Effects of Restricted Feeding and Re-Feeding in Growing Lambs: Intake, Growth and Body Organs Development

About 48 Lori-Bakhtiari lambs were used to measure the effects of restricted feeding and re-feeding on intake, body weight and development of body organs. The feeding management was divided to Feed Restriction Period (FRP) and Re-alimentation Period (RAP). During FRP, the 18 Control (C) animals were fed a low-quality roughage, ad libitum and 40 g kg BW(-0.75) day(-1) of concentrate and the 30 animals were only fed low-quality roughage as the Restricted (R) group. At the end of FRP and RAP, six lambs of each group were slaughtered. In the RAP, the 24 remaining lambs from restricted treatment were divided into two groups of R1 and R2 and received low-quality roughage plus 40 and 48 g kg BW(-0.75) day(-1), of concentrate, respectively. During FRP, Dry Matter (DMI), Metabolizable Energy (MEI) and Crud Protein Intake (CPI), Daily Gain (ADG), Final Body Weight (FBW), pelt, liver and kidneys of C group were higher (p<0.05) than R group. In the RAP all groups had similar FBW but feed conversion ratio, DMI, MEI, CPI and weights of all body organs of C group were higher (p<0.05), however ADG was lower (p<0.05) than R1 and R2 groups. In general, restricted feeding following re-feeding lambs caused more efficiency of performance which was associated with lower maintenance requirements.