M. Quaresma

Relationship between ultrasound measurements of body fat reserves and body condition score in female donkeys.

Several methods have been developed to monitor body fat reserves of farm animals and body condition scoring (BCS) is generally assumed to be the most practical. Objective methods, such as real time ultrasonography (RTU), are accepted methods for measuring fat reserves in several farm species but there is no published information about the use of RTU to monitor body fat reserves in donkeys. The aim of the present study was to determine the relationship between RTU measurements and BCS in female donkeys (jennies) (n=16) with a BCS of 3-7 on a 9 point scale. Ultrasound images were captured using an Aloka 500-V scanner equipped with a 7.5 MHz probe and subcutaneous fat (SF, range: 1.0-14.0mm) and thoracic wall tissue (TD, range: 5.6-21.4mm) depths measurements were determined. A significant correlation was found between BCS and all RTU measurements (0.65<r<0.86; P<0.01). Linear regression models described the relationships between RTU measurements and BCS and between log transformed RTU measurements and log transformed BCS. All equations with variables transformed into a logarithmic scale gave better coefficients of determination (0.42<r(2)<0.75) and an increase of 7-23% in this coefficient. The study suggested that RTU depth measurements have a logarithmic relationship with BCS and that RTU combined with image analysis permits accurate fat and tissue depths measurements to monitor fat reserves in jennies.

Cervical hypoplasia in jennets: a description of two cases

The authors describe two cases of cervical hypoplasia in jennets, detected during the gynaecological evaluation of two purebred females of the Portuguese donkey breed Asinina de Miranda. These jennets aged 10 and 15 years were referred for consultation by the local breeders association because of infertility detected during an artificial breeding programme. In both jennets the cervix was small, shorter than the usual and closed. In one of the females, outflow of semen during artificial insemination was reported. Clinical and ultrasonographic evaluation of the genital tract demonstrated that both ovaries were normally sized in both animals and presenting structures suggestive of regular ovarian activity. In one of the jennets, a small amount of air in the uterus was evidenced. In the other, signs indicative of atresia of the cervical canal were found. Vaginal examination showed that the cervix was reduced in size and shallowed in both animals. A diagnosis of congenital cervical hypoplasia was made in both cases and the animals were excluded from reproduction.

Viability analyses of an endangered donkey breed: the case of the Asinina de Miranda (Equus asinus)

The donkey breed Asinina de Miranda, with fewer than 1000 breeding females, is in danger of extinction. The objectives of this study were to predict the progression of the breed under present management and identify determinants for survival, by means of a population viability analysis program, in order to suggest suitable management strategies. The simulation showed a high risk of extinction. The most critical factor for breed survival was the percentage of females breeding per year, but the actual percentage needed depended on the carrying capacity of the breed. Reducing female mortality and age at production of first offspring, assuring registration in the Studbook, and tracking the foals will significantly foster this donkey breed’s recovery and maintenance. The breed comprised a potentially reproductive population of 589 individuals; however, just 54.1% of the adult females registered in the Studbook ever foaled, and of these 62.7% foaled just once. The overall neonatal mortality for the first month of life was 8.92% and was lower in females (6.51%) than in males (12.0%) (P = 0.028). Neonatal mortality was unevenly distributed throughout the year, with lower mortality rates recorded in February–May and October–November, and higher mortality rates in June–September and again in December–January. The neonatal foal mortality rate was lower with females aged 5–15 years (8.06%) than those younger than 4 years (10.3%) or older than 16 years (14.1%) at foaling.

Bilateral ovulation fossa inclusion cysts in Miranda jennets.

Multiple cysts ranging from 2-111 mm were noted bilaterally in the ovulation fossa of 11 mature Miranda jennets. These ovulation fossa inclusion cysts (OFICs) were lined by a simple low to columnar epithelium that included many ciliated cells. Although most cases were incidental findings, two of the jennets were presented with reduced fertility. Extensive cyst formation could have been responsible for the reproductive problems because they replaced most of the ovarian parenchyma. Due to their close proximity to the ovulation fossa, the OFICs may have mechanically interfered with passage of eggs into the oviduct. OFICs are histologically common in equids, but are reported uncommonly as gross lesions in either mares or jennets. Ovarian inclusion cysts are associated with neoplasia in women; however, these OFICs showed no evidence of epithelial hyperplasia or cellular atypia and no evidence of independent growth, therefore they were considered to be non-neoplastic. The bilateral occurrence and high incidence of OFICs in Miranda jennets, a breed with limited genetic variability, suggests that the lesion has a genetic causation.

Reproductive Patterns in the Non-Breeding Season in Asinina de Miranda Jennies

This study aims to characterize the reproductive patterns in Asinina de Miranda jennies during the non-breeding season. Reproductive activity was surveyed in 12 females, aged between 3 and 18 years old, using ultrasound and teasing with a jack. The animals were monitored from September to April, six in each consecutive year. Of these 12 females, nine showed disruption to the normal pattern of ovarian activity during the non-breeding season. Loss of normal cyclicity included anoestrus (41.7%), silent ovulatory oestrus (25%), and persistence of corpus luteum (8.3%). Only three females maintained a regular cyclic pattern with oestrous behaviour during the non-breeding season. Anoestrus began in early November and lasted for an average of 147 ± 28 days (113-191 days), ending near to the spring equinox. Onset of silent oestrous cycles began more erratically, between October and February. In both groups the first behavioural ovulation of the year occurred around the time of the spring equinox. Disrupted reproductive activity was preceded by a shorter oestrous cycle only in females entering anoestrus. The mean follicle size in the first ovulation of the year was larger than in the reproductive season (44.7 ± 2.45 mm vs 39.2 ± 3.60 mm) in anoestrous jennies with protracted oestrus. Though age and body condition score (BCS) were associated, changes in BCS below a threshold of four points (for anoestrus) and five points (for silent oestrus) contributed greatly to disruption of reproductive cycles. BCS in females with regular oestrous cycles during the winter season remained unchanged or exceeded five points prior to the winter solstice.