Monitoring of genetic diversity in the endangered Martina Franca donkey population

The Martina Franca (MF) donkey, an ancient native breed of Apulia, was mostly famous for mule production. The breed was at serious risk of ex- tinction in the 1980s following the decrease in demand for draft animals because they were increasingly re- placed by agricultural machinery. Much has been done in the last few decades to safeguard the existing don- key breeds, but the situation remains critical. Success- ful implementation of conservation measures includes an evaluation of the present degree of breed endanger- ment, so the aim of this work was to analyze the demo- graphic and genetic parameters of this breed to suggest effective conservation strategies. With a current breed register counting less than 500 recorded animals, the pedigree data set included 1,658 MF donkeys born be- tween 1929 and 2006. Analyses were carried out on the whole data set as well as on a smaller one consisting of 422 living animals. Demographic and genetic vari- ability parameters were evaluated using the ENDOG (v4.6) software. The pedigree completeness level was evaluated as well as the generation length, which was calculated for each of the 4 gametic pathways. This in- formation was obtained from animal birth date records together with those of their fathers and mothers. The effective number of founders (fe), the effective number of ancestors (fa), the founder genome (fg), individual inbreeding (F), average relatedness (AR), and the rate of inbreeding per generation were analyzed to describe the genetic variability of the population. Because pedi- gree depth and completeness were appropriate, espe- cially regarding the current population, the parameters defining genetic variability, namely, f e, fa, fg, F, and AR, could be reliably estimated. Analysis of these param- eters highlighted the endangerment status of the MF donkey. Our special concern was with the increased percentage of males and females exhibiting increased AR values. Moreover, the effective size of the current population, 48.08, is slightly less than the range of the minimum effective size, and the rates of inbreeding per generation found in the current MF population exceed the maximum recommended level of 1%. Such a scenar- io heightens concerns over the endangered status of the MF breed and calls for proper conservation measures and breeding strategies, such as selecting individuals for mating when relationships are below 12.5%.