scholarly journals Genetic parameters and direct, maternal and heterosis effects on litter size in a diallel cross among three commercial varieties of Iberian pig

animal ◽  
2019 ◽  
Vol 13 (12) ◽  
pp. 2765-2772 ◽  
Author(s):  
J.L. Noguera ◽  
N. Ibáñez-Escriche ◽  
J. Casellas ◽  
J.P. Rosas ◽  
L. Varona
Keyword(s):  
Litter Size ◽  
Genetic Parameters ◽  
Diallel Cross ◽  
Iberian Pig

scholarly journals A cross-specific multiplicative binomial recursive model for the analysis of perinatal mortality in a diallel cross among three varieties of Iberian pig

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Luis Varona ◽  
José Luis Noguera ◽  
Joaquim Casellas ◽  
Melani Martín de Hijas ◽  
Juan Pablo Rosas ◽  
...  
Keyword(s):  
Perinatal Mortality ◽  
Litter Size ◽  
Binomial Distribution ◽  
Genetic Relationships ◽  
Diallel Cross ◽  
Binomial Model ◽  
Average Litter Size ◽  
Or Groups ◽  
Iberian Pig ◽  
Piglet Mortality

AbstractPerinatal piglet mortality is an important factor in pig production from economic and animal welfare perspectives; however, the statistical analysis of mortality is difficult because of its categorical nature. Recent studies have suggested that a binomial model for the survival of each specific piglet with a logit approach is appropriate and that recursive relationships between traits are useful for taking into account non-genetic relationships with other traits. In this study, the recursive binomial model is expanded in two directions: (1) the recursive phenotypic dependence among traits is allowed to vary among groups of individuals or crosses, and (2) the binomial distribution is replaced by the multiplicative binomial distribution to account for over or underdispersion. In this study, five recursive multiplicative binomial models were used to obtain estimates of the Dickerson crossbreeding parameters in a diallel cross among three varieties of Iberian pigs [Entrepelado (EE), Torbiscal (TT), and Retinto (RR)]. Records (10,255) from 2110 sows were distributed as follows: EE (433 records, 100 sows), ER (2336, 527), ET (942, 177), RE (806, 196), RR (870, 175), RT (2450, 488), TE (193, 36), TR (1993, 359), and TT (232, 68). Average litter size [Total Number Born (TNB)] and number of stillborns (SB) were 8.46 ± 2.27 and 0.25 ± 0.72, respectively. The overdispersion was evident with all models. The model with the best fit included a linear recursive relationship between TNB and the logit of $$\phi$$ ϕ of the multiplicative binomial distribution, and it implies that piglet mortality increases with litter size. Estimates of direct effects showed small differences among populations. The analysis of maternal effects indicated that the dams whose mothers were EE had a larger SB, while dams with RR mothers reduced the probability of born dead. The posterior estimates of heterosis suggested a reduction in SB when the sow is crosbred. The multiplicative binomial distribution provides a useful alternative to the binomial distribution when there is overdispersion in the data. Recursive models can be used for modeling non-genetic relationships between traits, even if the phenotypic dependency between traits varies among environments or groups of individuals. Piglet perinatal mortality increased with TNB and is reduced by maternal heterosis.

scholarly journals Estimation of variance components, genetic parameters and genetic trends for litter size of swines

2010 ◽  
Vol 39 (10) ◽  
pp. 2155-2159 ◽  
Author(s):  
Leandro Barbosa ◽  
Paulo Sávio Lopes ◽  
Adair José Regazzi ◽  
Robledo de Almeida Torres ◽  
Mário Luiz Santana Júnior ◽  
...  
Keyword(s):  
Litter Size ◽  
Variance Components ◽  
Genetic Parameters ◽  
Random Effect ◽  
Additive Model ◽  
Fixed Effect ◽  
Likelihood Method ◽  
Phenotypic Variance ◽  
Estimation Of Variance ◽  
Genetic Trends

Records of Large White breed animals were used to estimate variance components, genetic parameters and trends for the character total number of born piglets (TNBP) as measure of litter size. For obtaining variance components and genetic parameters, it was used the Restricted Maximum Likelihood Method using MTDFREML software. Two mixed models (additive and repeatability) were evaluated. The additive model contained fixed effect of the contemporary group and the following random effects: direct additive genetic and residual effect for the first parturition. Repeatability model had the same effects of the additive model plus parturition order fixed effect and non-correlated animal permanent environment random effect for the second, third and forth parturition. Direct additive heritability estimates for TNBP were 0.15 and 0.20 for the additive and repeatability models, respectively. The estimate of the ration among variance of the non-correlated effect of animal permanent environment effect and the phenotypic variance, expressed as total variance proportion (c2) was 0.09. The estimates of yearly genetic trends obtained in the additive and repeatability models have similar behaviors (0.02 piglets/sow/year).

scholarly journals Genetic parameters and combining ability of some important traits in rice (Oryza sativa L.)

Genetika ◽  
2017 ◽  
Vol 49 (3) ◽  
pp. 1001-1014 ◽  
Author(s):  
Hasanalideh Haghighi ◽  
Ezatollah Farshadfar ◽  
Mehrzad Allahgholipour
Keyword(s):  
Combining Ability ◽  
Genetic Parameters ◽  
Amylose Content ◽  
Oryza Sativa L ◽  
Block Design ◽  
Regression Line ◽  
Diallel Cross ◽  
Combining Ability Analysis ◽  
Additive Gene ◽  
F2 Generation

In order to study the combining ability, genetic parameters and gene actions of yield, yield components and quality characters in rice, fifteen F2 generation of a 6?6 diallel cross, excluding reciprocals, was grown in a randomized complete block design (RCBD) with three replications. The results of analysis of variance showed significant differences between the genotypes for grain yield (GY), 100-grain weight (HGW), number of panicles per plant (PN), panicle length (PL), number of full grains per panicle (FGN) and for quality characters including amylose content (AC) and gel consistency (GC). The results of combining ability analysis revealed that general combining ability (GCA) and specific combining ability (SCA) were significant for characters GY, FGN, GC, AC, HGW and PN indicating the involvement of additive and non-additive effects in their inheritance, however high amounts of Bakers ratio remarked that additive gene effect had more portion in controlling these traits. The best combiners for GY, HGW, FGN, PN and PL, were RI18447-2, IR 50, Daylamani, RI18430-46 and Daylamani respectively. For AC and GC, the best combiner was Daylamani. Hayman's graphs showed that regression line passed below the origin cutting Wr axis in the negative region for HGW, PN, PL and GC, indicating the presence of over dominance. Estimates of genetic parameters showed significant amount of H1 and H2, and non-significant amount of D for the characters GY, PN, PL and GC, which confirmed the existence of dominance in the inheritance of these traits.

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

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.

Genetic analyses of piglet survival and individual birth weight on first generation data of a selection experiment for piglet survival under outdoor conditions

2007 ◽  
Vol 2007 ◽  
pp. 65-65
Author(s):  
R. Roehe ◽  
N. P. Shrestha ◽  
W. Mekkawy ◽  
P. W. Knap ◽  
K. M. Smurthwaite ◽  
...  
Keyword(s):  
Birth Weight ◽  
Litter Size ◽  
Genetic Improvement ◽  
First Generation ◽  
Genetic Parameters ◽  
Selection Experiment ◽  
Postnatal Mortality ◽  
Breeding Programmes ◽  
Potential Benefits ◽  
Piglet Survival

Peri- and postnatal mortality of piglets is reported to be around 20% and genetic improvement in piglet survival has great potential benefits in terms of animal welfare, economics and the environment. The indication of an unfavourable genetic correlation between litter size and survival in particular points to the importance of including piglet survival in those pig breeding programmes that currently only aim to increase litter size. Phenotypically, individual birth weight is closely associated with piglet survival (Roehe and Kalm, 2000). Genetic parameters for piglet survival traits and individual birth weight therefore need to be estimated in order to genetically improve piglet survival efficiency

scholarly journals Inbreeding depression load for litter size in Entrepelado and Retinto Iberian pig varieties1

2019 ◽  
Vol 97 (5) ◽  
pp. 1979-1986 ◽  
Author(s):  
Joaquim Casellas ◽  
Noelia Ibáñez-Escriche ◽  
Luis Varona ◽  
Juan P Rosas ◽  
Jose L Noguera
Keyword(s):  
Litter Size ◽  
Inbreeding Depression ◽  
Iberian Pig

Factors affecting reproductive performance and estimates of genetic parameters of litter size in Horro sheep

2002 ◽  
Vol 139 (1) ◽  
pp. 79-85 ◽  
Author(s):  
S. ABEGAZ ◽  
G. DUGUMA ◽  
E. NEGUSSIE ◽  
U. GELMESA ◽  
F. TEREFE ◽  
...  
Keyword(s):  
Animal Model ◽  
Litter Size ◽  
Age Structure ◽  
Reproductive Performance ◽  
Genetic Improvement ◽  
Genetic Parameters ◽  
Factors Affecting ◽  
Optimal Weight ◽  
Annual Means ◽  
Lambing Rate

Conception and lambing rate, and litter size were studied on data from a flock of Horro sheep. The CATMOD and GLM procedures of SAS were used for the analysis of these traits. A sire, direct additive genetic and a repeatability animal model were employed to obtain estimates of heritability and repeatability for litter size. The results obtained showed that year of mating, age and weight of ewes at mating and number of previous parities had significantly (P<0.01) affected the rate of conception and lambing while weight of rams at mating has shown no significant effect (P>0.05). An increase in both conception and lambing rates was observed with the increase in weight of ewes up to about 36 kg and declined thereafter. Ewes which previously had no or one parity had lower conception and lambing rates compared with ewes in later parities. However, a decline in both conception and lambing rates was also observed in old ewes. Year of lambing, parity and weight of ewes at mating had a highly significant (P<0.01) effect on litter size. The overall mean litter size in the flock was 1.34 with annual means ranging from 1.18 to 1.55. Litter size increased with parity from 1.26 in primiparous ewes to 1.44 for ewes of parities five and above. With respect to weight of ewes at mating, litter size increased by 2.5% for each kg increase in weight at mating. The estimates of direct heritability (h2) for litter size were 0.17, 0.11 and 0.06 under the sire, direct animal and repeatability models. Repeatability was estimated to be 0.12. Since heritability and repeatability estimates of litter size are low, genetic improvement by selection may not bring sizeable impact in increasing litter size. Therefore flock management for optimal age structure and optimal weight of ewes at mating should receive due consideration to improve rates of conception, lambing and litter size in Horro sheep.

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