Genetic parameters of the duration of fertility in hens

1992 ◽  
Vol 72 (2) ◽  
pp. 193-201 ◽  
Author(s):  
Catherine Beaumont
Keyword(s):  
Maximum Likelihood ◽  
Key Words ◽  
Genetic Parameters ◽  
Control Period ◽  
Genetic Correlations ◽  
The Other ◽  
Selection For ◽  
Heritability Estimates ◽  
Highly Correlated ◽  
Box Cox Transformation

After two successive artificial inseminations (AI) with 125 × 106 spermatozoa, various characteristics of the duration of fertility were observed in 2375 egg-type hens at 33 and 44 wk of age: number of fertile (F) or hatched (H) eggs during a 21-d control period after AI, early, medium or late embryonic mortalities occurring at the same time and efficient (De) and maximum (Dm) duration (i.e. time between AI and the first clear egg or the last fertile egg, respectively). Heritability estimates of F, H, De or Dm ranged from 0.08 to 0.31. All genetic correlations between these variables (measured at the same age) were high (0.45–0.99) as well as those between the same variable measured at different ages (0.30–0.97). Estimates of genetic parameters varied little when estimated by Henderson's method III or REML but with the second method only all estimates were within the parameter space. A Box-Cox transformation of data slightly modified heritability estimates and animal ranking after genetic evaluation. The best criterion of selection for duration of fertility seems to be H as it is economically important, well heritable and highly correlated with the other characteristics of duration of fertility. Key words: Genetic parameters, fertility, poultry, Restricted Maximum Likelihood

Within-farm estimates of genetic and phenotypic parameters for growth and reproductive traits for red deer

1993 ◽  
Vol 57 (1) ◽  
pp. 153-159 ◽  
Author(s):  
C. McManus
Keyword(s):  
Birth Weight ◽  
Maximum Likelihood ◽  
Eastern Europe ◽  
Red Deer ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Reproductive Traits ◽  
The Other ◽  
The United Kingdom ◽  
Terminal Sire

AbstractGenetic and phenotypic parameters were estimated for farmed red deer on eight farms distributed throughout the United Kingdom. Genetic parameters were estimated using restricted maximum likelihood (REML) analysis. Heritabilities for date of calving were low on seven of the eight farms (< 0–05), while repeatabilities were low to moderate (0·06 to 0·37). Heritabilities of all weights tended to be moderate to high on most farms (0·31 to 0·49; 0·22 to 0·89; 0·33 to 0·48; 0·37 to 0·45 and 0·37 to 0·90 for birth weight, weaning weight, mid-winter weight, turn-out weight and other weights respectively). The exception was farm 8 for which heritability estimates were very low (<0·08). This is attributed to inbreeding effects on this farm. Phenotypic and genetic correlations between post-weaning traits tended to be high, indicating selection at any stage of growth will be expected to lead to an increased growth at the other stages. Animals whose bloodlines originated in the forests of Eastern Europe (Yugoslavia, Hungary, Germany) were heavier at all stages indicating their usefulness as ‘terminal sire’ breeds. Hinds of mainland ‘European’ parentage also tended to calve earlier.

scholarly journals Host Genetics of Response to Porcine Reproductive and Respiratory Syndrome in Sows: Reproductive Performance

2021 ◽  
Vol 12 ◽  
Author(s):  
Felipe M. W. Hickmann ◽  
José Braccini Neto ◽  
Luke M. Kramer ◽  
Yijian Huang ◽  
Kent A. Gray ◽  
...  
Keyword(s):  
Reproductive Performance ◽  
Additive Genetic Variance ◽  
Genetic Correlations ◽  
Reproductive Traits ◽  
The Other ◽  
Nucleotide Polymorphisms ◽  
Host Genetics ◽  
Other Hand ◽  
Selection For ◽  
Heritability Estimates

Porcine Reproductive and Respiratory Syndrome (PRRS) is historically the most economically important swine disease worldwide that severely affects the reproductive performance of sows. However, little is still known about the genetic basis of reproductive performance in purebred herds during a PRRS outbreak through the comparison of maternal and terminal breeds. Thus, the objective of this work was to explore the host genetics of response to PRRS in purebred sows from two breeds. Reproductive data included 2546 Duroc and 2522 Landrace litters from 894 and 813 purebred sows, respectively, which had high-density genotype data available (29,799 single nucleotide polymorphisms; SNPs). The data were split into pre-PRRS, PRRS, and post-PRRS phases based on standardized farrow-year-week estimates. Heritability estimates for reproductive traits were low to moderate (≤0.20) for Duroc and Landrace across PRRS phases. On the other hand, genetic correlations of reproductive traits between PRRS phases were overall moderate to high for both breeds. Several associations between MARC0034894, a candidate SNP for response to PRRS, with reproductive performance were identified (P-value &lt; 0.05). Genomic analyses detected few QTL for reproductive performance across all phases, most explaining a small percentage of the additive genetic variance (≤8.2%, averaging 2.1%), indicating that these traits are highly polygenic. None of the identified QTL within a breed and trait overlapped between PRRS phases. Overall, our results indicate that Duroc sows are phenotypically more resilient to PRRS than Landrace sows, with a similar return to PRRS-free performance between breeds for most reproductive traits. Genomic prediction results indicate that genomic selection for improved reproductive performance under a PRRS outbreak is possible, especially in Landrace sows, by training markers using data from PRRS-challenged sows. On the other hand, the high genetic correlations with reproductive traits between PRRS phases suggest that selection for improved reproductive performance in a clean environment could improve performance during PRRS, but with limited efficiency due to their low heritability estimates. Thus, we hypothesize that an indicator trait that could be indirectly selected to increase the response to selection for these traits would be desirable and would also improve the reproductive performance of sows during a PRRS outbreak.

HERITABILITIES AND GENETIC CORRELATIONS IN MORPHOLOGIC CHARACTERISTICS OF BABY TEETH IN RAMBOUILLET AND ROMNELET SHEEP

1972 ◽  
Vol 52 (2) ◽  
pp. 273-281
Author(s):  
J. A. VESELY
Keyword(s):  
Genetic Parameters ◽  
Genetic Correlations ◽  
The Other ◽  
Adjacent Pair ◽  
The Third ◽  
Morphologic Characteristics ◽  
Sex Type ◽  
Upper Jaw ◽  
Heritability Estimates ◽  
Tooth Length

Data were used from 1009 Rambouillet and 1104 Romnelet lambs representing 40 sires of each breed. Traits studied were: width of the two central incisors measured at the bottom and the top of each tooth; length of the three pairs of central incisors; angle of the central incisors with the upper jaw; and distance between the two canines at the base. Least squares analyses estimated effects of year, age of dam, sex, type of rearing, sires, and regression of trait on age of lamb. Estimates of genetic parameters were obtained for each breed from paternal half-sib analysis. Heritabilities for width of the two central incisors measured at the top averaged 0.63. Heritability estimates for length of the central pair of incisors averaged 0.58, of the next adjacent pair, 0.51, and of the third pair (from the center) 0.41. Heritability estimates for the angle of the front teeth with the upper gum averaged 0.24 and the distance between the two canines, 0.38. Most of the genetic correlations between width of the central incisors and the other measurements were positive.

Genetic parameters of test day records of British Holstein-Friesian heifers

1992 ◽  
Vol 55 (1) ◽  
pp. 11-21 ◽  
Author(s):  
B. L. Pander ◽  
W. G. Hill ◽  
R. Thompson
Keyword(s):  
Maximum Likelihood ◽  
Milk Yield ◽  
Milk Fat ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Lactation Performance ◽  
Likelihood Methods ◽  
Holstein Friesian ◽  
Maximum Likelihood Methods ◽  
Heritability Estimates

AbstractEstimates of genetic parameters for test day records of yields of milk, fat and protein and concentrations of fat and protein were obtained on 47 736 British Holstein-Friesian heifers in 7973 herds, progeny of 40 proven (to improve connectedness) and 707 young sires (comprising about one-fifth of the progeny), using multivariate restricted maximum likelihood methods with a sire model.Heritability estimates for lactation yields of milk, fat and protein and concentrations of fat and protein were 0·49, 0·39, 0·43, 0·63 and 0·47, respectively. Estimates for individual test day records of these traits ranged from 0·27 to 0·43, 0·16 to 0·34, 0·22 to 0·33, 0·11 to 0·48 and 0·21 to 0·43, respectively. Generally, heritability estimates for test day records were lowest at start and highest in mid lactation.Estimates of genetic correlations among yields of a trait on different test days ranged from 0·57 to 0·99, and for fat and protein concentrations from 0·34 to 0·99, the correlations being highest for adjacent tests. Phenotypic correlations were lower than genetic correlations. Genetic correlations of test day records with corresponding lactation traits were high (0·76 to 0·99), being highest in mid lactation.Genetic correlations of test day milk yield with test day yields and concentrations of fat and protein throughout the lactation were similar to those for complete lactation.The high heritabilities of test day yields and their high genetic correlations with complete lactation, except for the first 1 or 2 test days, suggest that lactation performance may be predicted from test days in early and mid lactation.

scholarly journals Genetic and phenotypic parameters for productive traits in the first three lactations of Khuzestan buffaloes in Iran

2013 ◽  
Vol 56 (1) ◽  
pp. 423-429 ◽  
Author(s):  
M. Madad ◽  
N. G. Hossein-Zadeh ◽  
A. A. Shadparvar
Keyword(s):  
Maximum Likelihood ◽  
Animal Models ◽  
Genetic Correlation ◽  
Milk Production ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
The Other ◽  
The Third ◽  
Fat Yield ◽  
Productive Traits

Abstract. The objective of this study was to estimate genetic parameters for milk and fat yields in Khuzestan buffaloes of Iran. A total of 5 258 production records of the first three lactations of the Khuzestan buffaloes obtained from the Animal Breeding Centre of Iran between 1993 and 2009 were used for the analysis. Genetic parameters were estimated by the multivariate restricted maximum-likelihood (REML) procedure in the Wombat program. The averages of milk and fat production were 2 220.0 kg and 137.6 kg for first lactation; 2 236.8 kg and 137.9 kg for second lactation; and 2 303.6 kg and 143.3 kg for third lactation, respectively. Heritability estimates for milk and fat yields were 0.06 and 0.24 for the first; 0.06 and 0.28 for the second and 0.26 and 0.47 for the third lactation, respectively. Genetic correlation estimates between first and second, first and third, and second and third lactations were 0.77, 0.67 and 0.79 for milk and −0.61, −0.21 and −0.25 for fat yields. These estimates for milk yield are consistent with previous estimates obtained from animal models. Milk production of different lactations is essentially the same trait genetically and combining all lactation records as a single trait is appropriate. On the other hand, negative genetic correlations for fat yield in different lactations indicated that fat yields in all lactations were determined by different genes.

scholarly journals Genetic parameters and efficiency of early selection for half rotation-aged growth and form traits in Pinus taeda in China

2013 ◽  
Vol 62 (1-6) ◽  
pp. 277-284 ◽  
Author(s):  
Huixiao Yang ◽  
Tianyi Liu ◽  
Chunxin Liu ◽  
Jinbang Wang ◽  
Kaer Chen ◽  
...  
Keyword(s):  
Pinus Taeda ◽  
Genetic Parameters ◽  
Growth Traits ◽  
Genetic Correlations ◽  
Early Selection ◽  
Direct Selection ◽  
Individual Tree ◽  
Stem Straightness ◽  
Selection For ◽  
Heritability Estimates

Abstract Genetic parameters for height (H), diameter at breast height (DBH), stem straightness (STR), and under crown clear bole height (CH) of loblolly pine (Pinus taeda L.) were estimated for 255 families (209 open pollinated (OP) and 46 controlled pollinated (CP) families) using a family model and an individual tree model at age 1, 2, 3, 5, 11, and 15 years. Heritability estimates for growth traits of individual trees at age 11 years were the highest (0.17-0.78), and those at age 15 years were the lowest (0.05-0.74). Heritability estimates for DBH, STR, and CH were lower than those for H. Genetic correlations between H and DBH were generally strongly positive, attained a maximum values at age 2 to 3, and declined slightly thereafter. The genetic correlations between CH at age 11 and both H and DBH at different ages were moderate. Age-age genetic correlations for growth traits were moderate to high (0.56-0.91) at age 5 for half-rotation age (15 years), indicating the opportunity exists for early selection. Indirect selection from the age 5 to 11 years for H and DBH could be expected to produce gains of over 50% and 35% respectively, for these two ages, relative to direct selection at age 15. Efficiencies of early selection for H and DBH indicated that growth at maturity could be improved by early selection.

scholarly journals Realized Sampling Variances of Estimates of Genetic Parameters and the Difference Between Genetic and Phenotypic Correlations

Genetics ◽  
1996 ◽  
Vol 143 (3) ◽  
pp. 1409-1416 ◽  
Author(s):  
Kenneth R Koots ◽  
John P Gibson
Keyword(s):  
Genetic Correlation ◽  
Genetic Parameters ◽  
Genetic Parameter ◽  
Genetic Correlations ◽  
Phenotypic Correlation ◽  
Parameter Estimates ◽  
Sampling Variance ◽  
Phenotypic Correlations ◽  
Genetic And Phenotypic Correlations ◽  
Heritability Estimates

Abstract A data set of 1572 heritability estimates and 1015 pairs of genetic and phenotypic correlation estimates, constructed from a survey of published beef cattle genetic parameter estimates, provided a rare opportunity to study realized sampling variances of genetic parameter estimates. The distribution of both heritability estimates and genetic correlation estimates, when plotted against estimated accuracy, was consistent with random error variance being some three times the sampling variance predicted from standard formulae. This result was consistent with the observation that the variance of estimates of heritabilities and genetic correlations between populations were about four times the predicted sampling variance, suggesting few real differences in genetic parameters between populations. Except where there was a strong biological or statistical expectation of a difference, there was little evidence for differences between genetic and phenotypic correlations for most trait combinations or for differences in genetic correlations between populations. These results suggest that, even for controlled populations, estimating genetic parameters specific to a given population is less useful than commonly believed. A serendipitous discovery was that, in the standard formula for theoretical standard error of a genetic correlation estimate, the heritabilities refer to the estimated values and not, as seems generally assumed, the true population values.

HERITABILITIES AND GENETIC CORRELATIONS FOR ULTRASONIC BACKFAT MEASUREMENTS, GROWTH AND CARCASS TRAITS IN SWINE

1982 ◽  
Vol 62 (3) ◽  
pp. 665-670 ◽  
Author(s):  
D. C. JEFFRIES ◽  
R. G. PETERSON
Keyword(s):  
Key Words ◽  
Genetic Correlation ◽  
Genetic Parameters ◽  
Average Daily Gain ◽  
Genetic Correlations ◽  
Phenotypic Correlation ◽  
Ultrasonic Measurements ◽  
Yorkshire Pigs ◽  
Daily Gain ◽  
Season Interaction

Genetic parameters were estimated for 2403 purebred Yorkshire pigs over a 2-yr period, representing 21 sires. The traits studied included average daily gain, age adjusted to 90 kg, ultrasonic measurements of backfat at the mid-back and loin positions, total and adjusted total ultrasonic backfat and corresponding carcass backfat measurements. Least squares analyses were used to estimate and adjust for the effects of sex, year-season and sex by year-season interaction. Heritabilities and genetic correlations were calculated for all traits using both half- and full-sib estimates. Adjusted age and adjusted total ultrasonic backfat measurements were found to have the highest heritabilities of the live traits in this study. Estimates of heritability for adjusted age and adjusted total ultrasonic backfat were 0.24 ± 0.10 and 0.26 ± 0.10 based on half-sib and 0.56 ± 0.07 and 0.41 ± 0.06 from full-sib analyses. The genetic correlation between these two traits was −0.07 ± 0.28 based on the half-sib method. The total phenotypic correlation was −0.01 ± 0.02. Key words: Swine, ultrasonic backfat, heritabilities, genetic correlations

scholarly journals Genetic parameters of production and reproduetive traits in on a farm tested Danish Large White and Landrace swine in Greece

2000 ◽  
Vol 43 (3) ◽  
pp. 287-298
Author(s):  
J. Bizelis ◽  
A. Kominakis ◽  
E. Rogdakis ◽  
F. Georgadopoulou
Keyword(s):  
Maximum Likelihood ◽  
Genetic Correlation ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Production Traits ◽  
Likelihood Methods ◽  
Large White ◽  
Reproduction Traits ◽  
Maximum Likelihood Methods ◽  
Genetic And Phenotypic Correlations

Abstract. Production and reproduetive traits in Danish Landrace (LD) and Large White (LW) swine were analysed by restricted maximum likelihood methods to obtain heritabilities as well as genetic and phenotypic correlations. Production traits were: age, backfat thickness (BT), muscle depth (MD) and the ratio BT/MD, adjusted to Standard bodyweight of 85 kg. Reproduction traits were: number of pigs born (NB) and number of pigs weaned (NW) per sow and parity. Heritabilities for age, BT, MD and BT/MD were 0.60, 0.44, 0.51 and 0.42 for LD and 0.36, 0.44, 0.37 and 0.45 for LW, respectively. Genetic correlations between age and BT were −0.22 in LD and – 0.44 in LW. The genetic correlation between age and MD was close to zero in both breeds. Genetic correlation between BT and MD were −0.36 and −0.25 in LD and LW, respectively. Heritabilities for NB were 0.25 in LD and 0.13 in LW while heritabilities for NW were close to zero in both breeds. Genetic correlation between NB and NW was 0.46 and 0.70 in LD and LW, respectively.

scholarly journals PSVIII-38 Late-Breaking Abstract: Estimating genetic parameters of feed efficiency traits in American mink

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 347-347
Author(s):  
Pourya Davoudi ◽  
Duy Ngoc Do ◽  
Guoyu Hu ◽  
Siavash Salek Ardestani ◽  
Younes Miar
Keyword(s):  
Body Weight ◽  
Genetic Correlation ◽  
Feed Intake ◽  
Feed Efficiency ◽  
Fixed Effects ◽  
Genetic Parameters ◽  
American Mink ◽  
Genetic Correlations ◽  
Final Body Weight ◽  
Selection For

Abstract Feed cost is the major input cost in the mink industry and thus improvement of feed efficiency through selection for high feed efficient mink is necessary for the mink farmers. The objective of this study was to estimate the heritability, phenotypic and genetic correlations for different feed efficiency measures, including final body weight (FBW), daily feed intake (DFI), average daily gain (ADG), feed conversion ratio (FCR) and residual feed intake (RFI). For this purpose, 1,088 American mink from the Canadian Center for Fur Animal Research at Dalhousie Faculty of Agriculture were recorded for daily feed intake and body weight from August 1 to November 14 in 2018 and 2019. The univariate models were used to test the significance of sex, birth year and color as fixed effects, and dam as a random effect. Genetic parameters were estimated via bivariate models using ASReml-R version 4. Estimates of heritabilities (±SE) were 0.41±0.10, 0.37±0.11, 0.33±0.14, 0.24±0.09 and 0.22±0.09 for FBW, DFI, ADG, FCR and RFI, respectively. The genetic correlation (±SE) was moderate to high between FCR and RFI (0.68±0.15) and between FCR and ADG (-0.86±0.06). In addition, RFI had low non-significant (P &gt; 0.05) genetic correlations with ADG (0.04 ± 0.26) and BW (0.16 ± 0.24) but significant (P &lt; 0.05) high genetic correlation with DFI (0.74 ± 0.11) indicating that selection for lower RFI will reduce feed intake without adverse effects on the animal size and growth rate. The results suggested that RFI can be implemented in genetic/genomic selection programs to reduce feed intake in the mink production system.

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