Scatter diagram sowing pregnancy scores on the y axis from 0.9 at the bottom to 1.5 at the top. The years from 1998 to 2012 are listed along the X axis. Winter season is shown in blow and summer season results in red. Data shows during the first 3 yrs, the Summer group had numerically superior pregnancy rates, but in general this was reversed during the remainder of the trial. Higher pregnancy rates for Summer calvers were observed during the 5 yr. formal trial. Reasons for the change observed in this evaluation may be related to the disproportional use of young sire semen in the Summer calving herd, as part of a strategy to accelerate genetic change. It is known that the fertility of yearling bull semen is generally lower than that of older bulls. Another trend apparent in Fig. 3 is the reduction of breeding success as time progressed. Enter text here

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