Clinical, ultrasonographic, and endocrinological studies on donkey pregnancy

Although donkey breeding has gained new interest in the past two decades, knowledge about donkey reproduction is still scarce, particularly on jenny pregnancy. The aim of this study was to describe the ultrasonographic and endocrine profiles of the physiological pregnancy in the jenny. The study was performed on 12 pregnancies of 7 Amiata donkeys from Day 10 after ovulation to delivery. Because three pregnancies, respectively at weeks 42, 44, and 45, were considered pathologic and treated pharmacologically, data collected from 2 weeks before diagnosis to the end of pregnancy were removed from the analysis. Average length of the normal pregnancies was 353.4 ± 13.0 days (range, 339-370 days). Timing, dimensions, and development during the first phases of embryonic growth, evaluated using transrectal ultrasound, were similar to that previously described in jennies and mares: first detection of embryonic vesicle was at 11.8 ± 1.3 days of gestation and diameter was 6.5 ± 1.9 mm, loss of spherical shape occurred at 18.5 ± 1.4 days, and embryo and heart beat were first seen at 22.0 ± 1.1 and 25 ± 1.1 days, respectively. The intrauterine growth in the second half of pregnancy, evaluated using the transrectal and transabdominal approach, also showed strong positive correlations, similar to that reported for the mare. The trends of the combined thickness of the utero-placental unit and the echogenicity of the amniotic and allantoic fluids are examples. The diameters (mm) of fetal chest, eye orbit, and aorta increased throughout pregnancy and were 40.6 ± 2.9, 8.7 ± 1.5, and 3.5 ± 0.7, respectively, at week 13, and 190.9 ± 12.0, 21.4 ± 1.5, and 30.6 ± 1.8 at the last evaluation before parturition. In contrast, heart rate decreased as pregnancy progressed. Regression analyses between these parameters and day of gestation were statistically significant (P < 0.001). All fetuses consistently showed some intrauterine activity. Maternal plasma progestagens and estrone sulfate concentrations followed a pattern similar to that seen in mares, although the prepartal progestagen peak was lower in jennies. This study provides a range of ultrasonographic and endocrine values for normal pregnancy in jennies. © 2014 Elsevier Inc

Aspetti clinici, ecografici ed endocrinologici della gravidanza dell'asina Clinical, ultrasonographic and endocrinological aspects of donkey pregnancy

Nell’ultimo ventennio l’allevamento dell’asino in Italia sta nuovamente riscuotendo interesse. Lo scopo di questa tesi è stato quello di descrivere i quadri ultrasonografici ed endocrinologici della gravidanza fisiologica dell’asina, sulla quale esistono limitate informazioni bibliografiche. Lo studio è stato svolto su 12 gravidanze di 7 asine Amiatine dal 10° giorno post-ovulazione al parto. La durata media della gestazione è stata pari a 352,5±13,6 giorni (n=11). Tempistica, dimensioni e sviluppo nelle prime fasi di accrescimento embrionale, valutate per via transrettale, sono stati sovrapponibili a quanto riportato in letteratura nell’asina e nella cavalla. Le fasi di crescita intrauterina nella seconda metà della gravidanza, di cui non vi sono dati bibliografici sull’asino, monitorate sia per via transrettale che transaddominale, hanno evidenziato forti analogie con la cavalla. L’andamento medio dello spessore dell’unità utero-placentare e il grado di ecogenicità dei liquidi fetali ne sono degli esempi. Le analisi di regressione tra il giorno di gestazione e i diametri di torace, orbita e aorta fetali sono risultate statisticamente significative (P<0,001). Tutti i feti sono stati in presentazione anteriore al parto, avevano un buon grado di motilità intrauterina e una frequenza cardiaca che diminuiva col procedere della gravidanza. Il sessaggio fetale è stato possibile tra la 22° e la 42° settimana di gravidanza. Anche i profili delle concentrazioni plasmatiche dei progestageni e dell’estrone solfato sono risultati simili alla cavalla. In Italy, donkey breeding has again gained interest in the last two decades. The aim of this thesis, due to the scarce information present in literature, was to describe the ultrasonographic and endocrine profiles of the physiological pregnancy in the jenny. The study was performed on 12 pregnancies of 7 Amiata donkeys from day 10 post-ovulation to delivery. Average pregnancy length was 352.5±13.6 days (n=11). Timing, dimensions and development during the first phases of embryonic growth, evaluated by transrectal ultrasound, was similar to what previously described in jennies and mares. The phases of intrauterine growth in the second half of pregnancy, of which there was no literature on the donkey, evaluated both by the transrectal and transabdominal approach, showed strong similarities with the mare. The mean trends of the combined thickness of the utero-placental unit and the echogenicity of the amniotic and allantoic fluids are examples. Regression analyses between the day of gestation and the diameters of fetal thorax, orbit and aorta were highly significant (P<0.001). All fetuses were in anterior presentation at delivery, had a good intrauterine activity and a heart rate which decreased as gestational age increased. Fetal sex determination was possible between weeks 22 and 42 of gestation. Progestagens and estrone sulphate plasma concentrations were similar to what seen in mares