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PubMed2002

Quantitative trait loci affecting initial sensitivity and acute functional tolerance to ethanol-induced ataxia and brain cAMP signaling in BXD recombinant inbred mice.

In previous work, we identified genetic correlations between cAMP accumulation in the cerebellum and sensitivity to the incoordinating effects of ethanol. A genetic correlation suggests that common genes underlie the phenotypes investigated. One method for provisionally identifying genes involved in a given phenotypic measure is quantitative trait locus (QTL) analysis. Using a panel of 30 BXD recombinant inbred strains of mice and the progenitors (DBA/2J and C57BL/6J), and the dowel test for ataxia, we measured the blood ethanol concentrations at the time an animal first fell from the dowel and acute functional tolerance (AFT), and investigated cAMP signaling in the cerebellum. Cyclic AMP accumulation was measured in whole-cell preparations of cerebellar minces from individual mice under basal or stimulated conditions. We conducted a genome-wide QTL analysis of the behavioral and biochemical measures with >2000 genetic markers to identify significant associations. Western blot and comparative sequencing analysis were used to compare cAMP response element binding protein (CREB) levels and protein-coding sequence, respectively. QTL analyses correlating strain means with allelic status at genetic markers identified several significant associations (p < 0.01). Analysis of variance revealed an effect of strain on behavioral and biochemical measures. There was a significant genetic correlation between initial sensitivity and basal cAMP accumulation in the cerebellum. We identified 6 provisional QTLs for initial sensitivity on four chromosomes, 6 provisional QTLs for AFT on four chromosomes, and 11 provisional QTLs for cAMP signaling on nine chromosomes. Two loci were found to overlap for measures of initial sensitivity and for cAMP signaling. Given the genetic correlation between initial sensitivity and basal cAMP accumulation, we investigated candidate genes in a QTL on chromosome 1. Comparative sequence analysis was performed, and protein levels were compared between C57 and DBA mice for Creb1. No significant differences were detected in coding sequence or protein levels for CREB. These results suggest that although ethanol sensitivity and cAMP signaling are determined by multiple genes, they may share certain genetic codetermination.

Adrenergic beta-Agonists↗

PubMed2004

Factors that cause genotype by environment interaction and use of a multiple-trait herd-cluster model for milk yield of Holstein cattle from Brazil and Colombia.

Descriptive herd variables (DVHE) were used to explain genotype by environment interactions (G x E) for milk yield (MY) in Brazilian and Colombian production environments and to develop a herd-cluster model to estimate covariance components and genetic parameters for each herd environment group. Data consisted of 180,522 lactation records of 94,558 Holstein cows from 937 Brazilian and 400 Colombian herds. Herds in both countries were jointly grouped in thirds according to 8 DVHE: production level, phenotypic variability, age at first calving, calving interval, percentage of imported semen, lactation length, and herd size. For each DVHE, REML bivariate animal model analyses were used to estimate genetic correlations for MY between upper and lower thirds of the data. Based on estimates of genetic correlations, weights were assigned to each DVHE to group herds in a cluster analysis using the FASTCLUS procedure in SAS. Three clusters were defined, and genetic and residual variance components were heterogeneous among herd clusters. Estimates of heritability in clusters 1 and 3 were 0.28 and 0.29, respectively, but the estimate was larger (0.39) in Cluster 2. The genetic correlations of MY from different clusters ranged from 0.89 to 0.97. The herd-cluster model based on DVHE properly takes into account G x E by grouping similar environments accordingly and seems to be an alternative to simply considering country borders to distinguish between environments.

Analysis of Variance↗

PubMed2003

Genetic analysis of longitudinal trajectory of clinical mastitis in first-lactation Norwegian cattle.

Clinical mastitis records for 36,178 first-lactation daughters of 245 Norwegian Cattle (NRF) sires were analyzed with a Bayesian longitudinal threshold model. For each cow, the period going from 30 d before calving to 300 d after calving was divided into 11 intervals of 30 d length each. Absence or presence of clinical mastitis within each interval was scored as "0" or "1", respectively. A Bayesian threshold model consisting of a set of explanatory variables plus Legendre polynomials on time of order four was used to describe the trajectory of liability to clinical mastitis. Heritability ranged between 0.07 and 0.13 before calving, from 0.04 to 0.15 during the first 270 d after calving, and increased sharply thereafter, as a consequence of the form of the polynomial. Genetic correlations between adjacent days were close to 1, and decreased when days were further apart. Most genetic correlations were moderate to high. A measure of probability of future daughters contracting clinical mastitis during lactation was computed for each sire. A typical curve had a peak near calving followed by a decrease thereafter. The best sires had a low peak around calving and a low expected probability of mastitis among daughters throughout lactation. Expected fraction of days without mastitis was derived from the probability curves and used for ranking of sires. Rank correlations with genetic evaluations of sires obtained from cross-sectional models were high. However, sire selection was affected markedly, especially at high selection intensity. An advantage of the longitudinal model for clinical mastitis is its ability to take multiple treatments and time aspects into account.

Animals↗

PubMed2004

Heritability and correlations for body condition score and dairy form within and across lactation and age.

The objectives of the current study were to investigate the relationship between body condition score (BCS) and dairy form and changes in genetic parameters for BCS and dairy form within and across lactations and age. Body condition score and dairy form were obtained from the Holstein Association USA, Inc. Records were edited to include those cows classified between 24 and 60 mo of age and between 0 and 335 d in milk (DIM). A minimum of 20 daughters per sire and 15 cows per herd-classification visit were required. The dataset consisted of 135,178 records from 119,215 cows. Repeatability, multiple trait, and random regression models were used to analyze the data. All models included fixed effects for herd-classification visit, age within lactations 1, 2, and 3 or higher, and 5th-order polynomials for DIM. Random effects included sire and permanent environment for all models. Random regression models included age at classification nested within sire or DIM and lactation number nested within sire. Genetic variance for both BCS and dairy form was lowest in early lactation and highest in midlactation. Genetic correlations within and across lactations were high. The genetic correlation between DIM 0 in lactation 1 and DIM 305 in lactation 3 was estimated to be 0.77 for BCS and 0.60 for dairy form. The genetic correlation estimate between 30 mo of age at classification and 50 mo of age at classification was 0.94 for both dairy form and BCS. The repeatability models appeared to generate accurate evaluations for BCS or dairy form at all ages and stages of lactation.

Aging↗

PubMed1986

Sire and maternal grandsire effects on calving difficulty and calf mortality in Israeli Holsteins.

Associations among sire and maternal grandsire evaluations for calving difficulty and calf mortality were investigated in the Israeli Holstein population. Primiparous and multiparous calvings were analysed separately. Genetic correlations between calving difficulty and calf mortality were close to unity for primiparous calvings but lower for multiparous calvings. Genetic correlations between primiparous and multiparous sire evaluations were .94 and .72 for calving difficulty and calf mortality. Genetic correlations between sire and maternal grandsire evaluations were .6 for primiparous calvings and not-significant for multiparous calvings for both traits. These results correspond to findings that the direct genetic effect is larger than the maternal effect but that there is a slight negative correlation between them. We suggest that sire evaluations for calving difficulty of multiparous cows be used as a preliminary prediction of heifer calving difficulty and calf mortality and that the separate calving trait evaluations be combined into an overall calving selection index.

Animals↗

PubMed2006

[Genetic influences on the outcome of the progeny tests for behaviour traits in Hovawart dogs].

The objective of the present study was to evaluate the importance of genetic and environmental sources of variation for results of behaviour tests in young dogs being used for progeny evaluations in the Hovawart dog. In total, 4,113 dogs born in 1995 to 2000 have been available for these analyses. Traits used were appearance, hunting affinity, group of people, acoustical and optical influences and temperament. Variance components were estimated using multivariat linear animal models and Restricted Maximum Likelihood (REML). The models included test-year-season, sex, litter size, age and inbreeding coefficient of the animal as fixed effects. Additive genetic effects of the animal, permanent environmental effect of the litter and the effect of the kennel were considered as random factors. The sex of the dog was significant for all traits. The age of the dog at the test significantly influenced the traits temperament and appearance. Test-year-season was significant for all traits except for appearance, whereas the inbreeding coefficient of the animal was significant for acoustical influences and temperament. Litter size did not influence any of the traits significantly. The estimated heritabilities of the behaviour traits analysed here ranged from h2 = 0.03 to h2 = 0.11 with standard errors of up to 0.03. The additive genetic correlations between most of the traits were moderately to highly positive (rg = 0.16 to rg = 0.91). The traits hunting affinity and appearance showed an additive genetic correlation close to zero (rg = 0.03). Negative additive genetic correlations were found between temperament and appearance as well as acoustical and optical influences (rg = -0.14 to rg = -0.4).

Age Factors↗

PubMed2005

Genetic effects on sperm design in the zebra finch.

Sperm design and function are important determinants of male reproductive success and are expected to be under strong selection. The way that spermatozoa phenotypes evolve is poorly understood, because there have been few studies of the quantitative genetics of sperm. Here we show, in the zebra finch Taeniopygia guttata, an extraordinary degree of inter-male variation in sperm design that is independent of sperm swimming velocity. A quantitative genetics study using data from over 900 zebra finches in a complex breeding experiment showed that sperm head, mid-piece and flagellum length are heritable, that negative genetic correlations exist between sperm traits, and that significant indirect (maternal) genetic effects exist. Selection on the zebra finch sperm phenotype may be low because sperm competition is infrequent in this species, and this, in combination with negative genetic correlations and maternal genetic effects, may account for the variation in sperm phenotype between males. These results have important implications for the evolution of sperm in other taxa.

Animals↗

PubMed2002

International genetic evaluations of Holstein sires for milk somatic cell and clinical mastitis.

International genetic evaluations for milk somatic cell and clinical mastitis have been implemented on a routine basis by Interbull. This paper examines possible genetic consequences of such evaluations. Holstein data from 12 countries were used for this purpose. Trait definitions and national genetic evaluation procedures were first summarized and showed that differences between countries existed. Estimated genetic correlations among milk somatic cell in these countries ranged from 0.47 to 0.97, with a median of 0.88. Estimated genetic correlations among clinical mastitis in three Nordic countries ranged from 0.59 to 0.83, and estimated genetic correlations between clinical mastitis in the three Nordic countries and milk somatic cell in the non-Nordic countries ranged from 0.37 to 0.78 with a median of 0.55. Bulls without daughter information in the Nordic countries had low reliabilities on the Nordic clinical mastitis scales. International genetic evaluations for milk somatic cell and clinical mastitis enable a broader selection among foreign bulls, and higher selection differentials were found when using international evaluations compared with national evaluations.

Animals↗

PubMed1995

Multiple-trait prediction of transmitting abilities for herd life and estimation of economic weights using relative net income adjusted for opportunity cost.

Genetic and phenotypic (co)variances among linear type traits, final score, first lactation milk and fat yield, and 84-mo totals for longevity, relative net income, and relative net income adjusted for opportunity cost of postponed replacement were estimated with a multiple-trait sire model. Data were from 433,116 cows in herds participating in the classification program for conformation traits of the Holstein Association of America. Yield information from all cows in classified herds indicated that classified cows are not a random sample. Heritability of net income adjusted for opportunity cost was higher, .17, than unadjusted net income, .12, but the genetic correlation between the estimates of net income was high, .97. Adjusted net income also had high genetic correlations with first lactation milk yield, .80; fat yield, .60; and dairy form, .48. Heritability of longevity (months in milk to 84 mo) was .06. Adjustment of net income for opportunity cost lowered the genetic correlation with longevity from .84 to .70. Evaluation of lifetime merit using traits measured during first lactation with economic weights developed using adjusted net income was more accurate than indirect prediction of longevity; the approximate reliability of a first-crop AI sire for lifetime merit was .65 compared with .42 for longevity.

Animals↗

PubMed1984

Sire X environment interactions for growth traits of Hereford cattle.

Twelve Hereford bulls were used to sire calves in each of three locations in North Carolina over 6 yr. Three bulls were bred artificially to a random one-third of the cows at each location each year. Locations represented the Mountain, Piedmont and Coastal Plain regions of the Southeast. As yearlings, steer progeny were fed a concentrate diet in a feedlot or grazed on pasture and then slaughtered in the fall. Performance records from 816 calves were used to evaluate sire X location interaction effects for birth weight, preweaning average daily gain and weaning weight. Performance records from 355 steers were used to investigate sire X location and sire X diet interactions for average daily gain, carcass weight and percentage fat in the rib section. For all traits, sire X location and sire X diet interactions were not significant. Estimates of genetic correlations of sire progeny performance across environments ranged from .50 to 1.25. However, when estimates of sire variances within each environment were used to adjust the genetic correlations for bias due to scale effects, all genetic correlations were greater than .90. These results suggest that sires rank similarly for breeding values across the range of locations and diets used in this study.

Animal Feed↗

PubMed2003

[Studies on the adverse effects of fluvoxamine treatment in children with autistic disorder: correlation with genetic polymorphism in serotonin related genes].

Selective serotonin re-uptake inhibitors (SSRIs) have recently been applied to the children with autistic disorder. To create better treatment, we studied here clinical adverse effects of fluvoxamine and correlated them with genetic polymorphism of two genes, the promoter region of serotonin transporter gene (5-HTTLPR) and serotonin 2A receptor gene (5-HT2AR). Twenty-eight subjects, consisting of 23 boys and 5 girls, aged from 3 to 18 years old diagnosed as having autistic disorder were analyzed during fluvoxamine administration. The dosages and duration of fluvoxamine treatment are 1.5 to 3 mg/kg/day and 2 weeks to 17 months (mean 7.9 months), respectively. There were several clinical adverse effects such as sleep disturbance in 9 cases, climb up to high places in 8, gastrointestinal symptoms in 6, hyperactivities in 5, excitement in 4, general fatigability in 2 and urticaria in 1. Medication was discontinued in 2 patients with fatigability and 1 with sleep disturbance, diarrhea and poor appetite. There was no significant correlation between genetic polymorphism in 5-HTTLPR and the occurrence of clinical adverse effects of fluvoxamine. However hyperactivity was significantly more frequent in the subjects with 102T/102T polymorphism of 5-HT2AR, and patients with sleep disturbance were significantly less frequent in the subjects with 102C/102C polymorphism. We conclude that the clinical adverse effects such as climb up to high places and hyperactivity during fluvoxamine treatment may be relatively specific in children, and that genetic polymorphism of 5-HT2AR may be related to the appearance of clinical adverse effects.

Adolescent↗

PubMed2005

The coadaptation of parental supply and offspring demand.

The evolution of parent-offspring interactions for the provisioning of care is usually explained as the phenotypic outcome of resolved conflicting selection pressures. However, parental care and offspring solicitation are expected to have complex patterns of inheritance. Here we present a quantitative genetic model of parent-offspring interactions that allows us to investigate the evolutionary maintenance of a state of resolved conflict. We show that offspring solicitation and parental provisioning are expected to become genetically correlated through coadaptation and that their genetic architecture is dictated by an interaction between patterns of selection and the proximate mechanisms regulating supply and demand. When selection is predominately on offspring solicitation, our model suggests that the genetic correlations between provisioning and solicitation are usually positive if provisioning reduces solicitation. Conversely, when selection is predominately on parental provisioning, the correlations are mostly negative as long as parents show a positive response to offspring demand. Empirical estimates of the genetic architecture of traits involved in family interactions fit these predictions. Our model demonstrates how the evolutionary maintenance of parent-offspring interactions can result in variable patterns of coadaptation, and it provides an explanation for the diversity of family interactions within and among species.

Adaptation, Physiological↗

PubMed1984

Genetic interrelationships of parturition problems and production.

Data were 5091 calvings from 3904 cows for milk fever, retained placenta, mastitis within 48-h postpartum, calving difficulty, and 48-h calf livability collected from 27 large California dairies analyzed for genetic interrelationships among parturition problems. Heritability of each trait was small; however, retained placenta had large positive genetic correlations with milk fever (.34) and mastitis (.33). Adding difficulty-mortality classes to models to study genetic relationships of parturition problems had little effect on estimates but did influence incidence of parturition problems. With calving difficulty, incidence of milk fever increased by 4.9% and retained placenta by 5.3%. With calf mortality, milk fever increased by 4.4% and retained placenta by 13%. A combination of difficulty and mortality was related to a 9.6% increase of milk fever and a 20.2% increase of retained placenta. Genetic correlations of all problems with mature equivalent milk indicated that selection for increased production would be accompanied by lower incidence of retained placenta, 48-h mastitis, and milk fever. Genetic correlations of retained placenta with milk fever and 48-h mastitis were positive. Selection for increased milk yield should not increase incidence of parturition problems, and prescreening of bulls on parturition performance of daughters would be feasible.

Animals↗

PubMed1991

Genetic and environmental growth trait parameter estimates for Brahman and Brahman-derivative cattle.

Beefmaster, Brahman, Brangus, and Santa Gertrudis field data records were used to determine genetic and environmental parameter estimates using a multiple-trait, pseudo-expectation approach. Adjusted birth weight, 205-d weight, and postweaning gain records were analyzed for each breed. Also, Brangus weaning sheath and navel scores were both analyzed using a single-trait, pseudo-expectation method to determine genetic parameter estimates. Additive birth weight heritability (h2A) estimates ranged from .22 to .37 and maternal birth weight heritability (h2M) estimates ranged from .12 to .55. Estimates for 205-d weight h2A for the four breeds varied from .21 to .25, and 205-d weight h2M estimates ranged from .15 to .21. Postweaning gain h2A estimates ranged from .16 to .56. The genetic correlation between direct and maternal portions of birth weight was negative for all breeds. This was also true for the genetic correlation between direct and maternal portions of 205-d weight, except in Brahman cattle, for which it was .15. The genetic correlation between additive portions of birth weight and 205-d weight was large and positive in all breeds. A moderately positive correlation between 205-d weight and postweaning gain was found for all breeds except Santa Gertrudis, whereas the environmental correlation between these two traits was a small to moderately negative estimate in all breeds. Brangus weaning sheath and navel score heritabilities indicated that genetic change for the size and shape of the sheath and navel area is possible.

Analysis of Variance↗

PubMed2004

Genetic parameters for calving difficulty, stillbirth, and birth weight for Hereford and Charolais at first and later parities.

The aim of this study was to estimate direct and maternal genetic parameters for calving difficulty score, stillbirth, and birth weight at first and later parities for Charolais and Hereford cattle in Sweden. Calving traits have long been recorded for pure-bred beef cattle in Sweden, but only birth weight has been used in the selection in order to avoid calving difficulties. Linear animal model analyses included records on birth weight for 60,309 Charolais and 30,789 Hereford calves born from 1980 to 1999, and calving traits for 74,538 Charolais and 37,077 Hereford calves born from 1980 to 2001. The frequencies of difficult calvings and stillbirths were approximately 6% at first and 1 to 2% at later parities for both breeds. Fewer than half the stillborn calves were born from difficult calvings. Heritabilities estimated for birth weight in different univariate and bivariate analyses for Charolais and Hereford calves born at first and later parities ranged from 0.44 to 0.51 for direct effects and 0.06 to 0.15 for maternal effects. Heritabilities on the observable scale for calving difficulty score of Charolais and Hereford, scored in three classes, ranged from 0.11 to 0.16 for direct and 0.07 to 0.12 for maternal effects at first parity, and lower at later parities. All estimated heritabilities for stillbirth were very low (0.002 to 0.016 on the observable scale). Direct-maternal genetic correlations were negative, with few exceptions. Genetic correlations between the traits and between parities within traits were generally moderate to high and positive. Calving difficulty score should be included in the genetic evaluation of beef breeds in Sweden, whereas progeny groups in Swedish beef populations are too small for stillbirth to be considered directly.

Animals↗

PubMed1988

Genetic parameters for clinical mastitis, somatic cell counts, and milk production estimated by multiple-trait restricted maximum likelihood.

Heritabilities and genetic correlations for mastitis, SCC, and milk production in first lactation were calculated using data from the Swedish disease recording system. Genetic parameters were estimated from sire components of variance and covariance obtained from a multiple-trait restricted maximum likelihood procedure. Data were stratified into three subsets according to breed and AI stud. The numbers of cows were 46,431, 25,373, and 25,201, respectively. Heritabilities of mastitis and SCC averaged .014 and .080, but breed differences were seen. Genetic correlations between mastitis and SCC were moderately high, averaging .6. Milk production showed a slightly unfavorable genetic correlation with mastitis and SCC.

Animals↗

PubMed2002

Effect of heat stress on nonreturn rate in Holstein cows: genetic analyses.

The genetic component in heat tolerance for nonreturn rate in Holsteins was estimated using an animal linear model augmented by a random regression on a temperature-humidity index (THI). Data consisted of 18,059 nonreturn rates at 45,60, and 90 d after insemination and 81,674 first-parity test-day milk yields from 78 herds in Florida. The THI on the day of insemination or test day was added to each record. Only first-insemination records were used. The model for nonreturn rate included the effects of herd-year-season, age, days in milk, milk yield, THI as a covariable, regular additive effect, and random regression on THI for heat-tolerance additive effect. With a single-trait model, heritability estimates for NR45, NR60, and NR90 at THI = 70 for first-lactation cows were 0.006, 0.014, and 0.053, respectively. Genetic correlation between regular NR90 and heat tolerance was -0.95. A bivariate analysis for NR90 and test-day milk production yielded a correlation between regular merit and heat tolerance for NR90 of -0.35, substantially lower than by the univariate model, indicating a bias in the univariate estimates caused by ignored selection. The regular genetic correlation between NR90 and milk yield was -0.41. Genetic correlation between heat tolerance for NR90 and heat tolerance for milk yield was -0.04, indicating the need to separate selection.

Animals↗

PubMed1998

Selection for economic efficiency of dairy cattle using information on live weight and feed intake: a review.

The objective of this study was to review some of the latest evidence of genetic variation in feed intake and feed utilization and to determine how this variation might be used. The most important sources of genetic variation in gross efficiency are likely to be the quantities of feed eaten and used for yield or maintenance and the extent to which body tissue is mobilized. Accounting for just one of these components when selection is for improved feed efficiency might result in undesirable genetic changes. For example, in an ad libitum feeding system, the heritability of body condition score is reported to be 0.43 for heifers; genetic correlations of body condition score with milk production and live weight were -0.46 and 0.66, respectively. Also, the genetic correlation between milk yield and live weight depends on lactation stage. For example, over the first 26 wk of lactation, this correlation was reported to be -0.09, but, after genetic adjustment for body condition score, the correlation was 0.29. When economic values are being derived, energy norms or genetic correlations can be used, and double counting of the feed costs needs to be avoided. An index that contained linear type traits, however, gave high accuracy of selection. Hence, although there appears to be great potential to improve economic efficiency by selecting for feed intake and live weight or by possible indicator traits, there is still uncertainty about some of the genetic parameters, especially among traits related to health, reproduction, and energy balance.

Animal Feed↗