نوع مقاله : مقاله کامل علمی- پژوهشی
نویسندگان
1 گروه علوم دامی، دانشکده علوم دامی و صنایع غذایی دانشگاه کشاورزی و منابع طبیعی خوزستان
2 دانشجوی کارشناسی ارشد ژنتیک و اصلاح نژاد دام -گروه علوم دامی –دانشکده علوم دامی و صنایع غذایی -دانشگاه علوم کشاورزی و منابع
3 دانش آموخته دکتری ژنتیک و اصلاح نژاد دام- گروه علوم دامی –دانشکده علوم دامی و صنایع غذایی -دانشگاه علوم کشاورزی و منابع طبیعی خوزستان
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Objective: Sheep production, as a fundamental component of the livestock industry, plays a vital role in supplying animal protein worldwide. Growth efficiency and productive performance are key factors determining profitability in this sector. The leptin–melanocortin system (LMS) acts as a major regulatory pathway that governs energy balance, appetite, and body metabolism. The leptin gene, a central element of this system, influences feed intake, energy homeostasis, and lipid metabolism, thereby affecting growth and nutritional status in animals. Recent studies have demonstrated that supplementing diets with unsaturated fatty acid sources such as calcium salts of flaxseed oil can enhance energy utilization and modulate the expression of growth-related genes, ultimately improving animal performance. Moreover, the organic zinc–methionine complex plays a significant role in protein metabolism, enzyme activity, and the regulation of growth and energy-associated hormones, contributing to improved daily weight gain and feed efficiency in ruminants. Therefore, this study aims to evaluate the combined effects of dietary supplementation with calcium salts of flaxseed oil and organic zinc–methionine on leptin gene expression in the liver and muscle tissues of sheep.
Method: In this study, forty-four male Arabic lambs aged two to three months were used in a 2×2 factorial experiment arranged in a completely randomized design. The experiment consisted of four dietary treatments with eleven replicates per group: (1) a basal diet without any supplement (control), (2) the basal diet supplemented with 0.083% zinc–methionine (equivalent to 100 mg Zn/kg DM), (3) the basal diet containing 3% calcium salts of flaxseed oil, and (4) the basal diet including both 3% calcium salts of flaxseed oil and 0.083% zinc–methionine. At the end of the 94-day feeding trial, three lambs from each treatment were slaughtered, and liver and muscle samples were collected for leptin gene expression analysis. The collected tissues were immediately frozen in liquid nitrogen and stored at −80°C until further molecular assays. Total RNA extraction and cDNA synthesis were performed according to the manufacturer’s protocols of commercial kits. Leptin gene expression was quantified by the real-time qPCR, with GAPDH used as the reference gene. Relative gene expression levels were calculated using the 2−ΔΔCT method. The obtained data were statistically analyzed using SAS software (version 9.4), and treatment means were compared by the LSD test.
Results: The results indicated that dietary supplementation with calcium salts of flaxseed oil significantly downregulated leptin gene expression in the liver (P < 0.01), while no significant effect was observed in muscle tissue (P > 0.05). In contrast, the inclusion of zinc–methionine significantly increased leptin gene expression in both liver and muscle tissues (P < 0.01). Moreover, the combined supplementation of zinc–methionine and calcium salts of flaxseed oil did not cause any significant alteration in leptin gene expression compared with the control group (P > 0.05).
Conclusions: The overall findings of this study demonstrate that the type and combination of dietary supplements can markedly influence the genetic regulation of energy metabolism in sheep. The observed downregulation of leptin gene expression following omega-3 fatty acid supplementation, contrasted with its upregulation upon zinc–methionine administration, highlights the critical role of nutritional balance in modulating molecular pathways involved in growth and metabolism. Increasing leptin gene expression with zinc-methionine supplementation may help maintain energy balance and prevent excessive fat storage. At the same time, the calcium salt of flaxseed oil may promote fat storage by reducing leptin levels. The interaction between these two nutritional factors underscores the complexity of dietary regulation at the genetic and physiological levels and emphasizes the need for further investigations at molecular and systemic scales to better elucidate the underlying regulatory mechanisms.
کلیدواژهها [English]
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