No abstract

A study was conducted to test the hypothesis that injecting Gonadotropin-releasing hormone (GnRH) concurrently with Prostaglandin F2 alpha (PGF2α) followed by an injection of human Chorionic Gonadotropin (hCG), would advance follicular growth to ovulation in Holstein heifers bearing a corpus luteum (CL). After manual examination of the CL, group 1 (PGF; n = 12) received an injection of PGF2α (25 mg, im). Group 2 (PGF + GnRH; n = 13) received an injection of GnRH (100 μg, im) immediately after an injection of PGF2α. Group 3 (PGF + GnRH + hCG; n = 12) received concurrent injections of PGF2α and GnRH followed with hCG (1500 IU, im) two days later. Follicular size and day of ovulation were monitored by daily ultrasonographic examination from days 1 to 10. Blood was collected on days-7, 0 (PGF2α administration), 2, and 7. Progesterone was not different (P > .05) on days-7, 0, and 2 between the experimental groups. However, it was higher (P < .005) in the PGF + GnRH + hCG group on day 7 compared to PGF + GnRH heifers, but not significantly higher than the PGF. Additionally, heifers in the PGF + GnRH + hCG group ovulated earlier (P < .05) than heifers in the PGF + GnRH and the PGF group. This data indicates that hCG advances follicular growth to ovulation in spite of high levels of progesterone when injected 48 h after concurrent treatments of GnRH and PGF2α on heifers bearing a CL.

Lactating beef cows previously synchronized for estrus (d 0) were assigned to four treatments to assess their effectiveness in increasing blood progesterone (P4) and its effects on tumor necrosis factor-α (TNF-α) and prostaglandin F2α (PGF2α) after the transfer of embryos. At the time of transfer (d 7), cows received no treatment (control; n = 16), a controlled internal drug releasing device (CIDR; n = 16), human chorionic gonadotropin (hCG; n = 15), or gonadotropin releasing hormone (GnRH; n = 15). Blood samples were taken on d 7, 14, and 21 for analysis of P4 and tumor necrosis factor-α (TNF-α). Blood was collected (every 15 min for 2 h) in half the animals in each treatment group on d 14 and the remaining half on d 21 for analysis of prostaglandin F2α metabolite (PGFM). Retention rates were 56.2, 62.5, 46.7, and 13.3% for cows in the control, CIDR, hCG, and GnRH groups, respectively. Progesterone was greater (P ≤ 0.05) in cows receiving hCG compared to others on d 14. Progesterone in all treatment groups increased from d 7 to d 14 and declined (P ≤ 0.05) from d 14 to d 21. Contrary to pregnant cows, P4 and TNF-α declined from d 7 to d 21 in nonpregnant cows (P ≤ 0.05). Although PGFM increased by d 21, there was no difference between pregnant and nonpregnant cows.

A new speckle reduction method for ultrasonic images is presented. The proposed approach exploits the knowledge of multiplicative speckle model and a regularization scheme is applied to diffusion processing. The nonlinear diffusion is integrated with dyadic wavelet transform. Experimental results show the new algorithm can not only reduce speckle effectively, but also preserve and even enhance edge and details.