scholarly journals RESPONSE TO DIVERGENT SELECTION FOR NESTING BEHAVIOR IN MUS MUSCULUS

Genetics ◽  
1980 ◽  
Vol 96 (3) ◽  
pp. 757-765 ◽  
Author(s):  
Carol Becker Lynch
Keyword(s):  
Litter Size ◽  
Mus Musculus ◽  
Correlated Response ◽  
Family Selection ◽  
Average Litter Size ◽  
Entire Experiment ◽  
Building Behavior ◽  
Bidirectional Selection ◽  
Fertility Traits ◽  
Average Body

ABSTRACT Replicated bidirectional selection (with control lines) for nest-building behavior in Mus musculus, where nesting scores consisted of the total weight of cotton pulled through the cage lid during four days of testing, yielded an eight-fold difference between high and low lines after 15 generations of selection. The overall realized heritability pooled across lines and replicates was 0.18 ± 0.02 (0.15 ± 0.03 for high nesting scores and 0.23 ± 0.04 for low nesting scores), or 0.28 ± 0.05 when adjusted for within-family selection. Across the 15 generations and the entire experiment, average body weight and number of infertile matings increased, while average litter size decreased, although these changes were not consistent across lines. Inbreeding could account for average decreases in the fertility traits, but there was also a correlated response to selection, since both high lines showed increased litter size and decreased infertile matings.

scholarly journals Effect of inbreeding on fertility traits in five dog breeds

2019 ◽  
Vol 64 (No. 3) ◽  
pp. 118-129 ◽  
Author(s):  
Joanna Kania-Gierdziewicz ◽  
Sylwia Pałka
Keyword(s):  
Sex Ratio ◽  
Litter Size ◽  
Fixed Effects ◽  
Female Offspring ◽  
German Shepherd ◽  
Male And Female ◽  
Litter Traits ◽  
Average Litter Size ◽  
Inbreeding Level ◽  
Fertility Traits

The aim of the study was to analyze retrospectively the influence of inbreeding on fertility traits in five dog breeds: German Shepherd dog (GSD), Golden (GR) and Labrador (LR) Retrievers, Beagle and the Tatra Shepherd dog (TSD). The data were 436 litters, with the total of 2560 puppies: 1307 males and 1206 females. The parents of the litters were 163 dogs and 228 bitches. For each litter the litter size, number of male and female puppies, sex ratio, and sex difference were calculated. The fixed effects of breed, of litter birth year and linear regression coefficients on litter and parents’ inbreeding were included in the linear model for litter traits. The correlations between litter traits and litter parents’ inbreeding were also estimated. The average litter size was 5.87 (± 2.53) for all breeds. GSD had the smallest average litter size differences in years and the lowest fluctuations of sex ratio with litter size. In other dog breeds those differences were much bigger. The difference between the number of male and female offspring in a litter depended on the breed. The lowest percentage of inbred parents was found for LR, and the highest for TSD. Mating non-inbred animals, in most cases also unrelated, was frequent in all breeds. The inbreeding level of parents had significant influence on the litter traits only for TSD. For the Beagles low, positive and significant correlation between the number of female offspring in a litter and the dam’s inbreeding level and the sex ratio below 0.5 suggests sex ratio disturbance. The correlation coefficients between litter inbreeding and litter size for majority of examined dog breeds were positive but not significant. The conclusion is that in Poland at first obligatory monitoring of the inbreeding level for all breeds should be applied.

Correlated response to selection for litter size in pigs: II. Carcass, meat, and fat quality traits

2002 ◽  
Vol 80 (10) ◽  
pp. 2566 ◽  
Author(s):  
J. Estany ◽  
D. Villalba ◽  
M. Tor ◽  
D. Cubiló ◽  
J. L. Noguera
Keyword(s):  
Litter Size ◽  
Correlated Response ◽  
Quality Traits ◽  
Response To Selection ◽  
Fat Quality ◽  
Selection For

REPRODUCTIVE POTENTIAL AND SEX RATIOS OF SNOWSHOE HARES IN NORTHERN ALBERTA

1956 ◽  
Vol 34 (4) ◽  
pp. 273-281 ◽  
Author(s):  
Wm. Rowan ◽  
L. B. Keith
Keyword(s):  
Litter Size ◽  
Sex Ratios ◽  
Reproductive Potential ◽  
Post Mortem ◽  
Comparable Data ◽  
Snowshoe Hares ◽  
Average Litter Size ◽  
Northern Regions ◽  
Two Factors ◽  
Northern Alberta

In conjunction with studies of the "10-year cycle" of snowshoe hares, almost 900 hares were collected in the Anzac district of Alberta during the period May, 1949, to April, 1956. Embryo numbers and sex ratios were among the data gathered from post-mortem examinations of these hares. It was found that the average litter size was 3.82; the modal litter size was four and the range was from one to seven. The average number of litters each season was calculated at 2.75. The annual reproductive potential is thus 10.51 (3.82 × 2.75) young per female hare. This is more than 50% greater than that indicated by comparable data from Minnesota. It is suggested that herein lies the cause of higher peak populations in northern regions. Sex ratios shifted from a marked excess of females in the year 1949–1950 to about even numbers of both sexes during the two subsequent years. Since the change in sex ratio occurred at the peak of the cycle, the two factors are believed to be in some manner correlated.

Development of a Strain of Rabbits with Congenital Simple Nonsyndromic Coronal Suture Synostosis Part I: Breeding Demographics, Inheritance Pattern, and Craniofacial Anomalies

1994 ◽  
Vol 31 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Mark P. Mooney ◽  
H. Losken Wolfgang ◽  
Michael I. Siegel ◽  
Janice F. Lalikos ◽  
Albert Losken ◽  
...  
Keyword(s):  
Litter Size ◽  
Rabbit Model ◽  
Pedigree Analysis ◽  
Human Populations ◽  
Incomplete Penetrance ◽  
Coronal Suture ◽  
Inheritance Pattern ◽  
Average Litter Size ◽  
Midfacial Hypoplasia ◽  
Congenital Condition

The lack of an animal model of congenital coronal suture (CS) synostosis has prompted the widespread use of an experimental rabbit model using adhesive Immobilization of the CS. Such postnatal models have helped make significant scientific contributions but may still not fully represent all aspects of the human congenital condition. In the March 1993 issue of The Cleft Palate-Craniofacial Journal we reported a female rabbit born in our laboratory with complete bilateral CS synostosis. This follow-up study presents our attempts to breed this animal and establish a strain of cranlosynostotic rabbits. To date, we have accomplished 10 back- and intercrosses with these animals and have produced a total of 71 live offspring; 10 animals exhibited complete nonsyndromic unilateral (plagiocephalic) or bilateral (brachycephalic) CS synostotic deformities at birth, and 19 animals exhibited partial CS synostosis that showed more than 75% growth retardation across the CS (well below the 95% confidence interval for normals). Results revealed that gestational time and litter size averages were consistent with those reported for the strain, although the average litter size decreased with increased inbreeding. By 1.5 weeks of age the completely synostosed animals already exhibited brachycephalic cranial vaults and midfacial hypoplasia compared to unaffected siblings. Initial pedigree analysis suggested an autosomal dominant inheritance pattern with incomplete penetrance and variable expressivity. The development of such a congenital rabbit model may prove useful In helping to understand the etiopathogenesis of this condition In human populations.

scholarly journals Litter Survival Differences between Divergently Selected Lines for Environmental Sensitivity in Rabbits

2019 ◽  
Author(s):  
Ivan Agea ◽  
María-Luz García ◽  
Agustín Blasco ◽  
María-José Argente
Keyword(s):  
Litter Size ◽  
Mean Value ◽  
Correlated Response ◽  
Environmental Sensitivity ◽  
Probability Of Survival ◽  
High Line ◽  
Size Variability ◽  
Similar Survival ◽  
The Individual ◽  
Survival Differences

A divergent selection experiment on environmental sensitivity was performed in rabbits. The aim of this study was to estimate the correlated response in kits’ weight and its survival, and weight distance from birth to weaning. Weight distance was calculated as the absolute values of the differences between the individual value and the mean value of its litter. Also, relationship between probability of survival at 4 d of age and weight at birth was studied. Environmental sensitivity was measured as litter size variability. A total of 2484 kits from 127 does of the low line (selected for reducing litter size variability) and 1916 kits of 114 does of the high line (selected for increasing litter size variability) of the 12th generation were weighed. Bayesian methodology was used to estimate the correlated response to selection, and LOGISTIC procedure of SAS was used to estimate the relationship between weight and probability of survival. Both lines showed similar individual weight at birth and at weaning, and similar survival at birth and at 4 d of age. Survival at weaning was higher in the low line than in the high line (0.67 and 0.62; P= 0.93). Weight distance was higher at birth but lower at weaning in the low line (47.8 g and 54.1 g; P=0.98). Kit’s weight at birth affected its survival. In conclusion, selection for environmental sensitivity showed correlated response in kits survival and in homogeneity of litter weight at weaning.

scholarly journals Selection for growth on normal and reduced protein diets in mice: I. Direct and correlated responses for growth

1987 ◽  
Vol 50 (1) ◽  
pp. 7-15 ◽  
Author(s):  
B. Vivi Hunnicke Nielsen ◽  
Søren Andersen
Keyword(s):  
Protein Level ◽  
Protein Diet ◽  
Correlated Response ◽  
Family Selection ◽  
Direct Response ◽  
Protein Levels ◽  
Selection Environment ◽  
Normal Protein Diet ◽  
Selection For ◽  
Protein Diets

SummaryMice were selected for growth from 3 to 9 weeks of age on a normal protein diet (N) containing 19·3% protein and a reduced protein diet (R) containing 5·1% protein. On each diet there were 3 high (H), 3 low (L) and 3 unselected control (C) lines. After 6 generations of selection, half of the mice in each line were tested on each diet. Responses were obtained when selecting for both increased and decreased growth on both diets. The realized heritabilities from within-family selection were 33 and 26% for the divergences on the normal and reduced protein diets, respectively. Consistent genotype-environment interactions were found when all lines were tested on both diets in generation 7. Performance on each protein level was best improved by selection on that protein level. Further, the correlated response was significantly less than the direct response when selecting on both diets. The estimates of the genetic correlation between growth on the two protein levels were low, rN = 0·16 from selection on the normal protein diet and rR = 0·51 from selection on the reduced protein diet. Selection resulted in a change in environmental sensitivity in the lines, dependent on the diet and direction of selection. The average of the divergences on the two diets was not dependent on the selection environment.

A note on ovulation rate and embryonic survival in D'man ewes

1981 ◽  
Vol 32 (2) ◽  
pp. 227-229 ◽  
Author(s):  
A. Lahlou-Kassi ◽  
M. Marie
Keyword(s):  
Litter Size ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Embryonic Survival ◽  
Average Litter Size ◽  
Simultaneous Activity

ABSTRACTThe elements of prolificacy have been analysed for the D'man sheep, a prolific Moroccan breed, by laparotomy on 38 animals. The average ovulation rate was 2·50 (s.e.0·45); a slight difference was observed between nulliparous and multiparous ewes due to high simultaneous activity by both ovaries in the latter group. Embryonic survival (42% overall) was 94% (87 to 100%) for multiparous and 44% (36 to 52%) for the nulliparous ewes at one ovulation, decreasing with increasing numbers of corpora lutea. The average litter size showed an optimum at four ovulations.

scholarly journals Fine mapping genetic variants associated with age at puberty and sow fertility using SowPro90 genotyping array

2020 ◽  
Vol 98 (10) ◽  
Author(s):  
Hiruni R Wijesena ◽  
Stephen D Kachman ◽  
Clay A Lents ◽  
Jean-Jack Riethoven ◽  
Melanie D Trenhaile-Grannemann ◽  
...  
Keyword(s):  
Litter Size ◽  
Genetic Variants ◽  
Research University ◽  
Genome Wide Association Study ◽  
Candidate Snps ◽  
Nucleotide Polymorphisms ◽  
Positional Candidate ◽  
Age At Puberty ◽  
Estimated Breeding Values ◽  
Fertility Traits

Abstract Sow fertility traits, such as litter size and the number of lifetime parities produced (reproductive longevity), are economically important. Selection for these traits is difficult because they are lowly heritable and expressed late in life. Age at puberty (AP) is an early indicator of reproductive longevity. Here, we utilized a custom Affymetrix single-nucleotide polymorphisms (SNPs) array (SowPro90) enriched with positional candidate genetic variants for AP and a haplotype-based genome-wide association study to fine map the genetic sources associated with AP and other fertility traits in research (University of Nebraska-Lincoln [UNL]) and commercial sow populations. Five major quantitative trait loci (QTL) located on four Sus scrofa chromosomes (SSC2, SSC7, SSC14, and SSC18) were discovered for AP in the UNL population. Negative correlations (r = −0.96 to −0.10; P < 0.0001) were observed at each QTL between genomic estimated breeding values for AP and reproductive longevity measured as lifetime number of parities (LTNP). Some of the SNPs discovered in the major QTL regions for AP were located in candidate genes with fertility-associated gene ontologies (e.g., P2RX3, NR2F2, OAS1, and PTPN11). These SNPs showed significant (P < 0.05) or suggestive (P < 0.15) associations with AP, reproductive longevity, and litter size traits in the UNL population and litter size traits in the commercial sows. For example, in the UNL population, when the number of favorable alleles of an SNP located in the 3′ untranslated region of PTPN11 (SSC14) increased, AP decreased (P < 0.0001), while LTNP increased (P < 0.10). Additionally, a suggestive difference in the observed NR2F2 isoforms usage was hypothesized to be the source of the QTL for puberty onset mapped on SSC7. It will be beneficial to further characterize these candidate SNPs and genes to understand their impact on protein sequence and function, gene expression, splicing process, and how these changes affect the phenotypic variation of fertility traits.

scholarly journals Production systems of swine in the rural areas of Rangamati and Khagrachari districts of Bangladesh

2012 ◽  
Vol 40 (1-2) ◽  
pp. 28-33
Author(s):  
ME Hossain ◽  
S Chakma ◽  
MM Khatun ◽  
M Hasanuzzaman ◽  
MY Miah ◽  
...  
Keyword(s):  
Birth Weight ◽  
Litter Size ◽  
Rural Areas ◽  
Economic Condition ◽  
Production Systems ◽  
Economic Benefits ◽  
Disease Prevalence ◽  
Pig Production ◽  
Average Litter Size ◽  
The Mean

The study was undertaken for a period of 60 days to investigate the production systems of swine in Rangamati and Khagrachari districts, Bangladesh. Production systems, particularly housing, feeding, breeding, disease prevalence, vaccination, bio-security, marketing, socio-economic condition and constraints of pig production were investigated during the study period. It was found that the propensity of rearing pig differed significantly (P<0.01) among the pig owners. Pigs were reared mostly by poor and landless peoples (54.7%) followed by marginal (32.1%), medium (9.4%) and large (3.8%). Rearing systems were also different (P<0.01) and the mean figures were 43.4% for free range, 24.5% for tin shed housing , 20.8% for fencing and 11.3% for girth tethering systems. The average litter size, birth weight, post-weaning weight and weaning period were 9.3, 1.72 kg, 9.0 kg and 40.8 days respectively. Prevalence of diseases differed (P<0.01) and most prevalent diseases were diarrhea (35.8%), coccidiosis (20.8%), pneumonia (17.0%) and hemorrhagic septicemia (13.2%). The economic benefits generated from farming were selling of piglets.DOI: http://dx.doi.org/10.3329/bjas.v40i1-2.10787Bang. J. Anim. Sci. 2011. 40 (1-2): 28-33

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