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 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 d11 to weaning (at d28±1.2 of age) or LMR+S using an automatic liquid feeding system from d4 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 8 focal pigs/treatment, before weaning and at d21 and d114 PW. On d4 PW, 10 pigs/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, diarrhoea 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 d4 PW, jejunal and ileal villus height were increased by OPTIMAL hygiene and ileal sucrase activity was increased by LMR+S (P ≤ 0.05). On d4 PW, LMR+S-fed pigs from OPTIMAL farrowing pens had 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.