Relationship of serum testosterone, sperm production, and testis traits with fertility of Mangalarga Marchador stallions

Abstract

Relación entre testosterona sérica, producción espermática y características testiculares con la fertilidad en sementales Mangalarga Marchador Relação entre testosterona sérica, produção espermática e características testiculares com fertilidade em garanhões Mangalarga MarchadorAbstract Background: Assessing breeding soundness is important to predict the potential fertility of stallions. Objective: To investigate the association of testis traits, total number of spermatozoa, and testosterone with fertility of Mangalarga Marchador breed stallions. Methods: The traits measured were testicular length, width and height, right and left testicular volume and total testicular volume. We also evaluated the total number of spermatozoa (TNS), serum testosterone concentration and fertility of stallions (by embryo recovery from donor mares) in the breeding and non-breeding seasons during 1 year. Analysis of variance was performed to verify the effects of age category (AC; young/adult) and reproductive season on the traits. Correlations and repeatability of the traits were also calculated. Results: The AC did not influence testis traits (p>0.05). Reproduction season affected left testicular length, left testicular height, right testicular width and height (p<0.05). The AC and season affected testis volume (p<0.05). There were no effects of AC and season on TNS and testosterone (p>0.05). We observed strong correlations between all testicular measurements and testicular volume (0.53 to 0.75), medium correlation between TNS and testis volume (0.32), and low correlation between testosterone and testis traits (0.20). Repeatability of the characteristics of left and right testis was medium to high (0.22 to 0.78). Embryo recovery rate was 60% and its correlation with TNS was 0.44. Conclusion: Testis size evaluation is recommended over the 37 Rev Colomb Cienc Pecu 2018; 31(1):36-44Rua MA et al. Testis traits and stallion fertiliy evaluation of serum testosterone concentration to predict sperm output. Sperm output (TNS) is a good predictor of stallion fertility. ResumenAntecedentes: Es importante realizar examen andrológico de sementales para predecir su potencial reproductivo. Objetivo: Evaluar la asociación entre características testiculares, número total de espermatozoides y testosterona con la fertilidad de sementales de raza Mangalarga Marchador. Métodos: Las características medidas fueron: longitud testicular, ancho y altura del testículo. También fue calculado el volumen testicular derecho, izquierdo y total, así como el número total de espermatozoides (TNS), concentración sérica de testosterona y fertilidad (por recuperación embrionaria de las yeguas) de los sementales dentro y fuera de la temporada reproductiva durante un año. Se realizó análisis de varianza para evaluar el efecto de categoría de edad (AC) y estación reproductiva sobre las características. Resultados: La AC no influenció las características testiculares (p>0,05). La estación reproductiva influenció la longitud del testículo izquierdo, la altura del testículo ...

Pantaneiro stallions: did the environment influence seminal traits and testicular biometry?

“…The range of minimum and maximum of the testicular traits were in general low, suggesting lower variations among stallions. The pro le of the Pantaneiro testicular biometry has not been reported before, then we are bringing new informations.Comparing the values of testis biometry of Pantaneiro stallions from this study with others we could note that means of left and right testicular length (8.6 ± 0.2 and 8.5 ± 0.2 respectively) were similar to means of LTL and RTL reported byRua et al (2018), studying Mangalarga Marchador stallions in Brazil. However, the mans of LTW, RTW, LTH and RTH were lower in the present study.…”

“…Therefore, the Pantaneiro horse seminal traits were less explored and few information are available to refers them. The evaluation of testis biometry associated with seminal characteristics provide informations about the sperm production and sperm quality witch can allow the selection of stallions with better seminal traits to reproduction (Rua et al, 2018).…”

Age‐related changes in testicular morphometry and function in Egyptian donkeys

“…Also, McKinnon et al (2011) found the percentage of testicular cells and testicular volume tends to increase with the advancement of age in the horse. On the contrary, age did not affect testis traits in the horse (Rua et al, 2018). This difference might be attributed to species difference, sample size and biological variability between animals.…”