The aim of the study was to evaluate the effect of immune sterilization on body weight gain, carcass yield and fleece weight in Junin sheep by applying an anti-GnRH synthetic protein. The study was conducted at the SAIS "Tupac Amaru", Junin, Peru, at an altitude of 3587 m between September and December 2017. Eighty 11-13-month-old rams were used and randomly distributed into four treatments (20 per group). Treatments were T1: surgical castration, T2 and T3: application of 0.5 and 1.0 ml of anti-GnRH vaccine, and T4: control (application of a placebo). For the immune sterilization, two doses of Improvac® were subcutaneously applied in the axillary region at 21-day intervals. Body weight was taken every 15 days for three months and the weight of dirty fleece was taken immediately after shearing. The results show that the application of anti-GnRH vaccine at a dose of 1.0 ml improvement inc...

The aim of this study was to determine the physiological parameters related to body thermoregulation, as well as basic haematological parameters between Nellore cows and crossbreeds under heat stress. The study was carried out in the province of Satipo, Junín region, Peru, at 628 meters above sea level. Sixteen crossbred cows (Brown Swiss x Nellore) and 16 Nellore cows were used. The physiological parameters (body temperature, respiratory rate and heart rate) were evaluated in the morning (06:00-07:00) and in the afternoon (14:00-17:00). Blood samples were taken to determine haemoglobin (g/dl), haematocrit (%), mean corpuscular volume (MCV, fl), mean corpuscular haemoglobin (MCH, pg), mean corpuscular haemoglobin concentration (MCHC, g/dl). Thermoregulatory functions (rectal temperature, heart rate and respiratory rate) were affected during hours of heat stress in both racial groups (p&...

El objetivo del estudio fue evaluar el efecto de la inmunoesterilización mediante la aplicación de una proteína sintética anti-GnRH sobre la ganancia de peso, rendimiento de carcasa y peso de vellón en ovinos Junín. El estudio fue conducido en la SAIS «Túpac Amaru», Junín, Perú, a una altitud de 3587 msnm entre setiembre y diciembre de 2017. Se utilizaron 80 carnerillos de 11-13 meses y se distribuyeron al azar en cuatro tratamientos (20 por grupo). Los tratamientos fueron T1: castración quirúrgica, T2 y T3: aplicación de 0.5 y 1.0 ml de vacuna anti-GnRH, y T4: control (aplicación de un placebo). Para la inmunoesterilización se utilizaron dos dosis de Improvac® vía subcutánea a intervalos de 21 días. El peso vivo se tomó cada 15 días durante tres meses y el peso de vellón sucio se tomó inmediatamente después de la esquila. Los resultados muestran que la aplicaciÃ...

The aim of this study was to determine the physiological parameters related to body thermoregulation, as well as basic haematological parameters between Nellore cows and crossbreeds under heat stress. The study was carried out in the province of Satipo, Junín region, Peru, at 628 meters above sea level. Sixteen crossbred cows (Brown Swiss x Nellore) and 16 Nellore cows were used. The physiological parameters (body temperature, respiratory rate and heart rate) were evaluated in the morning (06:00-07:00) and in the afternoon (14:00-17:00). Blood samples were taken to determine haemoglobin (g/dl), haematocrit (%), mean corpuscular volume (MCV, fl), mean corpuscular haemoglobin (MCH, pg), mean corpuscular haemoglobin concentration (MCHC, g/dl). Thermoregulatory functions (rectal temperature, heart rate and respiratory rate) were affected during hours of heat stress in both racial groups (p&...

The aim of this study was to compare the capacity of embryonic development of oocytes recovered from slaughterhouse ovaries and recovered in vivo by guided ultrasound (ovum pick-up – OPU) in an in vitro production system. Nine sessions in 59 Holstein cows were done to obtain oocytes through OPU and 408 ovaries were collected from 204 cows in the slaughterhouse. For the in vitro maturation of oocytes, only those of grade 1 and 2 were used, matured and fertilized using MIV, FIV and CIV® medium until day 7. The recovery rate of oocytes, grade 1 and 2 oocytes and the percentage of embryos (blastocysts) produced in vitro on day 7 were evaluated. The recovery rate of oocytes collected from slaughterhouse ovaries was higher as compared with oocytes collected by OPU (10.0 vs. 7.2 oocytes per session/cow, p<0.05). There was a greater number of viable oocytes of grade 1 and 2 when the collec...

El objetivo del presente estudio fue comparar la capacidad de desarrollo embrionario de ovocitos recuperados de ovarios de matadero y recuperados in vivo mediante ultrasonografía guiada (ovum pick-up, OPU) en un sistema de producción in vitro. Se realizaron nueve sesiones de colecta en 59 vacas Holstein para la obtención de ovocitos mediante OPU y se colectaron 408 ovarios de 204 vacas de matadero. Para la maduración in vitro de ovocitos solo se utilizaron aquellos de grado 1 y 2 mediante medios MIV, FIV y CIV® hasta el día 7. Se evaluó la tasa de recuperación de ovocitos, ovocitos grado 1 y 2 y el porcentaje de embriones (blastocitos) producidos in vitro al día 7. La tasa de recuperación de ovocitos fue mayor cuando se colectaron de ovarios de matadero comparado con ovocitos colectados por OPU (10.0 vs. 7.2 ovocitos por sesión/vaca; p<0.05). Hubo una mayor cantidad de ovoc...