Effect of increased serum progesterone on luteal morphology and function, pregnancy, and gestational loss in Nelore cows.

The aim of the present study was to determine the impact of different strategies for increasing the level of serum progesterone (P4) on luteal morphology and function in bovine females. The effects of increasing P4 on pregnancy rate and gestational loss (GL) in Nelore cows subjected to timed artificial insemination (TAI) were also evaluated. A total of 939 cows were divided into three groups: P4LA (n = 305), 150 mg of long-acting injectable P4 7 days after TAI; GnRH (n = 306), 10 μg of buserelin acetate 7 days after TAI; and control (n = 328), no hormone treatment after TAI.

Mitigation of low pregnancy rate in excitable Nellore cows by administration of GnRH or P4.

This research aimed to determine the effect of temperament on reproductive parameters including cortisol and progesterone (P4) in Nellore cows. Additionally, two methods for increasing plasma progesterone (P4) levels in excitable animals to enhance pregnancy rate (P/AI) and reduce pregnancy loss were investigated. In total, 939 cows were subjected to timed artificial insemination (TAI) and divided into three groups: (P4LA; n = 305) 150 mg of injectable long-acting progestogen 7 days after TAI; (GnRH; n = 306), 10 μg of buserelin acetate on day 7 after TAI; control group (CG; n = 328) without hormonal treatment.

Development of a novel 21-day reinsemination program, ReBreed21, in Bos indicus heifers.

The aim was to develop a program for resynchronization of ovulation (ReBreed21) that allowed reinsemination of non-pregnant Bos indicus heifers every 21 d using timed AI (TAI) without the need for detection of estrus. The Rebreed21 program begins 12 d after previous TAI (Day 0) by inserting an intravaginal P4 implant (Day 12) that is removed 7 d later (Day 19) combined with treatment with 300 IU of eCG. On Day 21, early pregnancy diagnosis (Doppler PD) is performed based on CL vascularity.

Morphological characteristics of mule conceptuses during early development.

Hybrids between species are often infertile and extremely rare among mammals. Mules, i.e.

Central Nervous System and Vertebrae Development in Horses: a Chronological Study with Differential Temporal Expression of Nestin and GFAP.

The neural system is one of the earliest systems to develop and the last to be fully developed after birth. This study presents a detailed description of organogenesis of the central nervous system (CNS) at equine embryonic/fetal development between 19 and 115 days of pregnancy. The expression of two important biomarkers in the main structure of the nervous system responsible for neurogenesis in the adult individual, and in the choroid plexus, was demonstrated by Nestin and glial fibrillary acid protein (GFAP) co-labeling.

Organogenesis of the Musculoskeletal System in Horse Embryos and Early Fetuses.

Musculoskeletal system development involves heterotypical inductive interactions between tendons, muscles, and cartilage and knowledge on organogenesis is required for clarification of its function. The aim of this study was to describe the organogenesis of horse musculoskeletal system between 21 and 105 days of gestation, using detailed macroscopic and histological analyses focusing on essential developmental steps. At day 21 of gestation the skin was translucid, but epithelial condensation and fibrocartilaginous tissues were observed on day 25 of pregnancy.

Prenatal development of the digestive system in the horse.

Since the horse has a highly precocial reproductive strategy, most organs are functionally well developed at birth and thus, embryonic and fetal life is interesting. Data on the development of important organs are very limited. Here, we detailed macroscopically and histologically the equine digestive system, focusing on the first third of gestation.