Niveles de fósforo en la dieta y sus efectos sobre el crecimiento y performance reproductivo en alpacas hembras pos destete

Universidad Nacional Agraria La Molina. Escuela de Posgrado. Doctorado en Ciencia AnimalEl objetivo del estudio fue evaluar el efecto del fósforo sobre la performance reproductiva, crecimiento e inicio de la pubertad de alpacas hembras pre – púberes y púberes en dos etapas importantes de producción, como la temporada de reproducción (enero a febrero) y destete (agosto - septiembre). En la primera etapa del estudio, se determinaron los niveles sanguíneos de fósforo en 200 alpacas hembras de aproximadamente 11 a 13 meses de edad ubicadas en cuatro regiones de mayor importancia para la cría de alpacas en Perú. Se encontraron niveles de 8.25 ± 0.23, 5.25 ± 0.12, 6.42 ± 0.16, 4.8 ± 0.14 mg / dl para las regiones de Pasco, Junín, Cuzco y Puno, respectivamente. Diferencias significativas (p <0.05) entre las cuatro regiones fueron encontradas, y estos datos se compararon con el rango esperado para alpacas (Van Saun, 2014) (5-11.5 mg / dl). En una segunda parte del estudio, se realizó un experimento controlado con diferentes concentraciones de fósforo en la dieta: 0.16% (T1), 0.25% (T2) y 0.34% (T3). Se utilizaron cuarenta y ocho alpacas hembras después del destete (25.24 ± 0.17 kg), con alimentación ad libitum, con 16 animales por tratamiento alojados en corrales individuales durante un período de 7 meses y las edades oscilando entre los siete y los ocho meses. Hubo un efecto del fósforo (p <0.05) sobre la mayoría de variables evaluadas cuando los niveles en la dietas fueron de 0.25 y 0.34%, entre las que destacan el peso vivo y la condición corporal. El consumo de materia seca expresado en kg/día fue 0.71 ± 0.01, 0.82 ± 0.01 y 0.96 ± 0.02 mientras que, como porcentaje del peso vivo fue 2.07, 2.24 y 2.60 para los tratamientos T1, T2 y T3, respectivamente. La variables reproductivas como tamaño del folículo pre ovulatorio, mortalidad embrionaria, tasa de ovulación y la pubertad se vieron mejoradas cuando las dietas contenían 0.25 y 0.34% de fósforo. Es probable que el bajo fósforo dietario en el T1 (0.16%) pueda haber tenido influencia sobre las variables evaluadas especialmente sobre la pubertad. Se concluye que dietas con 0.25 y 0.34% de fósforo tienen un efecto positivo sobre crecimiento, pubertad y algunos parámetros reproductivos.The objective of the study was to know the effect of phosphorus on the reproductive performance, growth and onset of puberty of female pre - pubertal and pubertal alpacas in two important stages of production, such as the breeding season (January to February) and weaning ( August September). In the first stage of the study, blood levels of phosphorus were determined in 200 female alpacas of approximately 11-13 months of age located in four regions of greater importance for alpacas breeding in Perú. Levels of 8.25 ± 0.23, 5.25 ± 0.12, 6.42 ± 0.16, 4.8 ± 0.14 mg / dl were found for Cerro de Pasco, Junín, Cuzco and Puno regions, respectively. Significant differences (P <0.05) were found among the four regions, and these data were compared with the expected range for alpacas (Van Saun , 2014) (5-11.5 mg/dl). In a second part of the study, a controlled experiment with different concentrations of phosphorus in the diet was performed: 0.16% (T1), 0.25% (T2), and 0.34% (T3). Forty-eigth female alpacas post weaning (25.24 ± 0.17 kg) were used, with ad libitum feeding, with 16 animals per treatment housed in individual pens for a period of 7 months and ages range from seven to eight months. There was a phosphorus effect (p <0.05) on the majority of variables evaluated as live weight, body condition when the levels in the diets were 0.25 and 0.34%. Dry matter intake expressed in kg / day was 0.71 ± 0.01, 0.82 ± 0.01 and 0.96 ± 0.02 while, as a percentage of live weight it was 2.07, 2.24 and 2.60 for treatments T1, T2 and T3 respectively. The reproductive variables such as pre ovulatory follicle size, embryonic mortality, ovulation rate and puberty were improved when the diets contained 0.25 and 0.34% phosphorus. It is likely that low dietary phosphorus in T1 may have had an influence on the variables evaluated especially on puberty. It is concluded that diets with 0.25 and 0.34% phosphorus have a positive effect on growth, puberty and some reproductive parameters.Tesi

Statistical modeling approach for PM10 prediction before and during confinement by COVID-19 in South Lima, Perú

A total of 188,859 meteorological-PM10 data validated before (2019) and during the COVID-19 pandemic (2020) were used. In order to predict PM10 in two districts of South Lima in Peru, hourly, daily, monthly and seasonal variations of the data were analyzed. Principal Component Analysis (PCA) and linear/nonlinear modeling were applied. The results showed the highest annual average PM10 for San Juan de Mirafores (SJM) (PM10-SJM: 78.7 µg/m3) and the lowest in Santiago de Surco (SS) (PM10 -SS: 40.2 µg/m3). The PCA showed the infuence of relative humidity (RH)-atmospheric pressure (AP)temperature (T)/dew point (DP)-wind speed (WS)-wind direction (WD) combinations. Cool months with higher humidity and atmospheric instability decreased PM10 values in SJM and warm months increased it, favored by thermal inversion (TI). Dust resuspension, vehicular transport and stationary sources contributed more PM10 at peak times in the morning and evening. The Multiple linear regression (MLR) showed the best correlation (r = 0.6166), followed by the three-dimensional model LogAP-LogWD-LogPM10 (r = 0.5753); the RMSE-MLR (12.92) exceeded that found in the 3D models (RMSE < 0.3) and the NSE-MLR criterion (0.3804) was acceptable. PM10 prediction was modeled using the algorithmic approach in any scenario to optimize urban management decisions in times of pandemic.Campus San Juan de Luriganch

Efecto del pre-pastoreo con vacunos sobre las dietas de alpacas y ovinos en pastizales naturales

Universidad Nacional Agraria La Molina. Escuela de Posgrado. Maestría en Producción AnimalEl objetivo del estudio fue evaluar el efecto del pre-pastoreo con vacunos sobre la composición botánica, selectividad y composición química de dietas de alpacas y ovinos. El área experimental fue un pajonal de condición buena y el pastoreo se realizó en dos épocas del año; lluvias (abril) y época seca (agosto). Se utilizó un diseño de bloques con arreglo factorial 2 (tipo de pastoreo) x 2 (especie animal) donde los tratamientos fueron pastoreo excluyente solo con ovinos y alpacas, y pre – pastoreo de vacunos con pastoreo de ovinos y alpacas. El campo se dividió en 8 potreros de 40 x 40 metros cada uno, donde se introdujeron 15 ovinos, 15 alpacas y 4 vacunos, de los cuales 5 ovinos y 5 alpacas se utilizaron para el muestreo de dietas. Al final de dos días de pastoreo en cada tratamiento, se muestrearon las dietas de alpacas y ovinos mediante técnica de simulación manual (Austin et al., 1983) para evaluar la composición botánica, selectividad de las dietas comparándolas con la composición botánica del campo y la composición química de las mismas. El pastoreo mixto con vacunos mejoró la composición de las dietas de ovinos respecto al pastoreo solo con ovino. Los ovinos seleccionaron menor cantidad de gramíneas altas a favor de una mayor selección de plantas con menor cantidad de pared celular como la Alchemilla pinnata (rosáceas). El pre - pastoreo con vacunos mejoró la selectividad, digestibilidad y el nivel de proteína cruda de las dietas de ovinos respecto al pastoreo excluyente solo con ovinos (p<0.05). Las alpacas por el contrario no mostraron cambios significativos en la composición de sus dietas después del pastoreo de vacunos confirmando que esta especie tiene una capacidad adaptativa al cambio del sistema de pastoreo. En conclusión el pre-pastoreo con vacunos tuvo un efecto positivo sobre la composición botánica, selectividad y composición química de las dietas de ovinos y alpacas mejorando la calidad de dieta.The aim of the study was to evaluate the effect of pre-grazing cattle on botanical composition, selectivity and chemical composition of diets of alpacas and sheep. The experimental area was a natural grassland good condition and grazing was conducted in two seasons; rainy (April) and dry season (August). Block design with factorial arrangement 2 (Type grazing) x 2 (animal species) was used, where treatments were sheep and alpaca exclusive grazing, and sheep and alpaca with cattle pre - grazing. The field was divided into 8 paddocks of 40 x 40 meters, where 15 sheep, 15 alpacas and 4 cattle were introduced. Five alpacas and five sheep were used for sampling diets. At the end of two days of grazing in each treatment, diets of alpacas and sheep were sampled using technical manual simulation (Austin et al., 1983) to evaluate the botanical composition, selectivity diets by comparing them with the botanical composition of the field and chemical composition. Mixed grazing with cattle improved the composition of the diets of sheep. Sheep selected fewer tall grasses and prefer plants with fewer cell walls such as Alchemilla pinnata (Rosaceae). Cattle pre - grazing improved selectivity, digestibility and crude protein levels of sheep diets compared to sheep exclusive grazing (p <0.05). Alpacas on the other hand showed no significant changes in the composition of their diets after cattle pre-grazing confirming that alpacas have an adaptive capacity to different grazing systems. In conclusion, cattle pre-grazing had a positive effect on the botanical composition, selectivity and chemical composition of sheep and alpaca diets improving the quality diet.Tesi

Statistical modeling approach for PM10 prediction before and during confinement by COVID-19 in South Lima, Perú

A total of 188,859 meteorological-PM10 data validated before (2019) and during the COVID-19 pandemic (2020) were used. In order to predict PM10 in two districts of South Lima in Peru, hourly, daily, monthly and seasonal variations of the data were analyzed. Principal Component Analysis (PCA) and linear/nonlinear modeling were applied. The results showed the highest annual average PM10 for San Juan de Miraflores (SJM) (PM10-SJM: 78.7 μ g/m3) and the lowest in Santiago de Surco (SS) (PM10-SS: 40.2 μ g/m3). The PCA showed the influence of relative humidity (RH)-atmospheric pressure (AP)-temperature (T)/dew point (DP)-wind speed (WS)-wind direction (WD) combinations. Cool months with higher humidity and atmospheric instability decreased PM10 values in SJM and warm months increased it, favored by thermal inversion (TI). Dust resuspension, vehicular transport and stationary sources contributed more PM10 at peak times in the morning and evening. The Multiple linear regression (MLR) showed the best correlation (r = 0.6166), followed by the three-dimensional model LogAP-LogWD-LogPM10 (r = 0.5753); the RMSE-MLR (12.92) exceeded that found in the 3D models (RMSE < 0.3) and the NSE-MLR criterion (0.3804) was acceptable. PM10 prediction was modeled using the algorithmic approach in any scenario to optimize urban management decisions in times of pandemic