Litter performance until weaning in a Cuban Creole pig herd

Data from 598 farrowings of 182 Creole sows were used to study the litter p erformance of this genotype. Traits analysed were litter size at birth (TLS ), number of born alive (BA), number at 21 days (B21) and at weaning (BW) a nd litter weights at these ages (LW), As sources of environmental variation the effects of year (5) and bimester of farrowing (6) and their interactio n and the parity were studied. The latter was grouped in 1st., 2nd., 3rd., 4th. and 5th or more. In 549 farrowings, besides the already mentioned sour ces of variation, the random effect of the sire (29) was also analysed thro ugh a mixed model with all the Factors considered and anotner absorbing the effects of year, season and parity. The weaning traits were adjusted by li near regression on the lactation length (42 days). For the analysis, the le ast squre method was used. Least square means Found were: 7.7, 7.4, 6.8 and 6.4 litters for TLS, BA, B21 and BW, respectively and 10.7. 27.4 and 43.8 kg For LWB, LW21 and LWW. The most consistent environmental influence was t he year of farrowing; however, this effect is lost when considering the eff ect of the sire. There were no significant differences between parities for litter traits. Differences between sires were not significant, thus, the h eritabilities values were low (0.o1 - 0.09) and with high standard errors.