The aim of the present study is to define and compare the predictive power of two different Bayesian models for donkey sperm quality after the evaluation of linear and combined testicular biometry indices and their relationship with age and body weight (BW). Testicular morphometry was ultrasonographically obtained from 23 donkeys (six juveniles and 17 adults), while 40 ejaculates from eight mature donkeys were analyzed for sperm output and quality assessment. Bayesian linear regression analyses were considered to build two statistical models using gel-free volume, concentration, total sperm number, motility, total motile sperm, and morphology as dependent variables. Predictive model 1 comprised the covariate of age and the independent factors testicular measurements (length, height and width), while model 2 included the covariate of age and the factors of BW, testicular volume, and gonadosomatic ratio. Although goodness-of-fit was similar, the combination of predictors in model 1 evidenced higher likelihood to predict gel-free volume (mL), concentration (×106/mL), and motility (%). Alternatively, the combination of predictors in model 2 evidenced higher predictive power for total sperm number (×109), morphologically normal spermatozoa (%), and total motile sperm count (×109). The application of the present models may be useful to gather relevant information that could be used hereafter for assisted reproductive technologies.

In endangered donkey populations, reproductive performance is one the most important areas to study, provided its connection with conservation opportunities. Among reproductive traits, the knowledge on the evolution of seminal qualitative and quantitative parameters may achieve a particular relevance given its implication with improved or more efficient fertility and fecundation chances. The aim of the present study was to model the gonadosomatic index and the quantitative and qualitative seminal parameters along age in Miranda donkeys. Forty semen collections from 8 Miranda donkeys from 2.8 and 21.6 years of age, were fitted to eleven linear and nonlinear models. Cubic function modelling reported the best-fitting properties for almost all variables, except for sperm concentration (exponential model). Cubic model presented a slightly higher ability to capture interindividual variability than less parametrically complex models and more computationally complex models, such as exponential or logarithmic. Senility may course with and larger numbers of abnormal morphology spermatozoa, and also reduced sperm concentration and motility. HIGHLIGHTSTestis reach mature size rapidly which may be ascribed to a breed factor. Age promotes ejaculate volume increase and concentration reduction. Reduced motility may ascribe to increased abnormal morphology spermatozoa. Major age-related changes are linked to testicular functions degeneration.

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Citar: Avila, E.; Leiva, F.; Darghan, A. 2017. Friabilidad y su relación con algunas propiedades físicas y químicas de suelos cultivados con caña. Rev RESUMENLa friabilidad es un indicador importante de la calidad física de los suelos y su comportamiento está ligado a la variabilidad de otras propiedades edáficas. El objetivo de esta investigación fue evaluar la relación de la friabilidad con diferentes propiedades físicas y químicas de suelos cultivados con caña de azúcar. El muestreo de suelos se realizó en los dos primeros horizontes (Ap y A1) de 91 sitios correspondientes a 5 órdenes de suelos (Inceptisol, Molisol, Vertisol, Alfisol y Ultisol). Se seleccionaron 10 agregados por cada uno de los cuatro rangos de tamaño (2,0 a 4,79; 4,80 a 9,49; 9,50 a 19,00 y 19,01 a 35,70 mm) que fueron los predominantes en los 182 horizontes. Los 7280 agregados fueron secados en invernadero y horno y posteriormente sometidos a compresión para determinar la resistencia al rompimiento (RR) y el índice de friabilidad correspondiente al límite inferior (IF i ) del intervalo de confianza del coeficiente de variación. Se determinó el diámetro ponderado medio (DPM), el estado de agregación (Ea), la densidad aparente (Da), la porosidad total (Pt), el pH y la conductividad eléctrica (CE) de las muestras de suelos. Se utilizaron medidas de tendencia central y dispersión, gráficos de superficies tridimensionales y un modelo lineal para un Diseño Completamente al Azar en arreglo factorial incompleto. No se encontró efecto del DPM, Volumen 34(2):19-32

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The well-documented versatility of donkeys (Equus africanus asinus) means that issues concerning their welfare can vary depending on how they are mainly used and their geographic location. The present study is the first assessment of donkey welfare to be systematically conducted in the Iberian Peninsula. This area is characterised by the coexistence of high levels of mechanisation and industrialisation, and human populations with low levels of formal education, still making use of donkeys in their daily work. This study aims to evaluate the main welfare problems affecting donkeys within this context. The welfare assessment was carried out in accordance with the first level of the AWIN protocol for donkeys. Only 37.6% of the animals evaluated showed all positive indicators, with no physical problem detected while the remaining 62.4% revealed at least one negative health indicator. Body Condition Score (BCS) was one of the main concerns, with around half of the donkeys exhibiting an inadequate body condition. Dental evaluation revealed similarly concerning results, with 62.8% of the animals assessed requiring treatment. Indications of hoof neglect were noted in 39.5% of the animals evaluated with a 9.84% incidence of lameness. Skin problems affected 26.7% of individuals. Only 41% of the animals displayed positive results for all behavioural indicators. Aside from BCS, the most prevalent problems were sub-optimal behaviour, pain reaction to cheek palpation, hoof disease and integument alterations. These issues should be prioritised, both as regards this specific donkey population and the education of their caretakers.