Sire evaluation and herd level of milk production

To read the full-text of this research, you can request a copy directly from the authors.


Age-corrected milk records of 40,374 Holstein cows tested in 1,073 herds in Ontario were studied to determine if the level of herd production had an effect on the genetic expression of milk production. Heritability of milk production was estimated from paternal half-sib correlations at each of seven levels of herd production. The estimates obtained varied from 0.24 ± 0.05 to 0.36 ± 0.04, lowest values being associated with the lowest and highest levels of production. A significant quadratic component (P = 0.07) was obtained when these estimates were regressed on herd level of production. The sire component of variance increased from low to higher levels of herd production. The environmental component of variance increased in magnitude from the lowest to the highest production level, with a large increase at the highest level. Correlations among the contemporary comparison proofs of 19 sires, each evaluated on the production of 20 or more daughters at four levels of herd production, ranged from 0.73 to 1.01, indicating little change in ranking of sires across herd level of production.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

Six different variance structures were simulated across herds. Data structure corresponded to a sample data set and comprised 197 335 lactations of 82 062 cows distributed in 924 herds. The homogeneity case, as well as different combinations of heterogeneous variances, were considered. Variances were varied assuming a positive correlation of 0.4 with herd-year-season (HYS) average production. Two animal models, with and without sire-by-herd (S × H) interaction, were compared through within-HYS variance components estimates. A regression-analysis method was used for the estimation. Correlations between estimated and true variance components within HYS were around 0.7 for subclasses with at least 20 observations. The model fitting a S × H interaction showed a reduced correlation with true values and HYS average production, but the reduction, although significant, was very small (- 0.02). Thus, the effect of the interaction in absorbing heterogeneous variance was very small.
Six different variance structures were simulated across herds to fit a real data structure with 197 335 lactations in 924 herds. The homogeneity case, as well as different combinations of heterogeneous variances across herd-year-seasons (HYSs) were considered. A positive correlation of 0.4 was assumed between average production and phenotypic standard deviation within HYS. Two animal models, with and without sire-by-herd (S × H) interaction, were compared in their ability to rank the best animals. The interaction term was used as a correction factor for heterogeneity. In terms of accuracy of genetic proofs and estimated genetic progress, the model including the S × H interaction effect resulted in less accurate genetic proofs compared to a model without S × H interaction. Decrease in accuracy was greater for sires (- 0.03) than for cows (- 0.01). The estimated genetic progress was 2-3% lower when fitting the interaction into the model than when not considering S × H effects.
Full-text available
Pour étudier l'interaction génotype milieu sur la production laitière, on considère selon la théorie de FALCONER (1952) les expressions du même caractère dans deux milieux comme deux caractères différents mais génétiquement liés. Les données du fichier français de contrôle laitier sont séparées selon l'effet milieu étable en trois groupes auxquels nous associons par hypothèse trois milieux différents. L'héritabilité de la quantité moyenne de matière utile augmente avec le niveau de production (0,31, 0,33 et 0,42). Les corrélations génétiques entre milieux sont proches ou supérieures à 0,9. Ces résultats, qui confirment les nombreuses études déjà réalisées sur ce sujet, permettent quelques conclusions pour la sélection laitière en France. Le choix des taureaux sur un index laitier unique est suffisant quel que soit le niveau de production des élevages. Il n'est pas nécessaire d'entretenir des lignées spécialisées pour chaque niveau de production. L'augmentation de précision du testage sur descendance qui pourrait être obtenue en ne réalisant celui-ci que dans les élevages de bon niveau, ne compenserait pas la réduction de capacité de testage qui en résulterait. Aussi faut-il continuer à pratiquer le contrôle sur descendance dans l'ensemble des élevages.
Full-text available
Sur un fichier de données du contrôle laitier, nous étudions la liaison entre l’indice de sélection d’un taureau et la performance de sa fille. Il apparaît que le coefficient de régression de celle-ci sur l’indice du père est lié de façon positive au niveau de production de l’étable où la génisse est élevée. Ce coefficient augmente de 0,45 à 0,57 quand l’effet milieu étable passe de - 30 à 30 kg de quantité moyenne de matières utiles soit environ de - 800 à + 800 kg d’équivalent lait. L’augmentation de production liée au choix d’un taureau améliorateur est donc d’autant plus importante que les conditions de milieu sont plus favorables. Ceci révèle l’existence d’un phénomène d’interaction génotype X milieu qui sera analysé de façon plus précise dans une prochaine étude (Bonaiti 1982). L’importance de ce phénomène est cependant limitée et il faut continuer de tenir compte des indices de sélection des taureaux même dans les élevages de faible niveau de production.
Full-text available
Genetic parameters were estimated for yields and percentages of milk, fat, and protein for registered Italian Brown Swiss cows. Data were 72,690 mature equivalent 305-d first lactation yields split by herd average milk into four files. An expectation-maximization REML algorithm was used on a multiple-trait model with equal design matrices for fixed and random effects. Data were preadjusted for geographical area, age-month of calving, and days open. The model included herd-year and sire genetic group as fixed effects and sires as random effects. Estimates of heritability were .28, .30, .26, .42, and .34 for milk, fat, and protein yields, and fat and protein percentages, respectively. Genetic correlations of milk yield and milk component percentages were negative, as expected. Correlation of protein yield and protein percentage was null. Results show an increasing tend of variance components from low to high herd yields, indicating that dispersion of yield about the mean increases as average yield increases. Relative differences among environmental components were larger than those among genetic components, yielding larger estimates of heritability in herds with lower yield. Estimates of heritability for milk from low to high herd yields were .42, .38, .35, and .33.
Full-text available
Chondrocyte differentiation is characterized by distinct cellular phenotypes, which can be identified by specific extracellular matrix gene expression profiles. By applying in situ analysis on the mRNA and protein level in a series of benign and malignant human chondrogenic neoplasms, we were able to identify for the first time different phenotypes of neoplastic chondrocytes in vivo: 1) mature chondrocytes, which synthesized the characteristic cartilaginous extracellular tumor matrix, 2) cells resembling hypertrophic chondrocytes of the fetal growth plate, 3) cells resembling so-called dedifferentiated chondrocytes, and 4) well differentiated chondrocytic cells, which expressed type I collagen, indicating the presence of post-hypertrophic differentiated neoplastic chondrocytes. Chondrocytes exhibiting a range of phenotypes were found to be present in the same neoplasm. The different observed phenotypes, including the dedifferentiated phenotype, were in contrast to the anaplastic cells of high-grade chondrosarcomas. Comparison of expression data with tumor morphology revealed a relationship between the cellular phenotypes, the tumor matrix composition, and the matrix and cell morphology within the neoplasms. The distinctly different phenotypes of neoplastic chondrocytes are the basis of the characteristic high biochemical and morphological heterogeneity of chondroid neoplasms and shed light on their biological and clinical behavior.
The main object of the artificial insemination service is herd improvement. This is facilitated by the larger selection differential obtained when only a small number of bulls are used. Robertson and Rendel (1954) have shown that artificially bred daughters by bulls used at centres outwith the Milk Marketing Board system did not outyield naturally bred daughters milking in the same herds and these results have been substantiated by data from the Board’s centres. This failure to select bulls better than those used in the average herd has probably been due to the multiple aims of selection necessary to satisfy all those interested in the artificial breeding movement and to the methods which have been used to evaluate bulls. A method has been designed aimed at improving this evaluation.
By solitary benign enchondroma of bone we mean the benign cartilaginous growth which begins its development in the interior of an affected bone and involves only a single bone in any 1 subject. Our records include 28 instances1 of this type of lesion, and the discussion which follows is based largely on these. To judge from our experience, the lesion appears mainly in phalanges (particularly those of the hand), in metacarpal bones and in the humerus and femur, though other bones of the limbs are occasionally the site. Although our own cases do not include any in which the lesion was in a bone other than one of a limb, it should be noted that instances of such localization have also been reported.A benign enchondroma may be present in the interior of a bone without causing any obvious distention. However, it is not unusual to find, especially if
During the past decade considerable at- tention has been given to sire by herd inter- actions, but data have not been available to consider the broader regional aspects of this problem. Sire by region interactions for nlilk production, fat production, and fat test were examined, utilizing the first available DHIA record of 10,548 artificially sired daughters of 46 Holstein sires used in the northern and southern regions of the United States. Daughter records were ex- pressed as deviations from adjusted herd- mate averages. Correlations between the average breeding values of the sires in the two regions for the three traits approached 1.00, indicating that the ranking of sires was essentially the same in both regions. Estimates of the sire by region interaction variances for the three traits also were essentially zero. Although additional con- firmation is needed, these results suggest that influences associated with a particular region should not unduly confuse the rank- ing of sires in the different regions when herd-mate comparisons from artificially sired daughters are used.
A statistical study of butterfat records of the progeny and mates of 176 proved sires of the Guernsey, Holstein-Friesian, and Jersey breeds has been made. Each bull was represented by at least five daughter-dam comparisons in each of two or more herds. Curvilinear regression of daughter on dam within breeds, within sires and within herds accounted for a larger portion of the daughter variance than did linear regression. The difference, however, was not quite large enough to be statistically significant. The heritability of butterfat yield calculated by doubling the linear regression of daughter on dam within breeds, within sires and within herds was 27.4 per cent. Estimates of heritability on the basis of curvilinear regression gave values decreasing with increased butterfat yield. The pattern described by these estimates appears to hold a valid relation to the problems faced by breeders of dairy cattle and to the results of some experimental studies on similar problems.
The efficiency of selection of breeding animals is seriously limited because the phenotype of an economic quantitative characteristic is the result not only of genetic but also of environmental influences. The relative contribution of ge- netic and environmental influences is, therefore, information of significance. Heritability is used as the measure of the portion of phenotypic variability which can be attributed to additive genetic deviations. The remaining portion of variability may be ascribed to environmental deviations and to any deviations resulting from dominance, over-dominance, epistasis, and non-linear interactions of heredity and environment. A number of studies have shown that the heritability of most milk and but- terfat records is of the order of 20 to 30 per cent (4, 5, 6, 7, 8). Carneiro and Lush (2) in a preliminary observation on Brazilian cattle of low average pro- duction and unusual genetic heterogeneity found heritability to be about 50 per cent. Studies with other animals have raised the question of whether or not heritability is a constant. Wright (12), studying the quantitative inheritance of piebald spotting in guinea pigs found that homozygosity, produced by inbreed- ing, reduced the portion of variation in spotting which was inherited. Later, Hetzer, et al. (3) found that heritability of type in swine was greater in crosses between divergent types than it was in matings within a type. In the case of butterfat production of dairy cattle, one could speculate that either or both of the following situations would result in decreased estimates of heritability as production levels increased: (a) If high production is the result of homozygosity, lower genetic variance and heritability may be found at higher levels of production. (b) If high production is a consequence of dominance, over-dominance or epistasis, additive genetic variance and heritability may be smaller at higher levels.
Milk records in herds producing at high, medium, and low levels were analyzed for biases in adjustments for age at freshening. A highly significant relationship between age of cow and yield remained in the age-corrected records at all levels of environment. The bias appeared to be less marked in the high-environment herds for milk production but not for fat production. However, this apparent change in the yield-age relationship with increasing herd environment was not statistically significant. A method for predicting first-lactation from herd yield at older ages to minimize this bias and, at the same time, to provide a more efficient use of first-lactation records for sire evaluation in small herds is described.
First (45,876) and second (39,261) lactation records of New York A.I. Holstein daughters were divided into four groups depending on the level of their adjusted herd-mate averages relative to the DHIA season average. The high level was greater than 1,000 lb of milk above the season average, whereas the low level was more than 1,000 lb of milk below season average. Components of variance for sires and within sires were then estimated for each level from deviations of daughter records from their adjusted herd-mate averages. Genetic correlations between the genotypes in different environments were estimated. Application of the formula for relative genetic progress indicates that it may be advantageous to evaluate sires from daughter performance in all except the low-level herds. Excluding about a quarter of the herds would, however, decrease the number of young sires which could be tested. Considering both of these factors it seems preferable not to exclude any herds unless contract herds were being used to test young sires. Since the genetic correlations are high (near unity), the evaluation of the sires would be nearly the same in all herd levels. Results indicate that although there is little, if any, genotype-environmental interaction in the usual sense (ranking of sires in different environments), there is another form of genotype-environmental interaction: genetic variability is evidently different from one environmental level to another—the higher the level, the more genetic variability. The fraction of the total variability which is genetic is also lower in the lower levels of environment than in the higher levels.
Intra-sire, intra-herd variance and covariances of daughters and dams were used to estimate heritabilities, and phenotypie and genetic correlations between type ratings and milk and milk fat production records adjusted to a single record basis. Milk and milk fat production records and official type classification ratings of 14,727 Holstein- l%iesian cows and their dams were included in this study. tteritability estimates for milk and milk fat production were of the order of 0.20, and did not differ significantly among the three levels of herd production. The esti- mates of heritability for type ratings ranged from 0.03 for dairy character to 0.31 for rump. Phenotypic correlations between type ratings and milk and milk fat production ranged from +0.02, to +0.25, with a standard error of 0.01 to 0.02. Most of the genetic correlations concerning type ratings and production were not significant. The genetic correlations between dairy character and production were significant and ranged from 0.61 to 0.82 for the three stratified groups. Selection based on type ratings, with the exception of rating for dairy character, would cause little genetic improvement in milk or milk fat production. The relative genetic progress in milk production, if selection is on dairy character, is expected to be 35 to 50% of that which can be obtained by selecting on the basis of one milk production record.
Whether different bulls are needed for each of several different situations or whether one general group of bulls will serve effectively to improve the population under shy conditions depends upon the importance of interactions between sires and the herds in which they have daughters. Interaction between sires and herds has appeared to contribute little to the varia- tion of production of milk and fatby dairy cat- tle (6-8, 12, 14-26) ; however, this evidence does not necessarily eliminate the possibility of ge- netic-environmental interactions for produc- tion being found where the environmental con- ditions are defined more precisely than herds. Differences between herds make up about 2(} to 40% of the variation in production and only about one-tenth of this appears to be due to genetic differences between herds (8). The re- maining differences between herds are caused by differences in environments which are a composite of many constitutive environments. A few attempts have been made to define and to measure the general effects of some of these environments and systems of management (1, 3, 5, 7, 9, 20, 13), but little is known of the differential response of daughters of different bulls to these environments. Important genetic interactions with these individual environments could exist and be undetected where classifica- tion is so indefinite that an environment is de- fined to be a herd. This study is to ascertain the magnitude of interaction between sires with A.I. daughters in tested herds in Michigan DH2A and a few measurable constitutive environments.
Intra-herd-sire heritability estimates were computed to examine the relationship between these values and the herd level of fat yield for 1,825 Guernsey, 5,458 Holstein, and 3,465 Jersey daughter-dam pairs. Phenotypic and additively genetic variances showed a definite increase as the mean fat production for the herd increased, and in the Jersey data the correlation between the mean fat yield for the herd and the intra-herd-year variance was 0.46 ± .05. The coefficient of variation, however, declined for the higher herd levels.There was no significant relationship between the heritability values and the production levels for the groups of herds in any of the breeds. Heritability estimates obtained by pooling the results from each breed were: Guernsey, 0.21 ± .06; Holstein, 0.22 ± .04; and Jersey, 0.24 ± .05. These results do not indicate the need for using different heritability values to predict progress from selection, or to develop selection procedures for herds with different production levels.
Somatic mutations in isocitrate dehydrogenase 1 (IDH1) and IDH2 occur in gliomas and acute myeloid leukaemia (AML). Since patients with multiple enchondromas have occasionally been reported to have these conditions, we hypothesized that the same mutations would occur in cartilaginous neoplasms. Approximately 1200 mesenchymal tumours, including 220 cartilaginous tumours, 222 osteosarcomas and another ∼750 bone and soft tissue tumours, were screened for IDH1 R132 mutations, using Sequenom(®) mass spectrometry. Cartilaginous tumours and chondroblastic osteosarcomas, wild-type for IDH1 R132, were analysed for IDH2 (R172, R140) mutations. Validation was performed by capillary sequencing and restriction enzyme digestion. Heterozygous somatic IDH1/IDH2 mutations, which result in the production of a potential oncometabolite, 2-hydroxyglutarate, were only detected in central and periosteal cartilaginous tumours, and were found in at least 56% of these, ∼40% of which were represented by R132C. IDH1 R132H mutations were confirmed by immunoreactivity for this mutant allele. The ratio of IDH1:IDH2 mutation was 10.6 : 1. No IDH2 R140 mutations were detected. Mutations were detected in enchondromas through to conventional central and dedifferentiated chondrosarcomas, in patients with both solitary and multiple neoplasms. No germline mutations were detected. No mutations were detected in peripheral chondrosarcomas and osteochondromas. In conclusion, IDH1 and IDH2 mutations represent the first common genetic abnormalities to be identified in conventional central and periosteal cartilaginous tumours. As in gliomas and AML, the mutations appear to occur early in tumourigenesis. We speculate that a mosaic pattern of IDH-mutation-bearing cells explains the reports of diverse tumours (gliomas, AML, multiple cartilaginous neoplasms, haemangiomas) occurring in the same patient.
Thesis (M. S. in Animal Industry in Dept. of Animal Science) -North Carolina State College. Bibliography: p. 45-47.
MR studies of five chondrosarcomas and three enchondromas were performed with intravenous Gd-DTPA administration. All tumors showed enhancement of scalloped margins and curvilinear septa (ring-and-arc pattern) on T1-weighted SE sequences with Gd-DTPA. On radiologic-pathologic correlation, the enhanced areas corresponded to fibrovascular bundles surrounding hyaline cartilage lobules. The rings and arcs of enhancement with Gd-DTPA on MR is a reflection of the lobulated growth pattern of cartilaginous tumors and therefore helpful in differential diagnosis of bone tumors.
The present study was carried out to determine if healing metaphyseal injury in abused infants is accompanied by an increase in the thickness of the growth-plate zone of hypertrophic cartilage and if a radiolucent extension from the growth plate into the metaphysis correlates with this histologic indicator of healing fracture. The radiologic studies of 13 infants who died with evidence of inflicted injury were reviewed. Thirteen distal metaphyseal fractures were identified. Histologically, nine of these fractures were noted to be healing and four showed no evidence of healing. The nine healing injuries were accompanied by statistically significant thickening of the zone of hypertrophic cartilage. Seven of these demonstrated localized areas of hypertrophic cartilage extension; in six of these, corresponding radiolucent extensions of the growth plate into the metaphysis were seen. The extensions tended to be single and focal with minimal osseous injury and broad and multiple with extensive injury. No similar extension was visible in the four acute injuries. Because metaphyseal injuries are notoriously difficult to date, the presence of a reliable radiologic indicator of healing metaphyseal fracture can be important in the evaluation of infant abuse. Because the radiologic findings reflect the histologic alterations, extension of the growth-plate cartilage into the metaphysis may have implications for estimating fracture age.
The cases of nine children who survived the acute stage of meningococcal septicemia and secondary disseminated intravascular coagulation were reviewed. All of the children had major orthopaedic problems as a result of the acute disease. Detailed histological studies were performed on specimens of bone and cartilage, obtained when these patients had either acute amputation for gangrene or subsequent revision for a chondro-osseous deformity. In the specimens that were obtained from the children who had acute gangrene, the histological changes included small-vessel thrombi, osteonecrosis, subperiosteal new-bone formation, cortical disruption, cellular disorganization in the physis, and medullary inflammation. These findings were compatible with a combination of inflammation (acute osteomyelitis) and ischemia. In the specimens that were obtained during revision of the amputation, three years or more after the initial infectious or ischemic process, the clinically relevant findings involved the epiphyses and physes. The growth plates showed variable permanent ischemic damage. Bone bridges connecting the epiphysis and metaphysis were observed in various stages of formation, including several early bridges with involvement of only the physis and metaphysis. Endosteal and cortical bone, in contrast, showed complete recovery with no evidence of permanent ischemic damage. We concluded that children who survive meningococcal septicemia are at high risk for complex orthopaedic problems, both acute and chronic. The disseminated intravascular coagulation and focal infections of the acute phase are primarily responsible for the vascular injuries to the growing chondro-osseous tissues. Ischemic changes also selectively involve the physeal circulation, but may take several years to adversely affect longitudinal and transverse growth of bone.
Magnetic resonance (MR) images and histologic studies of 16 chondroid-matrix lesions were reviewed to determine if any distinctive morphologic or signal features might be discerned. Ten biopsy-proved nonchondroid bone lesions were compared in terms of configuration and signal characteristics. The tumor matrix had a distinctive appearance of homogeneous high signal intensity in a defined lobular configuration on images of all hyaline cartilage lesions obtained with a long repetition time and a long echo time. The areas of hyperintensity relative to muscle corresponded to areas of hyaline cartilage matrix with its uniform composition, low cellularity, and high water content; the lobular morphologic characteristic had an identical histologic correlate. The chondroblastomas, clear-cell chondrosarcoma, and synovial chondromatosis demonstrated a much more cellular stroma, with only scattered islands of chondroid matrix, and were isointense or hypointense compared with muscle on all MR sequences. The distinctive lobular, high-intensity MR appearance was not seen in the ten nonchondroid bone lesions.
Relationships between independent measures of a bull's breeding value at different levels of herd production were investigated. The data consisted of the 2 times, 305-day, mature equivalent (ME) first lactation records of the artificially inseminated (AI) progeny of 40 Holstein sires. Each bull had 1,000 or more daughters. Progeny were classified into one of four groups, based on milk yield level of herdmates (I = 4,536–5,442 kg; II = 5,443–6,349 kg; III = 6,350–7,256 kg; and IV = 7,257–8,164 kg). Daughter averages rose with increases in herdmate level, while the magnitude of the Predicted Difference measure of a sire's breeding value decreased 289 kg (103, 47, −39, and −186 kg, respectively) from low (I) to high (IV) herdmate levels.Correlations among sire progeny averages at the different herdmate levels were all very high (0.88 to 0.96) and indicated that bulls ranked in about the same order at all levels. Regressions computed in the same manner indicated the absence of a one-for-one relationship in the magnitude of measures of breeding value at the different herdmate levels. The Predicted Difference measure of a sire's breeding value only partially accounted for variation in herdmate milk yields among sires. It was an effective criterion for ranking bulls evaluated within the same herd levels, but somewhat less effective in establishing absolute breeding merit. The maximum bias in predicted differences of bulls with very high yielding herdmates (6,800 kg of milk or more) was about 5 to 10%.
Histopathologic sections of large pieces of tissue obtained from both surgical and postmortem specimens of osteochondromas and enchondromas were analyzed to elucidate the pathogenesis of these two lesions. The osteochondroma is derived from aberrant cartilaginous epiphyseal growth plate tissue, which proliferates autonomously and separates from the normal growth plate near its edge. As growth progresses, the aberrant tissue remains in a subperiosteal location, where it may either disappear through remodeling or proliferate as an early osteochondroma perpendicular to the orientation of the growth plate from which it was derived. The enchondroma also is derived from the actively proliferating cartilaginous tissue of growth plates. For unknown reasons certain groups of chondrocytes do not proceed to undergo hypertrophy and death. As a result, a column of uncalcified cartilage extends from the underside of the growth plate into the region in which all other cartilaginous tissue has been remodeled into primary bone. The bridge to the plate may either remain intact or become interrupted by normal bone. An isolated group of chondrocytes may (1) be walled off from normal tissue by lamellar bone; (2) undergo calcification and secondary osseous remodeling, either in part or in total; or (3) proliferate as an intraosseous chondroma (benign enchondroma). A similar but not identical process of enchondroma formation may occur in fibrous dysplasia of bone, systemic growth plate dysplasias similar to achondroplasia, and osteogenesis imperfecta.
To determine the prevalence of chronic wrist injuries among adolescent gymnasts and the consequences of repetitive stress. Students of a Chinese opera school underwent radiography of both wrists and answered a questionnaire. They were separated into study (n = 261) and control (n = 63) groups according to participation in or abstinence from exercise training, respectively. They were further separated into fused and unfused physis subgroups. The ulnar variance was measured on posteroanterior radiographs. Abnormalities of distal radii were investigated. An increase in both mean ulnar variance and frequency of ulnar-plus variance was noted in the study subgroups. Fourteen (8.2%) of 170 wrists of the fused physis study subgroup had an exceedingly large ulnar-plus variance. Sixty-one (17.3%) of 352 wrists had abnormal morphology of the distal radii in the unfused physis study subgroup. Widening of the physis was the most common finding. Chronic, repetitive stress in the wrists of adolescent gymnasts results in a localized growth disturbance of the distal radius with resultant ulnar-plus variance. Stress injuries of the physis may lead to permanent sequelae, even in asymptomatic individuals.
To investigate the magnetic resonance (MR) imaging appearance of a chronically stressed wrist and to assess the utility of MR imaging for evaluation of injuries to the growth plate. Coronal T1-weighted spin-echo and gradient-echo MR images were obtained of 93 wrists in 47 high-risk gymnasts of a Chinese opera school. MR imaging and radiographic findings were correlated in 93 wrists. The major MR imaging abnormalities of 47 radii with abnormal radiographic findings were horizontal fractures (n = 23), physeal cartilage extension to metaphysis (n = 17), and physeal widening (n = 17). The major MR abnormalities of 46 radii with normal radiographs included physeal cartilage extension (n = 12), metaphyseal bone bruise (n = 8), and vertical fractures (n = 4). Physeal cartilage extension into the metaphysis represents a healing sign in chronically stressed adolescent wrists. MR imaging findings including horizontal fracture and physeal cartilage extension to the metaphysis suggest that physeal widening occurred secondary to metaphyseal injury.
Cartilaginous tumors can be subdivided into several categories according to the following three criteria: (1) Is the lesion benign or malignant? (2) Is the lesion a pure or impure cartilaginous tumor? (3) Is the epicenter of the lesion intraosseous, juxtacortical, or in the soft tissues? This article focuses on the four most common benign cartilaginous tumors, enchondroma, osteochondroma, chondroblastoma, and chondromyxoid fibroma, and on chondrosarcoma. It reviews the biologic and developmental considerations of each and discusses in depth the basic concepts in the radiologic diagnosis of cartilaginous tumors.
To offer a descriptive review which characterizes and evaluates the significance of local physeal widening, (cartilaginous signal extending from the physis into the adjacent metaphysis), identified on magnetic resonance (MR) imaging. MR images (recollected from exams performed between 1988 and 1995) of 31 metaphyses in 22 children where we recognized local physeal widening were examined retrospectively. These areas of physeal widening were evaluated for morphology, depth, location, signal intensity, and the coexistence of epiphyseal alterations. The characteristics of the signal abnormalities were correlated with the duration and type of any identifiable insult to the adjacent metaphysis, and with the development of growth disturbance. Twenty-six metaphyses had identifiable insults (19 single event and 7 sustained or repetitive). The widened physes were of focal tongue (n = 15), broad band (n = 10), or mixed (n = 6) morphology. Most (n = 27) areas of widening were isointense with the physeal cartilage on all sequences. Subsequent growth disturbance was more likely when the metaphyseal insult was a single event rather than sustained or repetitive (P = 0.023), with focal tongues (P = 0.029), and with centrally located lesions (P = 0.030). In five cases, the adjacent epiphysis showed signal abnormalities; all developed growth disturbance. Histologic examinations available in two limbs confirmed that the MR findings represented extensions of hypertrophic physeal chondrocytes into the metaphysis. Incidentally observed local physeal widening in a growing bone may represent the imprint of a previous or ongoing interference with endochondral ossification from a prior metaphyseal insult, rather than a primary metaphyseal disorder. Single event insults, physeal widening of focal tongue morphology, central distribution in the metaphysis, and concomitant epiphyseal signal abnormalities on MR imaging are significant predictors of subsequent growth disturbance.
In part I, we reviewed the varied clinical presentations, pathogenesis, histologic findings, radiologic findings, and treatment of intramedullary cartilaginous lesions of bone. In this section, we will evaluate our cases and consultations of juxtacortical cartilaginous tumors. Radiographic differential diagnosis includes the numerous juxtacortical lesions particularly osteochondroma, parosteal chondroma, Trevor's disease, trauma (fracture and periostitis ossificans), and the low- and high-grade surface osteosarcomas. By emphasizing pathogenesis in conjunction with radiographic and histologic findings, pitfalls in diagnosis and subsequent treatment can be avoided in such cases.
The pathologic changes at the physis in patients with rickets have been well demonstrated histologically. Radiographs can depict only the associated osseous abnormalities. We report two children in whom MR imaging demonstrated rachitic changes in the physeal cartilage beyond the well-recognized bony features. The striking appearance of the physes and the physes of the secondary ossification centers confirm that MR imaging can successfully evaluate the cartilaginous structures of the developing skeleton. Though MR imaging is clearly unnecessary for the diagnosis of rickets, it is important that the typical features are not misinterpreted as other pathology.
Despite substantial knowledge on the clinicopathology of chondrogenic skeletal neoplasms, only limited insights into the biology of the different tumor variants are available. There are virtually no established molecular markers for identification and classification of these neoplasms. In this paper, we present a systematic review of the biochemistry and cell biology of chondrogenic neoplasms of the bone focussing on our own recent investigations. The hallmark of all differentiated chondrogenic tumors is the presence of neoplastic chondrocytic cells responsible for the formation of the characteristic cartilaginous tumor matrix. These cells can show the full differentiation potential of physiologic chondrocytes depending on the tumor entity investigated. The high phenotypic diversity of physiologic chondrocytes explains the previously poorly understood, striking heterogeneity of the neoplastic cells and their surrounding extracellular matrix not only between different but also within chondrogenic tumors. In our studies, tumor classifications, so far based only on histomorphological criteria, were either confirmed or corrected: mesenchymal chondrosarcomas represent the prototypic neoplasm of pre-chondrogenic undifferentiated cells undergoing multifocal chondrocytic differentiation. Enchondromas, osteochondromas, and conventional chondrosarcomas are neoplasms of multi-phenotypically differentiated chondrocytes. Clear cell chondrosarcomas appear to be neoplasms of hypertrophic chondrocytic cells. A peculiar biology is displayed by dedifferentiated chondrosarcomas, which at least in most cases show neither "anaplasia" nor "dedifferentiation", but most likely "transdifferentiation" of part of the neoplastic cells to a cellular phenotype of a different mesenchymal differentiation lineage. Chondroblastomas do not show any chondroblastic differentiation at all. Our studies delineate molecular markers of chondrogenic neoplasms of the skeleton, which have the potential to be the basis of a new biology-orientated classification of skeletal neoplasms. The expression analysis of extracellular matrix genes, in particular of the collagen types, might be able to play herein a leading role in classification and diagnosis, similar to the cytokeratin subtypes or the CDs (cluster of differentiation) for the classification and diagnosis of neoplasms of the epithelia and the lymphatics.
Rickets and the decreased ossification associated with it can give rise to abnormally low bone density and weakened osseous structures. Despite this association, rickets has rarely been associated with osteochondral defects, and the imaging findings of this association have not been previously described on magnetic resonance (MR) imaging. This case report presents an adolescent male with a clinical history of rickets and recent-onset knee pain that was determined to be caused by bilateral osteochondritis dissecans. Prompt recognition of osteochondritis dissecans is important, as this entity is a treatable cause of knee pain.
Objective: The objective of our study was to describe the MRI appearance of and possible mechanism responsible for physeal widening in the knees of high-level child athletes. Conclusion: Widened physes in the knees of skeletally immature child athletes have MR signal characteristics similar to the normal physis but likely are a sign of stress injury. These children should cease the offending sport and rest the knee to allow rapid healing.
The knee joint remains the articulation most frequently assessed by MR imaging, and osseous tumor and tumor-like lesions are not uncommon incidental imaging findings. This article reviews the most commonly encountered incidental lesions, emphasizing the characteristic MR imaging features. It is intended not as a complete review of the imaging findings associated with these lesions but as a summary, highlighting the MR imaging features that are most useful in suggesting a specific diagnosis. The authors organize incidental lesions into the following broad categories: cartilaginous, fibro-osseous, and degenerative. They do not address those lesions that are typically symptomatic and, as a result, likely to be directly related to the patients' clinical presentation and subsequent imaging.
The purpose of our study was to determine the prevalence of incidental enchondromas on routine MR knee imaging. We retrospectively reviewed 449 consecutive routine knee MR examinations for the presence of enchondromas. MRI was considered positive when a focal geographic area of lobular marrow replacement (nonsubchondral) was identified on T1 weighting and high signal intensity was seen on T2 weighting. Patients with enchondromas were further evaluated for demographics; lesion site, size, and relationship to the physeal plate; aggressive imaging features described with chondrosarcoma; concurrent internal derangement; and study indication. The prevalence of incidental enchondromas was 2.9% on routine knee MR examinations. The prevalence was highest in the distal femur (2.0%), followed by the proximal tibia (0.7%) and the proximal fibula (0.2%). The average lesion size was 1.9 x 1.2 x 1.3 cm (57% of lesions were < 1 cm). Most lesions were located in the metaphysis (71%) or diaphysis (21%). Enchondromas were within 1.5 cm of the physeal plate in 72% of cases. No aggressive imaging features to suggest chondrosarcoma were seen. All patients had evidence of internal derangement as the cause of symptoms and the request for imaging. Incidental enchondromas can be identified on 2.9% of routine MR knee examinations, most frequently in the distal femur (2.0%). This significant prevalence is much higher than in an autopsy series (0.2%), likely reflecting the increased sensitivity of MRI for detecting small lesions, and is important to recognize to avoid confusion with other pathologic entities.
Tumors of Cartilaginous Origin In: Greenspan A, Remagen W, editors. Differential diagnosis of tumors and tumor-like lesions of bones and joints
  • A Greenspan
  • Remagen
Bone disease resulting from disturbances in mineral homeostasis In: Bullough P, editor. Orthopaedic pathology
  • P Bullough
Über die Entstehung des Enchondrom und seine Beziehung zur Ecchondrosis und Exostosis cartilaginea
  • R Virchow
Intramedullary cartilage- and chondroid-producing tumors Bone tumors: clinical, radiologic and pathologic correlations
  • Jm Mirra
  • Mirra Jm
  • P Picci
  • Gold
Tltre progeny testing of dairy bulls at different levels of production
  • L L Meson
  • A Roonnrsox
MesoN, L L. and Roonnrsox, A. 1955. Tltre progeny testing of dairy bulls at different levels of production. J.ASr. Sci. 47, 367-375.
Genorype and environment in sire evaluation
  • Vi-Ncr Van
VaN VI-ncr, L. D. 1963. Genorype and environment in sire evaluation. J. Dairy Sci, 46,983-987.
The variance of intraclass correlation involving groups with one observation
  • L A Swrcen
  • W R Ianvov
  • D O Evensox
  • K Gnnconv
Swrcen, L. A.,1-Ianvov, W. R., EvEnsox, D. O. and Gnnconv, K, E. 1964. The variance of intraclass correlation involving groups with one observation. Biometrics 2O, 818-826.
Downloaded from by 78
  • Can
Can. J. Anim. Sci. Downloaded from by on 10/17/15 For personal use only.
The manifestation of heritabiliry of quantitative characters in dairy catde under different environmental conditions
  • Jonansson
JonaNssoN, L 1953. The manifestation of heritabiliry of quantitative characters in dairy catde under different environmental conditions. Acta Genet. Statist. Med. 4, 221-231.
Animal breeding plans
  • J L Lusn
Lusn, J. L. 1945. Animal breeding plans. Iowa State College Press, Ames.
Heritabiliry of fat yields in herds with different production Ievels
  • J E Lrcrres
Lrcrres, J. E. 1962. Heritabiliry of fat yields in herds with different production Ievels. J. Dairy Sci" 45,990-993.
Relationships between sire evaluations at different herdmate levels
  • B T Mcdanmr
McDanmr., B. T, and Cou-rv, E. L. 1967. Relationships between sire evaluations at different herdmate levels. J. Dairy Sci. SO, 735J41.
Heritability and phenorypic and genetic correlations between type ratings and milk and butterfat production in Holstein-Friesian cattle
  • R G Mrrcunr
  • E L Conrnv
  • E E Hnrzen
  • W J Tvren
Mrrcunr, R. G., Conrnv, E. L., Hnrzen, E. E. and Tvren, W. J. 1957. Heritability and phenorypic and genetic correlations between type ratings and milk and butterfat production in Holstein-Friesian cattle. J. Dairy Sr,i.4A,62. (Abstr.).
Progeny testing dairy bulls at different manasement levels
  • A Roserrson
  • L K O'connon
  • J Euwenos
RosERrsoN, A., O'CoNNon, L. K. and Euwenos, J, 196O. Progeny testing dairy bulls at different manasement levels. Animal Prod. 2-l+l-152,
Downloaded from by on 10/17/15 For personal use only
  • J Can
  • Anim
  • Sci
Can. J. Anim. Sci. Downloaded from by on 10/17/15 For personal use only.