Roswitha Baumung

A cis-acting regulatory mutation causes premature hair graying and susceptibility to melanoma in the horse

In horses, graying with age is an autosomal dominant trait associated with a high incidence of melanoma and vitiligo-like depigmentation. Here we show that the Gray phenotype is caused by a 4.6-kb duplication in intron 6 of STX17 (syntaxin-17) that constitutes a cis-acting regulatory mutation. Both STX17 and the neighboring NR4A3 gene are overexpressed in melanomas from Gray horses. Gray horses carrying a loss-of-function mutation in ASIP (agouti signaling protein) had a higher incidence of melanoma, implying that increased melanocortin-1 receptor signaling promotes melanoma development in Gray horses. The Gray horse provides a notable example of how humans have cherry-picked mutations with favorable phenotypic effects in domestic animals.

Analysis of diversity and population structure in the Lipizzan horse breed based on pedigree information

The pedigrees of 565 Lipizzan horses from eight European studs were traced back to the individuals considered as the founding population of the breed. The length of pedigrees was up to 32 generations, with an average of 15.2 complete generations. Average inbreeding coefficients varied from 8.6 to 14.4% between studs, with an overall mean of 10.8%. Increase in inbreeding was relatively small in the last generation. Other measures of genetic variability based on contributions of founders or important ancestors were also calculated, leading to partly different conclusions about the variability of the population at stud level. Average coancestries between studs showed that the two Romanian studs were most similar but also that the Austrian, Slovenian and Italian studs formed a cluster of genetically similar individuals. The pedigrees were also used to calculate gene proportions of founder breeds and individual founders. About 52% of the current genes are of Spanish or Italian origin, 21% Arabian, 8% Fredriksborg, 4% Kladruby, 3% English and 2% Shagya-Arab. The most important founder individual was Toscanello Hedera, followed by Neapolitano, one of the founders of the classical stallion lines, each contributing more than 6% of the current gene pool.

Comparison of production systems and selection criteria of Ankole cattle by breeders in Burundi, Rwanda, Tanzania and Uganda

A survey in Burundi, Rwanda, Tanzania and Uganda was conducted in order to determine the different production systems under which Ankole cattle are currently kept. Additionally, selection criteria of livestock keepers were documented. In Burundi, Rwanda and parts of Uganda, livestock keepers are sedentary and herds are small, whereas in the other areas Ankole cattle are kept in large herds, some of them still under a (semi-)nomadic system. Milk is the main product in all areas, and is partly for home consumption and partly for sale. Although the production systems vary in many aspects, the selection criteria for cows are similar. Productive traits such as milk yield, fertility and body size were ranked highly. For bulls, the trait ‘growth’ was ranked highly in all study areas. Phenotypic features (coat colour, horn shape and size) and ancestral information are more important in bulls than in cows. The only adaptive trait mentioned by livestock keepers was disease resistance. In areas of land scarcity (Burundi, Rwanda, western Uganda), a clear trend from pure Ankole cattle towards cross-bred animals can be observed.

Mating practices and the dissemination of genetic disorders in domestic animals, based on the example of dog breeding

On the basis of simulations and genealogical data of ten dog breeds, three popular mating practices (popular sire effect, line breeding, close breeding) were investigated along with their effects on the dissemination of genetic disorders. Our results showed that the use of sires in these ten breeds is clearly unbalanced. Depending on the breed, the effective number of sires represented between 33% and 70% of the total number of sires. Mating between close relatives was also found to be quite common, and the percentage of dogs inbred after two generations ranged from 1% to about 8%. A more or less long-term genetic differentiation, linked to line breeding practices, was also emphasized in most breeds. F(IT) index based on gene dropping proved to be efficient in differentiating the effects of the different mating practices, and it ranged from -1.3% to 3.2% when real founders were used to begin a gene dropping process. Simulation results confirmed that the popular sire practice leads to a dissemination of genetic disorders. Under a realistic scenario, regarding the imbalance in the use of sires, the dissemination risk was indeed 4.4 times higher than under random mating conditions. In contrast, line breeding and close breeding practices tend to decrease the risk of the dissemination of genetic disorders.

Pedigree analysis in the Austrian Noriker draught horse: genetic diversity and the impact of breeding for coat colour on population structure

The pedigree of the current Austrian Noriker draught horse population comprising 2808 horses was traced back to the animals considered as founders of this breed. In total, the number of founders was 1991, the maximum pedigree length was 31 generations, with an average of 12.3 complete generations. Population structure in this autochthonous Austrian draught horse breed is defined by seven breeding regions (Carinthia, Lower Austria, Salzburg, Styria, Tyrol, Upper Austria and Vorarlberg) or through six coat colour groups (Bay, Black, Chestnut, Roan, Leopard, Tobiano). Average inbreeding coefficients within the breeding regions ranged from 4.5% to 5.5%; for the colour groups, the coefficients varied from 3.5% to 5.9%. Other measures of genetic variability like the effective number of founders, ancestors and founder genomes revealed a slightly different genetic background of the subpopulations. Average co-ancestries between and within breeding areas showed that the Salzburg population may be considered as the nucleus or original stock whereas all other subpopulations showed high relationship to horses from Salzburg. The target of draught horse breeding in the 21st century does not meet the breeding concept of maximizing genetic gains any more. Stabilizing selection takes place. In this study, we show that demographic factors as well as structure given by different coat colours helped to maintain genetic diversity in this endangered horse breed.

Performance of crossbred and indigenous sheep under village conditions in the cool highlands of central-northern Ethiopia: growth, birth and body weights

Abstract Sheep in the cool highlands of central-northern Ethiopia are of the meat type, have coarse wool, and are often perceived to be low in productivity. To increase their productivity, they have been upgraded with Awassi sheep. The aim of this study was to compare the performance of 37.5% Awassi×indigenous crossbreds with that of indigenous lambs in terms of birth weights, body weights and average daily gains at different stages from birth to 210 days of age. Data were collected between 1997 and 1999, and analysed by GLM procedures of SAS. The effects of farmer, season and birth year, linear regression of lambs’ age, and dam postpartum body weights were significant for all traits studied. Sex variation was important as the lambs grew older. Crossbred lambs were heavier than indigenous lambs at birth and at all ages. However, crossbred lambs were not significantly better than indigenous lambs in average daily gains. The birth weight advantage was also lost with increasing age, indicating that the milk production of ewes of the dam breed was inadequate to rear large size crossbreed lambs.

Individual-based assessment of population structure and admixture in Austrian, Croatian and German draught horses

All over Europe, the number of draught horses has decreased drastically during the last 50 years. As a prerequisite for efficient management decisions, we analysed the conservation status in Austrian (Noriker Carinthia – NC, Noriker Salzburg – NS), Croatian (Croatian Coldblood – C, Posavina horse – P) and German (Altmaerkisch Coldblood – A, Black Forest horse – BF, Mecklenburg Coldblood – M, Rhenish German Draught horse – R, Saxon Thuringa Coldblood – ST, Schleswig Draught horse – Sch, South German Coldblood – SG) draught horses (434) using multilocus genotypic information from 30 (effectively 27) microsatellite loci. Populations located in areas with less intensive agricultural production (C, NC, NS, P and SG) had greater diversity within the population and estimated effective population size than A, BF, Sch, M, R and ST populations. The PCA plots revealed that populations form five separate groups. The ‘Noriker’ group (NC, NS and SG) and the ‘Rhenish’ group (A, M, R and ST) were the most distinctive (pairwise FST values ranged from 0.078 to 0.094). The ‘Croatian’ group (C and P) was in the centre, while the BF and Sch populations formed two out-groups. A posterior Bayesian analysis detected further differentiation, mainly caused by political and geographical factors. Thus, it was possible to separate the South German Coldblood from the Austrian Noriker population where no subpopulation structure was detected. The admixture analysis revealed imprecise classification between C and P populations. A small but notable separation of R from A, M and ST populations was detected, while Sch and BF populations remained as out-groups. The information obtained should aid in making efficient conservation decisions.

Economic values for performance and functional traits in dairy sheep

abstract In order to establish a total merit index, the relative economic values of the traits considered must be known. Hence, the objective of this study was to derive economic values, defined by the value of one unit of superiority of a trait, for essential traits in dairy sheep based on a herd model. These traits included dairy (milk carrier = water, lactose and mineral nutrients, fat and protein yield), fattening (daily gain, dressing percentage, and EUROP grading score) and functional traits (stillbirth rate, losses until first mating, litter size, lambing interval, and functional longevity). To avoid double counting, the economic value for each trait was derived while keeping all other traits constant. A sheep herd with milk production, lamb fattening and rearing of young sheep for replacement was modelled. The following economic values (in €) per ewe place and year and genetic standard deviation were derived: 21.45 (milk carrier yield), 11.73 (fat yield), 16.87 (protein yield); 3.62 (daily gain), 1.62 (dressing percentage), 1.45 (EUROP-grading score), -0.28 (functional longevity), 3.00 (litter size), 1.77 (stillbirth), 5.92 (losses before first mating), and 5.35 (lambing interval). When setting functional longevity to zero, relative economic values for the trait complexes in % were as follows: dairy:meat:functional traits = 68.8:9.2:22.0, respectively.

Genetic diversity and population structure of the synthetic Pannon White rabbit revealed by pedigree analyses

Demographic history, current status, and efficiency of the mating strategy were analyzed using the pedigree of Pannon White (PW) rabbits born between 1992 and 2007. Potential accumulation of detrimental effects and loss of genetic diversity were also considered. Calculations and estimates were done most often for rabbits born in 2007, whereas other reference populations (REFPOPXXXX) were specified explicitly. The pedigree contained 4,749 individuals and 580 founders, and its completeness was 82.1% up to 10 and 94.5% up to 5 generations, respectively. Generation intervals through different pathways averaged 1.2 yr. When adjusted to the pedigree completeness, the amount of inbreeding (F(i)) of rabbits was comparable (5.54%) with that of other livestock populations, whereas the 10 (30) founders contributing the most to inbreeding explained a large part of the population inbreeding [i.e., 42.24% (73.18%)]. The ancestral inbreeding coefficient of REFPOP2004 (10.67%) was one-half that of REFPOP2007 (20.66%), showing its strong dependence on pedigree length. Family variance, inbreeding, and realized effective population size were 84.18 (REFPOP2006; this variable could not be calculated for the last year examined), 37.19, and 91.08, respectively. The effective numbers of ancestors, founders, and founder genomes were 48, 26, and 7.33, respectively. Although the circular mating scheme applied was generally effective, the large accumulated reduction in genetic variability indicates the need to revise and improve the current breeding strategy.

Genetic and morphological characterisation of the Ankole Longhorn cattle in the African Great Lakes region

The study investigated the population structure, diversity and differentiation of almost all of the ecotypes representing the African Ankole Longhorn cattle breed on the basis of morphometric (shape and size), genotypic and spatial distance data. Twentyone morphometric measurements were used to describe the morphology of 439 individuals from 11 sub-populations located in five countries around the Great Lakes region of central and eastern Africa. Additionally, 472 individuals were genotyped using 15 DNA microsatellites. Femoral length, horn length, horn circumference, rump height, body length and fore-limb circumference showed the largest differences between regions. An overall FST index indicated that 2.7% of the total genetic variation was present among sub-populations. The least differentiation was observed between the two sub-populations of Mbarara south and Luwero in Uganda, while the highest level of differentiation was observed between the Mugamba in Burundi and Malagarasi in Tanzania. An estimated membership of four for the inferred clusters from a model-based Bayesian approach was obtained. Both analyses on distance-based and model-based methods consistently isolated the Mugamba sub-population in Burundi from the others.The study investigated the population structure, diversity and differentiation of almost all of the ecotypes representing the African Ankole Longhorn cattle breed on the basis of morphometric (shape and size), genotypic and spatial distance data. Twentyone morphometric measurements were used to describe the morphology of 439 individuals from 11 sub-populations located in five countries around the Great Lakes region of central and eastern Africa. Additionally, 472 individuals were genotyped using 15 DNA microsatellites. Femoral length, horn length, horn circumference, rump height, body length and fore-limb circumference showed the largest differences between regions. An overall FST index indicated that 2.7% of the total genetic variation was present among sub-populations. The least differentiation was observed between the two sub-populations of Mbarara south and Luwero in Uganda, while the highest level of differentiation was observed between the Mugamba in Burundi and Malagarasi in Tanzania. An estimated membership of four for the inferred clusters from a model-based Bayesian approach was obtained. Both analyses on distance-based and model-based methods consistently isolated the Mugamba sub-population in Burundi from the others.