Effect of pre-farrowing hygiene routine (sub-standard vs. optimal) and creep feeding regime (dry pelleted starter diet vs. liquid mixture of milk replacer and starter diet) on post-weaning intestinal parameters and growth to slaughter in pigs

The objective was to evaluate the effect of providing a dry pelleted starter diet (DPS) or a liquid mixture of milk replacer and starter diet (LMR + S) to suckling pigs housed in farrowing pens of sub-standard or optimal hygiene conditions on pig growth to slaughter, and post-weaning (PW) intestinal parameters. On day (d) 107 of gestation, 87 sows were randomly allocated to one of four treatments in a 2 × 2 factorial arrangement. The factors were creep feeding (DPS or LMR + S) and pre-farrowing hygiene routine (SUB-STANDARD or OPTIMAL). Pigs were provided with DPS (manually) from d 11 to weaning (at d 28 ± 1.2 of age) or LMR + S using an automatic liquid feeding system from d 4 to weaning. The SUB-STANDARD hygiene routine (pens washed and dried for ~18 h, sows not washed or disinfected) and the OPTIMAL hygiene routine (pens pre-soaked, detergent applied, washed, dried for 3 days, chlorocresol-based disinfectant applied, dried for 3 more days, and sows washed and disinfected with Virkon) were used to obtain SUB-STANDARD or OPTIMAL hygiene conditions, respectively, in farrowing rooms prior to entry of sows. Microbiome analysis was performed on fecal samples from eight focal pigs per treatment, before weaning and at d 21 and d 114 PW. On d 4 PW, 10 pigs per treatment were euthanized to collect intestinal tissue and digesta samples for histological, enzyme activity, and microbiome analysis. Feeding LMR + S to pigs born into the OPTIMAL hygiene increased total dry matter intake compared to all of the other groups (P ≤ 0.05) and increased weaning weight compared to DPS feeding under both OPTIMAL and SUB-STANDARD hygiene conditions (P ≤ 0.05). Pigs from OPTIMAL farrowing pens had lower clinical cases of disease, diarrhea prevalence, and were slaughtered 3.8 days earlier than those from SUB-STANDARD farrowing pens (P ≤ 0.05). Suckling piglet mortality was reduced with LMR + S (P ≤ 0.05). On d 4 PW, jejunal and ileal villus height were increased by OPTIMAL hygiene and ileal sucrase activity was increased by LMR + S (P ≤ 0.05). On d 4 PW, LMR + S-fed pigs from OPTIMAL farrowing pens had a lower relative abundance of Clostridium_P in the jejunum. In conclusion, the OPTIMAL hygiene routine increased pre-weaning LMR + S feed intake, reduced clinical cases of disease, improved intestinal structure, and reduced the weaning to slaughter duration, while LMR + S feeding increased weaning weight, intestinal maturity, and reduced pre-weaning mortality.