Short communication. Real-time ultrasonography for early pregnancy diagnosis and incidence of embryonic/foetal mortality in farmed Iberian red deer hinds

Abstract

The main objective of the present study was to evaluate the accuracy of the trans-rectal ultrasonography technique applied to the Iberian red deer hinds since it has not been previously documented in Spain. Experimentation was also used to test the hypothesis that a lower fertility in young hinds could be due to an increment in embryonic or foetal mortality. For this purpose, 116 hinds divided in three groups depending on its age (young, adults and senescent) were examined by rectal ultrasonography and the different foetal structures measured two months after the males were removed from the groups of hinds. With these data, specificity and predictive value of negative diagnoses of the technique has been calculated. Trans-rectal ultrasonography is an accurate technique to use in Iberian red deer dams with overall levels of pregnant detection near to 92%. Finally, the youngest hinds showed poorer fertility rates (17.24% vs. 59.30% and 58.33% of senescent and prime-age respectively) and also higher of embryonic or foetal mortality (2 deaths out of 7 positive pregnant diagnoses compared with no deaths in the senescent group and 4 deaths out of 39 positive pregnant diagnoses in the prime-age group).Additional key words: echography; fertility; reproduction; Spain. ResumenNota corta. Aplicación de la ultrasonografía transrectal en el diagnóstico precoz de gestación y evaluación de la mortalidad embrionaria/fetal en ciervas ibéricas mantenidas en granja El objetivo principal del presente estudio ha sido evaluar la precisión de la ultrasonografía transrectal aplicada a las ciervas ibéricas, ya que no ha sido documentado previamente en España. Paralelamente, se ha intentado comprobar la hipótesis de que la menor fertilidad en las hembras más jóvenes podría deberse a una mayor mortalidad embrionariofetal. Para ello, 116 hembras divididas en tres grupos en función de su edad (jóvenes, adultas y viejas) fueron ecografiadas a los 2 meses de la retirada de los machos y medidas las diferentes estructuras fetales. Con estos datos se ha calculado la especificidad y seguridad en el diagnóstico negativo de la técnica. La ultrasonografía transrectal es una técnica precisa para su uso en ciervas ibéricas, con niveles de detección de gestación cercanos al 92%. Finalmente, las ciervas más jóvenes muestran peores índices de fertilidad (17,24% vs 59,30% y 58,33% del grupo de viejas y adultas respectivamente) y mayores mortalidades embrionario-fetales (2 muertes de 7 diagnósticos gestantes positivos en comparación con ninguna muerte en el grupo de hembras de más edad y con 4 muertes de 39 diagnósticos gestantes en las hembras adultas).

Reproductive failure in moose (Alces alces) due to embryonic mortality and unfertilized oocytes

“…In free-ranging caribou ( Rangifer tarandus ), Russell et al ( 1998 ) reported embryonic mortality in 8.5 % (12/141) of the investigated radio-collared females, using repeated hormone analyses (progesterone, pregnancy-specific protein). Using transrectal ultrasonography after mating, and studying subsequent parturition rates, Gómez-Nieto et al ( 2011 ) stated that 13.0 % (6/46) of captive red deer ( Cervus elaphus ) most likely had experienced embryonic mortality. Embryonic mortality and lack of fertilization of oocytes are well-known occurrences in domestic species, e.g., cattle (Diskin et al 2011 ; Hanly 1961 ; King 1991 ), sheep (Cognie et al 1975 ; Dutt and Simpson 1957 ; Vázquez et al 2009 ; Viñoles et al 2012 ), goats (Armstrong and Evans 1983 ; Gonz et al 2004 ; Shelton 1978 ), pigs (Dziuk 1968 ; Geisert et al 2007 ; Soede et al 1994 ), and horses (Ball et al 1986 ; Dippert et al 1994 ; Newcombe and Cuervo-Arango 2011 ), and underlying causes of may be infectious (bacteria, virus, parasites, fungi) or of genetic, endocrine, and environmental origin (Diskin et al 2011 ).…”