scholarly journals Associations of Major Histocompatibility Complex Haplotypes with Body Weight and Egg Production Traits in S1 White Leghorn Chickens

1989 ◽  
Vol 68 (4) ◽  
pp. 464-469 ◽  
Author(s):  
C.D. KIM ◽  
S.J. LAMONT ◽  
M.F. ROTHSCHILD
Keyword(s):  
Body Weight ◽  
Major Histocompatibility Complex ◽  
Egg Production ◽  
Production Traits ◽  
Major Histocompatibility ◽  
White Leghorn ◽  
Histocompatibility Complex

scholarly journals DOMINANCE AND EPISTASIS IN HETEROSIS OF WHITE LEGHORN STRAIN CROSSES

1987 ◽  
Vol 67 (3) ◽  
pp. 663-680 ◽  
Author(s):  
R. W. FAIRFULL ◽  
R. S. GOWE ◽  
J. NAGAI
Keyword(s):  
Body Weight ◽  
Sexual Maturity ◽  
Egg Production ◽  
Significant Contribution ◽  
Production Traits ◽  
White Leghorn ◽  
Cross Combination ◽  
Commercial Strain ◽  
Better Than

Four unrelated pure strains of White Leghorns including a grandparent strain from industry and 12 two-strain, 24 three-strain, 24 four-strain and 12 F2 strain crosses produced contemporaneously were used to examine the role of dominance and epistasis in heterosis. A control strain and a commercial strain were also included. For egg weight, the heterosis observed closely approximated that expected due to dominance alone. For sexual maturity and body weight, dominance was the major component of heterosis, but epistasis made a significant contribution — additive by additive (A × A) genetic effects for sexual maturity and 140-d body weight, and parental epistasis for mature body weight. Both dominance and epistasis played a significant role in heterosis for egg production traits. A × A, dominance by dominance (D × D) and additive by dominance (A × D) epistasis were all important for hen-housed egg production and hen-housed egg yield. For hen-day rate of egg production, A × A epistasis was significant only early in the laying year (to 273 d), A × D and D × D were significant to 385 d and in the full year (to 497 d); however, none (A × A, A × D and D × D) was significant near the end of lay (386–497 d). Overall heterosis estimates for full year egg production measured as hen-housed egg production to 497 d or hen-day rate from housing to 497 d clearly showed that on average two-strain crosses were superior to three-strain crosses which were superior to four-strain crosses which in turn exceeded the F2 crosses. Nevertheless, several three-strain crosses had performance for egg production that was equal to or better than the two-strain cross with the highest egg production. Thus, in commerce, where the level of egg production is of great economic importance, the testing and use of a specific three-way cross combination will usually result in a better commercial product. Key words: Heterosis, egg production genetics, epistasis, stocking rate, strain cross, White Leghorn

scholarly journals ASSOCIATION OF MICROSATELLITE MARKERS WITH PRODUCTION TRAITS IN SANTA INÊS AND CROSSBRED SHEEP

2014 ◽  
Vol 19 (1) ◽  
Author(s):  
Cesar Daniel Petroli ◽  
Samuel Rezende Paiva ◽  
Tiago Do Prado Paim ◽  
Concepta Margaret McManus
Keyword(s):  
Major Histocompatibility Complex ◽  
Microsatellite Markers ◽  
Production Traits ◽  
Major Histocompatibility ◽  
Histocompatibility Complex ◽  
Santa Inês ◽  
Para Determinar

O objetivo deste estudo foi de associar alelos de 13 loci de microssatélites no cromossomo 20 de ovinos (Major Histocompatibility Complex - MHC) com características de desempenho e carcaça bem como resistência à parasitas  gastrointestinais em 138 ovinos Santa Inês e seus cruzamentos com Bergamasca, Texel e Ile de France. Os seguintes loci foram selecionados: BM1818, OarCP73, OarHH56, DYA, OLADRB, CP101, OMHC1, DQA2, DQA1, TFAP2A, DQBA27, Bf94_1, e INRA132.  Dados foram analisados em Cervus e SAS ® para determinar níveis de heterozygosidade e associações de marcadores com peso, carcaça e ovos por grama de fezes (OPG).  Os marcadores mostraram alta variabilidade genética entre indivíduos.  Para características de carcaça oito associações significativas (p<0.05) foram observadas, bem como associação positiva entre OPG e dois marcadores da MHC ovina.

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