Although early nutrition has gained increasing interest in the poultry industry, the long-term effects of early access to both feed and water post-hatch on broiler chicken meat quality parameters remain underexplored. This study aimed to evaluate the impact of three distinct feed and water deprivation periods post-hatch on meat quality parameters at slaughter in both fast growing and slower-growing broilers. A total of 960 Ross 308 and 960 Hubbard Redbro broilers were hatchery hatched and randomly allocated in the hatcher to three treatment groups in which access to feed and water was provided immediately (T0), 24 h (T1) or 48 h (T2) post-hatch. Slaughter and cut yields, breast meat colour, pH, drip, thawing and cooking loss and shear force were measured at slaughter. Breast muscle myopathies (wooden breast and white striping) were scored for prevalence and severity. For the fast growing broilers, T2 birds had lower body weight (BW) compared to T0 (p = 0.011) and T1 (p = 0.045). T0 fast growing birds showed higher breast fillet yields (p = 0.015), but lower thigh (p = 0.018) and drumstick (p = 0.037) yields compared to T2 birds. Furthermore, a treatment effect was observed in the fast growing broilers for both wooden breast (p = 0.047) and white striping (p = 0.065) myopathies, with T0 broilers showing the highest prevalence for both. Additionally, higher L* values (p = 0.017) as well as greater drip loss (p = 0.025) and cooking loss (p = 0.039) were recorded in T0 compared to T2 fast growing birds. The shear force of the breast meat of the fast growing broilers also tended to be higher for T0 than for T2 (p = 0.069). In contrast, in the slower-growing broilers, significant effects were only observed for BW and carcass yield, with higher BW (p = 0.006) and carcass yield (p = 0.012) for T0 compared to T2 birds. In conclusion, early feeding immediately post hatching increased body weight and carcass yield at slaughter in both the fast and slower-growing genotype. It also deteriorated meat quality in fast growing broilers, but not in slower-growing broilers.

Corticosterone (CORT) is the primary avian stress hormone and regulates key physiological processes, but chronically elevated levels can be detrimental. This study simulated chronic stress by exogenously increasing CORT to assess effects on gait score, bone morphometry, immune indicators, and fluctuating asymmetry (FA) in broiler chickens. A total of 60 one-day-old male Ross 308 broiler chickens were allocated to six treatment groups (T0–T5; n = 10 per group). T0 received a placebo and served as the control group, while T1–T5 were gavaged daily with increasing corticosterone doses (1–5 mg/kg body weight). Treatments were administered from day 1 to day 42. CORT did not affect gait score on day 11 (p = 0.232) or day 42 (p = 0.112), but gait score was significantly correlated with body weight (day 11: p < 0.001; day 42: p = 0.004). Elevated CORT reduced bursa diameter (p < 0.001) and increased bursa follicle scores (p < 0.001), while heterophil-to-lymphocyte ratios remained unaffected (p = 0.349). Carcass and bone dimensions decreased consistently with higher doses (p < 0.001), and body weight correlated positively with all bone traits (p < 0.001). Length-to-width ratios increased with CORT dose (p < 0.001). Composite carcass FA showed dose-related variation in carcass asymmetry, with highest in T4, intermediate in T2, T3, and T5, and lowest in T0–T1 (p = 0.026). Trait-specific FA effects were detected for metatarsus length (p = 0.005) and wattle (p = 0.018), while bone FA remained unaffected (p = 0.272). Overall, exogenously increasing CORT impaired growth, suppressed immune function, and increased fluctuating asymmetry, indicating reduced developmental stability.

Providing newly hatched chicks with immediate access to feed and water (i.e. early feeding, EF) has gained increasing interest as a management strategy to improve gut health, performance and welfare in broilers. However, the effects of EF on both short- and long-term welfare status have not yet been thoroughly investigated. This study aimed to evaluate the impact of EF in hatchery-hatched chicks on animal-based welfare indicators, providing a more comprehensive understanding of the potential benefits and consequences of implementing EF strategies in the hatcher. A total of 960 Ross 308 (fast-growing) and 960 Hubbard Redbro (slower-growing) broilers, hatched in a hatcher, were randomly allocated to three treatment groups: T0 (immediate feed and water access), T1 (24 h delay to feed and water access), and T2 (48 h delay to feed and water access). Short-term welfare assessments included plasma glucose, body temperature, time of first feed and water intake and plasma arginine vasotocin levels in the first days post-hatch. Fear responses were assessed on day 11 and day 18 using the novel object test. Litter quality, walking ability and femoral head necrosis lesions were scored at the end of the production cycle to determine potential lasting effects of EF. Data were analysed per breed using mixed models. Throughout the production cycle, body weight was higher for T0 compared to T2 in both fast (p < 0.001) and slower-growing (p = 0.009) birds. Similarly, average daily feed intake tended to be higher in T0 compared with T2 in fast-growing broilers (p = 0.070) and was significantly higher in T0 than T2 in slower-growing broilers (p = 0.004), whereas no significant differences in feed conversion rate (FCR) were observed. In both broiler breeds, plasma glucose levels were higher for T0 than T2 on day 1 (p = 0.031) and day 2 (p = 0.005). Body temperature of the fast-growing birds from 10 to 48 h post-hatch was higher for both T1 (p = 0.021) and T0 (p = 0.018) compared to T2. In the slower-growing birds, body temperature was higher for T0 compared to T1 (p = 0.037) and T2 (p = 0.001) between 10 - 48 h post-hatch. In both fast- and slower-growing broilers around 50% of chicks from T0 and T1 had a filled crop at 28 h post-hatch, increasing to approximately 100% at 58 h. Water intake started earlier, with 50% of T0 chicks observed drinking between 16 and 18 h and 100% by 36 h post-hatch. In the fast-growing broilers, plasma arginine vasotocin concentrations at 48 h post-hatch were higher for T2 compared to T1 (p = 0.011) and T0 (p = 0.002). A similar difference was observed in the slower-growing birds, with higher levels for T2 than T1 (p < 0.001). For both the novel object test and litter quality, no significant differences were observed between treatments in either breed. However, on day 46, slower-growing broilers in the T2 group exhibited better gait scores (p = 0.044) and a lower incidence of femoral head lesions (p = 0.032) compared to T0 birds. In conclusion, providing chicks with EF in the hatcher advances the onset of feeding and drinking when compared with commercial hatchery practice. This earlier onset benefits multiple short-term welfare indicators in both fast-and slower-growing broilers chicks, but negatively affects long-term indicators of locomotion in slower-growing birds.

Early posthatch nutrition is an important factor influencing broiler health and welfare. This study investigated the effects of delayed access to feed on production and health-related outcomes in slower-growing Hubbard Redbro broilers throughout the production cycle. Three treatments were tested: T0 (immediate access to feed), T24 (24 h delay), and T48 (48 h delay). Physiological, morphological, and welfare-related outcomes were assessed through plasma corticosterone (CORTp), bone measurements, skeletal fluctuating asymmetry (FA), gait score, litter moisture, and femur head necrosis (FHN). Delayed posthatch feeding altered CORTp dynamics in a time-dependent manner. On d 2, T48 birds tended to have lower CORTp compared to T0 (P = 0.068) and T24 (P = 0.089), while this pattern reversed on d 3, with T0 birds showing elevated corticosterone compared to both T24 (P = 0.013) and T48 (P = 0.005). Humerus length was reduced in the T48 group (P = 0.002), and the composite FA index followed a non-linear pattern, with the lowest asymmetry in T24 and the highest in T48. No differences were found in gait score, litter moisture, or FHN. Overall, delayed posthatch feeding had measurable short-term physiological and long-term morphological effects, but did not compromise welfare-related indicators by the end of the production cycle.

As early feeding (EF) is considered a promising strategy to improve broiler welfare, performance and health, new approaches to implement EF are becoming increasingly popular in the poultry industry. EF provided in the hatcher, commonly referred to as in-hatcher feeding, can offer a solution for the feed and water deprivation period experienced by chicks in traditional hatchery systems. However, in-hatcher feeding is still developing and scientific research regarding its impact on performance, health and welfare is limited. Therefore, the present study was designed to determine specific short-term physiological responses to EF in broiler chicks hatched in a hatcher, focusing on stress indicators and indicators for inferring time to first feed and water intake. A total of 320 Ross 308 broiler chicks, housed in 32 hatching baskets (10 chicks per basket; 8 replicates per treatment), were randomly assigned to one of four post-hatch feeding treatments until 48 h post-hatch: immediate access to feed and water (FW), to feed only (F), to water only (W), or deprived of both feed and water (D). At 4, 14, 24, 36, and 48 h post-hatch, blood and tissue samples (proventriculus and residual yolk) were collected to assess chick body weight (BW), residual yolk weight, plasma osmolality, plasma arginine vasotocin (AVT), plasma corticosterone (CORT) and ghrelin mRNA. Data were analysed using mixed models with the hatching basket as the experimental unit. From 24 h - 48 h post-hatch, BW differed between treatments with FW consistently showing the highest BW when compared to the other treatments (p < 0.001). An age-related increase in plasma osmolality was observed in water deprived treatments (D and F) from 24 - 48 h post-hatch, while levels in W and FW decreased slightly (p < 0.001). In D, AVT levels increased sharply from 24 h post-hatch onwards, whereas FW consistently showed lower levels compared to D (p = 0.005). Similarly, plasma CORT concentrations were lower in FW compared to D (p = 0.010) at 36 and 48 h post-hatch. Ghrelin mRNA expression did not differ between treatments during the first 14 h post-hatch but was consistently lower in FW when compared to D, F and W (p < 0.001) thereafter. Conversely, no treatment effects were observed for residual yolk weight. In conclusion, the physiological and neuroendocrine responses observed between 14 and 24 h post-hatch suggest a transition in metabolic and hydration status that is consistent with the onset of feeding and drinking during this time window. Additionally, higher body weights and reductions in corticosterone levels were only observed when both feed and water were provided.

As a consequence of the inevitable hatch window and the processing and transporting steps in conventional hatchery practices, broiler chicks may spend up to 20 - 60 h without access to feed and water post-hatch. To assess the immediate and long-term effects of post-hatch feed deprivation, 960 Ross308 broilers were allocated to a randomized complete block design with time of hatch during the hatch window as the blocking factor. Within each block, chicks were randomly assigned to one of three treatments: immediate feed access post-hatch (T0), feed access at 24 h (T1), or 48 h biological age (BA) (T2). Performance parameters were measured at the end of each feeding phase, while relative organ weights, duodenal morphological parameters and fasted nutrient metabolite concentrations were assessed as repeated measures at 24 h, 48 h, 72 h, 96 h, days 7 and 10 BA, and at days 14, 28 and 42. Between hatch and day 11, T2 chicks had a higher average daily feed intake compared with T0 and had the highest feed conversion ratio (FCR). Overall, between hatch and day 42, T2 chicks had the least efficient FCR and tended to have the lowest body weight at the end of each feeding phase. Significant effects of post-hatch feed deprivation on the physiological measurements were limited to the relative bursa (RBW) and liver (RLW) weights and were limited to the first two weeks post-hatch, with T2 chicks having a lower RBW compared with T1 between hatch and day 11. Concurrently T1 chicks had a lower RLW compared with T0, which reversed by day 14 as T1 had higher RLW than T0. No effects of post-hatch feed deprivation were present on duodenal morphology and fasted nutrient metabolites, however the effect of sex was present in several of these and relative organ weight parameters. Due to the frequent sampling schedule, insights were gained into the development of post-hatch nutrient metabolism, which may help to further optimize nutritional composition of starter feeds for on-farm hatched broilers.