The nested effect of sire within breed [Sire (B)] was
not significant for any trait, but the interaction of
sampling period ´ Sire (B) was significant for
myristoleic (14:1) and linolenic (18:3) acids (Table
2). Less than half of the fatty acid variables were
affected ( P < .05) by the interaction of calf breed (B)
´ sampling period (P). Partitioning of calf breed into
its variance components (D, S, and D ´ S) revealed
that the D ´ S ´ P interaction was significant for 16:0,
stearic acid (18:0) plus 18:1, the unsaturated:saturated
fatty acid ( UFA:SFA) ratio, and the monounsaturated
( MUFA):SFA ratio. For 14:1 and 18:0, the
interaction of B ´ P was attributed to the interaction
effects of S ´ P and D ´ P. Partitioning of the calf
breed effect into its different components only in the
presence of a significant ( P < .05) breed effect was a
more conservative approach and should have offered
more protection against type I statistical error.
Therefore, the partitioned model was used for discussing
the significant ( P < .05) effects of breeds,
sampling periods, and their interactions. Other significant
but irrelevant interaction effects (sire nested
under breed ´ sampling period) will not be discussed.