The endangerment of extinction of most donkeys’ breeds in Europe deems for a better characterization of the genetic diversity of these breeds and understanding the reasons for its declining numbers, biologically and socioeconomically. The main purpose of this study is to predict the viability of the Miranda breed, identify the variables that may be crucial for conservation, and suggest new management strategies. To achieve these aims, pedigree records were analysed and socioeconomic features of herds and owners were typified to identify current environmental and management factors affecting the breeds’ future. The available data showed that, under the current management, this breed faces extinction in the next 50 years. Identified parameters suggested that, keeping all the other variables at the current level, it would be needed to cumulatively:
The age pyramid of the breed is unbalanced and, without the implementation of an energetic strategy for breeding, in a few years the lack of replacement animals may raise a huge constraint to conservation programs. The analysis showed an important loss of founder genetic diversity, perceived by the low effective number of founders compared to the real number of founders. Less than 55% of the 580 adult females registered in the Studbook ever foaled and the average foaling rate per jenny was only 1.05. This is mainly due to social and demographic changes, which dictated the abandon of donkeys as a rural workforce. Most owners, especially the older ones possessing one or two animals, do not foresee the need to replace their animals in their lifetime and do not want the inconvenience of managing late gestation and raising foals. The relatively long generation intervals observed enhance the importance for a rapid onset of the recovery programs, since it will take time just to replace the current population and even more to rejuvenate it.
In the west of the Zamora Province in Castilla y León region, one of the most rural and isolated areas of Spain, the Zamorano – Leonés donkey – a native endangered breed -is still playing a central role in the traditional daily agriculture activities practiced by the local inhabitants. In February 2010 a study was carried out to understand the prevalence of equine piroplasmosis in the population of Zamorano – Leonés Donkey, collecting blood samples from 86 animals in 13 villages in the Zamora Proviince. Equine piroplasmosis is a tick-borne disease of equids, caused by Theileria equi and Babesia caballi. These intraerythrocytic parasites are responsible for a high morbidity and mortality in equids. The cELISA tests (competitive – inhibition Enzyme-Linked Immunosorbent Assay) revealed a positive seroprevalence of 21%, with 8 of the 86 donkeys positive for Theileria equi (9.3%), 10 for Babesia caballi (11.7%) and one of these 18 animals positive for both. The results of this study clearly demonstrate the importance of equine piroplasmosis affecting the Zamorano – Leonés donkey population. As far as we know this is the first study on intra-erythrocytic parasites in endangered Iberian breeds of donkeys and the results obtained reveal its importance in order to preserve this unique genetic heritage.
Salivary duct lithiasis is a condition characterized by the partial or total obstruction of a salivary gland or its excretory duct due to the formation of sialoliths. A 9-year-old female donkey, belonging to the unique and endangered indigenous breed of donkey in Portugal, was diagnosed with a sialolith in the rostral portion of the right parotid duct based on clinical, oral, dental, and radiographic examination results. Surgical removal of the sialolith was done through a percutaneous approach.
Most donkey and local horse breeds are vulnerable to extinction as mechanization of agriculture progress throughout the world. The present study analyzed the pedigree and herd records of the donkey Asinina de Miranda breed (RAM), identifying genealogical and human factors that may affect the breed genetic diversity in the future and suggesting suitable strategies to breed preservation, early on the conservation program. The breeding rate was very low, with a ratio of foaling/live animals of 0.23 (178/760). The estimated number of founders and ancestors contributing to the reference population was 128 and 121. The number of founder herds in the reference population was 64, with an effective number of founder herds for the reference population of 7.6. The mean age of herd owners was 65.50±0.884 years, with a negative association among the herd size and owner’s age (P<0.001). In contrast, the size of the herd and the ownership of a male were both positively associated (P<0.001) with the herd number of in-born foals. Both the owners’ age and the herd location (RAM home region v. dispersal region) were negatively associated with the foaling number (P<0.001). The main identified risk factors were: low breeding rates; low number of males and their unequal contribution to the genetic pool; unequal contribution of the herds to genetic pool; and advanced age of herd owners.
Dental disease is now recognised as a major but often unrecognised disorder of equids, including horses and donkeys. However, very few large clinical studies have documented the prevalence and type of dental disease present in different equid populations and no dental studies have been reported in Zamorano-Leonés or Mirandês donkeys, two endangered donkey breeds. Clinical and detailed oral examinations were performed in 400 Mirandês and 400 Zamorano-Leonés donkeys in Portugal and Spain. It was found that just 4.5 per cent had ever received any previous dental care. Cheek teeth (CT) disorders were present in 82.8 per cent of these donkeys, ranging from a prevalence of 29.6 per cent in the <2.5-year-old group to 100 per cent in the >25-year-old group. These CT disorders included enamel overgrowths (73.1 per cent prevalence but with just 6.3 per cent having associated soft tissue injuries), focal overgrowths (37.3 per cent), periodontal disease (23.5 per cent) and diastemata (19.9 per cent). Peripheral caries was present in 5.9 per cent of cases, but inexplicably, infundibular caries was very rare (1.3 per cent prevalence); this may have been due to their almost fully foraged diet. The high prevalence of enamel overgrowths in these donkeys, most which never received concentrates, also raises questions about the aetiology of this disorder. This very high prevalence of CT disorders, especially in older donkeys, was of great welfare concern in some cases and emphasises the need for routine dental care in these cases on welfare grounds and in order to help preserve these unique breeds.
Recent clinical and post-mortem studies documented a high prevalence of dental disorders in donkeys, but less information appears to be available specifically about incisor disorders in donkeys. A study to investigate the prevalence of oral and dental disorders affecting incisor teeth was performed, in two endangered breeds of donkeys: the Mirandês Donkey and the Zamorano-Leonés Donkey, through a prospective cross-sectional study in 800 donkeys, divided in 7 age groups (ranging 0-34 years), in 86 villages inside their geographic area of distribution, thinking on welfare and genetic preservation issues. The 74% of donkeys suffer from incisors disorders, ranging from 56.8% in the youngest group to 90.3% in group 7. Craniofacial abnormalities (49.25%), abnormalities in the occlusal surface (21.63%), fractures (17%), periodontal disease (16.13%) and diastemata (14.38%) were the main disorders recorded. Incisors disorders are significant, presenting at a much higher prevalence when compared to other studies involving the incisor teeth of equids, affecting all ages but particularly in older animals. This study provide essential information in dentistry applied to donkeys but also highlighted the importance of regular dental care in endangered breeds, improving their welfare and preserving a unique genetic heritage.