Close linkage established between the HAL locus for halothane sensitivity and the PHI (phosphohexose isomerase) locus in pigs of the Danish Landrace breed.
Explore the source record for details and available documents.
Anesthesia, Inhalation↗
SEARCH · PubMed Health
Results for “Landraces”
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
[The hydroxyproline content of blood plasma in the progeny of German landrace pigs as determined through gas chromatography].
Explore the source record for details and available documents.
Animals↗
[Statistics, heredity and correlations between some features of the circulatory system in female German Landrace swine. III. Correlations and regressions].
Explore the source record for details and available documents.
Age Factors↗
[Statistics, heredity and correlations between some features of the circulatory system in female German Landrace Swine. I. Mean values and environmental effects].
Explore the source record for details and available documents.
Age Factors↗
[Statistics, heredity and correlations between some features of the circulatory system in female German Landrace swine. II. Heritabilities and gene frequencies].
Explore the source record for details and available documents.
Animals↗
Plasma progesterone levels throughout the oestrous cycle and release of LH at oestrus in sheep with different ovulation rates.
The concentrations of progesterone in the peripheral plasma throughout the oestrous cycle and the preovulatory LH discharge were examined in Finnish Landrace, Galway and Fingalway (Finnish Landrace X Galway) ewes. Progesterone levels were significantly higher in Finnish Landrace ewes during the luteal phase of the cycle (Days 10--13) than in Galways of Fingalways in which the concentrations were similar. Luteal-phase progesterone levels were almost 50% higher during December than during October in all three breeds. The relationship between the number of CL and plasma progesterone was not a simple linear function. All aspects of the preovulatory LH discharge were similar in the three breeds with the exception of the timing of the LH release in relation to the onset of oestrus. This occurred earliest in the Galway and latest in the Finnish Landrace while the Fingalway was intermediate.
Animals↗
[Artificial insemination in pigs: study of conception conditions with use of 2 inseminations in heat with about 24 hours interval].
140 sows and gilts of Danish Landrace were inseminated twice per heat with an interval of approximately 24 hours. Half of the females had their first insemination with semen of Danish Landrace and their second insemination with semen of Yorkshire, the other half vice versa. 114 females became pregnant. At farrowing the number of offspring of Danish Landrace and/or Danish Landrace X Yorkshire per sow/gilt was registrated. The results have been set out in tables I and II, from which it can be seen, that 59% conceived only after first insemination, 18% only after second insemination and 23% after both first and second insemination. In the last group 52% of the offspring were from the first insemination and 48% from the second insemination. In the sows no increase in av. litter size after two inseminations was found. The results are discussed and apparent discrepancy with earlier results is explained with a presumbably existing competition in the female genital tract between sperms from two inseminations at different times in the heat, resulting in ageing of the first inseminated sperms.
Animals↗
Genetic and non-genetic effects on plasma LH concentrations in lambs at 4 and 8 weeks of age.
Plasma LH was measured at 4 and 8 weeks of age in purebred lambs born to Finnish Landrace, Galway, Fingalway and High Fertility ewes. The average litter sizes for these breeds vary from 1.4 to 2.5. Lambs born after the transfer of fertilized eggs (all Fingalway) to Finnish Landrace, Galway and Fingalway ewes were also studied. There was evidence for a significant positive effect of selection for litter size within the Galway breed on plasma LH at 8 weeks of age. Finnish Landrace lambs had significantly higher levels of plasma LH at 8 weeks of age than did Galway Control lambs. These two groups did not differ with respect to plasma LH at 4 weeks of age. Non-additive genetic effects were significant at 4 weeks of age. The ranking of genetic groups on plasma LH was not consistent with their ranking for litter size. There was no evidence for a maternal effect associated with breed of dam on plasma LH and the effects of litter size were generally insignificant. Female lambs had significantly higher levels of LH at 4 weeks of age but there was no sex difference at 8 weeks because LH levels in males had increased. The correlation between the level of plasma LH at 4 and 8 weeks of age was -0.04. It is concluded that plasma LH is unlikely to prove a practical aid to selection for increased fecundity in sheep.
Aging↗
[Blood characteristics of some french pig populations. Relationships with the malignant hyperthermia syndrome (author's transl)].
Lactic acid, glucose, creatine phosphokinase (CPK) and some mineral components were determined in the blood of piglets before and after a halothane test of five minutes (only before for CPK). Two different experimental groups were studied: 222 Pietrain piglets from an INRA experimental herd, and 325 piglets from the Large White, French Landrace and Belgian Landrace breeds entering performance testing stations. Animals reacting positively to halothane ("MHS" piglets) have significantly higher blood levels of lactic acid and potassium before anesthesia than normal animals. CPK is also higher, except for the Belgian Landrace: in this breed CPK shows the same average value and distribution in the two groups of piglets (normal and MHS). There are also breed differences in blood magnesium, independently of the reaction to halothane. But the breed differences observed in lactic acid and CPK are related to the proportion of MHS piglets in each breed. Anesthesia by means of halothane lowers the measured blood characteristics--except for glucose--in normal animals, and rises them--except for potassium--in MHS piglets. The results are discussed in view of the incomplete discrimination between the two types of pigs, with a 5 minutes test, and, particularly, considering possible breed differences in that respect.
Anesthesia↗
Genome-wide association and selective sweep analyses reveal genetic loci for teat number trait in pigs.
Teat number is a key reproductive trait for the commercial pig industry, as an optimum number enhances weaned piglet survival rate. This study aimed to identify single nucleotide polymorphisms (SNPs) and genomic regions that are associated with teat number in the Large White sow. A total of 1000 French Large White sows were used in an analysis of total, left/right, and maximum unilateral teat number. Environmental factor, Spearman correlation, genome-wide association study (GWAS), linkage disequilibrium, and selective sweep analyses were conducted, with validation performed in a population of 1145 Landrace pigs. Genetic statistics showed that this population's teat number had moderate-low genomic heritability (h2 = 0.17-0.21) and weak negative correlation with weaned piglet litter weight. Parity and season affected teat development. GWAS identified 17 candidate SNPs on SSC 4, 7, and 17. Combined with selective sweep analysis, two key regions on SSC 7 were found, with four teat number-related SNPs, annotated to VRTN, DIO2, NRXN3. These candidate genes are associated with thoracic vertebrae development, hormone regulation during the early stage of teat formation, and nervous system development. These five SNPs showed similar results in the Landrace pig validation population; non-mutant homozygotes had 0.25-1.15 more teats than mutant ones in both populations. This study contributes to the identification of key variant loci associated with teat number-related traits in sows, thereby providing reliable molecular markers and a theoretical basis for marker-assisted selection of sow reproductive performance.
Animals↗
Allozymic variation as an estimate of heterozygosity in Belgian pig breeds.
An electrophoretic survey of 13 enzymes corresponding to 19 loci has been carried out in Belgian Landrace and Pietrain pig breeds. Four of these enzymes have been shown to exhibit electrophoretically detectable polymorphism. The average heterozygosity per locus was found to be 0.066 in the Belgian Landrace and 0.028 in the Pietrain pigs.
Adenosine Deaminase↗
Gene frequencies of blood groups in Dutch swine breeds.
Gene frequencies of blood groups at 6 loci were estimated within two Dutch breeds of swine, Dutch Landrace and Dutch Large White. At all loci there were significant differences between breeds. The relationship of the two breeds with, respectively, the Germany Landrace breed and the German Large White breed could be confirmed by the gene frequencies.
Animals↗
From bottleneck to boom: Polyploidy, genetic instability and response to artificial selection resolve the peanut paradox.
This study, the second in a three-part series, shows how peanut's polyploid origin enabled rapid diversification and enhanced domestication potential. Building on the knowledge that cultivated peanut (Arachis hypogaea) originated from a narrow hybridization between Arachis duranensis and Arachis ipaënsis less than 10 000 years ago, we are confronted with a paradox: how did such a narrow origin give rise to so much diversity-two subspecies, six botanical varieties, and thousands of landraces differing in growth habit, seed size, and pod morphology? Although several diploid Arachis species were cultivated earlier, only the allotetraploid became fully domesticated and widely adopted. The global success of peanut, despite its narrow genetic origin, suggests that polyploidization itself facilitated domestication. To test this hypothesis, we investigated how the two diploid progenitors and neoallotetraploids derived from a single hybridization and polyploidization event responded under artificial selection. In a pollinator-free greenhouse, we advanced lineages of the neoallotetraploid and its diploid parents over 6 years, selecting for divergent seed weights. The neoallotetraploid showed a much stronger response to artificial selection than its diploid parents, while also spontaneously generating diverse phenotypic variation-including flower color, pod reticulation, and chlorophyll content-traits that distinguish A. hypogaea subspecies and landraces. These traits mirrored directional shifts in parental genome dosage caused by homoeologous exchange, supporting a causal connection with phenotype. These findings offer a compelling rationale for a domestication advantage in polyploid peanut, and provide a living demonstration of how a single ancestral tetraploid, despite an extreme genetic bottleneck, generates a phenotypic boom.
Arachis↗
Development and optimization of T-ARMS PCR assays for detection of lethal haplotypes of TADA2A, UR1B, and PORL1B in pigs in Vietnam.
Marker-assisted selection has increasingly relied on single-nucleotide polymorphisms (SNPs) as robust genetic markers, particularly in livestock breeding programs. In pig farming, embryonic mortality significantly affects litter size, and SNPs in reference genes have been implicated as potential causal factors. We developed and optimized a tetra-primer amplification refractory mutation system (T-ARMS) PCR assay for rapid, cost-effective detection of SNPs in 3 candidate genes-TADA2A, PORL1B, URB1-that are associated with embryonic lethality and reproductive performance. Primer sets were designed based on known mutation sites and validated using synthetic gene constructs and porcine genomic DNA from pigs of Duroc and Landrace breeds. Optimization of annealing temperatures and primer concentration ratios yielded distinct and reproducible allele-specific amplicon patterns that were corroborated by PCR-RFLP and Sanger sequencing. Our T-ARMS PCR protocol, which requires minimal equipment and reduces processing time to <3 h, had high specificity and efficiency in differentiating wild-type, heterozygous, and homozygous mutant genotypes in 20 Duroc and 20 Landrace pigs. Our Tetra-ARMS PCR assay is a robust and economically viable tool for SNP genotyping in pig breeding programs, potentially contributing to the reduction of embryonic lethality and the improvement of overall reproductive outcomes.
Sus scrofa↗
Repeatability of the duration of oestrus and breed differences in the relationship between druation of oestrus and ovulation rate of sheep.
The duration of oestrus and the time interval from removal of progestagen-impregnated pessaries to the onset and end of oestrus were examined in Texel, Finnish Landrace, Galway and Fingalway (Finnish Landrace X Galway) ewes. The differences among the breeds in the relationship between these variables and ovulation rate at the controlled oestrus were also investigated. Breed differences were significant for all traits except the interval from pessary withdrawal to the onset of oestrus. The relationship between ovulation rate and both the interval from pessary withdrawal to the onset of oestrus and the duration of oestrus differed significantly among the breeds. The repeatability of the duration of oestrus was significant for Texel and Rambouillet ewes (mean = 0.5) and for pooled data from ewe lambs of various breeds. It was concluded that, in view of the breed differences in the relationship between ovulation rate and duration of oestrus and other traits, generalizations should not be made from among-breed to within-breed relationships. The high repeatability for the duration of oestrus may mean substantial heritabilities for the physiological determinants of oestrus duration.
Animals↗
The absorption of immunoglobulin from colostrum by bottle-fed lambs.
Factors affecting the absorption of immunoglobulin from colostrum by new born lambs were studied. Merino, Scottish Blackface, Cheviot, Southdown, Border Leicester, Finnish Landrace and Finnish Landrace x Dorset Horn lambs were removed from their mothers before sucking and bottle-fed with measured amounts of colostrum, either from individual ewes, or from pools of colostrum, some of which had been frozen for up to two years. Afterwards the lambs were fostered onto other ewes or reared on milk substitute. Their serum IgG1 concentrations before and after colostrum intake, were compared with IgG1 concentrations in conventionally reared lambs. The concentrations in lambs given a single feed of 150 to 200 g 1 hour after birth, or 30 g/kg at 1 hour and 7 hours compared favourably with those in control lambs. Lambs fed 50 to 100 g at 1 hour had a high proportion of very low concentrations and lambs fed 30 g/kg at 1 h, or at 1 and 24 h had low mean concentrations but no very low individual concentrations. The concentrations after a feed at 1 hour were positively correlated with the total amounts of IgG1 in the colostrum and negatively correlated with the birth weights. Only very small amounts were absorbed at 24 hours. Absorption was more efficient in males than in females and in Cheviots than in other breeds. It was unaffected by the age of the colostrum. Similar proportions of bottle-fed and control lambs died before 6 months of age, but relatively more bottle-fed lambs died from respiratory infections. The IgG1 concentrations and growth rates of the bottle-fed lambs were not significantly correlated.
Absorption↗
[Use of radiography in the diagnosis of atrophic rhinitis (author's transl)].
In 126 gilts of the Netherlands Landrace breed and eighty-one gilts of the Large Yorkshire breed, slaughtered when they had attained a weight of 100 kg., radiography of the nasal cavities was carried out, followed by post-mortem studies of these cavities. Macrocopic examination of the transverse section at the level of the first premolar tooth showed that the incidence of atrophy as well as of hypertrophy of the turbinate bones was higher in pigs of the Large Yorkshire breed than it was in those of the Landrace breed. The ventral coils of the ventral conchae were most commonly affected in the two breeds. When the X-rays were assessed using the system suggested by Done (3), a discrepancy between the X-rays and the post-mortem findings was observed in a large number of cases. Possible causes of this discrepancy are discussed. The results do not warrant the development of a radiographic technique which can be used in field conditions in the Netherlands to examine the nasal cavities in establishing a diagnosis of atrophic rhinitis.
Animals↗
Mesangiocapillary glomerulonephritis in lambs. III. Quantitative and qualitative aspects of immunopathology.
Newborn Finnish Landrace lambs subsequently affected with mesangiocapillary glomerulonephritis (MCGN) were deficient in the third component of complement (C'3), serum levels being approximately 5 per cent. of those in unaffected lambs. Hypocomplementaemia persisted until symptoms of renal failure occurred at around 6-8 wk of age. Immunofluorescence examinations of renal cortex with antisera specific for IgG, IgM, IgA, C'3 and fibrin supported previous morphological evidence of a strong similarity between this disease and MCGN in man. Similar examinations of choroid plexus suggested that immune complexes containing IgG, IgM and C'3 were present in the interstitium.
Animals↗