Effect of l-tyrosine on fertility of native bulls and buffalo-bulls

Four native bulls and 4 buffalo-bulls [7-8 years of age] were used for investigating the effect of L-Tyrosine on libido [libido index and reaction time], semen quality and sperm fertilizing capacity. Serum and semen samples were collected for 3 weeks [twice per week] before treatment to serve as controls. A single oral dose of L-Tyrosine [100 mg/ kg. body weight] was given to each animal, and serum and semen samples were collected twice per week form all animals for 3 weeks post treatment. On collection, libido index and reaction time [in seconds] were measured and the collected semen samples were evaluated for: ejaculate volume, pH, individual sperm motility, percentage of live sperm, sperm cell concentration [in millions/ ml], total sperm number per ejaculate and sperm abnormalities [primary and secondary]. Testosterone concentration was assessed in serum samples using RIA technique. The fertility of each bull was assessed before and after treatment. The results revealed that, a single oral dose of L-Tyrosine leads to improvement in testosterone level, libido, semen quality and sperm fertilizing capacity in both bulls and buffalo-bulls

Peripheral serum progesterone and estradiol B17 hormone concentrations in saanen goats during synchronization of estrus with vaginal sponge

Estrus in saanen goats was synchronized using vaginal sponge during breeding and non breeding seasons. In the breeding season, the treated goats received 400 IU equine chorionic gonadotropin [eCG] at the day of the sponge removal, while in non breeding season the goats received 600 IU eCG two days before sponge removal. Serum progesterone and estradiol B17 were determined one day before, at day of, one day after and two days after sponge removal in both groups. The results revealed that during the breeding season all goats exhibited estrus 24 hours after sponge removal. The mean concentrations of progesterone were 5.43 +/- 0.83 and 5.31 +/- 0.37 ng/ml, respectively at one day before sponge removal and at the day of sponge removal. The level of progesterone sharply decreased to [0.26 + 0.08 ng/ ml one day after sponge removal and remained low two days after sponge removal [0.43 +/- 10.18 ng/ml]. The mean serum estradiol B17 was low before and at sponge removal. The maximum peak of serum estradiol B 17 [50.5 +/- 6.49 pg/ml] was observed 24 hours after sponge removal. The level of estradiol B 17 dropped abruptly and reached to 14.2 +/- 2.59 pg/ml 48 hours after sponge removal. On the other hand, in the non breeding season, the treated goats showed signs of estrus 20-24 hours after sponge removal. Mean serum progesterone concentration was found low in all goats. However, the mean estradiol serum levels increased after eCG injection and the maximum peak [60.8 +/- 11.2 pg/ml] was observed 24 hours after sponge removal. Forty eight hours after sponge removal, the estrediol level declined to 17.5 +/- 2.2 pg/ml. During breeding season, in control animals the serum progesterone was higher than 1 ng/ml at day 16 of the cycle, then started to decrease. The estradiol B 17 showed a steady increase at day 19 of the cycle. In non breeding season, the control goats had no ovarian activity along with constant low level of hormones. It could be suggested that the levels of progesterone and estradiol hormone were altered around time of induced estrus, as a result of a positive effect of eCG injection on estradiol 17 B production and a negative effect on progesterone and hence insure a high degree of synchronization

Determination of the minimal dose of iliren capable of inducing estrus in alpine goats

Various doses of iliren [0.25, 0.5, 0.75 and 1ml] were injected to 36 cycling Alpine dairy goats during 7-10 days of estrous cycle. Another 9 goats were injected with 1 ml saline served as control. All does were teased twice daily with a fertile buck and observed for sings of estrus for 5 days post-injection. Pre and post injection daily progesterone assay were determined. The results revealed that the mean concentration of progesterone in all does on the day of injection was 3.4 +/- 0.5 ng/ml. Concentration 24 hours post-injection were 0.2 +/- 0.02,0.15 +/- 0.05, 0.17 +/- 0.04, 0.16 +/- 0.05 and 4.5 +/- 1.1 ng/ml for does receiving 0.25, 0.5, 0.75,1 ml of iliren and 1ml saline respectively. The results indicated that 0.25 ml iliren was the minimal dose effective for induction of estrus in cycling does. Estrus was synchronized using 0.25 ml of iliren [2 injections 11 days apart] into 45 cycling does. Another 45 does injected with 1 ml saline at the same period serve as control. The does exhibited estrus were mated by a fertile buck. The pregnancy rate, kidding rate, and litter size were recorded in both Seventy one percent [32/45] of the does initially treated with 0.25 ml iliren came to heat within 48 +/- 4 hours after injection. Estrus was observed within 46 +/- 2 hours in 44 out of 45 does [97.9%] treated 11 days later with second injection of 0.25 ml iliren. No significant differences in the pregnancy rate were observed between the treated and the control groups. It could be concluded that the use of 0.25 ml i.m.of iliren was the minimal dose capable of inducing estrus in Alpine does. Moreover this dose was used 2 time with 11 days apart it was highly effective in synchronizing estrus in does. Fertility in comparison with the control was not altered

Influence of priming dose of GnRH analogue [cystorelin] on the ovarian activity in postpartum Egyptian buffalo-cows

This work aimed to study the effect of GnRH injection at 44 days postpartum when preceded by a priming dose, on the ovarian activity and consequently, the initiation of the postpartum ovarian cyclicity in Egyptian buffalos. Routine rectal examination was carried out to diagnose the postpartum [pp] conditions of the ovaries in 18 normal parturient buffalo-cows at day 30 pp. These animals did not show any signs of etrus till day 44 pp. The animals were assigned randomly at day 44 pp into 2 groups. Group 1 [n=12], was treated with 100 mul GnRH [Cystorelin]. Each animal received 2 injections of GnRH 50 mul i.m./one hour apart. Group 2 [n=6] defined as controls and received saline [1 ml i.m.]. Visual examination was done following GnRH injection to detect the sings of estrus. Rectal examinations were conducted in the 1st week [51 days postpartum] and 2nd week [58 days pp] to detect any ovarian changes after treatment on both groups. Serum samples were collected parallel to rectal palpation to detect the progesterone and estradiol 17 beta levels before and after treatment. The animals were allowed freely for natural service by a fertile buffalo-bull and examined for pregnancy at day 45 post service. The results revealed that, the injection of GnRH analogue preceded by 1 hour apart priming dose resulted in a significant increase in the treatment and consequently induced cyclicity and shortened of the period from calving to first postpartum estrus in Egyptian buffalos

Recovery and transfer of Egyptian buffalo embryos using non-surgical technique

The present study was undertaken to apply and evaluate the new technology of embryo transfer system and its success in Egyptian buffaloes. Eleven buffalo-cows were used in this study and were assigned into two groups. The first [n=8] was for donors and the second [n=3] was for the recipients. The animals were superovulated and synchronized for estrus using a total dosage of 50 mg FSH-p [Shering Corporation, USA] and 25 mg Lutalyse for each animals respectively. The animals were naturally mated at least 2 times 36-80 hours [hrs] after Lutalyse injection. The embryos were collected and evaluated at day 5 to 5.5 after estrus. The good transferable embryos were transferred non-surgically to the uterine horn ipsilateral to the corpus luteum [CL] to 2 recipient buffaloes. The percentage of animals that responded to superovulation was 100%. Eight embryos were collected [transferable] and the average number of transferable embryos/ animals was 1.6. One animal was confirmed pregnant 45 days after estrus. The present results revealed that the technique of embryo transfer in Egyptian buffaloes needs more investigations; at the same time the present protocol was found to be satisfactory to reduce the problems facing the embryo transfer technique in Egyptian buffaloes

Toluidine blue stain and sperm abnormalities in rabbits

Five mature New Zealand bucks were used in this study to examine the efficacy of the toluidine blue stain to determine the normal and abnormal spermatozoa recovered from testis and epididymis [unilateral cryptorchidism and free]. The results revealed that the sp"iatids released from the cryptorchid testis were deeply stained by the toluidine blue. Misshaped sperm heads were stained with toluidine blue and appeared faintly stained, where they were exposed to sever testiar degeneration. The normal spermatozoa wert unstained except the distal part of the head stained darkly due to the chroniatin condensation in this part. The abnormal spermatozoa either from the testis or the epididymis appeared deeply stained with the toluidine blue stain. It was observec that the toluidine blue stain has the ability to stain the unstabilized chromatin which was prominent in the abnormal sperrnatids or spermatozoa. This result will help in the diagnosis of the testicular degeneration [primary sperm abnormalities] which will be reflected on the sire and semen evaluations