The aim of this study was to determine the differences between three class intervals obtained from the levels of blood urea nitrogen (BUN) and the pregnancy rate in alpacas during the reproductive season. The study was conducted in a community cooperative in Cerro de Pasco, Peru at an altitude of 4318 m in February 2017. Fifty-two adult alpacas with more than two parturitions were evaluated. Blood samples were taken on the day of the single mount. BUN levels were determined using a commercial colorimetry kit and pregnancy was determined by ultrasonography 35 days post- mounting. The BUN levels varied between 15.07 and 46.88 mg/dl and the pregnancy rate was 59.6%. The pregnancy rate was associated with lower and higher levels of blood urea nitrogen.

El objetivo del estudio fue determinar las diferencias entre tres intervalos de clase obtenidos a partir de los niveles de nitrógeno ureico sanguíneo (NUS) y la tasa de preñez en alpacas durante la estación reproductiva. El estudio se realizó en una cooperativa comunal de Cerro de Pasco, Perú a una altitud de 4318 msnm en febrero de 2017. Se evaluaron 52 alpacas adultas con más de dos partos. Las muestras de sangre se tomaron en el día de la monta única. Los niveles de NUS se determinaron mediante un kit comercial por colorimetría y la preñez fue determinada mediante ultrasonografía a los 35 días de la monta. Los niveles de NUS variaron entre 15.07 y 46.88 mg/dl y la tasa de preñez fue de 59.6%. La tasa de preñez estuvo asociada a los niveles más bajos y más altos de nitrógeno ureico sanguíneo.

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...

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 know the levels of phosphorus and its effects on feed intake and body weight in female alpacas during the breeding season (January-February) and weaning (August-September). In the first phase, serum phosphorus levels were determined in 200 11-13-month-old alpacas, located in four alpaca regions of Peru. P levels were 8.25 ± 1.63, 5.25 ± 1.46, 6.42 ± 1.84 and 4.8 ± 1.61 mg/dl for the regions of Pasco, Junín, Cuzco and Puno, respectively, with significant differences (p<0.05) between regions. P values in one region were below the reference limit (5-11.5 mg/dl) and the another near the lower limit, which could be considered as deficient in P. In the second phase, a controlled experiment was carried out with three concentrations of P in the diet: 0.16% (T1), 0.25% (T2) and 0.34% (T3), using 16 weaned female alpacas per group (7-8 months, 25.25 ± 1.62 kg)...

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 know the levels of phosphorus and its effects on feed intake and body weight in female alpacas during the breeding season (January-February) and weaning (August-September). In the first phase, serum phosphorus levels were determined in 200 11-13-month-old alpacas, located in four alpaca regions of Peru. P levels were 8.25 ± 1.63, 5.25 ± 1.46, 6.42 ± 1.84 and 4.8 ± 1.61 mg/dl for the regions of Pasco, Junín, Cuzco and Puno, respectively, with significant differences (p<0.05) between regions. P values in one region were below the reference limit (5-11.5 mg/dl) and the another near the lower limit, which could be considered as deficient in P. In the second phase, a controlled experiment was carried out with three concentrations of P in the diet: 0.16% (T1), 0.25% (T2) and 0.34% (T3), using 16 weaned female alpacas per group (7-8 months, 25.25 ± 1.62 kg)...

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...