Estrus reaction of gilts as selection criteria for litter size

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.

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

Animal Production Science ◽

10.1071/an15657 ◽

2017 ◽

Vol 57 (4) ◽

pp. 614 ◽

Cited By ~ 2

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.

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Correlation of litter size traits

Biotechnology in Animal Husbandry ◽

10.2298/bah1604331r ◽

2016 ◽

Vol 32 (4) ◽

pp. 331-339

Author(s):

Cedomir Radovic ◽

Milica Petrovic ◽

Nenad Brkic ◽

Nenad Parunovic ◽

Dragan Radojkovic ◽

...

Keyword(s):

Litter Size ◽

Genetic Correlations ◽

The Other ◽

Weaned Piglets ◽

Litter Weight ◽

Individual Weight ◽

Other Hand ◽

Heritability Estimates

Heredity and correlation of litter size traits were observed in 3693 litters, i.e. in 1622 daughters of two genotypes Swedish Landrace genotype - SL; and F1 ? SLxLW. The study included daughters (minimum ten daughters per sire) of 24 sires. Heritability estimates for the total number of piglets per litter in the first, the first two parities, and for all three parities was 0.174; 0.167 and 0.135. Heritability estimates for the number of piglets born alive were 0.181; 0.160 and 0.121, and for the weight of litter at birth 0.166; 0.174 and 0.150. On the other hand, very low heritability was determined for the number of weaned piglets, litter weight of piglets reared, individual weight of born and reared piglets, i.e. for the traits that are under greater influence of the environment (from 0.004 to 0.037). Phenotypic and genetic correlations ranged from weak to complete (rp = 0.021 to rp = 0.973 and rg=0.188 to rg=0.999, respectively). Analysis of the significance of correlations showed that the genetic correlations were statistically highly significant (P <0.01).

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Estimation of genetic and phenotypic parameters of growth curve and their relationship with early growth and productivity in Horro sheep

Archives Animal Breeding ◽

10.5194/aab-53-85-2010 ◽

2010 ◽

Vol 53 (1) ◽

pp. 85-94 ◽

Cited By ~ 1

Author(s):

S. Abegaz ◽

J. B. Van Wyk ◽

J. J. Olivier

Keyword(s):

Body Weight ◽

Least Squares ◽

Growth Curve ◽

Selection Criteria ◽

Genetic Correlations ◽

Early Growth ◽

Optimum Growth ◽

Mature Weight ◽

Heritability Estimates ◽

Pearson Correlations

Abstract. Weight (kg)-age (days) data of 524 Horro sheep of Ethiopia were fitted to a Brody function to estimate parameters of growth curve and their genetic and phenotypic parameters. Genetic and phenotypic relationships were also estimated between growth curve parameters and weight at birth (BW), weaning (WW) six-month (WT6) and yearling (YW). For ewes Pearson correlations were also calculated between growth curve parameters and ewe productivity over first to fourth parities. Least squares means of growth curve parameters A (asymptotic mature weight, kg), B (proportion of mature weight attained after birth) and K (the rate of maturity, kg gain kg-1 body weight) were 37.6, 0.88, and 0.27∙10-2, respectively. Heritability estimates were 0.29, 0.18 and 0.14 for A, B, and K, respectively. Genetic correlations between A and B, A and K, and B and K were 0.39, −0.07, and 0.25 respectively. Genetic correlations of A and K with BW, WW, WT6, and YW were 0.27 and −0.13, 0.34 and 0.37, 0.44 and 0.61, and 0.67 and 0.66, respectively. The growth curve parameters have small but positive (r=0.05 to 0.28) relationship with indicators of lifetime productivity. Medium heritability estimates of A and K indicate that progress in improving these traits can be made through selection. WT6 and YW have medium genetic correlations with the growth curve parameters and these may allow the use of these weights as indirect early selection criteria for optimum growth curve.

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Analysis of the genetic relationship between litter size and weight traits in Segureña sheep

Canadian Journal of Animal Science ◽

10.4141/a95-137 ◽

1997 ◽

Vol 77 (1) ◽

pp. 17-21 ◽

Cited By ~ 7

Author(s):

M. Analla ◽

A. Muñoz-Serrano ◽

J. M. Serradilla

Keyword(s):

Birth Weight ◽

Key Words ◽

Litter Size ◽

Genetic Relationship ◽

Linear Models ◽

Genetic Correlations ◽

Meat Production ◽

Environmental Correlations ◽

Heritability Estimates ◽

The Relationship

A selection program is being implemented to improve meat production in the Segureña breed of sheep. Increasing litter size per ewe is the main objective, but possible repercussions on weight traits of lambs should be considered. The aim of this work is to determine the relationship between litter size and weight at birth, weaning and at 90 d. Records of 8117 animals, during 11 yr of production, taken from 1981 to 1991 in an experimental flock, were used to estimate heritabilities, repeatability, and genetic and environmental correlations by means of single-trait and multitrait linear models. Heritability estimates for litter size were approximately 0.08, and repeatability estimates were 0.14 and 0.11 for single-trait and multitrait models, respectively. Heritability estimates of weight traits obtained with single-trait and multitrait models were similar. Genetic correlations were 0.18 between litter size and birth weight, 0.48 between litter size and weaning weight, and 0.36 between litter size and weight at 90 d. Environmental correlations between litter size and weight traits were close to zero. Because genetic correlations between litter size and weight traits were all positive, no deterioration of breeding values of weight traits could be expected, when selecting for litter size. Key words: Sheep, weight, litter size, correlation, heritability

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

Genetics ◽

10.1093/genetics/143.3.1409 ◽

1996 ◽

Vol 143 (3) ◽

pp. 1409-1416 ◽

Cited By ~ 1

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.

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Genetic variation and correlation of agronomic traits in meadow bromegrass (Bromus riparius Rehm) clones

Ciência Rural ◽

10.1590/s0103-84782004000200026 ◽

2004 ◽

Vol 34 (2) ◽

pp. 505-510 ◽

Cited By ~ 14

Author(s):

Marcelo Renato Alves de Araújo ◽

Bruce Coulman

Keyword(s):

Genetic Variation ◽

Crude Protein ◽

Genetic Correlations ◽

Neutral Detergent Fiber ◽

Broad Sense ◽

Grass Species ◽

Broad Sense Heritability ◽

Bromus Riparius ◽

Heritability Estimates ◽

Meadow Bromegrass

Meadow bromegrass (Bromus riparius Rehm.) is a recently introduced pasture grass in western Canada. Its leafy production and rapid regrowth have made it a major grass species for pasturing beef animals in this region. As relatively little breeding work has been done on this species, there is little information on its breeding behaviour. The main objective of this study was to estimate total genetic variability, broad-sense heritability, phenotypic and genetic correlations. Forty-four meadow bromegrass clones were evaluated for agronomic characters. Genetic variation for dry matter yield, seed yield, fertility index, harvest index, plant height, plant spread, crude protein, neutral detergent fiber and acid detergent fiber, was significant. Broad-sense heritability estimates exceeded 50% for all characters. Heritability estimates were at least 3.5 times greater than their standard errors. Phenotypic and genetic correlation between all possible characters were measured. There was general agreement in both sign and magnitude between genetic and phenotypic correlations. Correlations between the different characters demonstrated that it is possible to simultaneously improve seed and forage yield. Based on the results, it appears that the development of higher yielding cultivars with higher crude protein, and lower acid and neutral detergent fibers concentration should be possible.

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An analysis of the variation in the lean tissue distribution of sheep

Animal Science ◽

10.1017/s0003356100010199 ◽

1982 ◽

Vol 34 (3) ◽

pp. 257-264 ◽

Cited By ~ 13

Author(s):

B. T. Wolf

Keyword(s):

Tissue Distribution ◽

Genetic Correlation ◽

Average Daily Gain ◽

Genetic Correlations ◽

Maximum Difference ◽

Lean Tissue ◽

Heritability Estimates ◽

The Relationship ◽

Daily Gain ◽

Sire Breed

ABSTRACTThe distribution of lean tissue between eight standard joints was examined in 956 crossbred lambs slaughtered at constant live weights of either 35 or 40 kg. The sire breeds used were the Dorset Down, Ile-de-France, Oldenburg, Oxford, Suffolk and Texel. Sire breed did not have a significant effect on the proportion of total carcass lean found in the higher-priced joints but did show significant differences in the proportion of total carcass lean found in individual joints, with a maximum difference of 7·7 g total lean per kg joint being recorded. Similarly, small but significant effects due to ewe age (1 to 3 years), rearing type (single, twin, triplet), sex (male castrate, female) and weight of total lean were reported for the proportion of total carcass lean found in different joints.Heritability estimates ranged from 0·07 (s.e. 008) to 0·65 (s.e. 0·16) for the proportion of total lean in the best-end neck and higher-priced joints respectively. Phenotypic standard deviations of 5·8g/kg and 17·9g/kg were reported for the proportion of total lean found in the best-end neck and the higher-priced joints respectively. The genetic correlations between the proportion of total lean in each of the higher-priced joints and the proportion of total lean in the higher-priced joints combined were positive. A genetic correlation of 017 (s.e. 0·20) was found for the relationship between average daily gain from birth to slaughter and the proportion of total lean in the higher-priced joints.

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Genetic-Quantitative Uni- and Bi-Trait Analysis for Growth Traits in the Colombian Creole Breed Blanco Orejinegro (BON)

10.21203/rs.3.rs-1125146/v1 ◽

2021 ◽

Author(s):

Marisol Londoño-Gil ◽

Juan Carlos Rincón Flórez ◽

Albeiro López-Herrera ◽

Luis Gabriel Gonzalez-Herrera

Keyword(s):

Growth Traits ◽

Genetic Correlations ◽

Genetic Effect ◽

Cattle Breed ◽

Live Weight ◽

Daily Weight Gain ◽

Additive Genetic Effect ◽

Selection Processes ◽

Heritability Estimates ◽

Maternal Heritability

Abstract The Blanco Orejinegro (BON) is a Colombian creole cattle breed that is not genetically well characterized for growth traits. The aim of this work was to estimate genetic parameters for birth weight (BW), weaning weight (WW), yearling weight (YW), daily weight gain between birth and weaning (DWG), time to reach 120 kg of live weight (T120), and time to reach 60% of adult weight (T60%), and establish the selection criteria for growth traits in the BON population of Colombia. Genealogical and phenotypic information for BW, WW, YW, DWG, T120, and T60% traits of BON animals from 14 Colombian herds were used. These traits were analyzed with the AIREML method in a uni- and bi-trait animal model including the maternal effect for BW, WW, DWG, and T120. The direct heritability estimates values were 0.22 ± 0.059 (BW), 0.20 ± 0.057 (WW), 0.20 ± 0.153 (YW), 0.17 ± 0.07 (DWG), 0.26 (T120), and 0.44 ± 0.03 (T60%). The maternal heritability estimates values were 0.14 ± 0.040 (BW), 0.15 ± 0.039 (WW), 0.25 ± 0.06 (DWG), and 0.16 (T120). The direct genetic correlations were high (>|0.60|) among all the traits, except between T60% with BW, WW, YW, and DWG (ranged from -0.02 to -0.51), all in a favorable direction. The results showed that there is genetic variation in the growth traits associated with the additive genetic effect and they might respond to selection processes. Furthermore, genetic gains would improve through selection, especially for YW and T60% when WW is used as criterion.

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Estimates Of Genetic Parameters For Economic Traits In West African Dwarf Goat

Nigerian Journal of Animal Production ◽

10.51791/njap.v19i.2089 ◽

2021 ◽

Vol 19 ◽

pp. 114-119

Author(s):

I. K. Odubote ◽

J. O. Akinokun

Keyword(s):

Body Weight ◽

Litter Size ◽

Genetic Parameters ◽

West African ◽

Economic Traits ◽

West African Dwarf ◽

West African Dwarf Goat ◽

Heritability Estimates ◽

Size At Birth ◽

Birth Body Weight

Records of 848 West African Dwarf goat kids and 220 kiddings over a period of eight years (1982-1989) were analysed. The records were used to provide heritability and repeatability estimates for litter size at birth, kidding interval (repeatability estimate alone) and body weight at birth, weaning, 3 months, 6 months, 9 months and 1 year of age. Heritability estimates of 0.28±0.005, 0.18±0.003, 0.14±0.003, 0.29±0.005, 0.11±0.003 and 0.17±0.004 were obtained for litter size at birth, body weight at birth, and at weaning, 3 months, 6 months, and 9 months of age respectively. Corresponding repeatability estimates were slightly higher than the heritability estimates. However, repeatability estimates of 0.04±0.030 was obtained for kidding interval.

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Genetic parameter estimates (full sib and half sib analysis) of fertility and hatchability in two strains of Rhode Island chickens

Nigerian Journal of Animal Production ◽

10.51791/njap.v38i1.706 ◽

2021 ◽

Vol 38 (1) ◽

pp. 14-22

Author(s):

M. Orunmuyi ◽

I. A. Adeyinka ◽

O.O Oni

Keyword(s):

Rhode Island ◽

Additive Genetic Variance ◽

Genetic Parameter ◽

Genetic Correlations ◽

Reproductive Traits ◽

Parameter Estimates ◽

Phenotypic Correlations ◽

Poultry Breeding ◽

Genetic And Phenotypic Correlations ◽

Heritability Estimates

A study was conducted to estimate the genetic parameters of fertility and hatchability in two strains of Rhode Island Red (RIR) Chickens denoted as Strain A and Strain B respectively using the full-sib (sire +dam variance) and maternal half-sib (dam variance) components. The birds were obtained from the selected populations of RIR Chickens kept at the poultry breeding programme of National Animal Production Research Institute, Shika, Zaria, Nigeria. Settable eggs were collected from mating 28 cocks to 252 hens in a ratio of 1cock:9 hens from each strain. Eggs were pedigreed according to sire and dam. Results showed that values obtained for number of egg set (EGGSET), number of fertile eggs (NFERT), number of hatched chicks (NHATCH), percentage of chicks hatched from total eggs set (PHATCH) and percentage of chicks hatched from fertile eggs (PHATCHBL) were all higher in strain A than strain B. Heritability estimates obtained from the full-sib and maternal half-sib analysis ranged from medium to high for the two strains (0.24-0.96). The maternal half sib estimates were higher (0.40-0.96) than the estimates obtained from full sibs (0.24- 0.48). Genetic and phenotypic correlations obtained for both strains were positive and similar regardless of method of estimation. Genetic correlations between EGGSET and PFERT were low in strain A using both full-sib and maternal half-sib analyses (0.09-0.14). Phenotypic correlations between EGGSET and PFERT, PHATCH and PHATCHBL were also low in both strains and regardless of method of analyses. Moderate to high heritability estimates suggest that genetic improvement can be obtained by selection of these reproductive traits. The full-sib analysis for estimating heritability will be preferred since it is assumed that only additive genetic variance contributes to the covariance between family members.

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