This investigation included two experiments. Experiment 1 was executed to study the effect of feeding different rations of protected protein of canola meal on digestibility and nutritive values within sheep. Twenty male, healthy sheep were divided into five treatments according to the methods of protein protection (control, heat, sodium hydroxide, formaldehyde, and acetic acid treatments). Experiment 2 was carried out on developing lambs to investigate the effect of protected protein on growth performance and some blood metabolites. Animals in this ex-periment were also divided into the same treatments as Experiment 1. Animals in the first and second experiment were fed concentrate ration (80%) and wheat straw (20%) to cover the feed requirements. Nutritive values expressed as total digestible nutrients (TDN %) and digestible crude protein (DCP%) of the experimental rations was calculated. In the second experimental all animals were weighed biweekly and the amounts of rations were adjusted throughout the experimental period (120 days) according to their body weight change. Results indicated that in the first experimental protected protein by heat (HE) and sodium hydroxide (NH) had positive (P<0.05) effects on most of digestibility coefficients of different nutrients. Protein protection methods also improved (P<0.05) the nutritive values (TDN and DCP) in the HE treatment and NH treatment. In the second experiment body weight increased by 14% and 7% and also daily gain by 27% and14 % in HE and NH, respectively, while FM and AC decreased body weight by 8% and 4.4%. Higher values (P<0.01) in both thyroid hormones were observed in HE and NH than those other treatments. Also, higher values (P<0.01) of total protein, albumin, and glucose were observed in HE and NH than other treatments. The control (CTL) group recorded higher concentrations of urea-N and creatinine at different periods of the experiment in comparison with other treatments. Generally, from the present investigation it can be concluded that protected protein of canola meal by heat or sodium hydroxide treatments were more efficient for productive performance and some blood metabolites of sheep