The experiment examined the effect of body weight, season of birth and GnRH injection i.v. (5 ug/kg body weight/animal 2-h intervals for 24 hours) on age at puberty and p4 concentration in 10 Rhamni ewe lambs six months of age with mean body weight 19.88 ± 0.78 kg. This study started on June 20, 2001 and continued until the expected time of puberty in the Farm of Animal Production Department, Faculty of Agriculture, Al-Azhar university, Assiut. The ewe lambs were divided at random into two equal groups. The first group included three lambs born in autumn and two ewe lambs born in winter and this group was considered as control (Ctrl). The second group also involved three ewe lambs born in autumn and two ewe lambs born in winter and this group was treated by GnRH i.v. injection and considered as treated ewe lambs (Tr.). After GnRH injection , two fertile rams were allowed to remain with each group for half an hour/day for estrous detection. All ewe lambs were fed the same ration with 11 % crude protein and 12 % ash. Each animal was given 750 g dry matter/daily of the ration which consisted of yellow corn , wheat straw, wheat bran and decorticated cotton seed meal. Green fodder, water and mineral blocks were freely available throughout the experiment. Blood samples were collected from the ewe lambs starting from June 20,2002 and the expected time of puberty . Blood (5 ml) was drawn from the jugular vein twice a week. Blood serum was separated and stored at -20 oC until assayed for P4. When the P4 concentration reached the peak for the first time over 1.0 ng/ml blood serum, this was taken as the occurrence of puberty. Results indicated that the difference between body weight of ewe lambs treated with GnRH and the Ctrl. Lacked significance. The overall mean of Rahmani body weight at puberty represented 38-42 % of the adult body weight . There was no significant difference between the two groups in age at puberty. Most treated lambs displayed higher P4 concentration than control lambs. Season of birth had also a highly significant effect (P0.01) on P4 concentration. The first peak of serum P4 (over 1.0 ng/ml) concentrations occurred 99 days after the beginning of GnRH treatment, while the second peak of over 1.0 ng/ml) concentration occurred 90 days after the first peak of P4. Treated lambs born in winter achieved the first peak of P4 concentration much earlier than control lambs born in autumn. So, GnRH was more effective in lambs born in winter than those born in autumn in accelerating the time of puberty in Rahmani ewe lambs

Abstract Adult Damascus does (n=18) were used in this experiment to investigate the relationship of Damascus’s does estrous activity (EA) to body weight (BW), body measurements (BM) and progesterone profile (P4) across seasons. Results indicated that season had significant effects on estrous activity, P4 level, BW and BM. Estrous percentage, estrous duration (ED), normal estrous cycle (EC), and P4 concentration decreased significantly with decreasing BW and some BM. ED increased with increasing normal EC. Short and long EC increased respectively in autumn and summer. P4 levels varied significantly among the three EC types and was influenced significantly by season during pro-estrus and di-estrus phases. Positive correlations occurred between (P4 level, ED and EC) and (BW and some BM). Conclusion, BW and some BM may be used as good criteria in raising the reproductive performance of farm animals, further, Damascus does displayed their maximal hormonal and estrus activity in autumn and winter.

Abstract: Goats are seasonally polyestrous having estrous activity during late summer, fall, and winter and showing no activity during summer and spring. The objective of the present study was to improve reproductive performance of Damascus doe goats in early summer including: estrous activity (EA), ovarian follicular (OF) growth, corpus luteum (CL) development, and progesterone (P4) profile by injection of glucose (Glu). A total of twelve apparently healthy Damascus doe goats were used in this experiment and were classified randomly into two equal groups. Animals in group A were injected by Glu via j.v.; each animal of the treated group received 94.584 g Glu daily for nine days before the expected day of ovulation. The second group (B) was injected with saline solution and used as control. All animals in both groups were synchronized by PGF2α (cloprostenol) three times (10 days between each interval and other) with notice that Glu was injected in the second interval. Blood samples were collected from each animal; the blood was then centrifuged and the serum was analyzed for P4 determination. All does were subjected to ultrasonographic examination on days 5, 9, and 19 after the third injection of PGF2α and post-treatment by Glu. The results revealed that Glu injection achieved estrous activity higher than in the control (100% vs. 50 %, p>0.05). All animals showed the estrous activity through 24-72 hours after each dose of PGF2α and post-treatment by glucose. The number of follicles (≤5mm) in the treated group was higher than in the control group (111 vs. 94 follicle, p>0.05), while the follicular diameter did not differ between the two groups. Left ovary was more active than in right ovary (107 vs. 98 follicle, p>0.05) and the ovulation rate detected from the number of corpora lutea and progesterone level was higher (p>0.05) in the treated group than in the control. Moreover, the ovulation was significantly higher in the right ovary than in the left ovary (19 vs. 9 follicles). Corpus luteum diameter in the treated group was significantly larger than in the control group (1.2±0.11 cm vs. 0.97±0.13 cm, p>0.05). The average progesterone concentration increased significantly (2.36±0.84 ng/ml) in the treated animals than in the control (0.96±0.23 ng/ml). It could be concluded that Glu treatment led to improvement of number of estruses, ovarian follicles, corpora lutea and progesterone concentration in Damascus doe goats during early summer. Therefore, treatment by energy-yielding nutrient (glucose injection) on the estrous and ovarian activity may be recommended in periods of reproductive activity impairment in goats. [Anas A. Salem, Hassan A. H, Nasrat Abd El-Ati, and Gamal B. M.. Improving Reproductive Performance by Glucose Injection in Damascus Does Goat during Early Summer. Journal of American Science 2011;7(6):884-892].(ISSN: 1545-1003). http://www.americanscience.org.