This study has been carried out in Ninevah Research station at Al – Rashidia General Assembly for agriculture investigations, under supervision of department of animal production –college of Agriculture and forestry.
The study was started on July and continued to until December of the year. Thirty six clinically healthy Awasi weand female weaned lambs of four months age were used. They were divided randomly into four groups. The first group was considered as a control group. The second group was given two twise weekly 100-000 I.U. Vitamin A, the third group was given two twise weekly 55 mg of Vitamin E, and the fourth group was treated with 100.000 I.U Vitamin A and 55 mg Vitamin E two times weekly. All the animals were fed a concentrate ration which contained 13.7% protein and 2465 kcal/ kg metabolic energy.
Weights of the female lambs were taken monthly up to nine months of age. At the fifth months, blood samples were taken from monthly from the jugular vein of the fasted animals, and the following parameters were measured taken to study the main levels of follicle-stimulating hormone (FSH) Luteinizing hormone (LH) and progesterone hormone.
At the seventh months of age the rams were used to the estrus was detect, lambs showed the first estrous was registered and its weight was taken. (weight at puberty).
The result revealed the following:
1- The mean weight of the weaned female lambs was 23.4 kg.
2- First estrus (puberty) was detected at seven month of age in groups of vitamin A, vitamin E and vitamin A and E during the period 26/10/2005 to 8/11/2005. Results also showed that, there were an improvement of conception rate in the group treated with both vitamin A and E (66.66%) followed by group of vitamin A (44.44%), while the control group showed a less conception rate (22.22%) followed by group of vitamin E (11.11%).
3- Results revealed also, that the age at puberty was seven months in the groups treated with vitamin A, vitamin E and vitamin A and E. whereas, the age at puberty in control group was eight months.
4- Results also showed that lambs body weights at puberty were 37.87, 35.05, 36.85 kg for groups of vitamin A, Vitamin E and vitamin A and E respectively. Where as the body weight of control at puberty was 34.12 kg.
5- All treated groups with vitamin A vitamin E and vitamin A and E. showed significant increase (p<0.05) in their body weight at ninth month of age (43.69, 43.33, 43.44 kg) as compared with control group (39.50 kg).
6- Statistical analysis of the data obtained from the all the groups, showed significant (p<0.05) of Vit E group on FSH level (0.7980 nanogram/ml plasma from the group treated with vitamin A and control and nanogram/ml. No such differences were obtained in the sixth, eighth and ninth months of age. However, group of vitamin E also showed significant differences (p<0.05) in LH level (1.8532 nanogram/ml plasma) as compared with group of vitamin A and control (0.0660 and 0.0482 nanogram/ml plasma).
Results also showed that group of both vitamins A and E had significantly (p<0.05) higher LH level (0.5264 nanogram/ml) than that of vitamin A (0.213 nanogram/ml). No such differences in LH levels were obtained in sixth and eight month of age. Results also showed a significant differences (p<0.05) in progesterone level of group treated with vitamin A vitamin E and group treated with both vitamin (1.2842, 1.5096, 1.1371 nanogram/ml) respectively. As compared with control 0.7378 nanogram/ml in the seventh month, however, group of animals treated with A and E and group treated with vitamin A, showed a significant (p<0.05) increase in their progesterone level. (3.3628, 2.53 nanogram/ml) as compared with group of vitamin E and control (0.2886, 1.1779 nanogram/ml) respectively.