Bovine somatotropin increases the pregnancy rate in fixed-time artificial insemination in beef cattle.

This study evaluated the effect of bovine somatotropin (bST) on pregnancy rate (PR) and size of the dominant follicle (DF) on the day of intravaginal progesterone (P4) removal in protocols for fixed-time artificial insemination (FTAI). Bos indicus (Nellore) females (n = 392) were distributed into three groups. The control group (CG; n = 92) received an intravaginal P4 device + estradiol benzoate on day (d)0; prostaglandin F2α on d7 (first application); removal of P4 + estradiol cypionate (EC) + PGF2α (second application) + ultrasound (US) of the DF on d9; the FTAI was performed on d11; and pregnancy diagnosis (PD) was performed on d45.

Effect of recombinant bovine somatotropin on the reproductive efficiency of beef cows subjected to differently timed-artificial insemination protocols.

This study aimed to verify the reproductive efficiency of beef cows treated with recombinant bovine somatotropin (rbST). Study 1, Bos indicus cows were distributed (three groups). The control group (CG) was subjected: on day zero (d0), the animals received a CIDR and oestradiol benzoate (EB); on (d8, CIDR was removed, and PGF2α and oestradiol cypionate (EC) were administered; on d10, timed Artificial Insemination (TAI) was performed; on d45, pregnancy diagnosis was made.

Reproductive performance of European-breed ewes in different seasons of the year under mid-latitude.

The study evaluated the reproductive performance of Ile de France, Texel, Suffolk and crossbred ewes in different seasons, considering season of mating, age, body condition score and breed. The herd was located at geographic coordinates -25.66114429 S, -49.

An Accurate Image Analysis Method for Estimating Body Measurements in Horses.

This study proposes a standardized image analysis method for assessing horse conformation. A total of 34 adult American Quarter Horses (mean age = 6.7 ± 2.

Timed artificial insemination in crossbred mares: Reproductive efficiency and costs.

Timed artificial insemination (TAI) has boosted the use of conventional artificial insemination (CAI) by employing hormonal protocols to synchronize oestrus and ovulation. This study aimed to evaluate the efficiency of a hormonal protocol for TAI in mares, based on a combination of progesterone releasing intravaginal device (PRID), prostaglandin (PGF ) and human chorionic gonadotropin (hCG); and compare financial costs between CAI and TAI. Twenty-one mares were divided into two groups: CAI group (CAIG; n = 6 mares; 17 oestrous cycles) and TAI group (TAIG; n = 15 mares; 15 oestrous cycles).

Impact of recombinant bovine somatotropin, progesterone, and estradiol benzoate on ovarian follicular dynamics in Bos taurus taurus cows using a protocol for estrus and ovulation synchronization.

This study aimed to evaluate the effect of recombinant bovine somatotropin (bST) in combination with progesterone (P4) and estradiol benzoate (EB) on ovarian follicular dynamics using a protocol for estrus and ovulation synchronization in crossbred Bos taurus taurus cows. Twenty-four non-lactating multiparous cows were randomly assigned to two groups: the recombinant bovine somatotropin group (GbST; n = 11) received an intravaginal P4 device (1.5 g), estradiol benzoate (EB = 1.

Resynchronization of ovulation with new and reused intravaginal progesterone-releasing devices without previous pregnancy diagnosis in Bos taurus indicus cows subjected to timed-artificial insemination.

The study aimed to evaluate pregnancy per artificial insemination (P/AI) of cows subjected to synchronization and resynchronization in ovulation protocols using intravaginal progesterone-releasing insert (P4) before pregnancy diagnosis (PD) and the relationship of PR with the diameter of preovulatory follicles (ØPOF) before TAI. Cows (n = 378) were distributed into two groups: a resynchronization group with new devices (GRN; n = 185) and resynchronization group with used devices (GRU; n = 193). On Day 0, both groups received a new P4 and estradiol benzoate (EB).

Impact of recombinant bovine somatotropin, progesterone, and estradiol benzoate on ovarian follicular dynamics in Bos taurus taurus cows using a protocol for estrus and ovulation synchronization.

This study aimed to evaluate the effect of recombinant bovine somatotropin (bST) in combination with progesterone (P4) and estradiol benzoate (EB) on ovarian follicular dynamics using a protocol for estrus and ovulation synchronization in crossbred Bos taurus taurus cows. Twenty-four non-lactating multiparous cows were randomly assigned to two groups: the recombinant bovine somatotropin group (GbST; n = 11) received an intravaginal P4 device (1.5 g), estradiol benzoate (EB = 1.

Effect of semen and donor factors on multiple ovulation and embryo transfer (MOET) in sheep.

Multiple ovulation and embryo transfer (MOET) is an important tool in the sheep industry for increasing numbers of genetically superior individuals. The objective of this study was to evaluate the effect of semen source (frozen or fresh), the number of embryo collection procedures for each donor (NECP), the season in which embryo transfer and collection was performed, and the age and breed of the donor, on the number of recovered embryos and pregnancy rates after embryo transfer. The Alamos Genetics' flushing station database was used.

Sperm subpopulations in ejaculated sperm and spermatozoa recovered from ovine epididymides up to 48h after death.

The objectives of this study were threefold: to identify subpopulations of sperm based on the kinetics of frozen/thawed sheep epididymal spermatozoa or semen collected with an artificial vagina; to evaluate the effects on sperm subpopulations in the thawed samples of post mortem storage at room temperature and the addition of 20% of seminal plasma to the freezing extender and to correlate the percentage of subpopulations with gestation rate following artificial intrauterine insemination. The categorization of the subpopulations was based on sperm kinetic data from Computer Assisted Sperm Analysis (CASA). A hundred ewes were inseminated with thawed spermatozoa and gestation rate was correlated with the proportions of each subpopulation using Pearson correlation matrix and linear regression.

Impact of a progesterone-releasing intravaginal device and inflammatory reaction on ovarian activity in embryo-recipient anestrus mares.

This study aimed to correlate the inflammatory reaction (IR) caused by a progesterone-releasing intravaginal device (P4) with ovarian activity and pregnancy rate (PR) in embryo-recipient anestrus mares (to decrease the spring transitional period). 50 animals were assigned to three groups: GP4 (P4 group; n = 16), GP4OH (P4 + oxytetracycline hydrochloride and hydrocortisone sprayed onto the device; n = 14), and GNP4 (no intravaginal P4; n = 20). The administration protocol for GP4 was: Day 0, 750 mg P4 + ovarian examination by ultrasonography (US) + vaginal sample collection; Day 8, US; Day 11, P4 removal + 7.

In vitro and in vivo fertilization potential of cryopreserved spermatozoa from bull epididymides stored for up to 30 hours at ambient temperature (18 °C-20 °C).

The aims of this study were to compare the viability and in vivo and in vitro fertilization potential post-thaw sperm collected at different times postorchiectomy from bull epididymides (EP) at 18 °C to 20 °C, with those of semen collected by electroejaculation (EJ) from the same bulls. Semen samples were collected by EJ from 10 Zebu bulls and cryopreserved. A week later 20 epididymides from these bulls were obtained by orchiectomy and randomly divided into five groups (G) to be maintained at ambient temperature for 6, 12, 18, 24, and 30 hours before sperm recovery by retrograde flow.