Pedigree and marker information requirements to monitor genetic variability

There are several measures available to describe the genetic variability of populations. The average inbreeding coefficient of a population based on pedigree information is a frequently chosen option. Due to the developments in molecular genetics it is also possible to calculate inbreeding coefficients based on genetic marker information. A simulation study was carried out involving ten sires and 50 dams. The animals were mated over a period of 20 discrete generations. The population size was kept constant. Different situations with regard to the level of polymorphism and initial allele frequencies and mating scheme (random mating, avoidance of full sib mating, avoidance of full sib and half sib mating) were considered. Pedigree inbreeding coefficients of the last generation using full pedigree or 10, 5 and 2 generations of the pedigree were calculated. Marker inbreeding coefficients based on different sets of microsatellite loci were also investigated. Under random mating, pedigree-inbreeding coefficients are clearly more closely related to true autozygosity (i.e., the actual proportion of loci with alleles identical by descent) than marker-inbreeding coefficients. If mating is not random, the demands on the quality and quantity of pedigree records increase. Greater attention must be paid to the correct parentage of the animals

Partial substitution of concentrates by maize silage in rations for organic dairy cows and its influence on performance and utilization efficiency

The aim of the present study was to investigate the influence of partial substitution of purchased concentrates with maize silage on feed intake, energy and nutrient supply, milk production and feed utilization efficiency in organic dairy cows. In the experiment, two winter rations were compared. In the experimental group (E) 2/3 of average herd concentrate intake were replaced by maize silage. In group E total dry matter, protein und energy intake was significantly lower than in the control group (C) (16.3 and 17.8 kg, 99 and 110 MJ NEL, 2170 and 2460 g crude protein, respectively). Milk yield decreased in group E by 1.7 kg, which was not statistically significant. Ruminal nitrogen balance and dietary protein to energy ratio was significantly lower in group E as compared to group C (-8 and 22 g, 21 and 24 g/MJ NEL, respectively). The diet for group E had no effect on milk composition, except milk urea content, which was in tendency lower in group E (15 and 17 mg 100ml-1). Estimated milk yield from forage was considerably higher in group E (15.9 vs 13.5 kg). Efficiency of nitrogen (N) utilization was tendencially higher in group E

Siliertes italienisches Raygras - eine wertvolle Grundfutterkomponente auch für die ökologische Milchkuhfütterung?

Das Ziel der Studie war es, ökologisch angebautes italienisches Raygras (Lolium multiflorum Lam.) auf seine Eignung für die Winterfütterung von ökologisch gefütterten Milchkühen zu testen. Der dafür durchgeführte Fütterungsversuch mit zwei Gruppen laktierender Holstein Friesian-Kühe fand im Winter 2008/09 statt. In der Raygrasration ersetzte siliertes italienisches Raygras 50 % des Silageanteils der Kontrollration, die auf Gras-Kleegrassilage basierte. Beide Grundfuttermischungen wurden mit mäßigen Mengen zugekauften Kraftfutters ergänzt, um isoenergetische und isonitrogene Gesamtrationen zu gewährleisten. Kühe, die mit der Raygrasration gefüttert wurden, nahmen signifikant mehr Grundfutter auf als Kühe, die mit der Kontrollration gefüttert wurden (14,5 bzw. 13,4 kg Trockenmasse). Aber da die Energie- und Proteingehalte der Grundfuttermischung der Raygrasration niedriger waren als die der Grundfuttermischung der Kontrollration, konnte die höhere Grundfutteraufnahme nicht in eine verbesserte Milchleistung (20,3 bzw. 21,0 kg bei Fütterung der Raygrasration bzw. Kontrollration) umgesetzt werden

Optimierung der Proteinversorgung durch Maissilage auf ökologisch wirtschaftenden Milchviehbetrieben im Grünland

The aim of the present study was to investigate and optimize the protein supply of organic dairy cows kept in Austrian grassland regions through the inclusion of maize silage into the diet. Therefore, two feeding trials were carried out. Trial I examined the effect of a partial substitution of purchased concentrates with home grown maize silage on feed and nutrient intake, milk performance and feed efficiency. Trial II was conducted to investigate the effect of maize silage or grain as an energy supplement to grass-clover silage based diets. In trial I milk yield decreased by 10%, however concentrate intake per kg milk was markedly reduced and dietary N efficiency and energy balance tendencially improved. Trial II revealed that even a small amount of maize silage supplementation had a marked influence on nutrient (protein, fibre) intake, ruminal N balance (RNB) and milk composition (milk fat and milk urea concen-tration)

Feldstudie zu Futtereigenschaften bei federpickenden Legehennen

Feedstuffs were analysed from 9 conventional and 12 organic farms which previously reported feather pecking in their laying hen flocks. Essential amino acid contents were significantly higher in conventional than in organic diets, while the latter matched suggested nutrient contents. Declared amino acid contents and results of analyses were in good agreement. Particle size of mash feedstuffs deviated from suggested values: percentages of coarse and medium particles were higher and lower, respectively, than suggested. Severity of feather pecking slightly correlated with dietary methionine content and with methionine:ME

Genetic diversity, population structure and subdivision of local Balkan pig breeds in Austria, Croatia, Serbia and Bosnia-Herzegovina and its practical value in conservation programs

<p>Abstract</p> <p>Background</p> <p>At present the Croatian Turopolje pig population comprises about 157 breeding animals. In Austria, 324 Turopolje pigs originating from six Croatian founder animals are registered. Multiple bottlenecks have occurred in this population, one major one rather recently and several more older and moderate ones. In addition, it has been subdivided into three subpopulations, one in Austria and two in Croatia, with restricted gene flow. These specificities explain the delicate situation of this endangered Croatian lard-type pig breed.</p> <p>Methods</p> <p>In order to identify candidate breeding animals or gene pools for future conservation breeding programs, we studied the genetic diversity and population structure of this breed using microsatellite data from 197 individuals belonging to five different breeds.</p> <p>Results</p> <p>The genetic diversity of the Turopolje pig is dramatically low with observed heterozygosities values ranging from 0.38 to 0.57. Split into three populations since 1994, two genetic clusters could be identified: one highly conserved Croatian gene pool in Turopoljski Lug and the"Posavina" gene pool mainly present in the Austrian population. The second Croatian subpopulation in Lonjsko Polje in the Posavina region shows a constant gene flow from the Turopoljski Lug animals.</p> <p>Conclusions</p> <p>One practical conclusion is that it is necessary to develop a "Posavina" boar line to preserve the "Posavina" gene pool and constitute a corresponding population in Croatia. Animals of the highly inbred herd in Turopoljski Lug should not be crossed with animals of other populations since they represent a specific phenotype-genotype combination. However to increase the genetic diversity of this herd, a program to optimize its sex ratio should be carried out, as was done in the Austrian population where the level of heterozygosity has remained moderate despite its heavy bottleneck in 1994.</p

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

Microsatellite diversity of the Nordic type of goats in relation to breed conservation: how relevant is pure ancestry?

In the last decades, several endangered breeds of livestock species have been re-established effectively. However, the successful revival of the Dutch and Danish Landrace goats involved crossing with exotic breeds and the ancestry of the current populations is therefore not clear. We have generated genotypes for 27 FAO-recommended microsatellites of these landraces and three phenotypically similar Nordic-type landraces and compared these breeds with central European, Mediterranean and south-west Asian goats. We found decreasing levels of genetic diversity with increasing distance from the south-west Asian domestication site with a south-east-to-north-west cline that is clearly steeper than the Mediterranean east-to-west cline. In terms of genetic diversity, the Dutch Landrace comes next to the isolated Icelandic breed, which has an extremely low diversity. The Norwegian coastal goat and the Finnish and Icelandic landraces are clearly related. It appears that by a combination of mixed origin and a population bottleneck, the Dutch and Danish Land-races are separated from the other breeds. However, the current Dutch and Danish populations with the multicoloured and long-horned appearance effectively substitute for the original breed, illustrating that for conservation of cultural heritage, the phenotype of a breed is more relevant than pure ancestry and the genetic diversity of the original breed. More in general, we propose that for conservation, the retention of genetic diversity of an original breed and of the visual phenotype by which the breed is recognized and defined needs to be considered separately