General and Specific Combining Ability of Channel Catfish (Ictalurus punctatus) Female x Blue Catfish (I. furcatus) Male for Early Performance Traits of F1 Hybrid Progeny  

Ramjie Y. Odin*, Khoi Vo, Dalton Robinson, David Drescher, William Bugg, Kamal Gosh, and Rex A. Dunham
 
School of Fisheries, Aquaculture, and Aquatic Sciences
Auburn University, Auburn, AL 36849, USA
ryo0001@auburn.edu
 

Hybrid catfish are considered best for commercial catfish farming due to their faster growth rate, better survival rate, disease resistance, better carcass yield and seinability. To improve its hybridization breeding program, the determination of the combining abilities of parental lines is vital. The estimation and analyses of general combining ability (GCA) and specific combining ability (SCA) are important indicators for expressing the potential value of parental lines that can produce superior performing hybrids. It will help us determine the best parental genotypes and the best cross for superior hybrids of catfish. Information on combining ability to develop high yielding lines and hybrids would be beneficial to the catfish industry.

Eleven female channel catfish and twelve male blue catfish were crossed in 11x12 factorial mating design. The progenies were reared in flow-through aquaria system for 323 days and fed ad libitum with 32% protein diet on a daily basis. The resultant 36 hybrid families were evaluated for their early performance traits (early growth, early FCR, and survival from Aeromonas and Ich infection).

The estimates for variance of combining ability showed that GCA variance for sire was higher than that of SCA for all the early performance traits (Table 1). This indicates the prevalence of additive gene actions contributed by the male parent than the female parent. The importance of additive gene effects for controlling inheritance of early traits of hybrid catfish is revealed. The estimation also revealed that dominant gene effect was negligible except for early growth. Overall, the reciprocal recurrent selection for early traits in terms of additive genetic value of the blue catfish male has the potential to improve the performance of hybrid catfish.