Document Type : Research Paper
This study was conducted in research department of animal resource / Al-Rashidiya, by using 21 of Awassi ewes in the last two months of gestation, ewes were divided according to their body weight, age and milk production during the previous season into three groups, daily feed intake in all groups was restricted with 1.5 kg / ewe on rations consist of barley, wheat bran, soybean meal, urea and straw. the first group was fed on ration contained barley untreated with formaldehyde (T1), while barley grain treated with formaldehyde in the ration of second group (T2), the third group fed on formaldehyde treated barley in late gestation and switch directly after lambing to the untreated barley (T3). Results indicated that differences was non-significant in colostrum yield 138±16.41, 163±19.26 and 127±19.43 g/ hr and in its components, milk yield was increased (P<0.05) in T2 1411±99.04 g/ day as compared with T1 and T2 1080±77.02 and 940±34.54 g/ day respectively, while no significant differences was noted in milk composition. Efficiency of protein and energy intake for milk production significantly higher (P<0.01) in T2 which were 26.42±2.01 and 42.24±3.55% compared to T1 (20.56±1.59 and 34.31±2.99%) and only in energy efficiency as compared with T3 which were (17.70±0.78 and 30.62±1.34%). Result of blood parameters after four week postpartum was indicated a significant (P<0.05) increase in cholesterol concentration in T1 69.60±4.85 mg/ dl compared to T2 and T3 56.55±3.67 and 54.73±3.99 mg/ dl, blood creatinine concentration decreased (P<0.05) in T3 5.03±0.53 mg/ dl as compared to T1 and T2 which were 9.60±0.77 and 9.35±0.53 mg/ dl respectively. In conclusion, reducing barley grain degradability improve feed efficiency and ewes performance, while the directly change of the feeding after lambing from low degraded barley to the normal barley grain had a negative effect in performance.