German Large White Research Articles

Axillary ultrasound-guided approach for the brachial plexus in pig cadavers: A descriptive study.

Effective multimodal analgesia techniques are required when pigs are used as models in orthopedic human research. Regional anesthesia is a widely used technique to provide perioperative analgesia in animals undergoing orthopedic surgery. The brachial plexus (BP) block is indicated to desensitize the forelimb in many species but has not been yet described in pigs. The main aims of this study were to develop an ultrasound-guided axillary approach for the BP and to evaluate injectate spread and nerve staining in pig cadavers. Eight fresh F1 cross breed German Large White and German Landrace male pig cadavers were enrolled. Two cadavers were used for anatomical dissection of the axillary space and to determine the disposition of the BP. Six cadavers were used to perform a bilateral axillary ultrasound-guided approach for the BP, and after injecting 0.3 ml/kg of a solution of 2% lidocaine and new methylene blue (L-NMB), these were dissected to determine injectate spread and nerve staining. Upon dissection, the BP was observed in all the cases surrounded by the axillary sheath and in close proximity to the axillary artery. Ultrasonographic scanning and guidance for the approach to the BP was feasible in all cadavers and upon dissection, all the nerves forming the BP were stained in all their quadrants and in all the cases. In conclusion, the injection of 0.3 ml/kg of L-NMB through an ultrasound-guided axillary approach to the BP was feasible and adequate to entirely stain the BP in all pig cadavers. Further clinical studies are required to evaluate the effectiveness of this technique in live animals.

Relationship between myocardial oxygenation and blood pressure: Experimental validation using oxygenation-sensitive cardiovascular magnetic resonance.

BackgroundThe relationship between mean arterial pressure (MAP) and coronary blood flow is well described. There is autoregulation within a MAP range of 60 to 140 mmHg providing near constant coronary blood flow. Outside these limits flow becomes pressure-dependent. So far, response of myocardial oxygenation to changes in pressure and flow has been more difficult to assess. While established techniques mostly require invasive approaches, Oxygenation-Sensitive (OS) Cardiovascular Magnetic Resonance (CMR) is a technique that can non-invasively assess changes in myocardial tissue oxygenation. The purpose of this study was to follow myocardial oxygenation over a wide range of blood pressure variation within and outside known coronary autoregulatory limits using OS-CMR, and to relate these data to coronary hemodynamics.MethodsTen anaesthetized swine (German Large White) underwent left-sided thoracotomy and attachment of a perivascular flow probe to the proximal left anterior descending (LAD) coronary artery for continuous measurement of blood flow (QLAD). Thereafter, animals were transferred into a 3T MRI scanner. Mean arterial pressure (MAP) was varied in 10–15 mmHg steps by administering alpha1-receptor agents phenylephrine or urapidil. For each MAP level, OS-CMR images as well as arterial and coronary sinus blood gas samples were obtained simultaneously during brief periods of apnea. Relative changes (Δ) of coronary sinus oxygen saturation (ScsO2), oxygen delivery (DO2) and demand (MVO2), extraction ratio (O2ER) and excess (Ω) from respective reference levels at a MAP of 70 mmHg were determined and were compared to %change in OS-signal intensity (OS-SI) in simultaneously acquired OS-CMR images.ResultsQLAD response indicated autoregulation between MAP levels of 52 mmHg (lower limit) and127 mmHg (upper limit). OS-CMR revealed a global myocardial oxygenation deficit occurring below the lower autoregulation limit, with the nadir of OS-SI at -9.0%. With MAP values surpassing 70 mmHg, relative OS-SI increased to a maximum of +10.6%. Consistent with this, ΔScsO2, ΔDO2, ΔMVO2, ΔO2ER and ΔΩ responses indicated increasing mismatch of oxygenation balance outside the autoregulated zone. Changes in global OS-CMR were significantly correlated with all of these parameters (p≤0.02) except with ΔMVO2.ConclusionOS-CMR offers a novel and non-invasive route to evaluate the effects of blood pressure variations, as well as of cardiovascular drugs and interventions, on global and regional myocardial oxygenation, as demonstrated in a porcine model. OS-CMR identified mismatch of O2 supply and demand below the lower limit of coronary autoregulation. Vasopressor induced acute hypertension did not compromise myocardial oxygenation in healthy hearts despite increased cardiac workload and O2 demand. The clinical usefulness of OS-CMR remains to be established.

Short-Term Subclinical Zinc Deficiency in Weaned Piglets Affects Cardiac Redox Metabolism and Zinc Concentration

BackgroundSubclinical zinc deficiency (SZD) represents the common zinc malnutrition phenotype. However, its association with oxidative stress is not well understood. The heart muscle may be a promising target for studying early changes in redox metabolism. ObjectiveWe investigated the effects of short-term SZD on cardiac redox metabolism in weaned piglets. MethodsForty-eight weaned German Large White × Landrace × Piétrain piglets (50% castrated males and 50% females; body weight of 8.5 kg) were fed diets with different zinc concentrations for 8 d. Measurements included cardiac parameters of antioxidative capacity, stress-associated gene expression, and tissue zinc status. Analyses comprised (linear, broken-line) regression models and Pearson correlation coefficients. ResultsGlutathione and α-tocopherol concentrations as well as catalase, glutathione reductase, B-cell lymphoma 2–associated X protein, and caspase 9 gene expression plateaued in response to reduction in dietary zinc from 88.0 to 57.6, 36.0, 36.5, 41.3, 55.3, and 33.8 mg/kg, respectively (P < 0.0001). Further reduction in dietary zinc promoted a linear decrease of glutathione and α-tocopherol (30 and 0.6 nmol/mg dietary Zn, respectively; P < 0.05) and a linear increase of gene expression [0.02, 0.01, 0.003, and 0.02 Log10(2−ΔΔCt)/mg dietary Zn, respectively; P < 0.05)]. Tissue zinc declined linearly with reduction in dietary zinc (0.21 mg tissue Zn/mg dietary Zn; P = 0.004) from 88.0 to 42.7 mg/kg (P < 0.0001), below which it linearly increased inversely to further reduction in dietary zinc (0.57 mg tissue Zn/mg dietary Zn; P = 0.006). H2O2-detoxification activity and metallothionein 1A gene expression decreased linearly with reduction in dietary zinc from 88.0 to 28.1 mg/kg [0.02 mU and 0.008 Log10(2−ΔΔCt)/mg dietary Zn, respectively; P < 0.05]. Fas cell-surface death receptor, etoposide-induced 2.4 and cyclin-dependent kinase inhibitor 1A gene expression correlated positively to cardiac zinc in piglets fed ≤42.7 mg Zn/kg (r ≥ 0.97; P < 0.05). ConclusionsShort-term SZD decreased cardiac antioxidative capacity of weaned piglets while simultaneously increasing stress-associated gene expression and zinc concentration. This is the first report to our knowledge on the effects of SZD on redox metabolism.

Can multi-subpopulation reference sets improve the genomic predictive ability for pigs?

In most countries and for most livestock species, genomic evaluations are obtained from within-breed analyses. To achieve reliable breeding values, however, a sufficient reference sample size is essential. To increase this size, the use of multibreed reference populations for small populations is considered a suitable option in other species. Over decades, the separate breeding work of different pig breeding organizations in Germany has led to stratified subpopulations in the breed German Large White. Due to this fact and the limited number of Large White animals available in each organization, there was a pressing need for ascertaining if multi-subpopulation genomic prediction is superior compared with within-subpopulation prediction in pigs. Direct genomic breeding values were estimated with genomic BLUP for the trait "number of piglets born alive" using genotype data (Illumina Porcine 60K SNP BeadChip) from 2,053 German Large White animals from five different commercial pig breeding companies. To assess the prediction accuracy of within- and multi-subpopulation reference sets, a random 5-fold cross-validation with 20 replications was performed. The five subpopulations considered were only slightly differentiated from each other. However, the prediction accuracy of the multi-subpopulations approach was not better than that of the within-subpopulation evaluation, for which the predictive ability was already high. Reference sets composed of closely related multi-subpopulation sets performed better than sets of distantly related subpopulations but not better than the within-subpopulation approach. Despite the low differentiation of the five subpopulations, the genetic connectedness between these different subpopulations seems to be too small to improve the prediction accuracy by applying multi-subpopulation reference sets. Consequently, resources should be used for enlarging the reference population within subpopulation, for example, by adding genotyped females.

Porcine SOX9 Gene Expression Is Influenced by an 18 bp Indel in the 5'-Untranslated Region.

Sex determining region Y-box 9 (SOX9) is an important regulator of sex and skeletal development and is expressed in a variety of embryonal and adult tissues. Loss or gain of function resulting from mutations within the coding region or chromosomal aberrations of the SOX9 locus lead to a plethora of detrimental phenotypes in humans and animals. One of these phenotypes is the so-called male-to-female or female-to-male sex-reversal which has been observed in several mammals including pig, dog, cat, goat, horse, and deer. In 38,XX sex-reversal French Large White pigs, a genome-wide association study suggested SOX9 as the causal gene, although no functional mutations were identified in affected animals. However, besides others an 18bp indel had been detected in the 5′-untranslated region of the SOX9 gene by comparing affected animals and controls. We have identified the same indel (Δ18) between position +247bp and +266bp downstream the transcription start site of the porcine SOX9 gene in four other pig breeds; i.e., German Large White, Laiwu Black, Bamei, and Erhualian. These animals have been genotyped in an attempt to identify candidate genes for porcine inguinal and/or scrotal hernia. Because the 18bp segment in the wild type 5′-UTR harbours a highly conserved cAMP-response element (CRE) half-site, we analysed its role in SOX9 expression in vitro. Competition and immunodepletion electromobility shift assays demonstrate that the CRE half-site is specifically recognized by CREB. Both binding of CREB to the wild type as well as the absence of the CRE half-site in Δ18 reduced expression efficiency in HEK293T, PK–15, and ATDC5 cells significantly. Transfection experiments of wild type and Δ18 SOX9 promoter luciferase constructs show a significant reduction of RNA and protein levels depending on the presence or absence of the 18bp segment. Hence, the data presented here demonstrate that the 18bp indel in the porcine SOX9 5′-UTR is of functional importance and may therefore indeed be a causative variation in SOX9 associated traits.

Analysis of non-synonymous SNPs of the porcine SERPINA6 gene as potential causal variants for a QTL affecting plasma cortisol levels on SSC7.

Recently, the SERPINA6 gene encoding corticosteroid-binding globulin (CBG) has been proposed as a candidate gene for a quantitative trait locus (QTL) affecting cortisol level on pig chromosome 7. The QTL was repeatedly detected in different lines, including a Piétrain × (German Landrace × German Large White) cross (PiF1) and purebred German Landrace (LR). In this study, we investigated whether the known non-synonymous polymorphisms c.44G>T, c.622C>T, c.770C>T, c.793G>A, c.832G>A and c.919G>A of SERPINA6 are sufficient to explain the QTL in these two populations. Our investigations revealed that SNPs c.44G>T, c.622C>T, c.793G>A and c.919G>A are associated with cortisol level in PiF1 (P < 0.01). Haplotype analysis showed that these associations are largely attributable to differences between a major haplotype carrying SNPs c.793G>A and c.919G>A and a haplotype carrying SNPs c.44G>T and c.622C>T. Furthermore, some SNPs, particularly c.44G>T and c.622C>T and the carrier haplotype, showed association with meat quality traits including pH and conductivity (P < 0.05). In LR, the non-synonymous SNPs segregate at very low frequency (<5%) and/or show only weak association with cortisol level (SNPs c.832G>A and c.919G>A; P < 0.05). These findings suggest that the non-synonymous SNPs are not sufficient to explain the QTL across different breeds. Therefore, we examined whether the expression of SERPINA6 is affected by cis-regulatory polymorphisms in liver, the major organ for CBG production. We found allelic expression imbalance of SERPINA6, which suggests that its expression is indeed affected by genetic variation in cis-acting elements. This represents candidate causal variation for future studies of the molecular background of the QTL.

Association of N‐terminal domain polymorphisms of the porcine glucocorticoid receptor with carcass composition and meat quality traits

The glucocorticoid receptor (GR) is a ubiquitously acting transcription factor that is responsible for mediating the physiological response to stress and adaptation to environmental conditions. Genetic variation of a GR gene (NR3C1) may therefore contribute to multiple phenotypic alterations and influence relevant traits of animal production. Here, we examined effects of two non-synonymous mutations of the porcine NR3C1, leading to amino acid exchanges p.Glu13Asp (c.39A>C) and p.Val19Leu (c.55G>C) in the N-terminal domain of the GR, on meat quality and carcass composition. In addition, we explored their influence on transcriptional activity of GR in vitro. A commercial crossbreed Pietrain×(German Large White×German Landrace) herd (n=545) in which genotypes and relevant traits had been collected was used to perform the association analysis. The single nucleotide polymorphism (SNP) c.55G>C was significantly associated with conductivity and meat color scores. These effects were highly consistent considering the physiological relationship between these traits. Association analysis of SNP c.39A>C also revealed significant effects on closely connected meat quality traits. In addition, SNP c.55G>C showed association with carcass traits, mainly those related to muscle deposition. The molecular mechanism of action of both amino acid substitutions remains obscure because neither showed significant influence on transcriptional activity of GR. Our study emphasizes NR3C1 as an important candidate gene for muscle-related traits in pigs, but further work is necessary to clarify the molecular background of the identified associations.

Use of magnetic resonance imaging to predict the body composition of pigs in vivo

The objective of the study was to evaluate whether magnetic resonance imaging (MRI) offers the opportunity to reliably analyze body composition of pigs in vivo. Therefore, the relation between areas of loin eye muscle and its back fat based on MRI images were used to predict body composition values measured by dual energy X-ray absorptiometry (DXA). During the study, a total of 77 pigs were studied by MRI and DXA, with a BW ranging between 42 and 102 kg. The pigs originated from different extensive or conventional breeds or crossbreds such as Cerdo Iberico, Duroc, German Landrace, German Large White, Hampshire and Pietrain. A Siemens Magnetom Open was used for MRI in the thorax region between 13th and 14th vertebrae in order to measure the loin eye area (MRI-LA) and the above back fat area (MRI-FA) of both body sides, whereas a whole body scan was performed by DXA with a GE Lunar DPX-IQ in order to measure the amount and percentage of fat tissue (DXA-FM; DXA-%FM) and lean tissue mass (DXA-LM; DXA-%LM). A linear single regression analysis was performed to quantify the linear relationships between MRI- and DXA-derived traits. In addition, a stepwise regression procedure was carried out to calculate (multiple) regression equations between MRI and DXA variables (including BW). Single regression analyses showed high relationships between DXA-%FM and MRI-FA (R2 = 0.89, √MSE = 2.39%), DXA-FM and MRI-FA (R2 = 0.82, √MSE = 2757 g) and DXA-LM and MRI-LA (R2 = 0.82, √MSE = 4018 g). Only DXA-%LM and MRI-LA did not show any relationship (R2 = 0). As a result of the multiple regression analysis, DXA-LM and DXA-FM were both highly related to MRI-LA, MRI-FA and BW (R2 = 0.96; √MSE = 1784 g, and R2 = 0.95, √MSE = 1496 g). Therefore, it can be concluded that the use of MRI-derived images provides exact information about important ‘carcass-traits’ in pigs and may be used to reliably predict the body composition in vivo.

In vivo body composition in autochthonous and conventional pig breeding groups by dual-energy X-ray absorptiometry and magnetic resonance imaging under special consideration of Cerdo Ibérico

The improvement of carcass quality is one of the main breeding goals in pig production. To select appropriate breeding animals, it is of major concern to exactly and reliably analyze the body composition in vivo. Therefore, the objective of the study was to examine whether the combination of dual-energy X-ray absorptiometry (DXA) and magnetic resonance imaging (MRI) offers the opportunity to reliably analyze quantitative and qualitative body composition characteristics of different pig breeding groups in vivo. In this study, a total of 77 pigs were studied by DXA and MRI at an average age of 154 days. The pigs originated from different autochthonous or conventional breeds or crossbreeds and were grouped into six breed types: Cerdo Ibérico (Ib); Duroc × Ib (Du_Ib); White Sow Lines (WSL, including German Landrace and German Large White); Hampshire/Pietrain (Pi_Ha, including Hampshire, Pietrain × Hampshire (PiHa) and Pietrain × PiHa); Pietrain/Duroc (Pi_Du, including Pietrain × Duroc (PiDu) and Pietrain × PiDu); crossbred WSL (PiDu_WSL, including Pietrain × WSL and PiDu × WSL). A whole-body scan was performed by DXA with a GE Lunar DPX-IQ in order to measure the amount and percentage of fat tissue (FM; %FM), lean tissue (LM; %LM) and bone mineral, whereas a Siemens Magnetom Open with a large body coil was used for MRI in the thorax region between 13th and 14th vertebrae in order to measure the area of the loin (LA) and the above back fat area (FA) of both body sides. A GLM procedure using SAS 9.2 was used to analyze the data. As expected, the native breed Ib followed by Du_Ib crossbreeds showed the highest %FM (27.2%, 25.0%) combined with the smallest LA (46.2 cm2, 73.6 cm2), whereas Ib had the lowest BW at an average age of 154 days. Pigs with Pi_Ha origin presented the least %FM (12.4%) and largest LA (99.5 cm2). The WSL and PiDu_WSL showed an intermediate body composition. Therefore, it could be concluded that DXA and MRI and especially their combination are very suitable methods to reliably identify differences in body composition and carcass traits among different pig lines in vivo.

Genes with expression levels correlating to drip loss prove association of their polymorphism with water holding capacity of pork

Six genes that were known to exhibit expression levels that are correlated to drip loss BVES, SLC3A2, ZDHHC5, CS, COQ9, and EGFR have been for candidate gene analysis. Based on in silico analysis SNPs were detected, confirmed by sequencing, and used for genotyping. The SNPs were genotyped in about 1,800 animals from six pig populations including commercial herds of Pietrain (PI) and German Landrace (DL), different commercial herds of Pietrain×(German Large White×German Landrace) (PIF1(a/b/c)), and one experimental F2-population Duroc×Pietrain (DUPI). Comparative and genetic mapping established the location of BVES on SSC1, of SLC3A2 and ZDHHC5 on SSC2, of CS on SSC5, of COQ9 on SSC6 and of EGFR on SSC9, respectively, coinciding with QTL regions for carcass and meat quality traits. BVES, SLC3A2, and CS revealed association at least with drip loss and with several other measures of water holding capacity (WHC). Moreover, COQ9 and EGFR were associated with several meat quality traits such as meat color and/or thawing loss. This study reveals statistic evidence in addition to the functional relationship of these genes to WHC previously evidenced by expression analysis. This study reveals positional and genetic statistical evidence for a link of genetic variation at these loci or close to them and promotes those six candidate genes as functional and/or positional candidate genes for meat quality traits.

Integrating expression profiling and whole-genome association for dissection of fat traits in a porcine model

Traits related to fatness, important as economic factors in pork production, are associated with serious diseases in humans. Genetical genomics is a useful approach for studying the effects of genetic variation at the molecular level in biological systems. Here we applied a whole-genome association analysis to hepatic gene expression traits, focusing on transcripts with expression levels that correlated with fatness traits in a porcine model. A total of 150 crossbred pigs [Pietrain × (German Large White × German Landrace)] were studied for transcript levels in the liver. The 24K Affymetrix expression microarrays and 60K Illumina single nucleotide polymorphism (SNP) chips were used for genotyping. A total of 663 genes, whose expression significantly correlated with the trait "fat area," were analyzed for enrichment of functional annotation groups as defined in the Ingenuity Pathways Knowledge Base (IPKB). Genes involved in metabolism of various macromolecules and nutrients as well as functions related to dynamic cellular processes correlated with fatness traits. Regions affecting the transcription levels of these genes were mapped and revealed 4,727 expression quantitative trait loci (eQTL) at P < 10⁻⁵, including 448 cis-eQTL. In this study, genome-wide association analysis of trait-correlated expression was successfully used in a porcine model to display molecular networks and list genes relevant to fatness traits.

Association of ZYX polymorphisms with carcass and meat quality traits in commercial pigs

Zyxin (ZYX) is one of the proteins in focal adhesions along the actin fibers playing a role in actin organization and signal transduction. By radiation hybrid and genetic mapping we assigned ZYX to porcine chromosome 18 in the area of quantitative traits loci for carcass and meat quality and muscle fiber traits and hence considered ZYX a functional positional candidate gene. Analysis of a newly detected SNPs (c.+279 C>T, c.+399 A>G, c.+522 A>G) in pigs from different commercial breeds (Pietrain [Pi], German Landrace [LR], German Large White × German Landrace [F1] and PiF1) revealed a significant association with carcass traits (including: side- and backfat thickness, loin weight and carcass lean content) and meat quality traits (including: pH, color and drip loss). However, the lack of consistent association across all pig populations in this study indicates that the association of the SNPs may be depending on causal mutations in linkage disequilibrium and/or interactions with other loci.

Effect of Polymorphisms in the Genes for LIF and RBP4 on Litter Size in Two German Pig Lines

The association of two diallelic polymorphisms in the porcine genes for leukaemia inhibitory factor (LIF) and retinol-binding protein 4 (RBP4) with number of piglets born alive (NBA) in two German pig lines was studied. The investigated single nucleotide polymorphism (SNP) in the porcine LIF gene has been located in the 3'-untranslated region of its third exon, whereas the SNP in the RBP4 gene genotyped in this study is intronic. At the LIF locus the allele frequencies were 0.613 for the A allele and 0.387 for the B allele in German Landrace (GL) and 0.276 for A and 0.724 for B in German Large White (GW). At the RBP4 locus, the allele frequencies were 0.586 for the A allele and 0.414 for the B allele in GL and 0.733 for A and 0.267 for B in GW. There was a significant additive effect of the LIF B allele on NBA in GW over all parities (p <or= 0.05) and a significant positive dominance effect of 0.69 +/- 0.22 (p = 0.002) was observed for first parity on NBA in GL. For RBP4, no association of genotypes and NBA was detected in GW but a significant additive effect of the A allele of 0.24 +/- 0.11 (p = 0.027) and a significant dominance effect of 0.31 +/- 0.13 (p = 0.020) were found in GL over all parities and confirmed through the evaluations by parity.

Effect of Polymorphisms in Four Candidate Genes for Fertility on Litter Size in a German Pig Line

We carried out an SNP discovery project in pigs for candidate genes playing potentially important roles in embryonic development. Using eight pigs one each from eight breeds (Meishan, Mangalitza, Duroc, Pietrain, German Landrace, Hampshire, Husum Red Pied, German Large White), 36 SNPs were identified in intronic sequences of 21 porcine candidate genes based on sequencing of PCR products. The primer pairs were designed using porcine EST sequences allowing amplification of introns. These SNPs were tested for their association with the number of piglets born alive in German Large White sows using a discordant approach. Significant effects (p < 0.001 and p < 0.05, respectively) of intronic SNPs on litter size were found for four genes: mitogen-activated protein kinase kinase kinase 3 (MAP3K3), vascular endothelial growth factor receptor (KDR), erbb2 interacting protein (ERBB2IP) and peroxisome proliferator-activated receptor delta (PPARD). These SNPs can be further tested in upcoming association studies for their influence on litter size in different breeds using larger sample sizes.

Suitability of three commercially produced pig breeds in Germany for a meat quality program with emphasis on drip loss and eating quality

This study aimed at characterising 606 crossbred pigs of three commercially available breed types in terms of their carcass and meat quality. Breed G and H were German Large White (LW) × German Landrace (LR) sows sired with Pietrain (PI) boars, i.e. PI × (LW × LR). Breed S was 25% Duroc (DU), i.e. PI × (DU × LR). Most of the parameters were affected by breed and/or date of slaughter. The meat of crossbred pigs with 25% Duroc proportion appeared most favourable because of higher intramuscular fat content, lower drip loss and higher sensory liking scores. Conductivity is closely related to drip loss while the data suggests that the relationship is dependent on breed and carcass weight. The application of conductivity and lean meat yield thresholds to select carcasses with uniform and superior meat quality effectively decreased drip loss and increased intramuscular fat content as well as sensory liking scores. The variation of meat quality traits remains high, though.

Abgangsursachen und ihr Einfluss auf die Lebensleistung bei Sauen der Rassen Deutsches Edelschwein, Deutsche Landrasse und Pietrain

Abstract. Title of the paper: Culling reasons and their effect on lifetime productivity in sows of the breeds German Large White, German Landrace and Pietrain Culling reasons in sows were analysed with respect to their importance for the different times of removal and their effects on longevity, length of productive life, number of piglets born alive and number of weaned piglets in the whole life of a sow. The investigation was based on records of 655 Large White (DE) sows, 13,005 German Landrace (DL) sows and 6,473 Pietrain (PI) sows born between1989 and 1994 and culled until 2002. In all the three breeds investigated, removal was highest due to fertility with 15 % (DE and PI) and 20 % (DL) and next highest due to diseases with 11 to 13 %. In PI sows, culling for low fattening performance and low efficiency in carcass yield ranked third (8 %), while removal for old age (9 and 10 %, respectively) was more important in DE and DL sows. The main timespan for the different culling reasons were after the fourth farrowing due to infertility, between the 2nd and 5th farrowing due to low fattening performance and low efficiency in carcass yield, after the first farrowing due to reproduction problems and up to 4th farrowing due to diseases, while culling due to old age did not occur before the 5th farrowing. Heritabilities of reasons for removal were in the range of h2 = 0.04–0.08 due to poor fertility, h2 = 0.01–0.09 due to low fattening performance and low efficiency in carcass yield, h2 = 0.02 due to reproductive problems, between h2 = 0.01 and h2 = 0.05 due to diseases and between h2 = 0.05 and h2 = 0.16 due to miscellaneous reasons.

Vergleichsuntersuchungen zur Verwendbarkeit des PIGLOG-Ultraschall- Gerätes für die Vorausbestimmung des Muskelfleisch-anteiles bei Sauen im Rahmen der Eigenleistungsprüfung

Abstract. Title of the paper: Comparative investigations about the application of ultrasound measurement (PIGLOG) for prediction ofthe lean meat content in gilts Ultrasound based Systems for in vivo estimation of lean meat content were comparatively investigated in 100 gilts (German Landrace, German Large White, Leicoma and F1). Rank correlations increased between ultrasound based estimations of lean meat and carcass Classification with growing age and live weight, respectively. Lean meat content was estimated with the PIGLOG System and the B-mode device with repeatabilites of R2 = 0.40 and R2 = 0.63, respectively. We can not recommend the use of PIGLOG derived estimates of lean meat content in selection of gilts without prior correction of the calculation algorithm in the investigated populations. Our investigations furthermore demonstrated the importance of sufficient training of the persona conducting the measurements.

Genetic and environmental trends in German swine herdbook populations.

Environmental and genetic trends for swine herdbook populations for Germany for the years 1979 to 1987 were estimated using mixed model methodology on test station data. Daily gain (DG), feed conversion efficiency (FCE), lean-to-fat ratio (R) and meat quality (Goefo) were analyzed simultaneously with different incidence matrices. Breed, season and test station were fixed effects; herd, litter and additive genetic effects for sib groups were random effects. Because the relationship data were incomplete, unknown ancestors were assigned to genetic groups. Carcass weight was included as a covariable for R. In DG, FCE and R, season was defined as month of test over all breeds and test stations. On the other hand, season for Goefo was replaced by slaughter location-date interaction. Cumulative genetic responses from the multivariate analysis for the component traits of the aggregate genotype ranged from 22 g to 55 g in DG, -.7 to 3.2 units in Goefo, -.1 to .5 in valuable cuts, and -.04 to -.15 in FCE. Cumulative monetary response over these 9 yr. per pig were $4.3, $3.7, $6.2 and $5.1 for German Landrace, German Large White, Pietrain and German Landrace B. Important environmental trends were found in FCE, Goefo and R. Total genetic improvement amounted to 1.6% of the value of national pork production in Germany during these 9 yr. With incomplete convergence, the genetic response was underestimated and environmental trends were overestimated.