UTILIZATION OF PC SOW-MANAGEMENT-PROGRAMS IN PIG-TESTING SCHEMES .2. UTILIZATION IN COMMERCIAL PIG EVALUATION

The measurement of reproductive performance is an essential part of pi g evaluation schemes. With the exception of Schleswig-Holstein no stat ion to measure reproductive performance is available in the Federal Re public of Germany. Therefore litter performance was estimated in a fie ld test in most German commercial pig evaluation tests. The criteria w ere number of sucking piglets counted per litter, The piglets and sows were counted twice in each farm with an interval of at least 6 weeks. The aim of the present investigation was to find out whether the util ization of sow-management-programmes (SMP) in weaner production farms allows a better estimation of reproductive performance in pig evaluati on tests. The aim of the present investigation was to find out whether the utilization of sow-management-programmes (SMP) in weaner producti on farms allows a better estimation of reproductive performance in pig evaluation tests. As against counting piglets many traits can be eval uated by using SMP-data. Litter size, rearing performance and interval between weaning and matings are accurately recorded. The results of c ounting sucking piglets are only a snapshot and an indirect measuremen t to estimate litter size and weaning performance. The correlation bet ween 'number of sucking piglets per litter' and 'number of piglets bor n alive' (r = 0.57) in the same litters. Considering all litters of so ws involved in the counting procedure these correlations decrease (0.4 4; 0.38). The correlations between average litter size at birth and nu mber of piglets weaned per litter of farms calculated by SMP-data of t he last two years and the farm-mean by counting suckling piglets per l itter twice are only 0.34 and 0.43, respectively. Finally, important r eproductive traits estimated by SMP-data were combined into an overall economic value. Differences between tested stock increase because a l ot of major economic effects were taken into consideration compared wi th the result received by counting sucking piglets per litter only. Th e weaning performance followed by stayability has the most important e ffect on the overall economic value of a sow. Due to the results of th e present investigation the use of sow-management-programme data in co mmercial pig evaluation is recommended. The size of the test in terms of the number of farms needed to detect practically important economic al differences between tested stocks with statistical significance is not reduced by using SMP-data.