The aim of the following review is to describe the seasonal reproductive behavior in male and female ungulates, and identify the determinants of reproductive synchrony. Intrinsic and extrinsic factors that influence the reproductive seasonality of ungulates analyzed. Intrinsic factors are related to the same individual such as genotypic and phenotypic characteristics, and implies that the reproductive aspects can not be extrapolated between species and breeds, and are modified by the action of external factors such as photoperiod, availability of food, temperature, latitude, among others. Among these factors are identified primarily photoperiod and food availability. The photoperiod and food availability are the main signals that determine melatonin levels, and this modulates the reproductive function. Photoperiod is related to the intensity of light and darkness that animals are exposed...

The aim of the following review is to describe the seasonal reproductive behavior in male and female ungulates, and identify the determinants of reproductive synchrony. Intrinsic and extrinsic factors that influence the reproductive seasonality of ungulates analyzed. Intrinsic factors are related to the same individual such as genotypic and phenotypic characteristics, and implies that the reproductive aspects can not be extrapolated between species and breeds, and are modified by the action of external factors such as photoperiod, availability of food, temperature, latitude, among others. Among these factors are identified primarily photoperiod and food availability. The photoperiod and food availability are the main signals that determine melatonin levels, and this modulates the reproductive function. Photoperiod is related to the intensity of light and darkness that animals are exposed...

The aim of the following review is to describe the seasonal reproductive behavior in male and female ungulates, and identify the determinants of reproductive synchrony. Intrinsic and extrinsic factors that influence the reproductive seasonality of ungulates analyzed. Intrinsic factors are related to the same individual such as genotypic and phenotypic characteristics, and implies that the reproductive aspects can not be extrapolated between species and breeds, and are modified by the action of external factors such as photoperiod, availability of food, temperature, latitude, among others. Among these factors are identified primarily photoperiod and food availability. The photoperiod and food availability are the main signals that determine melatonin levels, and this modulates the reproductive function. Photoperiod is related to the intensity of light and darkness that animals are exposed...

The aim of the following review is to describe the seasonal reproductive behavior in male and female ungulates, and identify the determinants of reproductive synchrony. Intrinsic and extrinsic factors that influence the reproductive seasonality of ungulates analyzed. Intrinsic factors are related to the same individual such as genotypic and phenotypic characteristics, and implies that the reproductive aspects can not be extrapolated between species and breeds, and are modified by the action of external factors such as photoperiod, availability of food, temperature, latitude, among others. Among these factors are identified primarily photoperiod and food availability. The photoperiod and food availability are the main signals that determine melatonin levels, and this modulates the reproductive function. Photoperiod is related to the intensity of light and darkness that animals are exposed...

La toxicidad del boro sigue siendo de conocimiento  limitado, aunque estudios experimentales indican efectos en el sistema reproductivo de manera que, el conocimiento sobre sus concentraciones en agua potable es de prioridad para la regulación ambiental. El propósito de este estudio fue determinar los niveles de boro en reservorio de agua potable de la cuenca hidrográfica Locumba, Región Tacna-Perú. Se realizó un muestreo probabilístico aleatorio en los meses de agosto y noviembre del 2016, encontrándose concentraciones de boro (8,681 y 4,148 mg.L-1) por encima al valor regulado (2,4 mg.L-1). La prueba t-Student indicó diferencias estadísticamente significativas (p≥0.05) entre los valores determinados. Se concluyó que, las concentraciones de boro en el reservorio de agua potable durante los meses de agosto y noviembre son un riesgo para la salud humana.