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

scholarly journals Heterosis in the second and third generation affects litter size in a crossbreed mink (Neovison vison) population

2014 ◽  
Vol 66 (3) ◽  
pp. 1097-1103 ◽  
Author(s):  
Janne Thirstrup ◽  
Cino Pertoldi ◽  
Peter Larsen ◽  
Vivi Nielsen
Keyword(s):  
Litter Size ◽  
Maternal Effects ◽  
Inbreeding Depression ◽  
Neovison Vison ◽  
Parental Line ◽  
Third Generation ◽  
Black Line ◽  
Environmental Variations ◽  
The Mean ◽  
One Year

Litter sizes in a cross between Brown and Black mink color types were observed through six generations. Litter size was significantly affected by yearly environmental variations. After adjusting for year effects, we found significant increases in litter size in the second and third generations (F2 and F3) after crossing. Thereafter, in the following generations, litter size dropped to a level comparable to the mean litter size of the midparent. Increased litter size in F2 compared to F1 indicated that maternal effects influenced litter size more than non-maternal effects. The heterosis was mainly caused by an increase in litter size compared to the Black parental line. This indicates that the Black line was affected by inbreeding depression prior to crossing. We also found that two-year old F1 females had significantly more offspring compared to one-year old F1 females.

Effect of founder allele survival and inbreeding depression on litter size in a closed line of Large White pigs

1998 ◽  
Vol 67 (3) ◽  
pp. 573-582 ◽  
Author(s):  
J. Rodrigáñez ◽  
M. A. Toro ◽  
M. C. Rodriguez ◽  
L. Silió
Keyword(s):  
Litter Size ◽  
Inbreeding Depression ◽  
Large White ◽  
Closed Population ◽  
Bayesian Techniques ◽  
Closed Line ◽  
Founder Allele

AbstractAn experimental herd of Large White pigs was established in 1931 and maintained as a closed population until 1992. The complete -pedigree (410 boars and 916 sows) has been analysed to measure along the succesive cohorts of breeding animals: thefounder representation and allele survival, the evolution ofcoancestry and inbreeding and the components of inbreeding due to each founder. Inferences about genetic and phenotypic parameters and effects of dam and litter inbreeding on litter size were obtained, using Bayesian techniques, from 2612 litter records. A significant mean reduction of 0·27 piglets born and 0·39 live born for each 10% of litter inbreeding was found but also evidence of variation among founder lineages in inbreeding depression. Alleles contributing to inbreeding depression were descendent from specific founder lineages.

scholarly journals Somatic development and embryo yield in crossbred F1 mice generated by different mating strategies

2010 ◽  
Vol 70 (1) ◽  
pp. 145-149 ◽  
Author(s):  
RITP. Batista ◽  
S. Wohlres-Viana ◽  
ISB. Pinto ◽  
VV. Maffili ◽  
JHM. Viana
Keyword(s):  
Litter Size ◽  
Inbreeding Depression ◽  
Hormone Treatment ◽  
Response Variability ◽  
Mating Strategies ◽  
Corpora Lutea ◽  
Parental Effect ◽  
Crown Rump Length ◽  
Somatic Development ◽  
Embryo Yield

The aim of this study was to evaluate different mating strategies among endogamic strains to create F1 populations of mice, minimising the effect of inbreeding depression on somatic development and embryo yield. Females from the strains Swiss, CBA and C57Bl/6 were divided in nine experimental mate arrangements. The total numbers of pups born alive per dam and somatic development, estimated by weighing and measuring the crown-rump length, were recorded. Superovulation response was evaluated in outbreed females. Litter size differed among endogamic dams, irrespective of the sire. Somatic development results suggest heterosis and imprinting phenomena, once a differential parental effect was demonstrated. There was no difference in corpora lutea, ova or embryos recovered (P > 0.05), but recovery and viability rates differ among F1 groups (P < 0.05). The association of dam prolificity with somatic development and superovulation response of the pups should be considered for experimental F1 populations establishment. The use of outbreed animals, however, did not reduce response variability to hormone treatment.

scholarly journals The effects of inbreeding on the components of litter size in mice

1967 ◽  
Vol 10 (1) ◽  
pp. 73-80 ◽  
Author(s):  
J. C. McCarthy
Keyword(s):  
Litter Size ◽  
Inbreeding Depression ◽  
First Generation ◽  
Inbreeding Coefficient ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Base Population ◽  
Pregnant Females ◽  
Sib Mating ◽  
Size At Birth

Twenty-four lines were bred from a base population of outbred Q mice by continued full-sib mating. Inbreeding depression in litter size at birth was observed. This decline in litter size was analysed in terms of ovulation rate, the incidence of preimplantation mortality and the incidence of postimplantation mortality. Pregnant females were dissected at 17½ days' gestation and the numbers of corpora lutea, or eggs, and of live and dead embryos were counted. Matings were arranged so that separate estimates of the effects of inbreeding in the mother and in the litter on the components of litter size could be obtained.In the first generation of inbreeding when the inbreeding coefficient of the litter was raised from 0 to 25% decline in litter size was attributable to an increased incidence of preimplantation mortality.In the second and fourth generations decline in litter size was attributable to (1) a reduction in the number of eggs ovulated by the inbred mothers, (2) an increased incidence of preimplantation mortality which resulted from inbreeding in the mother. No evidence of significant effects on mortality of inbreeding in the litter was obtained in the later generation of inbreeding.These findings are discussed in the context of previous work on the effects of inbreeding and crossing on litter size and its components in mice and pigs.

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.

Inbreeding effects on some reproductive traits in Markhoz goats

2018 ◽  
Vol 58 (12) ◽  
pp. 2178 ◽  
Author(s):  
P. Mahmoudi ◽  
A. Rashidi ◽  
M. Razmkabir
Keyword(s):  
Litter Size ◽  
Inbreeding Depression ◽  
Reproductive Traits ◽  
Information Criterion ◽  
Inbreeding Coefficient ◽  
Regression Coefficients ◽  
Litter Weight ◽  
Inbreeding Coefficients ◽  
Poisson Models ◽  
The Individual

The objective of this study was to estimate the inbreeding coefficient and its effects on reproductive traits in Markhoz goats. The pedigree file included 5351 kids produced by 234 bucks and 1470 does. Average inbreeding coefficient for the whole population was 2.68%, and the minimum and maximum inbreeding coefficients were 0.05% and 31.25%, respectively. Average coefficient of inbreeding for inbred population was 5.17% and the number of inbred animals in the population was 2777. For investigating effects of inbreeding coefficient on reproductive traits, 3443 records were available for litter size at birth (LSB), litter size at weaning (LSW), total litter weight at birth (TLWB) and mean of litter weight at birth (MLWB). Furthermore, available records for total litter weight at weaning (TLWW) and mean of litter weight at weaning (MLWW) were 2918. Inbreeding depression was estimated as the linear regression of performance on the individual inbreeding coefficient of kids and dams using the most appropriate animal model based on Akaike’s information criterion. Furthermore, inbreeding depressions for LSB and LSW were estimated using threshold and Poisson models. Regression coefficients of LSB, LSW, TLWB, TLWW, MLWB and MLWW on inbreeding coefficient of kids were –0.035, –0.019, –0.077 kg, –0.782 kg, –0.009 kg and –0.332 kg, respectively. Furthermore, regression coefficients of LSB, LSW, TLWB, TLWW, MLWB and MLWW on inbreeding coefficient of dams were 0.064, –0.013, 0.241 kg, 0.638 kg, 0.028 kg and –1.783 kg, respectively. The obtained results from this study showed that inbreeding depression is controlled by an appropriate mating system policy.

scholarly journals Analysis of inbreeding depression in the first litter size of mice in a long-term selection experiment with respect to the age of the inbreeding

Heredity ◽  
2007 ◽  
Vol 99 (1) ◽  
pp. 81-88 ◽  
Author(s):  
D Hinrichs ◽  
T H E Meuwissen ◽  
J Ødegard ◽  
M Holt ◽  
O Vangen ◽  
...  
Keyword(s):  
Litter Size ◽  
Inbreeding Depression ◽  
Selection Experiment ◽  
Term Selection

scholarly journals Genetic aspects of fertility and endocrine organ size in rats

1970 ◽  
Vol 16 (3) ◽  
pp. 251-259 ◽  
Author(s):  
R. J. Mullen ◽  
F. K. Hoornbeek
Keyword(s):  
Litter Size ◽  
Inbreeding Depression ◽  
Strain Differences ◽  
Seminal Vesicles ◽  
Ovulation Rate ◽  
Low Fertility ◽  
Ventral Prostate ◽  
High Fertility ◽  
Endocrine Organ ◽  
Successive Generations

SUMMARYAn investigation of the genetic aspects of fertility was conducted among inbred and hybrid generations of rats. The high-fertility LEW strain and the low fertility CAS strain were crossed and their hybrids inbred for four generations. Litter size, ovulation rate, sterility, and the weights of the thyroid, pituitary, adrenals, testes, seminal vesicles, ventral prostate, uterus, and ovaries were analysed in inbred and hybrid rats for evidence of strain differences and heterosis and in successive generations of sib matings for inbreeding depression.CAS females produced smaller litters and had smaller thyroids, pituitaries, adrenals, ovaries, and uteri than LEW females. CAS males had larger testes but smaller adrenals than LEW males. Results of crosses included heterosis for female pituitary and ovary weights, but inbreeding depression for the weights of male adrenals, seminal vesicles, and ventral prostates, and female thyroids and uteri. Ovulation rate did not differ between strains and was not an important determinant of litter size in this study.The decrease in litter size as a result of inbreeding was due partly to the inbreeding of the parents and partly to the inbreeding of the litter.

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