Production levels and health status in Iberian piglets at weaning.

The aim of this study was to describe the postweaning growth of Iberian piglets and its relationship with the occurrence of diarrhea. To assess these factors in response to different weaning ages, a total of 360 pure-breed Iberian piglets were studied. Three trials were conducted with 120 piglets from 24 litters randomly assigned to be weaned at 28 or 42 d of age (12 litters and 60 piglets each). In each trial and from each weaning age, 4 groups of 15 piglets were assembled with different sexes and sizes (3 litters by group and 5 animals from each litter; 12 replicates and 180 piglets/weaning age). The duration of study period was 42 d and all animals were weighed weekly from 21 to 63 d of age. Food intake and fecal consistency were examined with the same frequency. General linear models and chi-square procedure was used with SPSS statistical package to perform the analysis with a confidence interval of 95% (P < 0.005). Pearson and Spearman analyses were conducted to examine relationships between variables. At the beginning (P = 0.798) and end of the study (P = 0.450) there were no significant differences between piglet weights. After weaning, there were differences in food intake and in conversion rates (P < 0.001), but there were no differences in ADG for the whole study period (P = 0.335). All groups experienced a similar decline in production rates during the first week after weaning and similar recovery times during the next weeks. Both weaning groups had a similar overall prevalence (P = 0.044) and incidence of diarrheal onset (P = 0.467), and regression analysis showed relationships between postweaning diarrhea and the overall prevalence of piglets before weaning (P < 0.01) and food intake during first week postweaning (P < 0.01). Therefore, weaning age has a similar influence on postweaning growth and on postweaning diarrhea in Iberian piglets.