scholarly journals ESTIMATES OF PHENOTYPIC AND GENETIC CORRELATIONS IN WEST AFRICAN DWARF GOATS

2021 ◽  
Vol 21 ◽  
pp. 47-50
Author(s):  
I. K. Odubute ◽  
J. O. Akinokun
Keyword(s):  
Body Weight ◽  
Litter Size ◽  
Genetic Correlations ◽  
Correlation Coefficients ◽  
West African ◽  
West African Dwarf ◽  
West African Dwarf Goat ◽  
Body Weights ◽  
Selection For ◽  
Size At Birth

Records on 848 West African dwarf goat kids and 220 kiddings over a period of eight year's (1982-1989) were analyzed. The records were used to provide estimates of phenotypic and venetic correlations among parity, kidding interval, litter size at birth and body weight at various ages. Plenotypic correlation coefficients of +0.33 (P<0.01) and -0,17 (P<0.01) were obtained when parity was correlated with litter size at birth and kidding interval respectively. Phenotypic correlations among body weights were generally positive and significant (P<0.01). Parity was positively correlated (P<0.01) with body weight at the various ages except at 1 year (P>0.05). Litter size was, however, negatively correlated (P<0.01) with body weight at the various ages except at 1 year (P<0.05). The genetic correlations among body weights at variuus ages were positive and significant (P<0.01). Selection for body weight at in earlier age especially at 3 months is likely to result in improvement of yearling body weight.

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.

Comparative performance of Omani goats and sheep

1996 ◽  
Vol 127 (1) ◽  
pp. 117-121 ◽  
Author(s):  
F. M. S. Al-Nakib ◽  
E. S. S. Al-Shukaily ◽  
S. S. S. Al-Hanai ◽  
S. A. M. Al-Nabhani
Keyword(s):  
Body Weight ◽  
Litter Size ◽  
Performance Test ◽  
Comparative Performance ◽  
Rhodes Grass ◽  
Sheep Industry ◽  
Body Weights ◽  
Selection For ◽  
Performance Trial

SUMMARYAs part of a long-term breeding programme aimed at improving the performance of Omani goats and sheep, a 3-year performance trial was carried out between 1991 and 1993 to evaluate the reproductive and productive performance of three breeds of goat: Batinah (BT), Dhofari (DH) and Jabal Akhdar (JA), and one breed of local Omani sheep. In each year, flushing started on 1 September, mating started on 1 October and terminated on 15 November, and the kidding/lambing season started on average on 1 March. Kids and lambs were weaned at c. 3 months of age, then put on a 3-month performance test, fed on concentrates ad libitum and Rhodes grass hay. Some 3706 dam and 3011 progeny performance records were available over a 3-year period from 1991 to 1993. Ewes were lighter in body weight and lower in litter size weaned but higher in fertility than the does. Although the lambs had lighter birth weights, they were heavier at weaning and at 6 months of age. Among the goats, the DH does had lighter body weight but higher litter size weaned than both the BT and the JA goats. DH kids were somewhat lighter at birth, weaning and 6-month body weights than the other two breeds but had higher survival.The sheep had higher output per ewe exposed (3·28 kg, 33%) and per ewe lambed (3·27 kg, 26%) and were 35% more efficient in production than the goats. Although the DH goats had a lower output per doe exposed than the BT and JA goats (0·9 kg, 9 % and 0·76 kg, 7% respectively) and per doe kidded (1·11 kg, 9% and 1·29 kg, 10%), they had higher efficiency of production than both BT (0·05 units, 6%) and JA (0·11 units, 14%).In view of these results, attention should be paid to the sheep industry through the introduction of promotion schemes. The DH goats would be even more useful if involved in a crossbreeding scheme and the JA goats would benefit from selection for maternal care.

Growth performance, genetic parameters and selection index of pure and crossbred populations of Red Sokoto and West African Dwarf goats

2020 ◽  
Vol 42 (1) ◽  
pp. 11-18
Author(s):  
E. N. Nwachukwu ◽  
O. C. Nkemakolam ◽  
A. I. Adeolu
Keyword(s):  
Body Weight ◽  
Growth Performance ◽  
Growth Traits ◽  
Selection Index ◽  
Genetic Correlations ◽  
Pure Line ◽  
West African ◽  
Male And Female ◽  
West African Dwarf ◽  
Indigenous Goat

In 2008, a breeding programme was designed to develop hybrid goat suitable for the rainforest agro-ecological zone of South-Eastern, Nigeria. Two indigenous goat breeds namely, Red Sokoto (RS) and West African Dwarf (WAD) goats were utilized and mated in a main (RS x WAD), reciprocal (WAD x RS) and pure line (RS x RS and WAD x WAD) fashion. A total of 74 progenies were generated from the matings and were evaluated for 12week growth performance. As part of the ranking procedure, a selection index was constructed based on two major body components namely body weight (BWT) and heart girth (HGT) to objectively determine the genetic worth of the growing pure and crossbred progenies of Red Sokoto and West African Dwarf kids. The results showed that average body weight (BWT) of RS x RS (5.29±0.13kg) and RS x WAD (5.14±0.21kg) buck kids were similar but significantly (P< 0.05) heavier than that of their WAD x RS (4.84 + 0.17kg) and WAD x WAD (4.79 + 0.17kg) counterparts. The performance of crossbred RS x WAD compared to WAD x RS and WAD x WAD buck kids indicate that the main crossbred kids sired by Red Sokoto bucks but nursed by WAD dams received superior sets of genes from their large-sized sire. The RS x WAD buck kids in particular, had significantly longer body length (BLT), height-at-withers (HWT) and HGT than WAD x RS and WAD x WAD kids. The phenotypic and genetic correlations of BWT and HGT in both sexes for the different genotypes were high and positive which were indicative of the nature of association between these conformation traits in goats. Heritability estimates (h2) for BWT and HGT in males and females kids ranged from 0.31 – 0.36 versus 0.28 – 0.30, respectively in most of the growing kids. The relative economic values (REV) of chosen traits were generally higher for male kids compared to their female counterparts. Phenotypic variances for BWT and HGT in male and female kids ranged from 0.65 – 0.80. The selection index values were highest in male and female kids of RS x RS, followed by RS x WAD, while WAD x RS kids ranked low and WAD x WAD kids ranked the least. Thus, indicating that selection and improvement of growth traits in these pure and crossbred kids would be in favour of the RS x RS and RS x WAD individuals.

Studies on Growth Performance and Genetic Parameters of Three Varieties of Domesticated Japanese Quail

2020 ◽  
Author(s):  
M Monika ◽  
J J Rokade ◽  
R Narayan ◽  
V K Saxena ◽  
Snehasmita Panda ◽  
...  
Keyword(s):  
Body Weight ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Field Testing ◽  
Pure Line ◽  
Japanese Quails ◽  
Quantitative Genetic ◽  
Body Weights ◽  
Selection For ◽  
Mortality Percentage

The quantitative genetic study involving a pure line mating of 160 pairs of three varieties of domesticated Japanese quails (CARI-Ujjawal; CARI-Suneheri and CARI-Brown) were maintained under individual pedigree cages for breeding. A total of 6221 quail chicks from three hatches comprising three varieties were used for this study. Among them, CARI-Ujjawal has higher hatchability with less rearing mortality percentage. CARI-Ujjawal had highest (plessthan0.01) body weight at all ages when compared to the other two varieties. The heritability estimates on body weight (0-5 weeks) among the varieties range from low to moderate in all the three varieties. The positive correlation was observed among all the varieties at different ages. High genetic correlations between body weights at early as well as later ages confirms that selection for body weight at early ages would improve body weight at later (maturity) ages. Amongst all, CARI-Suneheri was having better heritability values and during further generations of selections it performed also well to improve because of its better heritability. Also from above results this variety could be recommended for broiler quail breeding after field testing.

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.

Predicted and realized responses to selection for an index of bone length and body weight in Scottish Blackface sheep 2. Correlated responses in lifetime productivity

1986 ◽  
Vol 43 (3) ◽  
pp. 437-445 ◽  
Author(s):  
K. D. Atkins ◽  
R. Thompson
Keyword(s):  
Body Weight ◽  
Population Genetic ◽  
Genetic Correlations ◽  
Reproduction Rate ◽  
Base Population ◽  
Correlated Responses ◽  
Genetic Response ◽  
Bone Length ◽  
Body Weights ◽  
Selection For

ABSTRACTA selection experiment with Scottish Blackface sheep was used to compare predicted and realized correlated responses to selection. Three lines were maintained between 1956 and 1974 in which selection was either at random or for high and low values of an index of cannon-bone length at 8 weeks of age adjusted for body weight at the same age.There was no evidence of asymmetrical responses in any trait. Selection for increased cannon-bone length, adjusted for body weight, resulted in (i) increased body weights at all ages between birth and maturity, (ii) increased reproduction rate, principally from increased litter size but also from small responses in ewe fertility and lamb survival and (iii) decreased survival of adult ewes. The realized genetic correlations were relatively small (up to 0·3) but mostly significantly different from zero, whereas base population genetic correlation estimates were very imprecise. The realized responses in reproduction rate were probably a consequence of the genetic response in body weight.

A genetic analysis of the components of lifetime productivity in Scottish Blackface sheep

1986 ◽  
Vol 43 (3) ◽  
pp. 405-419 ◽  
Author(s):  
K. D. Atkins
Keyword(s):  
Body Weight ◽  
Litter Size ◽  
Genetic Correlations ◽  
Direct Selection ◽  
Data Set ◽  
Body Weights ◽  
High Heritability ◽  
Adult Body Weight ◽  
Fleece Weight ◽  
Measures Of Performance

ABSTRACTReproductive performance, body growth, wool production and ewe survival were examined in Scottish Blackface sheep. The data set was from a large randomly selected population maintained under hill conditions between 1954 and 1974. Paternal half-sib analyses of variance were used to estimate heritabilities and genetic correlations, while maternal half-sib analyses of variance indicated the relative importance of maternal effects (both genetic and environmental).Among reproductive components, the heritability of fertility (ewes lambing per ewe mated) and lamb survival (lambs weaned per lamb born) were about zero. Litter size (lambs born per ewe lambing) had an estimated heritability of 0·12 (s.e. 0·04) and a repeatability of 0·22 (s.e. 0·02), indicating some scope for improvement. Additionally, the strong genetic correlation between adult body weight and litter size (0·66, s.e. 0·18) suggested greater response from a combination of indirect selection (on body weight) and direct selection (on dam's litter size). Prior to weaning, direct genetic effects on body weight were very small (heritability less than 0·1) with a large influence of maternal environment. After weaning, these maternal influences gradually diminished and the heritability of weight increased. Genetic correlations between body weights showed a similar increasing trend with age. Genetic improvement of early growth rate would be more effective by selecting on a post-weaning rather than a pre-weaning body weight. Fleece weight had a high heritability (about 0·5) but was genetically uncorrelated with other measures of performance. Ewe survival had a small genetic component although estimates of heritability were very imprecise.

A genetic analysis of body weight traits in young Bauscat and Giza White rabbits

1987 ◽  
Vol 45 (1) ◽  
pp. 135-144 ◽  
Author(s):  
M. H. Khalil ◽  
E. A. Afifi ◽  
J. B. Owen
Keyword(s):  
Body Weight ◽  
Litter Size ◽  
The Body ◽  
Month Of Birth ◽  
Components Of Variance ◽  
High Magnitude ◽  
Body Weights ◽  
Genetic And Phenotypic Correlations ◽  
Genetic And Environmental Factors ◽  
Size At Birth

AbstractThe effects of various genetic and environmental factors on body-weight traits were studied in 3051 records of Bauscat (B) and Giza White (G) rabbits in the period from October 1976 to September 1983. Sixty-five sires and 289 dams were used for analysis of data of body weight at 6 weeks and bi-weekly up to 12 weeks of age. Year and month of birth exerted a pronounced effect on body weights of rabbits. Sex differences on the other hand were small at all ages studied and no pattern of parity effects was observed. Effects of litter size at birth were significant for 6-week weight but not for weights taken at later post-weaning ages. Body weights at the four ages studied decreased as litter size at weaning increased. Litter-weight effects on body weights decreased significantly as the age of the rabbit advanced. Sire and dam affected significantly most of the body-weight traits studied. The proportion of variance attributable to both sire and dam components for all body weights studied in G rabbits were generally larger than those in B rabbits. Heritabilities from sire and dam components of variance for body weights n i B rabbits were substantially lower than the corresponding estimates in G rabbits. Genetic and phenotypic correlations among body weights at all ages studied were positive and of moderate or high magnitude, and tended to decrease in value as the differences between the two ages increased.

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