Effects of birth-rearing type on weaning weights in meat sheep are systematically associated with differences in mean performance among flocks

Table 4 Relative frequencies and additive and multiplicative adjustment factors to correct weaning weights for the interaction of birth-rearing type (TBR) and dam age class^a

^aFactors were derived from least-squares means for TBR × dam age class subclasses
^badjustment factors for this class could not be accurately estimated from the available data due to low subclass frequencies. Thus, additive adjustment factors for yearling dams with TBR = 33 were derived by adding corresponding additive factors for 2-year-old dams to the difference between 1- and 2-year-old ewes that raise twin lambs (e.g., as 5.26 + (4.38 -1.87 = 7.77). Multiplicative adjustment factors for these lambs were derived by multiplying corresponding factors for 2-year-old dams by the ratio of adjustment factors for 1- and 2-year-old ewes that raise twin lambs (e.g., as 1.22 × (1.18 / 1.07) = 1.35)

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