Low Incubation Temperature During Late Incubation and Early Feeding Affect Broiler Resilience to Necrotic Enteritis in Later Life

Abstract

Resilient animals can cope with environmental disturbances in life with minimal loss of function. Resilience can be enhanced by optimizing early-life conditions. In poultry, eggshell temperature (EST) during incubation and early feeding are two early-life conditions that are found to alter neonatal chick quality as well as immune response in later life. However, whether these early-life conditions affect disease resilience of chickens at later ages has never been studied yet. Hence, we studied the effects of EST [(37.8°C (control) or 36.7°C (lower)] during late incubation (≥embryonic days 17–19.5) and feeding strategy after hatch [immediately (early feeding) or 51–54 h delayed (delayed feeding)] on later-life broiler resilience in a 2 × 2 factorial arrangement. At hatch, 960 broilers of both sexes from a 54-week-old Ross breeder flock were equally divided over 32 pens (eight replicate pens per treatment combination) and grown for 6 weeks. Necrotic enteritis was induced by a single inoculation of Eimeria spp. at d 21 and repeated Clostridium perfringens inoculation (3×/d) during d 21–25. Mortality and body weight (BW) gain were measured daily during d 21–35 as indicators of resilience. Additionally, disease morbidity was assessed (gut lesions, dysbacteriosis, shedding of oocysts, footpad dermatitis, and natural antibody levels in blood). Results showed a lack of interaction between EST and feeding strategy for the vast majority of the variables. A lower EST resulted in lower BW gain at d 5 and 8 post Eimeria inoculation (P = 0.02) and more Eimeria maxima oocysts in feces at d 8 post Eimeria inoculation compared to control EST (P < 0.01). Early feeding tended to lower mortality compared to delayed feeding (P = 0.06), but BW gain was not affected by feeding strategy. Morbidity characteristics were hardly affected by EST or feeding strategy. In conclusion, a few indications were found that a lower EST during late incubation as well as delayed feeding after hatch may each impair later-life resilience to necrotic enteritis. However, these findings were not manifested consistently in all parameters that were measured, and conclusions are drawn with some restraint.

Effects of late incubation temperature and moment of first post-hatch feed access on neonatal broiler development, temperature preference, and stress response

“…A brief description of material and methods is provided in this section. For more details please see Wijnen et al (2021) .…”

“…Both diets did not contain coccidiostats and were provided ad libitum. The grower diet included fish meal (10%) and rye (5%) as predisposing factors for the development of necrotic enteritis after d 21 (see Wijnen et al, 2021 ). Newcastle disease (Avishield ND) and infectious bronchitis (Poulvac IB primer) spray vaccinations were administered at placement.…”

Route to resilience: long term effects of incubation temperature and early feeding in broilers

“…A brief description of material and methods is provided in this chapter. For more details please see Wijnen et al (2021).…”

“…After decapitation, blood was collected in serum tubes (Vacuette 5 ml, Greiner Bio-One), stored on ice, and serum was collected after centrifugation at 5,251 x g for 10 min at 4°C. Serum was stored at -20°C until samples were analyzed for natural antibodies against keyhole limpet hemocyanin (NAb) isotypes IgM and IgY according to an adjusted protocol from , described by Wijnen et al (2021). Titers were calculated according to the protocol from .…”

“…Consequently, it can be speculated that early feeding may enhance disease resilience at later age as well. Some indications have been found that early fed broilers have higher resilience to intestinal diseases compared to delayed fed broilers Wijnen et al, 2021). However, studies investigating effects of post-hatch feeding strategy on disease resilience are limited and resilience to respiratory diseases, such as colibacillosis, have not been studied yet.…”