Bishop M D, Davis M E, Harvey W R, Wilson G R, VanStavern B D
Anim. Sci. Dept., Ohio State University, Columbus 43210.
J Anim Sci. 1991 Nov;69(11):4360-7. doi: 10.2527/1991.69114360x.
A single generation divergent selection study, replicated four times (1983, 1984, 1985, and 1986), was conducted to assess genetic differences between progeny of high and low feed conversion sires in Angus beef cattle and to determine correlated response for weight gain (ADG140), feed intake (AVFD140), and BW (OFFTSTWT) in a time- (140-d) and fat-constant (8.9 mm) period. Realized heritability estimates for unadjusted (feed/gain; FEFF140; .26) and adjusted feed conversion (adjusted as recommended by the BIF, 1986; ADJFDEFF; .46) were obtained. The difference in heritability estimates reflects variation accounted for by adjustment for BW differences, and thus maintenance requirements, of individual progeny. Phenotypic and "pseudo" realized genetic correlations of FEFF140 with ADG140, AVFD 140, and OFFTSTWT were -.33 and -.66, .49 and -.26, and .15 and -.41, respectively. Phenotypic and "pseudo" realized genetic correlations of ADJFDEFF with ADG140, AVFD140, OFFTSTWT, and FEFF140 were -.54 and -.59, .30 and -.23, .27 and -.36, and .97 and .49, respectively. Subcutaneous fat (as estimated by ultrasonic measurement; BF140) had phenotypic and "pseudo" realized genetic correlations with FEFF140 of -.33 and .66, respectively, and with ADJFDEFF of -.44 and -.58, respectively.
开展了一项单代品系差异选择研究，并重复进行了4次（1983年、1984年、1985年和1986年），以评估安格斯肉牛中高饲料转化率和低饲料转化率父系后代之间的遗传差异，并确定在140天时间和8.9毫米脂肪恒定期内，体重增加（ADG140）、采食量（AVFD140）和体重（OFFTSTWT）的相关反应。获得了未调整的（饲料/增重；FEFF140；0.26）和调整后的饲料转化率（按照牛肉改进联合会1986年的建议进行调整；ADJFDEFF；0.46）的实际遗传力估计值。遗传力估计值的差异反映了个体后代体重差异调整所导致的变化，进而反映了维持需求的差异。FEFF140与ADG140、AVFD 140和OFFTSTWT的表型和“伪”实际遗传相关系数分别为-0.33和-0.66、0.49和-0.26、0.15和-0.41。ADJFDEFF与ADG140、AVFD140、OFFTSTWT和FEFF140的表型和“伪”实际遗传相关系数分别为-0.54和-0.59、0.30和-0.23、0.27和-0.36、0.97和0.49。皮下脂肪（通过超声测量估计；BF140）与FEFF140的表型和“伪”实际遗传相关系数分别为-0.33和0.66，与ADJFDEFF的相关系数分别为-0.44和-0.58。
