I. De Amicis

Electrolytes changes in mammary secretions before foaling in jennies

No knowledge regarding the peripartum changes in mammary secretions in the jenny are presently available in literature. In the mare, instead, several studies report the role of these changes as indicators of foetal readiness for birth and impending parturition. This experiment was designed to determine calcium, sodium, potassium concentrations, and the value of sodium/potassium ratio in mammary fluids during prepartum in the jenny. Samples were daily collected by hand milking, after mammary gland size increased noticeably, from 17 Martina Franca jennies. Prepartum mammary secretions were analysed every other day between day 10 and day 2 antepartum, and then once a day from the day before to the day of parturition. Calcium concentration showed a significant increase between day 10 and day 6 antepartum and then between day 6 and days 4 and 2. Afterwards, another statistical significant increase was observed at parturition. Sodium concentration significantly decreased from day 10 to day 2 prepartum. Potassium concentration significantly increased between day 10 and day 8 before parturition, then showed a further increase at day 4, followed by none significant changes until foaling. All jennies showed a reversal in sodium/potassium ratio between 2 days antepartum and the day before. In conclusion, the evaluation of mammary fluid calcium concentrations and the reversal of sodium/potassium ratio could be used as good indicators of foetal maturity in the jenny. As far as the prediction of parturition is concerned, the reversal of sodium/potassium ratio is the best parameter, since it was detected 48-24 h before parturition in all considered animals.

Characteristics of donkey spermatozoa along the length of the epididymis

In mammals, the epididymis has numerous interrelated functions including absorptive and secretory activity that affect luminal environment and cell membrane, and the maturation and storage of sperm. Spermatozoa acquire their motility and fertilizing ability during their passage through the epididymis and the motility of epididymal spermatozoa should be a balance between the maturation of flagellum and the inhibition of the flagellar machinery. In this study maturational change in sperm characteristics were evaluated in the epididymis of donkey. Spermatozoa collected from four portions of the epididymis (head, cranial corpus, caudal corpus, tail) were compared before and after ejaculation for viability, mitochondrial activity, kinetic parameters, and morphology. A significant increase in the mitochondrial activity along the epididymis was reported, suggesting a possible involvement in the motion mechanism. This should be corroborated by the significant correlation between mitochondrial activity and the total and progressive motility and the increase in velocities of spermatozoa recorded by computer-assisted sperm analysis. The percentage of most of the abnormal spermatozoa were similar in all tracts, with a great variability between jackasses. Only the bent midpiece percentage decreased significantly along epididymis. A significant increase in the percentage of distal cytoplasmic droplets (DCD), and a simultaneous decrease in the proximal cytoplasmic droplets (PCD), was found. The DCD fell down after ejaculation suggesting the late loss of the cytoplasmic residual (DCD) in the donkey, as hypothesized in the stallion. Because the prevalence of PCD were similar in both tail epididymal and ejaculated spermatozoa, a defect of the maturative process in the PCD sperm should be speculated.

Luteal function in jennies following PGF2α treatment 3 days after ovulation

Native PGF(2alpha) and its analogs have been used in the horse mare to manipulate ovarian activity, primarily as luteolytic agents to induce estrus. Despite numerous studies on the effects of these luteolysins in the mare, to date only a single investigation has been conducted in the jenny. The aim of this study was to evaluate the response of the corpus luteum (CL) to a single dose of PGF(2alpha) given 3 days (72h) after ovulation and to establish the plasma progesterone (P4) profile from pre-treatment to post-treatment ovulation in the Martina Franca donkey. Twenty-two jennies were ultrasonographically monitored and treated 72h after the detection of ovulation with 0.075 mg i.m. of R-cloprostenol. From the day of ovulation until ovulation post-treatment, blood was collected daily for P4 determination by enhanced luminescence immunoassay. All the jennies except one, exhibited behavioral signs of PGF(2alpha)-induced estrus within 4 days of treatment lasting 5.4+/-1.16 days. Post-treatment ovulation was also hastened, reducing the interovulatory interval (9.6 days). In response to treatment, plasma P4 concentrations fell to estrus levels and then remained constant until the next ovulation in all but the non-responding animal. Our findings indicate that PGF(2alpha) treatment on Day 3 post-ovulation causes the functional regression of the CL in the jenny, reflected both by the rapid induction of estrus and ovulation and by an abrupt drop in circulating P4 concentrations.

Selected Metabolic and Hormonal Profiles during Maintenance of Spontaneous Ovarian Cysts in Dairy Cows

Information is lacking regarding the relationship between metabolic and hormonal profiles and the maintenance of spontaneous ovarian cyst disease in dairy cows. For this reason, the concentrations of non-esterified fatty acids (NEFA), insulin-like growth factor I (IGF-I) and cortisol (C) were investigated during the spontaneous course of ovarian cyst disease in dairy cows (n=6) between the 7th and 16th weeks post-partum (PP). The control group consisted of normally cycling cows (n=6). Blood samples were collected twice a day, and plasma was analysed using different techniques. Progesterone and 15-ketodihydro-PGF(2α) plasma profiles were investigated to confirm the ovulatory or anovulatory conditions of the cows. Cortisol plasma levels were not significantly different among sampling times within each group or between the two groups. NEFA plasma levels were significantly higher in cycling cows compared to cystic cows at the 16th week PP (p<0.01), but with rather low values, indicating by now sparse mobilization of fat stores. Insulin-like growth factor I plasma concentrations were higher in cystic cows during the 8th, 10th, 11th (p<0.01) and 16th week PP (p<0.05), indicating that the presence of ovarian cysts coincides with increased IGF-I levels. These results suggest no influence of cortisol and NEFA levels in cysts maintenance, while a possible involvement of IGF-I can be suspected not only in the pathogenesis, as already known, but also in the maintenance of spontaneous cystic ovarian disease in cattle.

Effect of the season on some aspects of the estrous cycle in Martina Franca donkey

The Martina Franca (MF) donkey breed, with 48 jackasses and 515 jennies, is considered an endangered breed according to the data from the Monitoring Institute for Rare Breeds and Seeds in Europe. The knowledge of the estrous cycle characteristics has a great impact for assisted reproduction, especially in endangered species. In this study, the estrous cycle characteristics were investigated in 12 MF jennies throughout the year. Estrous cycle, estrous and diestrous lengths, follicular growth and ovulation, and estradiol-17β (E2) and progesterone (P4) plasma concentrations were monitored in MF jennies and compared in different seasons. In all jennies (100%) estrous cycle was detected during the whole year, with no differences in the estrous cycle length among seasons. However, a significant increase of estrous length in spring and summer compared with autumn and winter was found. Diestrus was shorter in summer than in the other seasons. Estrous behavior was always shown and characterized by rhythmic eversion of the vulvar labia (winking) with exhibition of the clitoris, urination, male receptivity and clapping, with sialorrhoea, neck and head extension, and back ears. Estrus was characterized by the ovulation of a larger follicle in spring and summer than in autumn and winter. The pattern of E2 and P4 plasma concentrations during the estrous cycle were similar to that reported for the mare, but without differences among the four seasons, so that a negligible effect of environmental conditions on ovarian E2 and P4 secretion was hypothesized, despite the larger diameter of the ovulating follicle in spring and summer.

Corpus Luteum Sensitivity to PGF2α Administration in the Martina Franca Jenny

A. Carluccio1,∗, U. Tosi1, A. Contri1, I. De Amicis1 and M.C. Veronesi2 1Department of Veterinary Clinical Sciences, Division of Obstetrics-Gynaecology and Animal Reproduction, Faculty of Veterinary Medicine, University of Teramo, 64020, Teramo, Italy; 2Department of Veterinary Clinical Sciences, Division of Obstetrical and Gynaecological Clinics, Faculty of Veterinary Medicine, University of Milan, 20133, Milan, Italy ∗Correspondence: E-mail: carluccio@unite.it

Ultrasonographic evaluation of sexual glands before and after ejaculation in the jackass

Ultrasonographic evaluation of sexual glands before and after ejaculation in the jackass A. Contri & U. Tosi & I. De Amicis & M. C. Veronesi & S. Panzani & A. Carluccio Published online: 7 August 2008 # Springer Science + Business Media B.V. 2008

Hormonal and metabolic profiles in post partum ovarian cysts in dairy cows

Hormonal and metabolic profiles in post partum ovarian cysts in dairy cows F. Cairoli & A. Comin & S. Scocca & U. Fazzini & I. De Amicis & M. Battocchio Published online: 7 August 2008 # Springer Science + Business Media B.V. 2008

Effect of Dry Period Length on NEFA and IGF-I Plasma Concentrations and Postpartum Ovarian Activity Resumption in Dairy Cows

The current study was carried out to examine the effects of dry period duration on NEFA and IGF-I plasma concentrations and postpartum ovarian activity resumption in dairy cows. Twenty-five pregnant Friesian cows (second and third lactation) were randomly assigned to one (standard dry period, 9 weeks, group C, n = 12) of two (short dry period, 5 weeks, group T, n = 13) treatments. Blood samples for NEFA and IGF-I analyses were collected once a week during the last 5 weeks prepartum and the first 14 weeks of lactation. Milk whey collection (twice/week) for progesterone analysis began 2 weeks after parturition and was used to detect ovarian activity resumption (at least three consecutive samples with P4 ≥ 300 pg/mL). The data obtained were analyzed by ANOVA for repeated data (mixed) and GLM of the SAS statistical package. Short dry periods reduced milk production (26.55 vs. 27.55 kg/day; P ≤ 0.01), without modifying milk quality. The mean interval from calving to first postpartum cycle was shorter in group T than in group C (34.5 vs. 46.9 days, P ≤ 0.01). No differences were found in NEFA plasma concentrations between groups either before or after calving, while IGF-I circulating concentrations were higher in group T than in group C during both the dry period and the first 14 weeks of lactation (P ≤ 0.01). In conclusion, the reduction in the dry period had a positive impact on metabolic balance and time of postpartum resumption of ovarian activity.