scholarly journals Genetic response to short-term index selection in females and mass selection in males of the Nigerian heavy local chicken ecotype

2020 ◽  
Vol 44 (2) ◽  
pp. 1-17
Author(s):  
C. C. Ogbu ◽  
C. C. Nwosu
Keyword(s):  
Body Weight ◽  
Genetic Gain ◽  
Egg Production ◽  
Index Selection ◽  
Mass Selection ◽  
Indigenous Chicken ◽  
Multiple Trait ◽  
Breeding Values ◽  
Expected Gain ◽  
Selection For

The study aimed to determine genetic gain in growth and egg production in the Nigerian indigenous chicken (NIC) subjected to multiple trait index selection for females and mass selection for males. The experimental birds (G generation) were generated from a reference 0 population of NIC and reared according to sire families from hatch. At point of lay, females were housed individually in laying cages for egg production. Hens were selected based on index scores calculated using an index of weighted breeding values constructed from own performance in body weight at first egg (BWFE), egg weight (EW) and egg production (EN), trait heritabilities and relative economic weights while cocks were selected based on own performance in body weight at 39 weeks of age (BW ). Selected parents were mated to 39 generate the G generation which in turn yielded the parents of the G generation. A control 1 2 population was used to measure environmental effects. Data were analyzed using the Restricted Maximum Likelihood (REML) computer programme. For hens, expected average direct genetic gain per generation was 12.58, 2.98g and 25.04g for EN, EW and BWFE, respectively while realized genetic gain was 2.19 and 1.59 for EN, 1.65 and 0.26g for EW, and -25.60 and 123.64g for BWFE for G and G generations, respectively. The corresponding 0 1 values for ratio of realized to expected genetic gains were 2.27 and 1.22, 3.15 and 0.24, and 0.95 and 2.21, respectively. Heritability (h2) ranged from 0.12 to 0.24 for EN, 0.34 to 0.43 for EW and 0.57 to 0.69 for BWFE, across the three generations. Similar improvements in BW 39 were observed in males with an average expected gain of 508.50g per generation. In conclusion, growth and egg production in the NIC can be improved using mass selection for cocks and index of weighted breeding values for hens.

RESPONSE TO SELECTION FOR BODY WEIGHT OR FEED EFFICIENCY IN MICE TESTED ON CORN, RYE AND WHEAT DIETS

1986 ◽  
Vol 66 (2) ◽  
pp. 389-397
Author(s):  
R. I. McKAY ◽  
R. J. PARKER ◽  
W. GUENTER
Keyword(s):  
Body Weight ◽  
Feed Efficiency ◽  
Mass Selection ◽  
Response To Selection ◽  
Initial Weight ◽  
Commercial Diet ◽  
Final Weight ◽  
Dc Line ◽  
Selection For ◽  
Seven Generations

Mass selection for adjusted feed efficiency (AFE, g gain/g feed) and adjusted body weight (ABW, g) of male mice was practiced for seven generations on each of three diets: corn, rye and wheat. The three experimental diets, fed between 21 and 35 d, were isocaloric (approximately 16.5 MJ GE kg−1) and isonitrogenous (CP approximately 13%). A common commerical diet (PC) was fed at all other times. With each diet two control lines, randomly mated, were tested on either the experimental diets (DC) or a commercial diet (PC). Selection was based upon linear adjustment to a common initial weight (10 g) for either final weight (ABW) or feed efficiency (AFE) measured between 21 and 35 d of age. Response was determined as a deviation from the appropriate DC line. All animals were placed in specially designed individual cages during the test period. Half-sib estimates of heritability in the PC line were 0.13(± 0.11) for ABW and 0.19(± 0.10) for AFE. Half-sib estimates pooled across lines and diets were 0.16(± 0.07) for ABW and 0.28(± 0.07) for AFE. Realized heritabilities for ABW were 0.24(± 0.06), 0.06(± 0.07) and 0.14(± 0.06) for the corn, rye and wheat diets, respectively. Response to selection for AFE was poor with the highest heritability obtained on the wheat diet (h2 = 0.13 ± 0.02). Key words: Selection, mice, body weight, feed efficiency, diets

Mass selection for 70-day body weight in rabbits.

1996 ◽  
Vol 74 (7) ◽  
pp. 1481 ◽  
Author(s):  
S D Lukefahr ◽  
H B Odi ◽  
J K Atakora
Keyword(s):  
Body Weight ◽  
Mass Selection ◽  
Selection For

scholarly journals Breeding for the improvement of indigenous chickens in Bangladesh: performance of second generation

2017 ◽  
Vol 3 (1) ◽  
pp. 66-71
Author(s):  
Shakila Faruque ◽  
AKFH Bhuiyan ◽  
Md Yousuf Ali ◽  
MSK Sarker ◽  
Ziaul Faruque Joy
Keyword(s):  
Body Weight ◽  
Egg Production ◽  
Second Generation ◽  
Breeding Value ◽  
Genotype 3 ◽  
Indigenous Chicken ◽  
Egg Weight ◽  
Slaughter Age ◽  
Dressing Percentage ◽  
Egg Production Rate

The improvement of productivity of indigenous chicken is a long desire in the country. Present research is a part of the long-term selection program being undertaken to evaluate the carcass characteristics and expected response to selection of second generation (G2) of indigenous chicken under intensive management in Bangladesh. A total of 1643-day-old chicks comprising of 3 types of chicken namely Naked Neck (NN), Hilly (H) and Non-descript Desi (ND) were hatched in a two batches for this study. In second generation (G2), selection was practiced at 3 (three) stages of birds life, firstly and secondly at 8 and at 16 weeks of age, selection was performed on the basis of breeding value for 8 and 16 week body weight. Thirdly, at 40-week of age, on the basis of an index comprising the parameters of age at sexual maturity (ASM), body weight (BW), egg production (EP) and egg weight (EW). Improvement target of egg weight was to increase by 1g and improvement target of egg production rate was to increase by 2 % per generation. The main target was the mean body weight in H, ND and NN chicken has to be gone up from the initial eight-week body weight of 375, 342 and 331g to 500 g at eight weeks of age. At 8, 10 and 12 weeks of age, six birds from each genotype were slaughtered to analyze the meat yield traits. Slaughter data were analyzed in a 3(genotype)×3(slaughter age) factorial arrangement in CRD by General Linear Model (GLM) Univariate Procedure in SPSS Computer Program. Genotype and slaughter age had significant effect (p<0.001) on dressing percentage. Body weight at 8 weeks of age was expected to improve by 51.21 vs. 24.03; 37.74 vs. 15.47 and 26.26 vs. 9.65g; respectively for ND, H and NN males and females. In terms of body weight H genotype was superior and NN genotype was for dressing percentage. As a result of selection; EP, BW increased and ASM reduced in second generation than that of the foundation stock.Asian J. Med. Biol. Res. March 2017, 3(1): 66-71

scholarly journals EFFECT OF SELECTION ON HERITABILITY AND GENETIC CORRELATION OF TWO QUANTITATIVE TRAITS IN MICE

1974 ◽  
Vol 16 (3) ◽  
pp. 599-609 ◽  
Author(s):  
T. K. Cheung ◽  
R. J. Parker
Keyword(s):  
Body Weight ◽  
Genetic Correlation ◽  
Quantitative Traits ◽  
Random Mating ◽  
Tail Length ◽  
Control Group ◽  
Mass Selection ◽  
Initial Population ◽  
Significant Difference ◽  
Selection For

The effects of different intensities of single trait directional selection on the heritability and genetic correlation of two quantitative traits in random mating populations of mice were observed during 14 generations. The initial population was divided at random into five groups (A, B, C, D and E). Group A and Group B were under 30% and 60% mass selection for large 6-week body weight, respectively. Group C and Group D were under 30% and 60% mass selection for long 6-week tail length, respectively. Group E acted as control group with no selection applied. In all groups, the parent population consisted of 15 males and 30 females each generation, mated at random.Direct selection had no apparent effect on the heritability of either the trait under selection or the correlated trait over the 14 generations. Heritability of 6-wk tail length was higher than the heritability of 6-wk body weight. Estimates of heritability of 6-wk tail length ranged from 0.15 ± 0.22 to 0.68 ± 0.24, while estimates of heritability of 6-wk body weight ranged from 0.05 ± 0.17 to 0.33 ± 0.09. There was no significant difference among the estimates of genetic correlation between the two traits in the five selection groups. Estimates of realized genetic correlation between 6-wk body weight and 6-wk tail length seemed to indicate that more intense selection led to some decrease in genetic correlation between the two traits.

Selection for fertility in Australian Merino sheep

1963 ◽  
Vol 14 (4) ◽  
pp. 460 ◽  
Author(s):  
SSY Young ◽  
HN Turner ◽  
CHS Dolling
Keyword(s):  
Body Weight ◽  
Genetic Correlations ◽  
Fibre Diameter ◽  
Likelihood Method ◽  
Mass Selection ◽  
Genetic Progress ◽  
Subsequent Performance ◽  
Fertility Trait ◽  
Selection For ◽  
The Difference

Phenotypic and genetic parameters for fertility in sheep, in terms of number of lambs born and number weaned, have been estimated in a flock of medium Peppin Merinos. Repeatability of fertility traits over all ages is low, but there is an age effect, the record at 3 years of age having a higher value than those at 2 or 4 years. The regression of subsequent performance on a difference of 1 lamb at the initial lambing was higher for the difference between 1 and 2 lambs than between 0 and 1 lamb, which indicated that selection for twins is likely to raise fertility in the current flock more rapidly than selection against barrenness. The estimate of heritability for 2 years of age was negligible for each fertility trait, but the estimates for the 3-year-old record were higher, the value for lambs born being over 0.3. Mass selection for number of lambs born at 3 years of age would thus be expected to lead to appreciable genetic progress, while there would be at least some progress in number of lambs weaned. Phenotypic and genetic correlations were also estimated between fertility at different ages and 10 sheep and wool traits measured at 15–16 months of age. Phenotypically, fertility is positively correlated with body weight and negatively with skin wrinkle score. Genetically, it is suggested from the estimates that fertility is positively correlated with body weight and staple length and negatively correlated with fibre diameter, clean scoured yield, and wrinkle score. No phenotypic or genetic correlation was found between greasy or clean wool weight and either measure of fertility. The application of the findings to breeding for higher fertility is discussed. In an appendix, a maximum likelihood method of estimating heritability for all-or-none traits in half-sib data is presented.

scholarly journals Mass Selection for Body Weight in Quail

1970 ◽  
Vol 49 (4) ◽  
pp. 926-933 ◽  
Author(s):  
W.M. Collins ◽  
Hans Abplanalp ◽  
W.G. Hill
Keyword(s):  
Body Weight ◽  
Mass Selection ◽  
Selection For

scholarly journals SELECTION FOR HIGH ADULT BODY WEIGHT IN DROSOPHILA POPULATIONS WITH DIFFERENT STRUCTURES

Genetics ◽  
1975 ◽  
Vol 81 (1) ◽  
pp. 163-175
Author(s):  
A J Katz ◽  
S S Y Young
Keyword(s):  
Body Weight ◽  
Random Mating ◽  
Large Mass ◽  
Mass Selection ◽  
Adult Body ◽  
Large Populations ◽  
Subdivided Populations ◽  
Adult Body Weight ◽  
Selection For ◽  
Selection Intensities

ABSTRACT Selection for high adult body weight in Drosophila melanogaster was practiced for 18 generations in three selection lines. These lines were genetically similar and of equal size but different in population structure. One line represented a large mass-selected, random-mating population, while the other two lines simulated large populations that had been subdivided into partial isolates or demes. Mass selection and random mating occurred within each deme. These two subdivided lines were different only in the rate of effective migration among the demes (5% and 10%). Selection intensities of approximately 20% were applied to these populations. A fourth line served as a random mating control. Heritability of adult body weight in the base population was estimated to be 0.58± 0.22. The results indicate that significantly greater responses were achieved in the subdivided lines than in the large mass-selected line, in spite of the fact that larger selection differentials were applied to the latter. No significant differences in response were observed between the two subdivided lines. Wright (1930, 1931) postulated that selection would be most efficient in subdivided populations with limited interdeme migration. The present findings appear to support this theory.

scholarly journals Breeding for the improvement of indigenous chickens of Bangladesh: performance of foundation stock

2017 ◽  
Vol 3 (1) ◽  
pp. 80-87
Author(s):  
Shakila Faruque ◽  
AKFH Bhuiyan ◽  
Md Yousuf Ali ◽  
Ziaul Faruque Joy
Keyword(s):  
Body Weight ◽  
Egg Production ◽  
Reproductive Traits ◽  
Shape Index ◽  
Daily Weight Gain ◽  
Stock Selection ◽  
Indigenous Chicken ◽  
Egg Weight ◽  
Dressing Percentage ◽  
Foundation Stock

Selection is one of the vital tools for improving the indigenous chicken genetic resources. A total of 1585-day-old chicks comprising of 3 types of chicken namely Naked Neck (NN), Hilly (H) and Non-descript Deshi (ND) were hatched for this study to form foundation stock. Improvement target of egg weight was to increase by 1g and improvement target of egg production rate was to increase by 2 % per generation. In foundation stock, selection was practiced at 40-week of age, on the basis of an index comprising the parameters of age at first egg (ASM), body weight(BW), egg production(EP) and egg weight(EW). Data were analyzed in CRD by General Linear Model (GLM) Univariate Procedure. Significantly highest fertility (82.71%) and hatchability (82.20%) were found in ND genotype. Significantly (P<0.001) highest body weight of day-old chicks and daily weight gain was found in H genotype than other two genotypes. There was a non-significant (P>0.05) variation in FCR among the native chicken genotypes. NN genotype (3.46%) had non-significantly (?2 = 3.62; P > 0.05) higher chick mortality than ND (1.63%) and H (2.11%) at brooding period (0-4 weeks). Significantly (P<0.01) higher dressing percentage was found in NN (64.58) genotype than ND (60.26) and H (61.70) genotypes. Non-significantly higher egg production in selected group was found in H (70) genotype than ND (68) and NN (67) genotypes. Significantly (P<0.001) highest shape index and Haugh unit were found in H and ND genotypes, respectively. As a result of selection, egg production is expected to improve by 0.562, 0.932 and 0.755%, respectively for ND, H and NN genotypes. In terms of reproductive traits ND was superior, in terms of productive traits H genotype was superior and in terms of dressing percentage and breaking strength NN genotype was superior. These findings of the study also give an impetus for continuing the research for more generations to fulfill the objectives of the long-term programme.Asian J. Med. Biol. Res. March 2017, 3(1): 80-87

scholarly journals Two-way within-family and mass selection for 8-week body weight in different mouse populations

1984 ◽  
Vol 43 (2) ◽  
pp. 191-200 ◽  
Author(s):  
Ines von Butler ◽  
Henning Willeke ◽  
Franz Pirchner
Keyword(s):  
Body Weight ◽  
Inbred Strains ◽  
Selection Response ◽  
Mass Selection ◽  
Individual Selection ◽  
Family Selection ◽  
Body Weights ◽  
Selection For ◽  
Size At Birth ◽  
Better Than

SUMMARYTwo mouse populations, randombred albino mice and a cross of four inbred strains, were divergently selected for high (H8) and low (L8) 8-week body weight over 18 generations using within-family and individual selection. The crossbreds showed asymmetry of selection response and realized heritabilities (H8 0·29 ± 0·01; L8 0·17 ± 0·01). In the randombred population realized heritabilities were symmetrical (H8 0·23 ± 0·01; L8 0·22 ± 0·02). Over the first nine generations individual selection was nearly 40 per cent better than within-family selection, as was expected from the full sib correlation in both populations. As selection progressed, within-family selection reached 82% and 61% of the responses obtained with individual selection in the crossbreds and randombred respectively. Correlated responses for 3-week (weaning) and 5-week body weights agreed with observations made on direct responses, but selection for L8 did not reduce weaning weight. Selection for L8 decreased and selection for H8 increased first litter size at birth. However, mass-selected L8-pairs had a higher life-reproduction and life-span than H8-pairs.

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