A nonsense mutation in the COL7A1 gene causes epidermolysis bullosa in Vorderwald cattle.

BACKGROUND: The widespread use of individual sires for artificial insemination promotes the propagation of recessive conditions. Inadvertent matings between unnoticed carriers of deleterious alleles may result in the manifestation of fatal phenotypes in their progeny. Breeding consultants and farmers reported on Vorderwald calves with a congenital skin disease. The clinical findings in affected calves were compatible with epidermolysis bullosa. RESULTS: Pedigree analysis indicated autosomal recessive inheritance of epidermolysis bullosa in Vorderwald cattle. We genotyped two diseased and 41 healthy animals at 41,436 single nucleotide polymorphisms and performed whole-genome haplotype-based association testing, which allowed us to map the locus responsible for the skin disease to the distal end of bovine chromosome 22 (P = 8.0 × 10-14). The analysis of whole-genome re-sequencing data of one diseased calf, three obligate mutation carriers and 1682 healthy animals from various bovine breeds revealed a nonsense mutation (rs876174537, p.Arg1588X) in the COL7A1 gene that segregates with the disease. The same mutation was previously detected in three calves with dystrophic epidermolysis bullosa from the Rotes Höhenvieh cattle breed. We show that diseased animals from Vorderwald and Rotes Höhenvieh cattle are identical by descent for an 8.72 Mb haplotype encompassing rs876174537 indicating they inherited the deleterious allele from a recent common ancestor. CONCLUSIONS: Autosomal recessive epidermolysis bullosa in Vorderwald and Rotes Höhenvieh cattle is caused by a nonsense mutation in the COL7A1 gene. Our findings demonstrate that deleterious alleles may segregate across cattle populations without apparent admixture. The identification of the causal mutation now enables the reliable detection of carrier animals. Genome-based mating strategies can avoid inadvertent matings of carrier animals thereby preventing the birth of homozygous calves that suffer from a painful skin disease.

Genetic analysis of lifetime productivity traits in goats.

As part of the development of a breeding programme for dairy goats to support sustainable production in organic farming, the overall aim of the present study was to identify traits that can be used as selection criteria for lifetime productivity. The breeding goal is high lifetime productivity with a good milk composition and a good level of robustness in the animals, especially within grazing systems. The lifetime productivity traits analysed in this study were the length of the animal's productive life (LPL), the lifetime efficiency (LEF), and the animal's milk yield efficiency with respect the total number of lactating days (EDM); the average fat and protein content over the animal's lifetime, the fat-to-protein ratio (FPR), and the urea content (UC) were also included as indirect health traits and potential indicators of robustness in dairy goats. The traits' influencing factors, phenotypic and genetic correlations, and heritability were examined. Furthermore, factors influencing milk yield in the first 120 d of lactation during the animal's first lactation were analysed. The aim of investigating milk yield during the first lactation was to consider a connection between early performance recoding in the life of an animal and LPL, LEF, and EDM. In total, lactation and pedigree data from 9192 dairy goats of the common German Fawn (GF) and German White (GW) dairy breeds were used. Prerequisites were that the investigated birth cohorts had to have definitively completed their lifetime production, and a high proportion of goats had to have completed extended lactation. The data analysis showed that breed did not influence milk yield. The age at first kidding, the average number of kids born during the animal's lifetime, and the lactation length did influence the milk yield. This applies to the milk yield during the first 120 d of the first lactation as well as over the lifetime of an animal. Considering the influencing factors, the results showed that LPL was genetically and positively correlated with LEF and EDM ( r g = 0.65 ± 0.06 and 0.29 ± 0.07 respectively). The heritability of LPL, LEF, and EDM was 0.22 ± 0.02 , 0.29 ± 0.03 , and 0.44 ± 0.03 respectively. Regarding the lifetime milk composition, the heritability of protein and fat content, FPR, and UC was 0.63 ± 0.02 , 0.52 ± 0.02 , 0.32 ± 0.03 , and 0.47 ± 0.04 respectively. The heritability regarding the milk yield during the first 120 d of the first lactation was 0.34 ± 0.03 . We found that the milk yield during the first 120 d of the first lactation showed a genetic correlation with LPL, LEF, and EDM of 0.30 ± 0.08 , 0.82 ± 0.04 , and 0.89 ± 0.03 respectively. In summary, LPL, LEF, and EDM are suitable traits to indicate lifetime productivity in dairy goats. An additional indicator for lifetime productivity could be the milk yield during the first 120 d of the first lactation. Moreover, FPR and UC appear to be promising indicator traits for the health and robustness of dairy goats. The present study showed the importance of considering extended lactation in selective breeding programmes as well as the importance of modelling extended lactation in the breeding value estimation.

The candidate gene XIRP2 at a quantitative gene locus on equine chromosome 18 associated with osteochondrosis in fetlock and hock joints of South German Coldblood horses.

A whole-genome scan for radiological signs of osteochondrosis (OC) and osteochondrosis dissecans (OCD) in South German Coldblood (SGC) horses using 250 microsatellite markers identified a genome-wide significant quantitative trait locus (QTL) for fetlock OCD and a chromosome-wide QTL for hock OC on Equus caballus chromosome (ECA) 18 at a relative position of 45.9-78.2 cM. The aim of this study was to analyze associations of single-nucleotide polymorphisms (SNPs) in candidate genes for OC in this QTL region using 96 SGC horses. The OC-QTL on ECA18 could be confirmed and narrowed down to an interval of 13 Mb between GALNT13 and Xin actin-binding repeat containing 2 (XIRP2). SNPs in the XIRP2 gene were significantly associated with fetlock OC, fetlock OCD, and hock OC. The significant associations of SNPs in XIRP2 could be confirmed in linear animal models controlling for systematic environmental and residual quantitative genetic effects. The significant additive genetic effects of the intronic SNPs (AJ885515:g.159A>G, AJ885515:g.445T>C) in XIRP2 were 0.15 (P = 0.01) for fetlock OC, 0.27 (P = 0.01) for fetlock OCD, and 0.15-0.16 (P = 0.01-0.02) for hock OC. Homozygous (A/A or T/T) and heterozygous horses were at a 1.3- to 2.4-fold higher risk for fetlock and hock OC. These results suggest that dominant variants of XIRP2 may be involved in pathogenesis of equine OC.

Scanning the genomes of parents for imprinted loci acting in their un-genotyped progeny.

Depending on their parental origin, alleles at imprinted loci are fully or partially inactivated through epigenetic mechanisms. Their effects contribute to the broader class of parent-of-origin effects. Standard methodology for mapping imprinted quantitative trait loci in association studies requires phenotypes and parental origin of marker alleles (ordered genotypes) to be simultaneously known for each individual. As such, many phenotypes are known from un-genotyped offspring in ongoing breeding programmes (e.g. meat animals), while their parents have known genotypes but no phenotypes. By theoretical considerations and simulations, we showed that the limitations of standard methodology can be overcome in such situations. This is achieved by first estimating parent-of-origin effects, which then serve as dependent variables in association analyses, in which only imprinted loci give a signal. As a theoretical foundation, the regression of parent-of-origin effects on the number of B-alleles at a biallelic locus - representing the un-ordered genotype - equals the imprinting effect. The applicability to real data was demonstrated for about 1800 genotyped Brown Swiss bulls and their un-genotyped fattening progeny. Thus, this approach unlocks vast data resources in various species for imprinting analyses and offers valuable clues as to what extent imprinted loci contribute to genetic variability.

Associations between candidate gene markers at a quantitative trait locus on equine chromosome 4 responsible for osteochondrosis dissecans in fetlock joints of South German Coldblood horses.

A previously accomplished whole-genome scan for osteochondrosis (OC) and OC dissecans (OCD) in South German Coldblood horses using 250 microsatellite markers identified putative quantitative trait loci (QTL). A chromosome-wide significant QTL for fetlock OCD was found on Equus caballus chromosome (ECA) 4q at a relative position of 70.0-73.3 cM. The aim of this study was to analyze associations of single nucleotide polymorphisms (SNPs) in candidate genes for OC in this region. The association analysis included 32 affected and 64 unaffected horses. Three SNPs located in intron 8, intron 9, and 3'-untranslated region (UTR) of the acyloxyacyl hydrolase (AOAH) gene on ECA4q were significantly associated with OCD in fetlock joints. In order to control for systematic environmental and quantitative genetic effects, we employed a linear animal model. The association of the SNP (AJ543065:g.703A>G) in the 3'-UTR of exon 21 was confirmed in the animal model analysis and a significant additive genetic effect for fetlock OCD of 0.42 (P = 0.002) and a dominance effect of -0.32 (P = 0.03) was estimated. This is the first report on a marker in population-wide linkage disequilibrium with equine OCD in fetlock joints.

A retrospective study on the prevalence of primary cataracts in two pedigrees from the German population of English Cocker Spaniels.

OBJECTIVE: Two pedigrees from the German English Cocker Spaniel population are presented to illustrate the familial occurrence of primary cataract (CAT) in single- and multicolored English Cocker Spaniels. The aim was to characterize similarities and differences in the prevalence and formation of CAT in these separately bred color variants of English Cocker Spaniels. MATERIALS: The study was based on the veterinary records for presumed inherited eye diseases of 1232 English Cocker Spaniels which were provided by the German panel of the European Eye Scheme for diagnosis of inherited eye diseases in animals (DOK, ). Data included information on 615 single-colored and 617 multicolored English Cocker Spaniels. RESULTS: CAT was diagnosed in 92 (14.96%) of the single-colored and 34 (5.51%) of the multicolored English Cocker Spaniels. The pedigree of the single-colored English Cocker Spaniels included 40 ophthalmologically examined dogs with 18 unaffected and 22 affected dogs. The pedigree of the multicolored English Cocker Spaniels contained 16 ophthalmologically examined dogs with 11 unaffected and five affected dogs. CONCLUSIONS: In both color variants of the English Cocker Spaniels different forms of primary CAT with respect to location within the lens occurred among close relatives. Appearance of CAT was very heterogeneous without obvious sex differences. The sample pedigrees do not support the assumption of familial segregation of specific forms of primary CAT in English Cocker Spaniels.

Factors associated with the prevalence of osseous fragments in the limb joints of Hanoverian Warmblood horses.

Factors associated with the prevalence of osseous fragments (OF) in fetlock and hock joints were investigated in a population of young Hanoverian Warmblood horses selected for sale at auction from 1991 to 1998. The study was based on results of a standardized radiological examination of 3127 horses. The prevalences of OF in the two joints were significantly dependent on the date, type and quality of the auction, the region of origin and on the anticipated suitability of the horses for dressage and/or show-jumping. The probability of finding OF increased with wither-height. Furthermore, there was a significant association of the individual sire with the prevalence of OF in both fetlock and hock joints, and of the maternal grandsire with the prevalence of OF in the hock joints. Consequently, both non-genetic and genetic parameters should be taken into account in order to reduce the prevalence of OF in young Warmblood riding horses.

Polymorphisms within the canine MLPH gene are associated with dilute coat color in dogs.

BACKGROUND: Pinschers and other dogs with coat color dilution show a characteristic pigmentation phenotype. The fur colors are a lighter shade, e.g. silvery grey (blue) instead of black and a sandy color (Isabella fawn) instead of red or brown. In some dogs the coat color dilution is sometimes accompanied by hair loss and recurrent skin inflammation, the so called color dilution alopecia (CDA) or black hair follicular dysplasia (BHFD). In humans and mice a comparable pigmentation phenotype without any documented hair loss is caused by mutations within the melanophilin gene (MLPH). RESULTS: We sequenced the canine MLPH gene and performed a mutation analysis of the MLPH exons in 6 Doberman Pinschers and 5 German Pinschers. A total of 48 sequence variations was identified within and between the breeds. Three families of dogs showed co-segregation for at least one polymorphism in an MLPH exon and the dilute phenotype. No single polymorphism was identified in the coding sequences or at splice sites that is likely to be causative for the dilute phenotype of all dogs examined. In 18 German Pinschers a mutation in exon 7 (R199H) was consistently associated with the dilute phenotype. However, as this mutation was present in homozygous state in four dogs of other breeds with wildtype pigmentation, it seems unlikely that this mutation is truly causative for coat color dilution. In Doberman Pinschers as well as in Large Munsterlanders with BHFD, a set of single nucleotide polymorphisms (SNPs) around exon 2 was identified that show a highly significant association to the dilute phenotype. CONCLUSION: This study provides evidence that coat color dilution is caused by one or more mutations within or near the MLPH gene in several dog breeds. The data on polymorphisms that are strongly associated with the dilute phenotype will allow the genetic testing of Pinschers to facilitate the breeding of dogs with defined coat colors and to select against Large Munsterlanders carrying BHFD.

Hereditary ataxia in the Jack Russell Terrier--clinical and genetic investigations.

Hereditary ataxia in the Jack Russell Terrier (JRT) is characterized by a gait disturbance with symmetric generalized ataxia and hypermetric and spastic movements. Histopathology shows a disease of the entire central nervous system, predominantly an axonopathy. In the present study, 35 clinically affected dogs were examined. Gait abnormalities began at 2-9 months of age. Generalized seizures occurred in 13 dogs in addition to the ataxia, and 7 dogs developed respiratory distress. Brain stem auditory-evoked potentials (BAEPs) were abnormal in 4 of 8 examined dogs, in which only waves I and II were detected. Abnormal BAEPs suggest the possibility of hereditary ataxia in the JRT. Investigations regarding the mode of inheritance were performed by complex segregation analyses on 3 pedigrees with a total of 115 JRTs (27 clinically affected dogs and 88 unaffected littermates and ancestors). Different modes of inheritance were tested, including monogenic, mixed, and polygenic models, as well as a model with environmental effects only. Models with genetic effects explained the data significantly better than the environmental model. The monogenic model had to be rejected in this study because of an insufficient match of data when compared to that of the most general model. The polygenic and mixed major gene models explained the pedigree data best and therefore have to be regarded as possible hypotheses for the mode of inheritance of hereditary ataxia in the JRT. The polygenic model proved best suited to explain the segregation pattern in the JRT, because it had the fewest number of parameters.

Risk factors associated with bacteriological cure, new infection, and incidence of clinical mastitis after dry cow therapy with three different antibiotics.

Factors affecting bacteriological cure rates (BCR) and new intramammary infections (IMI) during the dry period as well as clinical mastitis (CM) during early lactation were investigated in 414 German Holstein dairy cows receiving dry cow therapy. Cows were treated with either benethamine benzylpenicillin (300,000 IU), penethamate hydriodide (100,000 IU), and framycetin sulphate (100 mg, n = 136), or cefquinome (150 mg, n = 135), or benzathine cloxacillin (1,280 mg, n = 143). Overall BCR, IMI, and CM at parturition were 86.4%, 20.7%, and 4.3%, respectively. The three antibiotic treatments differed only in BCR, with cloxacillin yielding better results than the others. Udder quarters from cows with > 4 lactations had a higher risk of IMI and CM at calving. Chronic changes in udder tissues were linked to a lower BCR and were associated with a higher risk of CM during early lactation. The risk of CM at calving was higher in udder quarters with unspecific or subclinical mastitis before drying off. In conclusion, with antibiotic dry cow therapy, age and health status of the udder appear to be major determinants of IMI and CM during the dry period and early lactation, while BCR was associated with the antibiotic type and udder tissue status.

[Estimation of population genetic parameters for radiographical findings of elbow dsyplasia in the Labrador Retriever]. / Schätzung populationsgenetischer Parameter für röntgenologische Befunde der Ellbogengelenkdysplasie beim Labrador Retriever.

The aim of this study was the analysis of non-genetic and genetic factors influencing elbow dysplasia (ED) in a Labrador retriever population. We analysed scores of elbow dysplasia from the official screening programme of the Labrador Club Deutschland (LCD) following the protocol of the International Elbow Working Group. The data set included X-rays from 2931 Labrador retrievers. These dogs were born between 2000 and 2004 and originated from 834 litters and 315 kennels. The pedigree file contained 27 305 dogs pertaining to 20 generations. We analysed four different traits including ED-Mit as the averaged result of ED scores from both elbow joints, ED-Max as the higher score of both elbow joints and ED-links and ED-rechts as the ED score of left or right elbow joint. Animal models were employed to estimate heritabilities, additive genetic correlation and residual correlation using residual maximum likelihood (REML). Significant effects for all four ED-traits were gender, month of birth and inbreeding coefficient. The fixed effect of birth year showed only significant effects for ED-Mit and ED-rechts. Age at examination was not significant. Heritability estimates for ED-Mit were 0.12 +/- 0.03, for ED-Max 0.11 +/- 0.03 and 0.13 +/- 0.03 for ED-links as well as 0.07 +/- 0.02 for ED-rechts. Heritability for female dogs was 0.12 +/- 0.03 and 0.10 +/- 0.03 for male dogs. The additive genetic correlation between ED-links and ED-rechts was 1 and the residual correlation 0.64. The heritabilities for ED were low to moderate based on models employed here and taking this into consideration, selection response will be small when employing phenotypic ED scores from breeding animals as the sole selection criterion. Therefore, breeding programmes should be supported by breeding values as tools for selection of breeding dogs. There was no difference in heritabilities between the mean ED score of the joints or the ED score of the joint with the higher ED grade. Furthermore, either specific genetic effects from a body side or sex-specific genetic effects could be observed for the expression of ED. Dogs showing radiographic signs of ED or dogs having been submitted for a surgery due to clinical signs of ED have to be precluded from breeding. The veterinary practitioner can help to reduce the frequency of dogs exhibiting a genetic disposition to ED when the radiographs of the elbow joints of many as possible purebred dogs are submitted to the respective dog breeding associations.

Bone strength and keel bone status of two layer strains kept in small group housing systems with different perch configurations and group sizes.

The objective of the present study was to investigate whether an arrangement of perches at two different heights within individual compartments of small group systems (back perch elevated (BE), front perch elevated (FE) or both perches heightened (FBE)) combined with an enlarged group size would increase humerus and tibia bone breaking strength and impact keel bone status. Bone strength and keel bone status of two layer strains (LSL, LB) kept in small group systems (SG 40-60 (40, 60 hens), SG 20-30 (20, 30 hens) with different perch configurations) and furnished cages (FC, 10, 20 hens, perches in standard position) were compared in two trials. Investigations were carried out in the laying months 6 and 12, comprising a total of 576 hens. When all compartments of SG 40-60 had been incorporated with perches at two different heights, humerus and tibia bone strength in LSL layers significantly increased compared to FC, whereas keel bone status was negatively impacted. Within SG 40-60, BE and FE perches significantly increased humerus strength in LSL layers compared to FBE perches. LB layers had significantly higher bone strength in groups of 20 compared to 30 hens in SG 20-30, whereas no effect of group size was detected for LSL hens. Keeping hens in SG 40-60 with modified perch positions was associated with increased bone strength but brought about the problem of inferior keel bone status.

[Estimation of population genetic parameters and breeding values for elbow dysplasia in Rottweilers]. / Schätzung von populationsgenetischen Parametern und Zuchtwerten für Ellbogengelenkdysplasie beim Rottweiler.

We analysed scores of elbow dysplasia following the IEWG protocol from the official screening programme of the Allgemeiner Deutscher Rottweiler Club (ADRK). The data set included X-rays from 5100 Rottweiler dogs born between 1995 and 2004. Out of these 5,100 dogs, 46.9% were free from ED, 9.8% showed borderline signs (ED-UG), 31.8% ED-grade 1 (mild ED), 10% ED-grade 2 (moderate ED) und 1.6% ED-grade 3 (severe ED). Male dogs were more often affected by ED-grade 2 and 3 than female dogs. Traits analysed were ED-grade (dogs free from ED and dogs with ED-grades 1 to 3) and borderline ED (ED-UG). Birth year, birth season and inbreeding coefficient were significant for ED-grade. Higher inbreeding coefficients were associated with higher ED scores. ED-UG was significantly influenced by birth year and the interaction of birth year and birth season. A bivariate linear animal model was employed to estimate heritabilities using Residual Maximum Likelihood (REML) for ED-grade and ED-UG. Heritability estimates and their standard errors were 0.387 +/- 0.028 for ED-grade and 0.017 +/- 0.009 for ED-UG. The additive genetic correlation between ED-grade and ED-UG was -0.5. Heritabilities for ED-grade in female and male dogs were 0.350 +/- 0.033 and 0.497 +/- 0.047. We do not recommend use of ED-UG in breeding work because of the low heritability estimate and the negative additive genetic correlation with ED-grade.

[Population genetic analysis of behaviour traits in Hovawart dogs]. / Populationsgenetische Analyse von Verhaltensmerkmalen bei Hovawart Hunden.

The aim of this study was to determine genetic and environmental influences on behaviour traits in Hovawart dogs. Trait definition was based on a survey which was conducted by the breeding association for Hovawart dogs in Germany in 2002. Questionnaires of 601 dogs born between 1991 and 2001 were used for the analysis of 23 traits that were grouped to the following five trait complexes: behaviour towards strangers and kids, response to external influences, response to dominance gestures of the owner, response to other dogs, and behaviour towards other dogs. Analyses were performed using residual maximum likelihood in multivariate linear animal models. Heritability estimates ranged between h2 = 0.01 and h2 = 0.22 (standard error < or = 0.07). Within the trait complexes, additive genetic correlations were in most cases moderately to highly positive (rg = 0.20 to rg = 1.00); in few cases they were clearly negative (up to rg = -0.81). Residual correlations were in the range of re = -0.12 to re = 0.50. In summary, the results of this study support the heritable nature of behaviour traits in the Hovawart dogs. Accordingly, traits like the response of the dog to unfamiliar situations (h2 = 0.20) and the behaviour towards strangers approaching the home property (h2 = 0.22) may be considered when selecting breeding animals.

[Analysis of systematic environmental and genetic effects on body weight and body measurements in German shepherd dogs]. / Analyse von systematischen Umwelt- und genetischen Effekten auf Körpergewicht und Körpermasse beim Deutschen Schäferhund.

In dog breeding permission for breeding is only given when the body measurements of the dog are within the lower and upper limits which are defined in the breed standard. Therefore, the objective of this study was to analyse the systematic and genetic effects on body weight and body measurements recorded at licensing in German shepherd dogs (GSD) over a period of 10 years. The data included withers and chest height, chest circumference and body weight from 36,028 breeding dogs born between 1992 and 2003. Birth year, month of birth and region were significant for the traits analysed. Age at breeding approval was significant for the body measurements withers height and chest height and only significant for male dogs for chest circumference. Inbreeding coefficient was significant as a nonlinear covariate for withers and chest height. The genetic parameters were estimated in linear animal models using residual maximum likelihood (REML) and the relationship matrix of 53,429 dogs. Uni- and bivariate analyses were performed for both sexes together and separately for males and females. Heritability estimates for both sexes together were 0.41 +/- 0.01 for withers height and 0.27 +/- 0.01 for body weight. For the other traits studied, heritability estimates were lower with values of 0.20 +/- 0.01 for chest height and 0.13 +/- 0.01 for chest circumference. In the separate analyses for male and female dogs, heritability estimates were higher for females. Additive genetic correlations were at 0.91 to 0.98 between corresponding traits in males and females. The high genetic correlations indicate that selection for conformation traits equally affects both sexes and does not increase sexual dimorphism in dogs.

Genetic and phenotypic trends in canine hip dysplasia in the German population of German shepherd dogs.

Phenotypic and genetic trends were examined in 157,455 German shepherd dogs of the German population born between 1985 and 2003 which were Xrayed for canine hip dysplasia (CHD). A subset of 40,270 dogs born between 1998 and 2003 was examined for which information was available on age at examination and X-raying veterinary practitioner. Relative breeding values were predicted using best linear unbiased prediction methods (BLUP) and Gibbs Sampling. There was an almost linear and significant decline in both phenotypic and genetic trends for CHD scores (scale 1 to 5 for CHD free to severe CHD) over a period of 19 years, with b = -0.021 +/- 0.002, and b = -1.69 +/- 0.05, respectively. After introduction in 1999 of a selection scheme based on relative breeding values (RBVs, mean 100, standard deviation 20) of a linear animal model, phenotypic and genetic trends declined less than before 1999, with b = -0.019 +/- 0.011 and b = -1.43 +/- 0.29. Analysis of the effects of RBVs of parental combinations among sires and dams on the percentage of non-affected progeny showed that lower RBVs were associated with a higher percentage of non-affected progeny than were higher RBVs. In addition, it was also shown that selection procedures based on RBVs are more efficient than selection schemes based on phenotypic records of parents. When the maternal RBV was above 100, the proportion of non-affected progeny was between 10% and 20% lower than when the maternal RBV was below or equal to 100. There was a significant relationship between higher inbreeding coefficients and higher RBVs of the animal.

Fat status in Lohmann Silver and Lohmann tradition laying hens kept in modified small group housing systems, small group housing systems, furnished cages and an aviary system.

The influence of different housing systems on adiposis of liver, abdomen and heart was evaluated in 670 Lohmann Silver (LS) and 240 Lohmann Tradition (LT) laying hens during two trials. Examinations took place in the 3rd, 6th, 9th and 12th laying month. In addition, serum concentration of triglycerides (TRI) was analysed. Housing systems included in this study were a furnished cage system (Aviplus (AP)), a small group housing system (Eurovent 625a-EU (EV)), with perches on the same (first trial) and on different levels (second trial, MEV), and an aviary system (Voliere Natura (AV)). In both trials, a significantly lower fat status of abdomen and liver could be observed in hens housed in AV. Consistently in both trials, body weight and housing system had the largest influence on fat status of liver, abdomen and heart. Scores of fat status of liver and abdomen in EV and MEV were in between of those observed in AV and AP, while heart fat status did not differ among housing systems. With an increasing macroscopic fat status of the liver, liver weight and TRI concentration significantly increased. Different perch positions in MEV did not have a significant influence on fat status in layers.

[Estimation of genetic parameters for radiographic signs of hip dysplasia in Labrador Retrievers]. / Schätzung von populationsgenetischen Parametern für röntgenologische Befunde der Hüftgelenkdysplasie beim Labrador Retriever.

The aim of this study was the analysis of environmental factors and estimation of genetic parameters for hip dysplasia in Labrador Retrievers. We analysed hip dysplasia scores of 2970 dogs from the official screening programme of the Labrador Club Deutschland (LCD) according to the FCI protocols. Traits evaluated were HD-Mit (average value of HD scores), HD-Max (higher score of both hip joints), HD-LI and HD-RE (HD score of the left or right hip joint). A linear animal model was employed to estimate heritabilities, additive genetic and residual correlations using Residual Maximum Likelihood (REML). Only inbreeding was significant after testing all non-genetic effects. Higher inbreeding coefficients were associated with higher HD scores. Heritability estimates and their standard errors were 0.38 +/- 0.04 for HD-Mit, 0.40 +/- 0.04 for HD-Max, 0.33 +/- 0.03 for HD-LI and 0.38 +/- 0.04 for HD-RE. The additive genetic correlation between HD-LI and HD-RE was 1. Heritability for female dogs was 0.31 and 0.30 for male dogs. The analysis of HD scores of Labrador Retrievers showed that the highest HD score of the hips should be used in breeding programmes, that heritabilities are not different among females and males, and that genetic components are much more important than environmental factors.

Keel bone condition in laying hens: a histological evaluation of macroscopically assessed keel bones.

The objective of the present study was to conduct a corresponding histological analysis of 162 macroscopically assessed keel bones (1: severe, 2: moderate, 3: slight, 4: no deformity). Four layer lines were used and hens were kept in furnished cages, small group systems (both allowing more activities due to the provision of perches) and an aviary system, which fully conformed to the EU standards. Investigations were carried out in the 3rd, 6th, 9th and 12th laying month of two experimental trials. In 97.9% of grade 4 keel bones, no histological deviations were found, whereas in keel bones manifesting deformities of grade 1 and 2, the predominant histological observation was the incidence of fracture callus material (FCM) and new bone in the form of woven bone. FCM was also detected in 50.9% of grade 3 keel bones, whereas in 40.7%, only s-shaped deviations of keel bones were found, which were related to extended pressure loading while perching activities rather than short-duration trauma. Histological analysis showed that keel bones of grade 1 and 2 were mainly attributed to traumatic origin and therefore associated with pain experience in layers. Grade 3 keel bones manifested either FCM as a result of trauma or adaptational deformities without any evidence of a preceding fracture in response to mechanical pressure loading and were most likely not associated with pain. Therefore, histological analysis was found to be a mandatory tool when evaluating grade 3 keel bones with respect to layers'welfare. Furthermore, this analysis corroborates the findings that in aviary systems deformities of keel bones are predominantly caused by painful fractures.

Analysis of systematic and genetic effects on the prevalence of different types of primary lens opacifications in the wild-boar-colored wirehaired Dachshund.

The aims of this study were to analyze the influence of systematic environmental effects on the prevalence of primary non-congenital cataract (CAT), fibreglass cataract in the nucleus (FCN), and prominent suture lines (PSL) and to estimate the heritabilities of these eye diseases in the wild-boar-colored wirehaired Dachshunds (WWD) bred in the German Dachshund Club 1888 e.V. (DTK). Data included 2,430 WWD born between 1995 and 2003 that were examined between 1996 and 2005 by veterinary ophthalmologists. CAT was diagnosed in 3.83% of the 2,430 dogs, FCN in 3.74%, and PSL in 2.76%. Sex, size, inbreeding coefficient, the age of the dog at examination, experience of the veterinary ophthalmologist and the additive genetic effect of the animal were considered in the multivariate linear model. The age of the dog at examination had a significant influence on the prevalence of FCN. The degree of experience of the veterinary ophthalmologist significantly influenced the prevalence of FCN and PSL. Using a transformation into the Dempster-Lerner threshold model, heritability estimates (h(DL)2) for WWD were h(DL)2 = 0.39 +/- 0.13 for CAT, h(DL)2 = 0.36 +/- 0.11 for FCN and h(DL)2 = 0.49 +/- 0.12 for PSL. Positive genetic correlations (r(g)) were found between CAT and FCN (r(g) = 0.58 +/- 0.21), between PSL and FCN (r(g) = 0.83 +/- 0.23), and between CAT and PSL (r(g) = 0.79 +/- 0.06). The eye diseases investigated here in the Dachshund were found to be genetically influenced and positively correlated traits.