Semen collection and ejaculation trigger changes in the blood flow of the reproductive system in rams.

The aim of this study was to determine if ejaculation modifies the testicular and accessory sex glands' blood flow after ejaculation, and if those changes differ according to the process that leads to ejaculation. Twelve adult Corriedale rams were used and assigned at random to the four procedures that lead to ejaculation: (G1) electroejaculation; (G2) artificial vagina; (G3) transrectal ultrasound-guided massage of the accessory sex glands; (G4) natural mating. Hemodynamic characteristics evaluation of the male reproductive system was conducted immediately before and at 30 and 90 min after ejaculation. The internal iliac artery peak systolic velocity (PSV) decreased (P=0.01) and supratesticular artery PSV increased (P=0.042) 90 min after ejaculation in all groups. In conclusion, ejaculation modifies the reproductive system's blood flow, with slight variations depending on the studied ejaculation methods. Additionally, ejaculation altered the internal iliac and supratesticular arteries PSV, and the supratesticular artery end-diastolic velocity (EDV) in rams. The supratesticular artery PSV was the only studied variable that differed according to the procedure that triggered the ejaculation.

Growth of foetal bones and metabolic profile during gestation in primiparous ewes and multiparous ewes.

Primiparous ewes and multiparous ewes show physiological differences during pregnancy, which can have an impact on the development of their offspring. The objective of this study was to compare the changes in the metabolic profile and in the size of some foetal bones throughout gestation between primiparous and multiparous ewes. Twelve primiparous (PM) ewes and 14 multiparous (MT) ewes were used. According to the dates of lambing, two groups of ewes were formed: Group 1 (G1, n = 6 PM and n = 7 MT) and Group 2 (G2, n = 6 PM and n = 7 MT). The body weight, body condition score, metabolic and foetal morphometric parameters were determined from before conception until the end of gestation. After lambing, the body weight and survival rate during the first 72 hr of life of lambs, as well as the maternal behaviour score were recorded. The PM ewes were lighter (p < .01) and had a greater mobilization of body reserves during gestation, mainly evidenced by a greater serum concentration of NEFAs and lower serum concentration of total proteins (p < .05) compared with the MT ewes. The parity did not affect the foetal morphometric variables. The lambs of MT ewes were heavier at parturition (p = .002) and tended to have a greater survival rate than those lambs of PM ewes (p = .09). In conclusion, PM ewes and MT ewes differ in their metabolic profile throughout the gestation. However, in the present study, we did not find parity differences in the dimensions of foetal bones during growth in gestation.

Immunohistochemical determination of estrogen receptor-α in canine vaginal biopsies throughout proestrus, estrus, and early diestrus.

The aim of this study was to describe the presence of estrogen receptor-α (ERα) in several vaginal histological compartments in healthy adult bitches throughout three estrous cycle stages (proestrus, estrus, and early diestrus) and to relate ERα presence with serum progesterone and estradiol-17ß concentrations. For this purpose, serial blood samples and vaginal biopsies were taken from five bitches every 48 hours, starting at the clinical onset of proestrus, marked by the beginning of serosanguineous vaginal secretion. Serum progesterone and estradiol-17ß concentrations were determined by RIA, whereas detection of steroid receptors was carried out through immunohistochemistry. Subjective image analysis was conducted by two independent observers in the following histological compartments: superficial, intermediate, and deep epithelia and superficial (loose) and deep (dense) stroma (connective tissue). Nuclear ERα immunoreactivity was detected in every histological compartment and estrous cycle stage studied. ERα expression varied among histological compartments and during stages of the cycle. Receptor expression was associated with estradiol-17ß and progesterone serum profiles. Most relevant cyclic changes were detected in the superficial and deep epithelia and in the dense connective tissue. The highest ERα expression was detected during diestrus, although each compartment had a different pattern throughout the other cycle stages. Thus, vaginal ERα expression in the bitch varied throughout proestrus, estrus, and early diestrus according to the histological compartment involved.

Características Morfológicas de Ovarios y Ovocitos de Nutrias (Myocastor coypus) en Condiciones de Criadero / Morphological Characteristics of Ovaries and Oocytes of Otters (Myocastor coypus), in Breeding Conditions

El objetivo del presente trabajo fue estudiar las características morfológicas de los ovarios y ovocitos de la nutria (Myocastor coypus, coypu) en las diferentes estaciones del año y etapas del ciclo estral. La nutria (MC) es un roedor autóctono de Sudamérica, muy utilizado en la industria peletera. Se sacrificaron 20 hembras, de un peso promedio de 4996,2 g recogiéndose muestras vaginales para realizar colpocitología y determinar el momento del ciclo estral, 11 se faenaron en invierno de las cuales 7 estaban en anestro, 1 en proestro y 3 en diestro y 9 en verano, encontrándose 1 en anestro, 1 en proestro y 7 en diestro. Cada ovario fue transportado en una solución de cloruro de sodio isotónico estéril a 37C al laboratorio. Los ovarios fueron pesados y medidos y se desmenuzaron en placas de Petri con 2 agujas n28, bajo microscopio estereoscópico. Se identificaron los ovocitos, se lavaron en solución Buffer Fosfato Salino (PBS) y se caracterizaron en A, B y C. Los resultados de las medias y desviación típica de los pesos de los ovarios fueron: 0,304 g (0,062); largo 9,05 mm(0,19) y ancho 5,05 mm (0,69). Se realizó el análisis de varianza para la condición de los ovocitos, y no se constató diferencias estadísticamente significativas asociadas a la estación ni a la condición estral sobre la condición de los ovocitos (p<0,05). En lo que respecta al número de cuerpos lúteos, se realizó el test de Fisher, y se observaron diferencias significativas entre las etapas del ciclo estral (diestro versus anestro) con una F=20,57(p=0,0001), entre las estaciones del año (verano versus invierno) con una F=72,21 (p=0,0000) y la interacción entre las etapas y las estaciones con una F=10,29(p=0,0018).

The aim of this work was to study the morphological characteristics of ovaries and oocytes of the otter (Myocastor coypus, coypu) in different seasons and stages of the estrous cycle. The otter (MC) is a rodent native to South America and is widely used in the fur industry. Twenty females with a mean weight of 4996.2 g were sacrificed, vaginal swabs or colpocytology were collected and the time of the estrous cycle was determined. Eleven were slaughtered in winter, of which 7 were in anestrus, 1 in proestrus, and 3 in diestrus; of the 9 slaughtered in summer, 1 was in anestrus, 1 in proestrus and 7 in diestrus. Each ovary was transported to the laboratory in a solution of sterile isotonic sodium chloride at 37° C. The ovaries were weighed and measured and crumbled into Petry dishes with two No.28 needles, under a stereoscopic microscope. Oocytes were identified, washed in phosphate buffered saline solution (PBS) and were characterized as A, B and C. The results of mean and standard deviation of the weights of the ovaries were: 0.304 g (0.062), length 9.05 mm (0.19) and 5.05 mm wide (0.69). We performed the analysis of variance for the condition of oocytes and found no statistically significant differences associated with the station or estrus status on the status of the oocytes (p <0.05). Regarding the number of corpora lutea, Fisher´s test was used, with significant differences between stages of estrous cycle (diestrus vs. anestrus) with F=20.57 (p = 0.0001) between seasons (summer vs. winter) with F = 72.21 (p = 0.0000) and interaction between the stages and stations with an F = 10.29 (p = 0.0018).