Abstract

This experiment was conducted in the sheep farm of Department of Animal Production, College of Agriculture, University of Anbar, during the period of 17/10/2021 to 9/1/2022. Sixteen local male lambs were chosen between 5-6 months of age and 35.31 ± 3.72 kg of average body weight. The aim of the experiment was to determine the effect of melatonin implants and nutritional restriction on some blood biochemical parameters of local male lambs. The experimental period lasted for 69 days, the experiment involved two phases, feed restriction phase (42 days), and realimentation phase (27 days). Lambs were randomly distributed into four equal groups with four lambs of each. During the restriction phase, first group (T1) was used as a control and feed ad libitum. The second group (T2) was feed ad libitum and treated with two implants of melatonin (36mg) subcutaneously at the base of the ear. The third group (T3) was feed restriction 75% of ad libitum intake. The fourth group (T4) was feed restriction 75% of ad libitum intake and treated with two implants of melatonin subcutaneously at the base of the ear. Blood samples were collected from all treated groups at day 0, 42 and 69 for the measurement the level of glucose, total protein, triglyceride, aspartate aminotransferase (AST), alanine transaminase (ALT) and malondialdehyde (MDA) in the plasma. The results restricted feeding, with or without melatonin, did not affect significantly on blood biochemical parameters, while it was observed that the restricted feeding with or without melatonin significantly reduced the level of malondialdehyde. It was concluded from this experiment that feeding local male lambs at a level of 75% of ad libitum  with or without melatonin implants for 42 days followed by realimentation for 27 days improved oxidative status in male lambs.