Genetic parameters and effect of selection for body weight in lines of mink (Neovison vison) on ad libitum and restricted feeding

Abstract

Selection was performed for high November weight on ad libitum (AL) and restricted feeding (RF) in mink in two generations. A farm fed line (FF) was maintained as a control. The estimates of heritability for November weight were large (0.62, 0.52, and 0.73 in males and 0.68, 0.51, and 0.60 in females in the FF-, AL-, and RF-line). The results indicate that selection on AL feeding increased appetite and thereby improved feed conversion ratio while selection on RF improved feed utilization. Furthermore, the results suggest that selection for August weight produces lean mink while selection for November weight produces fat mink.

Longitudinal analysis of residual feed intake and BW in mink using random regression with heterogeneous residual variance

“…In pigs, Huisman et al (2002) using random regression models obtained 0.14 to 0.19 heritabilities for live BW during growth. Furthermore, the current study showed a notable increase in genetic variance by age for BW which is in agreement with results of Nielsen et al (2012). The heritabilities of BW for males and females did not differ within each time point, however, the phenotypic variances were greatly different ranging from 55% to 67% and consequently the genetic variances were also different.…”

“…This can further be observed from substantially larger genetic and phenotypic variance in the furring compared to the growing period, suggesting that genes responsible for BW gain are switch on and off during growingfurring period. In agreement with genetic correlations obtained in the current study, Nielsen et al (2012) reported genetic correlations between August and November BW in male (0.77 to 0.90) and female (0.86 to 0.94) mink using the same data set as in the current study for different selection lines. Sørensen (2002) estimated the growth curve of mink using multiphasic models and observed that the growing period is associated with mainly lean BW growth and the furring period is associated with fat deposition and fur development.…”

“…This indicates large genetic variance for BW in the furring period suggesting high genetic gain by selection for BW at later stages of this period. Nielsen et al (2012) reported heritabilities of August BW for males 0.44 to 0.55 and females 0.57 to 0.64 along with November BW for males 0.52 to 0.73 and females 0.51 and 0.68 for different selection lines using the same dataset as in the current study. The August and November BW of Nielsen et al (2012) corresponds to the late growing period (105 to 126 days of age) and late furring period (189 to 210 days of age) in the current study, respectively.…”

“…Nielsen et al (2012) reported heritabilities of August BW for males 0.44 to 0.55 and females 0.57 to 0.64 along with November BW for males 0.52 to 0.73 and females 0.51 and 0.68 for different selection lines using the same dataset as in the current study. The August and November BW of Nielsen et al (2012) corresponds to the late growing period (105 to 126 days of age) and late furring period (189 to 210 days of age) in the current study, respectively. The differences in heritability estimates can be due to using different methods of analysis as in the current project random regression has been used compared with the bivariate animal model of Nielsen et al (2012).…”

“…The August and November BW of Nielsen et al (2012) corresponds to the late growing period (105 to 126 days of age) and late furring period (189 to 210 days of age) in the current study, respectively. The differences in heritability estimates can be due to using different methods of analysis as in the current project random regression has been used compared with the bivariate animal model of Nielsen et al (2012). Moreover, Sørensen (2002) reported large heritability (0.64) for BW in November in mink, which is in agreement and slightly lower than estimates obtained in the current study.…”