Litter Productivity in Large White Pigs: 2. Heritability and repeatability estimates

1970 ◽  
Vol 12 (2) ◽  
pp. 235-243 ◽  
Author(s):  
G. S. Strang ◽  
J. W. B. King
Keyword(s):  
Litter Size ◽  
Direct Selection ◽  
Large White ◽  
Litter Weight ◽  
Phenotypic Correlations ◽  
Performance Traits ◽  
Genetic And Phenotypic Correlations ◽  
Selection For ◽  
Heritability Estimates ◽  
Selection Differentials

SUMMARYEstimates of the heritability, the repeatability and the genetic cor-relation coefficients of litter performance traits were calculated from data on 38000 Large White litters farrowed in 146 British herds.The repeatability estimates of number of live pigs per litter at birth, three weeks and eight weeks were 0·15, 0·14 and 0·14 respectively. The corresponding heritability estimates were 0·07±0·02, 0·07±0·02 and 0·09±0·03, respectively. The repeatability estimates of litter weight at three weeks and eight weeks were 0·15 and 0·04, while the corresponding heritabiUty estimates were 0·08±0·02 and 0·03±0·02. High positive genetic and phenotypic correlations were obtained between litter size and litter weight.A number of model culling schemes were considered and it was found that even at relatively high culling levels the improvement in overall herd mean performance was very small. Direct selection for litter size may yield a useful rate of improvement if selection is con-fined to one trait and large selection differentials are achieved, but could not be economically justified.

scholarly journals Genetic Analysis Of Rabbit Litter Traits At Birth And Weaning

2021 ◽  
Vol 19 ◽  
pp. 64-69
Author(s):  
I. K Odubote ◽  
B. Somade
Keyword(s):  
Birth Weight ◽  
Genetic Analysis ◽  
Litter Size ◽  
Weaning Weight ◽  
Litter Weight ◽  
Phenotypic Correlations ◽  
Litter Traits ◽  
Genetic And Phenotypic Correlations ◽  
Selection For ◽  
Size At Birth

Data on 260 litters were used to provide therefore to estimate the heritability and estimates of heritability, repeatability, genetic and phenotypic correlations for litter traits at birth and at weaning. Breed, sire within breed and doe within sire effects were found to be significant, (P<0.05) for litter size at birth and at weaning and for litter weight at birth and at weaning. Heritability estimates of 0.33±0.08, 0.38±0.02, 0.03±0.02 and 0.16±0.05 were obtained for litter birth weight, litter size at birth, litter size at weaning and litter weaning weight, respectively. Repeatability estimates were found to be generally moderate to high. Genetic and phenotypic correlations were positive and significant (P<0.01). Selection for litter size at birth and litter birth weight are likely to result in improved litter size at weaning and litter weaning weight respectively.

A genetic analysis of litter traits in Bauscat and Giza White rabbits

1987 ◽  
Vol 45 (1) ◽  
pp. 123-134 ◽  
Author(s):  
M. H. Khalil ◽  
J. B. Owen ◽  
E. A. Afifi
Keyword(s):  
Genetic Analysis ◽  
Litter Size ◽  
Litter Weight ◽  
Phenotypic Correlations ◽  
Large Litter ◽  
Litter Traits ◽  
Genetic And Phenotypic Correlations ◽  
Size At Birth

AbstractAn analysis of doe productivity traits was carried out on 884 litter records including 52 sires and 210 daughters (paternal half sisters) of Bauscat (B) and Giza White (G) rabbits. Traits examined included litter size and weight at birth and at weaning, pre-weaning mortality and mean weight of young at weaning. Year-of-kindling affected most litter traits but no pattern of parity effects on litter size and pre-weaning mortality was observed. Litter weight and mean weight of young at weaning generally increased linearly as parity advanced. Litter size and weight and mean weight of young tended to increase as month of kindling advanced from October to March, and to decrease again during April and May. Pre-weaning mortality decreased as month of kindling advanced up to March and increased thereafter during April and May. The sire of the doe affected all litter traits studied, with the exception of litter size at birth and pre-weaning mortality in the B breed. Estimates of heritability for most of the litter traits were moderate or high. Genetic and phenotypic correlations among litter size traits and between litter size and litter weight traits were positive and relatively moderate or large. Litter weight traits were positively correlated both genetically and phenotypically. The genetic and phenotypic correlations between litter size traits and mean weight of young at weaning were negative and relatively moderate or large.

scholarly journals Hritabilities and genetic and phenotypic correlations of litter uniformity and litter size in Large White sows

2016 ◽  
Vol 15 (4) ◽  
pp. 848-854 ◽  
Author(s):  
Tian ZHANG ◽  
Li-gang WANG ◽  
Hui-bi SHI ◽  
Hua YAN ◽  
Long-chao ZHANG ◽  
...  
Keyword(s):  
Litter Size ◽  
Large White ◽  
Phenotypic Correlations ◽  
Genetic And Phenotypic Correlations

An analysis of reproductive performance in pigs based on records of performance of the boar

1977 ◽  
Vol 17 (85) ◽  
pp. 256 ◽  
Author(s):  
K Baharin ◽  
RG Beilharz
Keyword(s):  
Birth Weight ◽  
Litter Size ◽  
Reproductive Performance ◽  
Conception Rate ◽  
Gestation Length ◽  
Large White ◽  
Average Birth Weight ◽  
Litter Weight ◽  
Commercial Farm ◽  
Heritability Estimates

The reproductive performance of 308 boars with total records of 9220 matings from a large commercial farm was analysed. The boars were purebred Large White, Landrace and from the newly synthesized M breed and were mated to purebred and crossbred sows of the same breeds. The M breed was derived from crossing between Large White and Landrace pigs with foundation females selected on the basis of their ability to produce large litters. Over half the total records were from matings with sows of parity 1 and parity 2. Overall production statistics were 78.8 per cent conception rate, an average total litter size of 9.3 pigs born per litter, 6.5 per cent stillbirths, an average litter weight (live piglets) at birth of 12.2 kg, average birth weight per piglet of 1.43 kg and average gestation length of 11 5 days. Most of the traits analysed showed significant effects due to parity of dams, with performance increasing from parity 1 to parity 6 to 8, after which the performance began to decline. There were significant heterosis effects (mainly maternal) on reproduction of the sows and survival performance of the litters resulting in an estimated improvement of 11 per cent in number of live pigs born, 12.4 per cent in total litter weight at birth and 35 per cent reduction in stillbirths. Heritability estimates were generally low for most traits except for boar conception rate which was moderate (0.29).

Estimates of genetic and phenotypic parameters for growth traits of D'Man lambs

1990 ◽  
Vol 51 (1) ◽  
pp. 173-178 ◽  
Author(s):  
I. Boujenane ◽  
M. Kerfal
Keyword(s):  
High Weight ◽  
Growth Traits ◽  
Genetic Correlations ◽  
Phenotypic Correlations ◽  
High Magnitude ◽  
Genetic And Phenotypic Correlations ◽  
Selection For ◽  
Heritability Estimates

ABSTRACTThe heritability of growth traits from birth to 6 months of age and the genetic and phenotypic correlations among them were determined from paternal half-sib analyses of 1689 records of D'man lambs. Heritability estimates were 0·34 (s.e. 0·08), 0·23 (s.e. 0·06), 0·52 (s.e. 0·10) and 0·43 (s.e. 0·09) for weights at birth, 30 days, 90 days and 180 days, respectively. Heritabilities for average daily gains from birth to 30 days and from 30 to 90 days were estimated to be 0·12 (s.e. 0·05) and 0·56 (s.e. 0·11), respectively. Genetic and phenotypic correlations among growth traits were all positive and of high magnitude. The former estimates varied from 0·66 to 0·98, the latter estimates ranged from 0·23 to 0·92. Selection for high weight at 90 days would be expected to have large effect on other growth traits as a result of their large positive genetic correlations.

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.

Selection and response within the nucleus of a sheep group-breeding scheme

1990 ◽  
Vol 51 (3) ◽  
pp. 593-599 ◽  
Author(s):  
S. Anderson ◽  
M. K. Curran
Keyword(s):  
Litter Size ◽  
Age Groups ◽  
Selection Response ◽  
Sheep Flock ◽  
Breeding Scheme ◽  
Average Value ◽  
Group Breeding ◽  
Selection For ◽  
Progeny Group ◽  
Selection Differentials

ABSTRACTAn evaluation of the response to selection for prolificacy within a nucleus sheep flock of a commercial group-breeding scheme is presented. In 1979, the Romney Group Breeders formed a nucleus flock of 120 prolific ewes chosen from 12 contributing flocks. A control flock was established in 1982 from the same source. The analysis was conducted on the trait of litter size. Selection differentials are presented for each year of birth progeny group in both flocks. Expected selection response was calculated from selection differentials and was found to have an average value of 1·5% of parent mean litter size per year. Using least squares procedures the litter size performance of control and nucleus ewes of 2, 3 and 4 years of age was corrected for environmental effects. Realized response was estimated from the differences between corrected litter size means of control and nucleus flocks. Response in litter size was found to be significant within years and within ewe age groups (P < 0·05).

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

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.

scholarly journals Effect of parity on reproductive performance sows of different breeds

2020 ◽  
Vol 50 (3) ◽  
pp. 434-441
Author(s):  
R. Klimas ◽  
A. Klimienė ◽  
W. Sobotka ◽  
W. Kozera ◽  
P. Matusevičius
Keyword(s):  
Survival Rate ◽  
Litter Size ◽  
Reproductive Performance ◽  
Weaned Piglets ◽  
Large White ◽  
Litter Weight ◽  
Piglet Survival

The aim of this study was to determine the effect of parity on reproductive performance by sows of different breeds. The sows were raised on three farms, and had seven or more litters of not fewer than seven piglets. A total of 1511 litters from various parities of Lithuanian White (N =721), Large White (N = 162) and Landrace (N = 628) sows were contained in the data that were used in this study. Multiparous sows had larger litters than primiparous sows. Piglet survival rate declined from parity 7. An increase in litter size was observed until parity 5 in Large White and until parity 6 in improved Lithuanian White (P <0.05). In comparison with parity 1, Landrace sows up to parity 5 showed not only increased prolificacy, but also increased number and litter weight of piglets at 21 days old, and the number and litter weight of weaned piglets (P <0.01). The current findings indicate that sows of these breeds can be used effectively in breeding herds until parity 5 and parity 6.Keywords: Landrace, Large White, Lithuanian White, litter size

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