الفهرس | Only 14 pages are availabe for public view |
Abstract This study was carried out to investigate the effect of using oral dose of L-tyrosine on some productive and reproductive performance of female New Zealand White (NZW) rabbits and growth performance of the offspring as well. Sixty five immature females (two months old) were randomly distributed into five equal groups according to interval doses of L-tyrosine (100 mg/kg BW). The 1st group (control) was served as a control (no treatment), while the 2nd group (TR1) was given a single dose of L-tyrosine at two months of age, the 3rd (TR2) was given two doses at 2 and at 4 months of age, the 4th group (TR3) was given three doses at 2, 4 and at 6 months of age and the last group (TR4) group was given four doses at 2, 4, 6, and at 8 months of age. Treatment was administrated orally after dissolving L-tyrosine dose in water. The results revealed that the administration of L-tyrosine at 2 months of age with single dose (100 mg/kg LBW) improved significantly sexual receptivity rate, doe receptivity time (sec), the conception rate, kindling intervals (days), milk yield, economic efficiency, average of total litter size and their weights at birth and at weaning. Also increased levels of progesterone and estradiol hormones in treated does compared with control. A single oral dose of L-tyrosine (100 mg/kg LBW) at two months of age maximized the productive and reproductive performance of NZW rabbits under commercial production condition. |