The objective of this study was to evaluate effects of dehydration on sperm DNA with the aim of eventually using this method for preserving llama spermatozoa. Two experiments were conducted: 1) sperm preservation at 5 °C for 60 days in different hyperosmotic solutions (500, 800, 1000 and 1200 mOsmol/l) (n = 6, replications = 2) and 2) sperm preservation at 5 and -20 °C for 60 days in the same hyperosmotic solutions, with supplementary antibiotics (n = 6, replications = 2). Sperm motility, membrane functional integrity, viability and morphology were evaluated at 0 and 48 h of the preservation period (Experiment 1) and at 30 min and 24 h (Experiment 2).
View Article and Find Full Text PDFThe objective of this study was to evaluate the effects of air-drying preservation on llama sperm DNA. Semen collections were carried out using electroejaculation under general anesthesia. A total of 16 ejaculates were processed from 4 males ( = 4, = 4).
View Article and Find Full Text PDFThe aim of the present study was to evaluate the application of a GnRH-PGF based synchronization and superstimulation protocol for fixed-time natural mating in llama embryo donors. All females ( = 8) received 8 μg IM of GnRH analog (GnRHa; buserelin) on day 0, regardless of follicular status. After eight days, another GnRHa dose was administered followed by 250 μg IM PGF (cloprostenol).
View Article and Find Full Text PDFReprod Domest Anim
December 2018
The aims of the study were twofold: first, the comparison of the pharmacokinetics parameters of two doses of Progesterone BioRelease LA, (BioRelease Technologies, Lexington, KY, USA) one of 300 mg and other of 150 mg and their effects on ovarian dynamics in llamas. Based on the results from the first study, the aim of the second study was to evaluate the effect of the doses of 150 mg of progesterone on follicular activity considering the stage of the largest follicle at the beginning of treatment. The results in Study 1 showed that both doses of the formulation induced plasma progesterone concentrations higher than 1 ng/ml during the first 6 days of treatment in all females, progesterone concentrations steadily decline until Day 5 following by a slowly decrease.
View Article and Find Full Text PDFThe current review summarizes progress in the field of and production of South American Camelid embryos. Both methods require ovarian superstimulation (with FSH and eCG) to obtain multiple ovulations ( embryo production) or to induce follicle growth for oocyte collection ( embryo production). Moreover, superstimulation entails prior administration of hormones that inhibit follicular growth (progesterone, progestagens, and estrogens).
View Article and Find Full Text PDFThe aim of the present study was to evaluate the effect of the embryo transfer (ET) maneuvers on plasma progesterone concentrations in recipient Lama glama females and the relationship between the site the embryo was transferred to and corpus luteum (CL) localization. Experiment I (effect of transcervical threading): adult non-pregnant, non-lactating llama females were randomly assigned into two groups: control group (without cervical threading, n=10) and group A (with cervical threading, n=10). In both groups, CL activity was evaluated through measurement of progesterone plasma concentrations.
View Article and Find Full Text PDFMany theories have been postulated concerning the possible effects of cryopreservation on spermatozoa, including suggestions the freeze-thawing process produces membranes that have greater fluidity and are more fusogenic, thus inducing changes similar to those of capacitation. The main objectives of this study were to determine at what stage of the freeze-thaw process membrane changes occur and whether evaluation with chlortetracycline (CTC) stain could predict the freezability of stallion sperm. Sperm viability and state of capacitation were simultaneously evaluated using CTC and Hoechst 33258 (H258) techniques.
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