared on mainly
homegrown roughage and grains may be affected as a consequence of nutritional deficiency. Recently, the
use of organic sources of mineral supplements (complexes, chelates and proteinates) has increased.
However, the results of organic and inorganic sources in ruminants are contradictory. Furthermore, few
studies have investigated the effect of zinc on lipid parameters in ruminants. Therefore, the aim of the
present study was to compare the effect of supplementation of 30 mg/kg Zn from the three organic sources
and conventional inorganic source on performance, hematological parameters and mineral profile of
Mehraban growing lambs.
Materials and Methods Thirty male lambs with 4-5 months of age and 30.8±2.8 kg average in weight
randomly allotted to 5 groups. Treatments were: 1) Basal diet without zinc supplement (containing 19.72
mg/kg DM zinc); 2) Basal diet+30 mg/kg DM zinc as zinc methionine; 3) Basal diet +30 mg/kg DM zinc as
zinc proteinate; 4) Basal diet +30 mg/kg DM zinc as zinc glycinate, and 5) Basal diet +30 mg/kg DM zinc as
zinc sulfate. This trial lasted for 70 days. The dry matter intake, daily gain and feed conversion ratio were
determined. Blood samples were taken on days 0, 35 and 70 before the morning meal. Chemical composition
of experimental samples including (crude protein, neutral detergent fiber, acid detergent fiber, and dry
matter) and blood parameters including (hematological, mineral and lipid profiles) were measured according
to standard methods. This experiment was analyzed in a completely randomized design.
Results and Discussion Average daily gain and dry matter intake for all groups fed the supplement were
significantly higher than control group and feed conversion ratio also improved (P<0.01). Lambs fed basal
diet with no Zn supplement received lower Zn (19.72 mg Zn/kg) than their requirements and considering the
effect of Zn on gene expression, protein synthesis, enzyme activity and immunity, it was expected to be
decreased in performance of control group. Plasma concentrations of zinc and hemoglobin, red blood cells
and white blood cells count significantly increased with zinc supplementation (P<0.01). The reason might be
due to higher fragility of erythrocytes and the blockage of protein synthesis in control group. However, there
were no significant differences between the supplemented treatments for these parameters (P>0.05). Due to
inhibitory effect of inorganic zinc on iron absorption, plasma iron concentration in lambs receiving zinc
sulfate significantly decreased compared to the control group (P<0.05). There was no difference among
treatments (P>0.05) for plasma copper, calcium and phosphorus, triglyceride, cholesterol and lipoproteins
(HDL, LDL and VLDL).
Conclusion It may be concluded that 30 mg/kg DM zinc supplementation as zinc methionine, zinc
proteinate, zinc glycinate and zinc sulfate improved growth performance, plasma zinc level and
hematological parameters of fattening lambs fed basal diet containing 19.72 mg/kg DM zinc. There were no
differences among treatments supplemented with organic sources of zinc. However, plasma iron
concentration decreased significantly in lambs supplemented with zinc sulfate.
