Performance and intestinal health of piglets weaned at 21 or 25 days of age challenged with Escherichia coli K88+

Abstract

The objective of this study was to evaluate the effects of weaning at the 21 and 25 days old of piglets challenged or not by Escherichia coli K88+ and its effects on the performance, diarrhea incidence, intestinal morphometry, microbiological counts and volatile fatty acids concentration on cecal content in the first weeks of nursery phase. A total of 84 barrows (DB90 × PIC337) were divided into two groups: 42 animals weaned at 21 days (5.2 ± 0.3 kg) and 42 animals weaned at 25 days (6.8 ± 0.3 kg). The experimental design was a 2x2 factorial, two weaning ages (21 x 25 days), and with and without challenge, totaling four treatments, seven replicates and three piglets per pen. The experimental period was 24 days. On days 4 and 5, the challenged group received orally 1 mL of the solution with the concentration of 106 CFU/ mL E. coli K88+. Data were analyzed using SAS software (P ≤ 0.05 and trend 0.05 ≤ 0.10 and the Tukey test used for comparison of means. At four experimental days, the animals weaned at 25 days old had higher BW (P <.0001), ADG ( P =0.0006) and ADFI (P<.0001) compared the animals weaned at 21 days old. Piglets weaned at 25 days had higher ADG and ADFI throughout the experimental period (P<0.0001). The challenged group presented lower ADFI (P=0.05) than the non-challenged group. From 0 to 4 experimental days, weaning at 21 days resulted in a higher incidence of diarrhea (P = 0.0001) compared to weaning at 25 days. From 4 to 12 days, higher incidence of diarrhea occurred in non-challenged animals (P=0.03) than challenged. Piglets weaned at 25 days had higher villus height in the jejunum (P= 0.0345) and ileum (P = 0.0421) than piglets of 21 days. There was a higher E. coli count in piglets weaned at 21 days compared to 25 days weaning (P = 0.039). Age and challenge did not affect the Lactobacillus count (P> 0.05). The production of acetic, propionic and butyric volatile fatty acids (AGV) was higher (P <0.05) in the inoculated groups compared to the not inoculated groups. In conclusion, weaning at 25 days of age improves performance, decrease diarrhea incidence and E.coli in the first days of nursery phase, suggesting greater maturity and adaptation to stressors.