Efficacy of Ovsynch protocol in cyclic and acyclic Egyptian buffaloes in summer.

The aim of the present study was to evaluate the efficacy of an Ovsynch protocol in the cyclic and non-cyclic Egyptian buffaloes in the summer. The present study was carried out on 21 Egyptian pluriparous buffalo cows (11 cyclic and 10 acyclic) and 8 heifers (5 cyclic and 3 acyclic). All animals were administered 100 microg GnRH i.m. at Day 0, 500 microg of PGF2 proportional, variant i.m. at Day 7 and a second dose (100 microg) of GnRH i.m. at Day 9. Ovarian structures of the animals were recorded by means of transrectal ultrasonography (6-8 MHz linear-array transducer) daily from Day 0 (before treatment) to Day 9 (the second GnRH administration) and thereafter, at 12-h interval till ovulation or for a maximum of 48 h. After ultrasound examination, a blood sample was taken daily from each animal for progesterone analysis. The buffalo cows were inseminated at 16-20 h after 2nd GnRH administration. After the first administration of GnRH, 46% (5 of 11) of cyclic and 50% (5 of 10) of acyclic cows and 40% (2 of 5) of cyclic and 33% (1 of 3) of acyclic heifers responded by ovulation or luteinization of the follicles. The mean diameters (+/-S.E.M.) of the follicles in the responding cows and heifers were significantly higher than those in non-responding animals (9.7 +/- 0.4 mm vs. 6.7 +/- 0.6 mm, P < 0.0001; 11.1 +/- 1.5 mm vs. 7.3 +/- 0.7 mm, P < 0.05, respectively). After the second administration of GnRH, 81% (9 of 11) of cyclic and 60% (6 of 10) of acyclic cows and 80% (4 of 5) of cyclic and 33% (1 of 3) of acyclic heifers ovulated, respectively. Ovulations occurred earlier (P = 0.059) and over a wider range of time in the non-cyclic cows (26 +/- 4.8 h; range: 12-36 h) and in a heifer (12 h,) than in the cyclic cows (34.7 +/- 1.3 h; range 24-36 h) and heifers (33 +/- 3 h; range: 24-36 h). The conception rate was 18% (2 of 11) and 0% (0 of 10) in cyclic and non-cyclic cows, respectively. In conclusion, the Ovsynch protocol could be used effectively for synchronization of ovulation in cyclic cows and heifers in summer.

Estimation of gestational age in Egyptian native goats by ultrasonographic fetometry.

The main aim of the present study was to estimate the gestational age of Egyptian goats by B-mode ultrasound measurement of embryonic or fetal parts throughout pregnancy. Trans-rectal (TR) ultrasonography (7 MHz) was carried out on 15 pregnant Egyptian does at Day 10 post mating on alternate days until Day 25 and then once at 3-5-day intervals until Day 50. Trans-abdominal (TA) ultrasonography (3.5-5 MHz) was carried out on the same animals from Days 25 to 130 at 3-5-day intervals. After imaging the embryo or the fetus, the following parameters were measured: length of the embryo or fetus (CRL), heart rate (FHR), biparital diameter (BPD), trunk diameter (TD), placentome size (PS), umbilical cord diameter (UCD) and femur length (FL). The average of days at which the embryonic vesicle was first determined by TR and TA ultrasonography was 16.98+/-1.97 and 27.87+/-3.48, respectively. The embryo proper with a beating heart was first determined by TR and TA ultrasonography at an average of 22.36+/-2.66 and 30.36+/-4.75 days, respectively. All the fetal measures were significantly (P<0.0001) correlated with the gestational age. With the exception of fetal heart rate (R(2)=0.551), all the measured fetal structures were highly correlated (R(2)> or =90) with the gestational age. In conclusion, the age of embryo or fetus in Egyptian does can be estimated by ultrasound measuring the crown rump length, biparital diameter, trunk diameter, placentome size, umbilical cord diameter and femur length.

Effect of pretreatment with insulin on the response of buffaloes with inactive ovaries to gonadotrophin-releasing hormone agonist treatment in summer.

The aim of the present study was to evaluate the effect of a pretreatment with insulin on the response of buffalo cows with inactive ovaries to gonadotrophin-releasing hormone agonist (GnRHa) treatment during hot summer months (July and August). Thirty-six Egyptian buffalo cows with inactive ovaries were randomly allocated into three groups: (1) group treated with GnRHa (G1, n = 16) in which each buffalo received an intramuscular injection of 250 mg of GnRHa (Day 0; gonadorelin, Fertagyl); (2) group treated with insulin before the GnRHa injection (G2, n = 8) in which each buffalo received a subcutaneous injection of biphasic insulin at a dose of 0.25 IU kg(-1) bodyweight once daily starting at Day -3 for 3 consecutive days, followed by an intramuscular injection of 250 mg of GnRHa on Day 0; and (3) the control group (G3, n = 12) in which each buffalo cow received an intramuscular injection of 2.5 mL of sterile saline on Day 0. The ovaries of all animals were examined by trans-rectal ultrasonography (5 MHz) on Days -7, -3 and 0 and continued thereafter at 4-day intervals until oestrus or the end of the experiment. On the same days that ultrasound examinations were performed blood samples were collected to measure the progesterone concentrations. Administration of insulin for 3 days before GnRHa injection (G2) significantly (P < 0.05) increased the diameter of the largest follicle from 6.85 +/- 0.64 to 12.4 +/- 0.88 mm. There was a significant (P < 0.01) increase in the oestrous induction rate in G2 compared with both G1 and G3 during the first 12 days after the treatment interval. It is concluded that pretreatment with insulin for 3 days before GnRHa injection increases the diameter of the dominant follicle and therefore the oestrous induction rate of acyclic buffaloes.