author(s)
Nadar Khan, Shoaib Sultan, Sadiq Shah, Javid Ali, Shah Murad Khan, Ihsanuddin and Jauhar Ali Khan

abstract
The aim of the study was to determine the effect of different dietary energy levels on dry matter intake, reproductive hormonal profile body weight, condition score and blood metabolites of early lactating Friesian cows. Nine early lactating cows of nearly the same body weight (410±10) and score (2.70±0.10) were selected from the university dairy farm and randomly divided into three groups with three animals in each group under completely randomized design. Ration were formulated being iso-nitrogenous (CP 16%) and different in dietary Metabolizable energy (ME) levels, viz; (i) NRC100% (2.75Mcal/kg ME),(ii) NRC(-12)% low ME (2.57Mcal/kg) and (iii) National Research Council (NRC +12%) high (2.93Mcal/kg). Significantly higher dry matter intake (P<0.05) was recorded for group +12% ME (13.78±0.17kg/day), followed by NRC 100% (13.14±0.12 kg/day) and NRC -12 was (12.68±0.11kg/day) recorded. Loss in body weight was decreased (p<0.05) with increasing dietary ME level in the diet from 2.57 to 2.93Mcal/kg ME and overall gain in body weight and condition score was improved in group NRC +12% than other groups. Results of blood metabolites show that blood glucose level was significantly increased with increased in energy level whereas blood urea nitrogen levels showed (p<0.05) decrease with increase in energy level of ration. It was concluded that diets containing high dietary energy (12%) above than the NRC recommended level for early lactating cows conferred in an increase in intake, improved the body score, body weight gain and managed the optimum level of blood metabolites which may result good health, fertility and productivity parameter of dairy cattle.