Broiler resilience to colibacillosis is affected by incubation temperature and post-hatch feeding strategy

Abstract

Colibacillosis is a poultry disease that negatively affects welfare and causes economic losses. Treatment with antibiotics raises concerns on antimicrobial resistance. Consequently, alternative approaches to enhance poultry resilience are needed. Access to feed and water directly after hatch (early feeding) may enhance resilience at later ages. Additionally, a high eggshell temperature (EST) during mid incubation may improve chick quality at hatch, supporting potential positive effects of early feeding. Effects of EST [37.8°C (control) or 38.9°C (higher)] during mid-incubation (embryo days 7-14) and feeding strategy (early feeding or 48 h delayed feeding) were tested in a 2 × 2 factorial arrangement. At hatch, ̴ 1,800 broilers were divided over 36 pens and grown for 6 wk. At d 8 post hatch, avian pathogenic E. coli (APEC) was inoculated intratracheally as model to investigate broiler resilience against respiratory diseases. Incidence and severity of colibacillosis, local infection, and systemic infection were assessed at 6 moments between 3 h and 7 d postinoculation. Broilers were weighed daily during 13 d postinoculation and weekly thereafter. At higher EST, early feeding resulted in higher incidence of systemic infection compared to delayed feeding whereas at control EST, systemic infection was not different between feeding strategies. Regardless of EST, early compared to delayed feeding resulted in lower incidence of local infection, fewer BW deviations, and higher growth until d 35. In conclusion, early feeding could be considered as a strategy to enhance broiler resilience, but only when EST is not too high.

Keywords: colibacillosis; delayed feeding; early feeding; eggshell temperature; incubation.

Figure 1

Effect of the interaction between eggshell temperature (37.8°C [Control] or 38.9°C [Higher]) during mid-incubation (embryo days 7–14) with post-hatch feeding strategy (direct access to feed and water after hatch [Early] or 48 h deprivation [Delayed]) on broiler BW weekly post avian pathogenic E. coli inoculation performed at d 8. Data are presented as LSMean. Error bars indicate SEM. * indicates significant interaction between EST and feeding strategy. ^abc indicates least square means within a week lacking a common superscript differ significant. Significant = P < 0.05.

Figure 2

Effect of (A) eggshell temperature (37.8°C [Control] or 38.9°C [Higher]) during mid incubation (embryo days 7–14) and (B) post-hatch feeding strategy (direct access to feed and water after hatch [Early] or 48 h deprivation [Delayed]) and (C) interaction between incubation temperature and post hatch feeding strategy on broiler survival probability during 34 d post avian pathogenic E. coli (APEC) inoculation at d 8 post hatch. ^a-b survival probabilities differ (P < 0.05).