3584

3387

كارشناسي ارشد

علوم دامي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1385

هشت، 87،[II] ص: مصور، جدول، نمودار

ص.ع. به فارسي و انگليسي

حميد رضا رحماني

غلامرضا قرباني، محمد هاشم فاضلي

20/4/86

مسعود عليخاني، محمد فضيلتي

مهندسي كشاورزي

ID3387

به فارسي و انگليسي: قابل رويت در نسخه ديجيتال

AbstractIn dairy cattle the increase in milk yield has been accompanied by a more negative energybalance during early lactation and a decrease in fertility The 167 amino acid protein productof the ob gene was named leptin The leptin hormone as a 16 kDa protein is synthesizedmainly by adipose tissue and is involved in regulation of food intake energy balance fertilityand immune function The expression and secretion of leptin are correlated with body fat massand are acutely affected by changes in food intake The objectives of this study was toinvestigate the fluctuations of leptin concentrations during late pregnancy and early lactation effect of parity and BCS on plasma leptin concentration and to investigate it s fluctuationeffects on milk yield percentage of milk components and reproductive status Blood samplesof 54 Holstein cows were taken at a fixed time of the day after milking but before foodingfrom 2 weeks before calving until 6 weeks after calving BCS and plasma leptin concentrationwere measured at 2 wk intervals Leptin concentrations was affected by parity Primiparouscows and cows in first parity had higher leptin concentrations compared with multiparouscows p 0 05 Leptin concentration was not different in late pregnancy and early lactation BCS was negatively correlated with plasma leptin concentration p 0 05 Plasma leptinconcentration did not influence milk production and percentage of milk components fat protein and lactose as well as reproductive traits days in milk at first breeding service perconception and open days

حميد رضا رحماني

غلامرضا قرباني، محمد هاشم فاضلي

مسعود عليخاني، محمد فضيلتي