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Effect of Selection for Residual Variance of Litter Size on Components of Litter Size in Rabbits
A divergent selection experiment for residual variance of litter size (Ve) has been carried out in rabbits at the University Miguel Hernández of Elche in Spain. The Ve was estimated as the phenotypic variance of litter size (LS) within female after correcting LS for the effects of year-season and lactation status. After seven generations of selection, the High (H) line showed a higher Ve (D=1.19 kits2, (P(D>0)=99%). Selection for increasing Ve decreased total number of kits born (D=-0.70 kits, P(D<0)=100%) and alive (D=−0.58 kits, P(D<0)=98%) in the H line. This difference in LS was related to lower embryonic (−1.38 embryos, P(D<0) = 100%) and fetal survivals (−0.57 fetuses, P(D<0) = 85%). In conclusion, there has been response to selection for Ve, and selection for Ve has shown a negative correlated response in litter size at birth by means of lower embryonic and fetal survivals
Keywords:
Rabbits
Residual Variance
Litter size
