Genetic study of visual scores and hip height at different ages in Nelore cattle

2017 ◽  
Vol 57 (4) ◽  
pp. 614 ◽  
Author(s):  
D. D. Silveira ◽  
L. De Vargas ◽  
V. M. Roso ◽  
G. S. Campos ◽  
F. R. P. Souza ◽  
...  
Keyword(s):  
Variance Components ◽  
Selection Criteria ◽  
Selection Process ◽  
Selection Index ◽  
Genetic Correlations ◽  
Genetic Associations ◽  
Correlated Responses ◽  
Genetic Changes ◽  
Heritability Estimates ◽  
Nelore Cattle

The objective of the present study was to evaluate the genetic variability of visual scores used as selection criteria in Nelore cattle, as well as their associations with yearling hip height (YH) and mature hip height (MH), to determine whether the selection considered would change the hip height of animals. (Co)variance components were obtained by two-trait animal model using Gibbs sampling, including YH or MH in each analysis. Breeding values for YH and MH were used to obtain the response to selection. The posterior mean of the heritability estimates for conformation, finishing precocity (or body condition) and muscling at weaning (WC: 0.21 ± 0.02; WP: 0.21 ± 0.02; and WM: 0.18 ± 0.02 respectively) were lower than those obtained for the same traits at yearling (YC: 0.34 ± 0.02; YP: 0.37 ± 0.02; and YM: 0.38 ± 0.02 respectively). Heritability estimates for YH and MH were 0.28 ± 0.01 and 0.33 ± 0.03 respectively. The results suggested that these traits should respond to selection process, but in different magnitudes. Positive and high genetic correlations were estimated between WC and YH and YC and YH (0.80 ± 0.03 and 0.76 ± 0.03 respectively), and lower values between these scores and MH (0.48 ± 0.09 and 0.36 ± 0.07 respectively). Weak genetic associations were obtained between finishing precocity score and YH and muscling score and YH (ranging from 0.05 ± 0.05 to 0.18 ± 0.06). Moreover, negative and favourable genetic associations between each of WP, WM, YP and YM, and MH (ranging from –0.21 ± 0.07 to –0.12 ± 0.09) were estimated. Correlated responses are expected to be unfavourable for hip height, measured at yearling and at maturity, when animals better genetically evaluated for conformation in relation to finishing precocity and muscling scores are selected. Genetic changes obtained for YH and MH were null (–0.02 cm/year and 0.03 cm/year respectively). It can be explained, in part, by smaller weights in the selection index for conformation rather than finishing precocity and muscling, as applied in the studied herds. However, in herds of beef cattle not evaluated and selected for finishing precocity and muscling scores or that have cows with larger size than acceptable, the adoption of mature hip height as one of the selection criteria can be one alternative for obtaining females with a desirable size.

Quantitative study of genetic gain for growth, carcass, and morphological traits of Nelore cattle

2019 ◽  
Vol 99 (2) ◽  
pp. 296-306
Author(s):  
Daniel Duarte da Silveira ◽  
Lucas De Vargas ◽  
Rodrigo Junqueira Pereira ◽  
Gabriel Soares Campos ◽  
Ricardo Zambarda Vaz ◽  
...  
Keyword(s):  
Genetic Variability ◽  
Carcass Traits ◽  
Genetic Correlations ◽  
Correlated Response ◽  
Genetic Associations ◽  
Muscle Area ◽  
Genetic Gains ◽  
Fat Thickness ◽  
Nelore Cattle ◽  
Genetic Trends

The aim of this study was to evaluate the genetic variability, genetic and phenotypic associations, and genetic gains of birth (BW), weaning (WW), and yearling (YW) weights, loin muscle area (LMA), backfat thickness (BF), rump fat thickness (RF), scores of body structure (BS), finishing precocity (FS), and muscling (MS) in Nelore cattle. Genetic parameters were obtained through Bayesian inference using BLUPF90 programs. All studied traits showed genetic variability, with heritability ranging from 0.29 to 0.47. In all studied ages, weights presented positive genetic correlations with LMA (ranging from 0.13 to 0.53), being generally stronger in comparison with the other carcass traits analyzed (BF and RF). Similarly, weights were higher genetic associated with BS (0.47–0.92) than with FS (0.18–0.62) and MS (0.22–0.65), respectively. The BF and RF showed positive and moderate genetic associations with FS and MS (0.31–0.36). Genetic trends were significant (P < 0.05) and favorable for WW, YW, and visual scores. Selection for increasing BW, WW, YW, and LMA will result in modest or no change in BF and RF (correlated response ranging from −0.04 to 0.07 mm per generation). In this population, carcass traits must be included in the selection indexes to obtain genetic gains in carcass quality, if desired.

scholarly journals Estrus reaction of gilts as selection criteria for litter size

2009 ◽  
Vol 25 (5-6-1) ◽  
pp. 535-538
Author(s):  
V. Vidovic ◽  
D. Punos ◽  
M. Tadic
Keyword(s):  
Litter Size ◽  
Selection Criteria ◽  
Genetic Correlations ◽  
Heritability Estimates

The analysis of estrus symptoms has been done on 656 purebred and 884 crossbred gilts. Heritability estimates for estrus reaction in purebreds were low, 0.12 and 0.14 for crossbreds. The heritability for number of ovulation egs in purebred and crossbreds were 0.40. Genetic correlations between estrus reaction and litter size in first litter were high:0.88 than estrus reaction and life production 0.76. Correlation between same traits for crossbreds were higher: 0.93 and 0.87. In carantin room we measured age and weight of gilts together with estrus. The first estrus showed 90.8% and second 90.2% in purebred and 94.7% and 93.8% at F1 gilts. The gilts which did not show regular first and second estrus get born between 2 and 9, average 6.23 for purebred and 7.11 F1 alive piglets. Later on they had longer interval between birth and next estrus, 17- 48, average 32 empty days for purebred and 28 crossbreds gilts. Those animals had significant lover life production. In conclusion, it is necessary to note estrus reaction in carantin room at the beginning of production life of gilts. Gilts with irregular oestrus is necessary to get out of production imediately from carantin room to decrease economical losess in production.

Correlations between food intake in young bulls and production, fertility and health disorders in lactating dairy cattle

1999 ◽  
Vol 24 ◽  
pp. 153-158
Author(s):  
R. Wassmuth ◽  
D. Boelling ◽  
J. Jensen
Keyword(s):  
Food Intake ◽  
Dairy Cattle ◽  
Milk Yield ◽  
Performance Test ◽  
Selection Process ◽  
Disease Incidence ◽  
Genetic Correlations ◽  
Calving Interval ◽  
Black And White ◽  
Heritability Estimates

AbstractDisease incidence in dairy cattle is to be reduced for animal welfare and economical reasons. This should be achieved not only by improvement of management but preferably also by genetic means. This study looks at the possibility of decreasing disease incidence in first lactation cows by increasing food intake. The latter is not measured on the cows directly but on young bulls during their performance test. Data consisted of 2203 Danish Red, 4527 Danish Black and White and 1022 Danish Jersey potential AI-bulls and 56 494 Danish Red, 264107 Danish Black and White and 57 661 Danish Jersey first lactation cows. Measures of food intake were provided by two Danish performance test stations. Information on incidence of mastitis, retained placenta, metritis, sole ulcer and ketosis as well as calving interval and energy corrected milk yield of first lactation cows was based on data extracted from the national data base in Denmark. Genetic (co)variances were estimated using restricted maximum likelihood. Heritability estimates of disease incidence and calving interval were low, ranging from <0.01 to 0.13 depending on breed. Heritability estimates of energy corrected milk yield were in the range of 0.28 to 0.33. In all breeds, an unfavourable genetic relationship between milk yield and disease incidence was found, while genetic correlations between food intake and ketosis were favourable, ranging between -0.03 and -0.25. Fertility disorders had an inconsistent correlation with food intake traits across breeds. Food intake of bulls could be included in the selection process in order to avoid nutrition-related disorders like ketosis.

Quantitative genetic studies on wool yellowing in Corriedale sheep. 1. Wool yellowing susceptibility and wool production traits—genetic parameter estimates

1998 ◽  
Vol 49 (8) ◽  
pp. 1195 ◽  
Author(s):  
M. V. Benavides ◽  
A. P. Maher ◽  
M. J. Young ◽  
P. R. Beatson ◽  
T. C. Reid
Keyword(s):  
Selection Index ◽  
Genetic Parameter ◽  
Genetic Correlations ◽  
Fibre Diameter ◽  
Parameter Estimates ◽  
Production Traits ◽  
Correlated Responses ◽  
Percentage Yield ◽  
Fleece Weight ◽  
Average Information

The potential for the reduction of wool yellowing susceptibility (YPC) in Corriedale sheep via selection was examined. The heritabilities of YPC and greasy fleece weight (GFW) and clean fleece weight (CFW), yield percentage (Yield), mean fibre diameter (MFD), and subjective greasy wool colour assessment (Visual), and phenotypic and genetic correlations among these traits were estimated from records on 1492 progeny of 53 sires of a Corriedale flock by using restricted maximum likelihood procedures using an average information algorithm. The heritability of YPC was 0·27 ± 0·06. Genetic correlations between YPC and GFW, CFW, Yield, MFD, and Visual were 0·20 ± 0·14, 0·11 ± 0·14, –0·15 ± 0·13, 0·24 ± 0·14, and 0·95 ± 0·06, respectively. Phenotypic correlations were low between these traits and YPC. Visual had a heritability of 0·30 ± 0·06 and medium-high genetic correlations with all traits, except CFW. Heritability estimates of GFW, CFW, Yield, and MFD were 0·55 ± 0·07, 0·52 ± 0·07, 0·51 ± 0·07, and 0·52 ± 0·07, respectively. The expected correlated responses to selection against YPC are likely to cause reductions in CFW and MFD. Correlated responses from the reduction of Visual are predicted to be greater for all production traits than those from the reduction of YPC. Responses in YPC are predicted to be slightly higher when selection is on Visual (–0·21 score/year) than when selection is on YPC itself (–0·19 score/year). A selection index, including CFW, MFD, and YPC as aggregate breeding and breeding objective traits, calculated at I = +3·26CFW – 0·14MFD + 0·03YPC, predicted a YPC increase, worsening the problem.

Quantitative genetic studies on wool yellowing in Corriedale sheep. II. Clean wool colour and wool production traits: genetic parameter estimates and economic returns

2000 ◽  
Vol 51 (2) ◽  
pp. 191
Author(s):  
M. V. Benavides ◽  
A. P. Maher
Keyword(s):  
Selection Criteria ◽  
Selection Index ◽  
Genetic Parameter ◽  
Genetic Correlations ◽  
Fibre Diameter ◽  
Economic Losses ◽  
Direct Selection ◽  
Parameter Estimates ◽  
Selection Indices ◽  
Visual Colour

The potential for improvement of clean wool colour (CWC) in Corriedale sheep via selection was examined. The heritability, and phenotypic and genetic correlations, of CWC, brightness (Y), greasy (GFW) and clean (CFW) fleece weights , yield percentage (Yield), mean fibre diameter (MFD), and visual colour score were estimated from 440 progeny of 19 sires of a Corriedale flock using restricted maximum likelihood (REML) procedures with average information algorithm (AIREML). The heritability of CWC was estimated at 0.27±0.13. Clean wool colour showed strong positive genetic correlations with CFW and MFD. Visual colour score and CWC were also positively genetically correlated. As expected, direct selection criteria against MFD, CWC, or visual colour score would reduce CWC; however, direct selection against MFD would improve clean wool colour with negligible reductions on CFW, thus resulting in small economic gains. Several selection indices were calculated having either CFW, MFD, and CWC or CFW and MFD as selection criteria. The b-values of an unrestricted index were estimated at I1 = + 1.15 CFW + 0.13 MFD + 0.43 CWC, with positive correlated responses for all 3 breeding objective traits (CFW, MFD, and CWC). A second index, where CFW was restricted to nil genetic change, was estimated at: I2 = + 0.14 CFW − 0.02 MFD + 0.01 CWC. This index was expected to cause a negligible genetic gain for CWC (−0.04 Y–Z units/head.year). To avoid economic losses with the reduction on CFW, a third selection index was calculated where CWC was restricted to nil change. The index was estimated at I3 = +0.61 CFW − 0.07 MFD + 0.02 CWC with expected increases in CFW and decreases in MFD. Selection indices with (a) CFW and MFD (I4) and (b) CFW, MFD, and visual colour score (I5) as selection criteria would increase CFW, MFD, and CWC at the same rates observed in I1.

The use of product traits such as lean growth rate as selection criteria in animal breeding

1987 ◽  
Vol 45 (2) ◽  
pp. 307-316 ◽  
Author(s):  
G. Simm ◽  
C. Smith ◽  
R. Thompson
Keyword(s):  
Growth Rate ◽  
Selection Criteria ◽  
Genetic Parameters ◽  
Selection Index ◽  
Genetic Correlations ◽  
Or Efficiency ◽  
Economic Values ◽  
Lean Growth ◽  
Component Traits ◽  
Economic Selection

ABSTRACTIn meat animals there is some interest in lean growth rate or lean food conversion efficiency as selection criteria. These traits may be estimated as the product of growth rate (or efficiency), killing-out proportion and carcass lean proportion. When used as selection criteria these product traits do not require estimates of genetic parameters or economic values for component traits. Hence, they may be more stable, and of longer-term use than classical economic selection indices. The purpose of this study is to compare expected responses to selection on product traits with expected responses from selection, either on individual component traits, or on an economic selection index. Formulae were derived for predicting the phenotypic and genetic correlations between a product and one component, and for predicting the heritability of the product trait; these depend on the coefficients of variation and heritabilities of components, and on the genetic correlations among them. When the coefficient of variation of one component is much higher than that of the other, (× 3), this component will tend to dominate the product trait. In cattle and sheep, and to a lesser extent in pigs, killing-out proportion and leanness are usually less variable than growth rate or efficiency. Thus, in many cases, there is little loss in response in lean growth (or lean efficiency) from selection solely on growth rate (or efficiency) regardless of leanness. Although product traits do not require derivation of economic values, their component traits do have implied economic values. Often more appropriate weightings will be given to components by using an economic selection index, even when economic values and genetic parameters are not estimated precisely.

Genetic relations and indirect response to selection based on indices for scrotal circumference, visual scores and weight gain in beef cattle

2018 ◽  
Vol 58 (7) ◽  
pp. 1210 ◽  
Author(s):  
A. A. Boligon ◽  
P. P. Farias ◽  
V. M. Roso ◽  
M. L. Santana ◽  
A. B. Bignardi ◽  
...  
Keyword(s):  
Weight Gain ◽  
Beef Cattle ◽  
Selection Process ◽  
Selection Index ◽  
Genetic Correlations ◽  
Correlated Response ◽  
Indirect Response ◽  
Genetic Gains ◽  
Scrotal Circumference ◽  
Selection For

Genetic improvement in beef cattle involves evaluation for fertility, growth, carcass and visual scores traits. In general, genetic and economic parameters of these traits are considered for selection index construction. The present study was conducted to establish the magnitude of genetic and phenotypic correlations between visual scores of conformation, precocity and muscling at weaning and at yearling, birth to weaning weight gain, weaning to yearling weight gain and yearling scrotal circumference, and between these traits with selection indices applied in this population. In addition, the expected gains were obtained in such traits by taking under consideration the adopted selection criteria based on indices. Positive and high genetic correlations were estimated between weaning traits (visual scores and weight gain), ranging from 0.70 ± 0.02 to 0.97 ± 0.01. In genetic terms, the same visual scores, but evaluated in two ages (weaning and yearling) showed positive and high associations, with values of 0.90 ± 0.01 (conformation), 0.88 ± 0.01 (precocity) and 0.84 ± 0.02 (muscling). Genetic associations between yearling visual scores with scrotal circumference and weaning to yearling weight gain ranging from 0.36 ± 0.02 to 0.53 ± 0.01. Using the weaning index, are expected genetic gains ranging from 0.26% to 0.70%/year of the phenotypic mean of each weaning trait. Using the yearling index, annual genetic gains estimated for weaning traits (ranging from 0.25% to 0.63% of the phenotypic mean of the trait) were lower than that obtained at yearling (ranging from 0.27% to 0.98% of the phenotypic mean of the trait). Selection for one of traits obtained at weaning should result, by correlated response, in gain for the others. Also, the choice of animals with higher breeding values for weaning visual scores, beyond anticipate the selection process, should lead to favourable changes in these traits at yearling. Selection for better body composition at yearling (higher scores) should provide increase in scrotal circumference and weight gain. The use of higher values of the indices should result in positively correlated response, but in different magnitudes for each trait used in these indices. However, in both weaning and yearling, higher genetic gains to visual scores are expected in the same period, when the selection is based on the values of these indices.

scholarly journals Ways to improve the gene pool of pigs of the Russian Federation

2019 ◽  
Vol 22 (8) ◽  
pp. 912-921 ◽  
Author(s):  
V. A. Bekenеv
Keyword(s):  
Selection Process ◽  
Selection Index ◽  
Genetic Correlations ◽  
Organizational Factors ◽  
Experimental Proof ◽  
Closed Mode ◽  
World Class ◽  
The Russian Federation ◽  
Positive Effect ◽  
Rapid Transformation

An analysis of the system of breeding work in the pig industry of our country has been carried out. The scientifc and organizational factors that determine the improvement of breed and productive qualities of pigs have been analyzed. On the basis of many years of experimental data, selection practices obtained in the process of creating new breeding achievements, and using the scientifc results of the world science on genetics and animal breeding, proposals have been developed for a new system for assessing and improving the genetic potential of animal productivity based on modern achievements in genetics. In particular, a critical analysis was performed on the existing instructions for boning pigs, linear breeding, which does not meet the criteria of reality in the systematization of biological objects. The positive effect of breeding pigs in a closed mode in the form of a “line-population”, using such genetic markers as erythrocyte antigens, erythrocyte enzymes, lipoproteins, allowing intensifcation of the selection process, has been experimentally proved. When hogging pigs and developing breeding plans with a herd, it was proposed to use such selection and genetic parameters as heritability factors, phenotypic and genetic correlations, selective differential, selective effect, etc. for assessment of animals and prognostication of productivity. A system of continuous scoring of each selectable feature was developed, in contrast to the interval to the classes used in our country at the present time. A model of the selection index, taking into account the selection and economic signifcance of each of its components, has been proposed. Theoretical paths have been shown towards and experimental proof given to a relatively rapid transformation of breeds of animals bred in Russia to world-class productivity, as opposed to the constant import of breeding animals.

scholarly journals Perbandingan Hasil Uji Performans Calon Induk (Heifer) Sapi Aceh dengan Metode Indeks Seleksi (IS) dan Nilai Pemuliaan (NP)

2017 ◽  
Vol 7 (1) ◽  
pp. 61
Author(s):  
W P B. Putra ◽  
Su Madi ◽  
T. Hartatik ◽  
H. Saumar
Keyword(s):  
Selection Criteria ◽  
Selection Index ◽  
Genetic Correlations ◽  
Secondary Data ◽  
Breeding Value ◽  
Family Tree ◽  
Cattle Breeding ◽  
Final Weight ◽  
Genetic And Phenotypic Correlations ◽  
Estimate Heritability

This research was conducted to investigate the results of selection in Aceh cattle candidate<br />bull using breeding value (BV) and selection index (SI) methods. The Secondary data in this research was records data from 2010 to 2013 and consisted of family tree, birth and body weight records at Indrapuri’s Breeding and Forages Centre (IBFC) of Aceh Cattle. Data records collected for estimate heritability nor the genetic and phenotypic correlations. The research showed that heritability value of weaning weight (WW), yearling weight (YW) and final weight (FW) included high category. Genetic correlation between WW with YW and FW were positively moderate. The concluded of this research was 48 % heifers had same rank on BVFW and SI from 29 heifers. Index selection method could be use for livestock selection criteria.<br />Key words: Aceh cattle, breeding value, selection index, heritability, genetic correlations

scholarly journals Heritability of sow longevity and lifetime prolificacy in Finnish Yorkshire and Landrace pigs

2013 ◽  
Vol 22 (3) ◽  
pp. 325-330 ◽  
Author(s):  
Marja-Liisa Sevón-Aimonen ◽  
Pekka Uimari
Keyword(s):  
Genetic Variation ◽  
Variance Components ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Sow Longevity ◽  
Piglet Mortality ◽  
Heritability Estimates ◽  
Mortality Percentage

The objective of this study was to estimate genetic parameters for longevity traits in Finnish pig populations. Analyzed traits were length of productive herd life (LPL), total number of parities (TNP), total number of piglets born (TNB), total number born alive (TBA) and stillborn (TSB), percentage stillborn (SB%), total number of piglets dead before weaning (TPM), mortality percentage (PM%), and total number weaned (TNW). Data contained litter records from 29 805 Finnish Landrace and 25 807 Finnish Yorkshire sows. Variance components were estimated using the AI-REML method. Heritability estimates varied from 0.06 to 0.11 in Finnish Landrace and from 0.09 to 0.12 in Finnish Yorkshire. Genetic correlations were high (> 0.9) between LPL, TNP, TNB, TBA, and TNW, and low between piglet mortality traits (SB% and PM%) and other longevity traits. The obtained heritability estimates indicate that there is sufficient genetic variation for selection.

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