TY - JOUR JF - JSTNAR JO - jwss VL - 13 IS - 47 PY - 2009 Y1 - 2009/4/01 TI - Effect of Leptin Fluctuation on Parity, BCS and Reproductive Status in Dairy Cows TT - تغییرات میزان لپتین بر اساس نمره وضعیت بدنی و دوره شیردهی و اثر این تغییرات روی تولید مثل گاو شیری N2 - In dairy cattle, the increase in milk yield has been accompanied by a more negative energy balance during early lactation and a decrease in fertility. The 167 amino acid protein product of the ob gene was named leptin (derived from the Greek term ‘leptos’ meaning thin). The leptin hormone, as a 16-kDa protein is synthesized mainly by adipose tissue and is involved in regulation of food intake, energy balance, fertility and immune function. The expression and secretion of leptin are correlated with body fat mass and are acutely affected by changes in food intake. The objective of this study was to investigate the fluctuations of leptin concentrations during late pregnancy and early lactation, the effect of parity and BCS on plasma leptin concentration, and to investigate its fluctuation effects on reproductive status. Blood samples of 54 Holstein cows were taken at a fixed time of the day after milking but before feeding, from 2 weeks before calving until 6 weeks after calving. BCS and plasma leptin concentration were measured at 2-wk intervals. Leptin concentrations were affected by parity. Primiparous cows and cows in first parity had higher leptin concentrations compared with multiparous cows (P SP - 473 EP - 483 AU - Shrifi, S AU - Rahmani, H AU - Motamedi, M AD - KW - Leptin KW - Body condition score KW - Reproduction KW - Parity. UR - http://jstnar.iut.ac.ir/article-1-1069-en.html ER -