Chick Quality Research Articles

Comparison of Chick Quality, Health, and Inflammation from Two Hatchery Environments

Comparison of Chick Quality, Health, and Inflammation from Two Hatchery Environments

Effects of Chick Quality and Pre-Starter Feed on Fattening Performance and Carcass Characteristics of Broilers

Effects of Chick Quality and Pre-Starter Feed on Fattening Performance and Carcass Characteristics of Broilers

Improving the incubation results by sealing the eggshell of cracked hatching eggs with surgical tape

In broiler breeder production, up to 2% of hatching eggs are rejected because of cracked or broken shells. Eggs with cracks give a reduced hatchability and a lower chick quality and cause economic loss. The main goal of this study was to determine the effect of sealing eggshell cracks with surgical tape on hatching parameters. A total of 3,000 eggs from a 34 weeks old Cobb 500 broiler breeder flock was used in the experiment. Six hundred intact eggs represented a positive control. Other eggs were artificially cracked by the operator either on the first day of storage (1,200 eggs) or on the fourth day of storage (1,200 eggs). In both groups, cracks on 600 eggs were sealed by the adhesive surgical tape while the other 600 eggs remained untreated and were used as a negative control. Within each experimental group, eggs were assigned randomly to 4 setter trays representing 4 replicates of 150 eggs. The egg weight loss during incubation was the highest (P < 0.01) in groups of nonsealed cracked eggs. The egg weight loss in sealed groups was higher compared to the control group (P < 0.01). Percentage of egg contamination was not different between groups. Embryonic mortality was higher in non-sealed groups in all stages of embryonic development (P < 0.01) compared to groups of sealed cracked eggs and the control group. Hatching percentage was significantly lower in non-sealed groups (P < 0.01) compared to sealed groups and positive control. No significant difference in hatching parameters was observed between sealed groups and positive control, indicating that surgical tape can be used for sealing cracks on the eggshell to support embryonic survival.

Effect of Chick Quality on Viability, Performance Traits and Meat Quality Characteristics of Broiler Chickens

The chick quality in broiler production is a major factor that has a direct impact on the profitability of both hatcheries and producers. In recent years, there has been considerable interest in the correlations between chick quality, which is measured by quantitative or qualitative methods, and yield characteristics. This study aims to compare the viability, performance traits, and meat quality characteristics of broiler chickens classified into two chick quality categories based on the Tona score method. In the study, broilers in the first-grade group had a lower mortality rate of 1.67%, while the average mortality rate of those with poor chick quality was 23.33% (P&amp;lt;0.05). There were no statistically significant correlations between post-hatch performance and chick quality characteristics such as Tona score, chick weight, chick length (all P&amp;gt;0.05). According to the Tona score, there were no differences between the mean values of body weight, feed efficiency, Gompertz growth curve parameters, slaughter carcass traits, and meat quality characteristics of first- and second-grade broiler chickens (all P&amp;gt;0.05). Although there is no difference between high and low quality chicks in terms of performance characteristics, it is possible that the use of low quality chicks in conventional broiler production will increase the general mortality of the flock. Due to their superior yield potential, it is recommended that low-quality chicks be utilized in more suitable production systems without culling, rather than in conventional broiler production.

Effects of hatching system on chick quality, welfare and health of young breeder flock offspring

Alternative hatching systems have been developed for broiler chickens to provide immediately feed and water after hatch and reduce the number or severity of early life stressors. Besides beneficial effects of these alternative hatching systems on chick quality and performance, broiler health and welfare may be positively affected as well. Especially offspring from young broiler breeder flocks may benefit, as they have been shown to be more sensitive to preturbations than offspring from older breeder flocks. This study evaluated effects of hatching systems on chick quality, health and welfare of young breeder flock offspring, using 3 different hatching systems: conventional hatchery-hatched (HH), hatchery-fed (HF), and on-farm hatching (OH). A total of 24 pens were used in a completely randomized block design, with 8 pens per hatching system and 30 chickens per pen. Chick quality at hatch and performance until 35 d of age was improved in the HF and OH compared to HH treatment, but only minor effects were found on the welfare indicators: footpad dermatitis, hock burn, cleanliness, skin lesion and gait score. No effect was observed on the dynamics of a humoral immune response after NCD vaccination, given at d 0 and 14 of age, as no differences between NCD titers were found at d 18. Animals were vaccinated with a live attenuated infectious bronchitis vaccine virus (IBV) at d 28 to address treatment related differences to disease resilience. The expressions of inflammation and epithelial integrity related genes in the trachea and histo-pathological changes in the trachea were examined at 3 d after vaccine administration. No differences between treatment groups were observed. Although beneficial effects of HF and OH systems were found for young breeder flock offspring on chick quality at hatch and body weight posthatch, only one effect of alternative hatching systems on welfare and health indicators were found. No effect of hatching system on humoral immune response or disease resilience was found.

Toxico-pathological effects of ochratoxin A and its diastereoisomer under in ovo conditions and in vitro evaluation of the toxicity of these toxins against the embryo Gallus gallus fibroblast cell line

Herein, we conducted a comparative study on the embryotoxicity of ochratoxin A (OTA) and its diastereomer 2'R-ochratoxin A (2'R-OTA) under in ovo conditions, as well as assess the in vitro embryotoxicity of these substances together with ochratoxin B and α-ochratoxin, using chicken (Gallus gallus domesticus) embryo cell lines. In ovo tests involved egg incubation of 8 different groups (i.e., control "0"-no puncture or injection (standard incubation); "00"-punctured eggs without injection; "OTA 0.25," "OTA 0.50," "OTA 0.75," "2'R-OTA 0.25," "2'R-OTA 0.50," "2'R-OTA 0.75"-eggs containing OTA or 2'R-OTA at 0.25, 0.50, and 0.75 µg/egg concentration, respectively). The results confirmed OTA's impact on early and late embryo mortality, where chick hatchability decreased with increasing toxin dosage. Both OTA and 2'R-OTA demonstrated embryotoxicity, however, in the case of the highest OTA diastereomer dose, nearly 11% higher chick hatchability was observed compared with the group that received OTA. 2'R-OTA dosage did not reduce parameters chick quality compared to chicks hatched from control group eggs. OTA concentrations were higher than 2'R-OTA detected in chicken organs such as liver and kidney, whereas 2'R-OTA concentrations were higher in blood serum and heart. The presented studies highlighted the differences in the ability to accumulate toxins in certain organs, which, to a certain extent, may affect the potential toxicity on individual organs. Additionally, during in vitro tests, when assessing the cytotoxic effects of OTA and its analogues toward the chicken embryonic cell line in an MTT assay, the cell metabolic activity was inhibited to a comparable extent at 27-times higher concentration of 2'R-OTA than OTA (0.24 µM). Also, comparably lower toxicity was attributed to the remaining OTA derivatives.

Research Note: Responses of broiler chickens to in ovo feeding with clove and cinnamon extract under hot-humid environments

An experiment was carried out to evaluate the responses of broiler chickens to in ovo injection of aqueous extracts of clove and cinnamon under a hot-humid environment. The study involved the use of seven hundred hatching eggs from broilers (Ross 308) which were incubated with the use of standard protocol (37.8°C). The incubating eggs (100 each) were randomly selected and assigned to 7 treatments on day 17.5 of incubation, viz.: un-injected eggs (UE), eggs injected with 0.5 mL distilled water (DW), 2 mg clove (CL2), 4 mg clove (CL4), 2 mg cinnamon (CN2), 4 mg cinnamon (CN4), and 3 mg ascorbic acid (AA).Data on physiological parameters, hatchability, chick quality, and anatomical characteristics of the chicks were collected and analyzed using one-way analysis of variance. The results obtained revealed that the hatchability of eggs of AA and CN2 was higher compared to DW and UE. However, the hatchability of DW and UE was higher than those of CN4. The total chick quality scores of the control were similar to the other groups. Chick weights at hatch were similar in CL2, CN2, and AA but heavier than CN4, CL4, UE, and DW. The chick-to-egg ratio in AA was comparable to CL2 and CN2 but higher than UE, DW, CN4, and CL4. Total scores for chick quality of AA birds were similar to those of UE, CL2, and CL4 birds but higher than DW, CN2, and CN4 birds.

Effects of in ovo injection of black cumin (Nigella sativa) extract on hatching performance of broiler eggs

Abstract The objective of this research is to state the impact of black cumin (Nigella sativa) extract in ovo injected at different doses on the hatchability of Cobb 500 Broiler fertile eggs. Injected doses of black cumin were 3 and 6 mg, applied to the air sac of the eggs on the 17.5th day of incubation. It has been established that, black cumin extract given to fertile broiler eggs had a positive effect on chick weight and chick length, but did not have a significant impact on hatching power and chick quality.

Thermal manipulation modifies embryonic growth, hepatic free amino acid concentrations, and hatching performance in layer-type chicks

Thermal manipulation (TM) of incubation temperature has been demonstrated to alter metabolism and post-hatch thermotolerance in broiler strains (meat-type chickens). Fewer reports were focused on layer-type chickens and there was no report on amino acid metabolism during TM in layer-type embryos. In this study, we investigated the effects of TM on embryonic development, hepatic amino acid metabolism, and hatching performance in layer-type chickens. Fertilized eggs were incubated under control thermoneutral temperature (CT, 37.6°C) and TM with high temperature (TMH, 39°C, 8 h/day) or low temperature (TML, 20°C, 1 h/day) from embryonic day (ED) 8 to ED 15. The embryonic weight and relative embryonic weight (yolk-free embryonic weight to the initial egg weight) significantly declined in the TML group at ED 13 (P < 0.01) and ED 16 (P < 0.0001), and were significantly increased (P < 0.001) in the TMH group at ED 16, in comparison with the embryos in the CT group. The concentrations of all hepatic free amino acids were significantly increased (P < 0.01) with embryonic development. Interestingly, TMH and TML caused similar effects on hepatic amino acid metabolism, in which most of the essential and non-essential amino acids were significantly declined (P < 0.05) under TM treatments at ED 13 but not affected at ED 16. Until hatching, TML, but not TMH, caused a significant (P < 0.05) delay (31-38 min/day from ED 8) in incubation duration. The hatchability in the TML group was lower than the other two groups, which indicated that 20°C as cold stimulation was not suitable for layer embryos. The body weight, yolk weight, yolk-free body mass, and chick quality were not affected by TM treatments. However, the relative weight of the liver, but not the heart, was significantly reduced (P < 0.05) at hatching by TML treatment. In conclusion, TML, but not TMH, caused to delay in embryogenesis and affected the internal organ of chicks at hatch. Similar changes in amino acid metabolism under TMH and TML indicated that thermal stress induced by both high and low extreme ambient temperatures influences embryonic amino acid metabolism in a similar fashion in layer-type embryos.

Effects of In Ovo Injection of α-Ketoglutaric Acid on Hatchability, Growth, Plasma Metabolites, and Antioxidant Status of Broilers.

Recently, α-ketoglutaric acid (AKG) has gained importance as an antioxidant. Its dietary supplementation in animals and humans has proved beneficial. Moreover, an extensive group of studies on in ovo feeding has proved that it produces better day-old chicks and overall performance. Combining the two, we hypothesized that in ovo feeding of AKG could improve the antioxidant status in addition to chick quality and broiler performance. At 17.5 days of incubation, eggs were divided into one of five groups: eggs that received (i) no injection (U-CON), (ii) distilled water (DDW) only (0 AKG), (iii) 0.5% AKG dissolved in DDW (0.5 AKG), (iv) 1.0% AKG dissolved in DDW (1.0 AKG), or (v) 1.5% AKG dissolved in DDW (1.5 AKG). Chicks were raised until 21 days of age. Biological samples were collected on day 0 and day 21. Body weight (p = 0.020), average daily gain (p = 0.025), and average daily feed intake (p = 0.036) were found to quadratically increase with the amount of AKG during the grower phase. At day 0, the absolute (p = 0.040) and relative weight (p = 0.035) of the liver increased linearly with an increasing amount of AKG. The 0.5 AKG group had significantly higher plasma protein (p = 0.025), absolute and relative heart indices at day 0 (p = 0.006). An in ovo feeding of AKG improved the plasma antioxidant capacity of chicks at day 0 as compared to 0 AKG. AKG effect was seen on the plasma antioxidant balance, which increased linearly with the increasing dose of in ovo AKG. Furthermore, 1.0 AKG and 1.5 AKG showed a significant (p = 0.002) upregulation of the hepatic mRNA expression of nuclear factor erythroid 2-related factor (NRF2) in comparison to 0 AKG. The results imply that without negatively affecting hatchability performance, in ovo feeding of AKG has beneficial effects on the antioxidant status of broilers.

The effect of injecting HEPES buffer into eggs of broiler breeder ROSS 308 before storage on the hatching characteristics and chick quality

The experiment studies the injection of a HEPES buffer into the stored eggs in three groups (14 days for the first group, 7 for the second, and 4 for the third). It also investigates the prolongation of the storage period of hatching eggs by injecting them with HEPES buffer in addition to its effect on the qualitative hatching characteristics and chicks specification. The groups of eggs were injected with HEPES buffer of (H50 mM, H75 mM) concentration and then stored for 14, 7 and 4 days. The eggs were brought in groups from the fields of broiler mothers, ROSS 308 breed, from the Modern Poultry Company in (Wasit, Azizia). The first group of 294 days old (42 weeks) was stored for 14 days. The second group of age 308 days (44 weeks) was stored for 7 days and the third, at the age of 311days, was stored for 4 days. The eggs were divided into 15 treatments of 30 eggs each. At the end of the storage period, the results of the experiment show that injecting HEPES buffer with a concentration of H50 and H75 helps reduce the pH value of the white and yolk in the eggs of the treatments that are stored for 4 and 7 days. As for the treatments of eggs stored for 14 days, the buffer does not help to reduce the pH value of the white and yolk at the end of the storage period. The results of the experiment also show significant superiority of (P≤0.05) in the percentage of hatching of the fertilized eggs injected with the buffer. The results also show there is an effect of the injection on the chick weight (gm) and chick length CRL (cm) in the treatments of the eggs stored for 4, 7 and 14 days. The results of the internal specifications of the hatched chicks show superiority in the relative weight of the gizzard, the glandular stomach, and the intestines of the injected eggs (14 and 4 days storage). The same characteristics were superior with the injection of H75 buffer into treatments of 7 days stored eggs.

Floor eggs: Hatchability, microbiological analysis, and effects of post-hatch use of ceftiofur on performance of broiler chicks

The present study aimed to determine the effects of egg type (nest clean or floor eggs) on eggshell microbiological, hatching performance, chick quality, yolk sac microbiology, and the interaction between egg type and post-hatch use of ceftiofur on broiler performance at 7, 14, 21, 28 and 35 days. A total of 2500 fertile eggs were obtained from a commercial flock of Cobb Slow® broiler breeders. Half of the eggs were collected directly from the floor, and the other half were collected from the nests. Microbiological evaluation of eggshells was performed before and after sanitization. After hatching, 420 male chicks were randomly selected and distributed in a completely randomized design in a 2 × 2 factorial scheme, separated by the type of egg (clean nest or floor) and the inclusion or not of subcutaneous ceftiofur, totaling four treatments. Egg type did not influence hatchability although the contamination level was 1.3% higher. The body weight and body weight gain of chicks at seven days were greater for chicks from nest eggs that received ceftiofur than chicks from floor eggs that also received ceftiofur. There was no interaction between the studied factors or individual effects for performance at 14, 21, 28, and 35 days. It is concluded that incubation of floor eggs, after standard sanitization, does not influence the hatch results and chick quality. Furthermore, it has been proven that the use of ceftiofur is unnecessary when there is correct management during broiler rearing.

High nest failure but better nestling quality for early breeders in an alpine population of Northern Wheatear (Oenanthe oenanthe)

Climate change is leading to the advancement of spring conditions, resulting in an earlier snowmelt and green‐up, with highest rates of change in highly seasonal environments, including alpine habitats. Migratory birds breeding at high elevations need to time their arrival and lay dates accurately with this advancement, but also with the annually variable spring conditions at their breeding sites, to maximize nest survival probabilities and reproductive output. Nest survival probability and mean nestling mass were analysed in relation to lay date and habitat conditions in an alpine population of the migratory Northern Wheatear Oenanthe oenanthe collected over six consecutive breeding seasons in the Western Italian Alps. This open grassland species showed the lowest nest survival probability in years with an early onset of spring conditions. Within‐season, nest survival was highest when breeding late, at lower elevations, and when grass cover and grass height were higher. Both across‐ and within‐season, severe weather conditions may indirectly lead to higher early season nest failure rates by increasing predation risk. By contrast, mean nestling mass, and thus the quality of the fledglings, was lower when breeding late. This might be driven by a mismatch with the peak in food abundance. Breeding early is thus generally advantageous in terms of chick quality in our high‐elevation population, but reproductive success is limited by the risk of nest failure that is higher in early springs and early in the season. This trade‐off between breeding early and late may thus allow Northern Wheatears to maximize fitness under highly variable spring conditions. However, climate change may cause disruption to this trade‐off, and shifts in phenology could become a threat for migratory alpine birds that might not be able to keep track of advancing spring conditions.

Evaluation of in ovo feeding of low or high mixtures of cysteine and lysine on performance, intestinal morphology and physiological responses of thermal-challenged broiler embryos.

The objective of this study was to evaluate the effect of in ovo feeding cysteine, lysine or their combinations on the perinatal and post-hatch physiological responses of broiler embryos exposed to heat stress during incubation. A total of two thousand fertile eggs of broiler breeders (Ross 308) flock (at 38 weeks of age) were used for this study. In the first 10 days, the eggs were incubated using the conventional protocol of relative humidity and temperature of 55% and 37.8°C respectively. From day ten onward, the temperature was increased to 39.6°C for 6 h per day. On day 17.5, 1,500 eggs with the evidence of living embryos were randomly selected and assigned to 6 treatments having five replicates of 50 eggs each. The treatments were: un-injected eggs (UI), eggs injected with only 0.5 ml distilled water (DW), 3.5 mg/egg cysteine (CY), 2mg/egg lysine (LY), 3.4 mg cysteine+2 mg lysine (CLH) and 1.7 mg cysteine+1 mg lysine (CLL). On day 21, the hatchability, anatomical characteristics, chick quality and the antioxidant status of the chicks were evaluated. During the post-hatch phase, data were collected on the haematology, biochemical parameters, growth performance and intestinal morphology of the birds. The results revealed that the hatchability of CY chicks was higher (p < 0.05) than in the other treatments, while the lowest values were recorded in CLH. The hatching muscle of the chicks of CLL was similar to those of CY but higher (p < 0.05) than the others. The MDA of DW and UI chickens was similar and higher than birds in the other treatment groups. The serum SOD of CLL birds was comparable to that of CY but higher than the values recorded in the other treatments. The final weights of CLL chickens were similar to those of LY but significantly higher (p < 0.05) than those of the other treatments. The duodenal villus heights of the birds of CLL were higher than those of the other treatment groups, whereas the villus height of the birds of CLH was higher than those of UI, DW and CY. Overall, in ovo feeding of cysteine alone improved the hatchability of thermally-challenged broiler embryos. In contrast, a low-dose mixture of cysteine plus lysine improved the post-hatch growth performance.

Evaluation of dried Khat (Catha Edulis) leaf as natural additives on egg quality, embryonic mortality, and chick quality of white leghorn layers

An experiment was conducted to evaluate the effects of supplementation of Khat leave as a natural feed additive on egg quality, fertility, embryonic mortality, hatchability, and chick quality of White Leghorn (WL) layers. One hundred fifty-six hens and twenty-four cocks of WL at twenty-four weeks of age were randomly dis-tributed to four treatments, each replicated three times with thirteen layers and two cocks per replication and kept on a deep litter system. Treatment rations were formulated by the addition of Khat leave on layers ration with the proportion of 0% (T1), 0.2% (T2), 0.4% (T3), and 0.6% (T4). All data were subjected to analysis of variance. The egg weight of layers in T3 (54.1) was higher (P&lt;0.05) than that of layers in T4 (51.5) and T1 (51.8). Roche color reading was significantly higher for T4 (4.7±0.19) than T3 (3.4±0.19), T2 (2.2±0.19), and T1 (1.7±0.19). There were no significant differences (P &gt; 0.05) among treatments in yolk height, yolk index, yolk diameter, albumen height, Haugh unit, fertility, hatchability, chick weight, and visual score. Embryonic mortality percentage was significantly (P&lt;0.05) higher for T1 than for other treatments. Chick length was significantly (p&lt;0.05) higher in T2, T4, and T3 than in T1. Finally, this study can be concluded that the use of dried Khat leaves as an additive up to 0.6% in ration of White Leghorn layers increased eggshell weight and yolk coulor and reduced embryonic mortality.

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

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.

Improved offspring performance of broiler breeder hens fed amino acid complexed trace minerals

The present study aimed to evaluate the effects of partial substitution of inorganic trace minerals ( ITM ) by amino acid complexed minerals ( AACM ) on broiler breeder hens’ performance and offspring. A total of 640 Cobb 500 broiler breeder hens, 22 wk of age, were allocated to four dietary treatments: T1- (Control) contained ITM forms of Zn, Mn, Cu, Fe and Se at 100, 100, 10, 50 and 0.30 ppm, respectively; T2- (Partial replacement) of Control by AACM Zn, Mn, Cu, and Se at 60, 60, 3, and 0.15 ppm of ITM, and 40, 40, 7, and 0.15 ppm of AACM, respectively.; T3- (Partial replacement) of Control, same as T2 but with Fe at 10 and 40 ppm of ITM and AACM, respectively; T4- (On Top) supplementation of Zn, Mn, Cu, Se and Fe (T1+T3). Laying production was evaluated from 26 to 66 wk, whereas egg quality was evaluated at 35, 45, 55, and 65 wk of age. At each period, eggs were incubated and evaluated for hatchability parameters and chick quality. At 66 wk of age, eggs were incubated to obtain 800-day-old male chicks for the progeny performance trial. Total and settable egg production and incubation parameters were not affected by supplementation treatments (P > 0.05). Eggshell breaking strength significantly increased (P < 0.05) in the On Top supplementation group compared to the Control. The offspring from hens fed partially Zn, Mn, Cu, Se and Fe AACM had higher body weight gain ( BWG ) in the first week (P < 0.05) and maintained a smaller feed conversion ratio ( FCR ) from 1 to 35 d compared to the offspring of Control ITM group (P < 0.05). Maternal AACM supplementation increased offspring BWG and FCR from 1 to 7 d and 1 to 35 d, respectively.

Impact of growth curve and dietary energy-to-protein ratio of broiler breeders on offspring quality and performance

The impact of growth curve (GC) and dietary energy-to-protein ratio of broiler breeder hens on chick quality and broiler performance was investigated. Pullets (n = 1,536) were randomly allotted to 24 pens and assigned to 1 of 8 treatments from hatch onwards, according to a 2 × 4 factorial arrangement with 2 GC (standard growth curve = SGC or elevated growth curve = EGC, +15%) and 4 diets, differing in energy-to-protein ratio (96%, 100%, 104%, and 108% AMEn diet). At 28 and 36 wk of age, 60 hatching eggs per maternal pen were selected for incubation and 768-day-old broilers were assigned to 32 pens according to maternal treatment.Broilers from EGC breeders were 1.9 g heavier at hatch (P < 0.001) and 36 g heavier at slaughter (P = 0.001) than broilers from SGC breeders due to a 1.0 g/d higher growth rate (P = 0.003) and 1.5 g/d higher feed intake (P = 0.006) from hatch to 32 d of age. An increase in breeder dietary energy-to-protein ratio resulted in a linear decrease in embryonic mortality in the first 3 d of incubation (β = -0.2% per % AMEn; P = 0.05). At hatch, broiler BW decreased with an increasing breeder dietary energy-to-protein ratio (β = -0.1 g per % AMEn; P = 0.001), whereas at slaughter broiler BW increased with an increasing breeder dietary energy-to-protein ratio (β = 3.2 g per % AMEn; P = 0.02). This was due to a linear increase in growth rate (β = 0.1 g/d per % AMEn; P = 0.004) and feed intake (β = 0.1 g/d per % AMEn; P = 0.02). Additionally, an increase in breeder dietary energy-to-protein ratio resulted in a linear decrease in body weight corrected feed conversion ratio (β = -0.002 per % AMEn; P = 0.002). Overall, it can be concluded that a higher GC of breeders and an increase in breeder dietary energy-to-protein ratio enhances offspring performance.

Eggshell temperature during early and late incubation affects embryo and hatchling development in broiler chicks

This study aimed to investigate effects of eggshell temperature (EST) during early and late incubation on embryo and hatchling development of broiler chicks. A total of 720 eggs were randomly allocated to 3 treatment groups: control EST (37.8°C during the first 14 d and 36.8°C between d 15 and 21 of incubation), early high EST (as control, but 38.9C between d 4 and 7), and late high EST treatment (37.8°C during the first 14 d and 38.2°C between d 15 and 21). At d 18 of incubation, the length of the femur, tibia, and metatarsus were found to be lower in the early high EST treatment than in both other treatment. Hatchability was higher in the early high and control EST treatment than in the late high EST treatment (Δ = 4.2% on average; P = 0.02), whereas the opposite was found for late term embryonic mortality (Δ = 4.0% on average; P = 0.02). Navel score was higher for the late high EST treatment than for the early high EST and control treatment (1.36 vs. 1.19 and 1.17, respectively; P < 0.001). At hatch, chick weight, and organ weights were lower in the late high EST treatment than in the control treatment, with the early high EST treatment in between. At hatch, most femur, tibia, and metatarsus characteristics were lower for the early high EST treatment compared to both other treatments. The same was found for tibia ash, Ca, and P concentrations. Blood ALP and P levels were higher in the control group than in both other treatment groups. It can be concluded that early high EST particularly affected bone development during incubation, whereas late high EST particularly resulted in a decline in hatchability and chick quality in broiler chicks.

Longitudinal study on background lesions in broiler breeder flocks and their progeny, and genomic characterisation of Escherichia coli

In broiler breeders, background mortality is rarely addressed, however, it represents the death of a vast number of birds, a constant productivity loss, welfare concerns and it might affect chick quality. The study aimed to unveil lesions leading to mortality in a study population perceived as healthy, combined with whole-genome sequencing (WGS) of Escherichia coli, a well-known contributor to disease problems in poultry. Broiler breeders (n = 340) originating from three distinct, putative healthy flocks and their progeny (n = 154) were subjected to a comprehensive post-mortem examination, bacteriological sampling, and sequencing of 77 E. coli isolates. Productivity data confirmed an exemplary health status of the enrolled flocks, and post-mortem examination further verified the absence of general disease problems. Among the submitted broiler breeders, exudative peritonitis (31.2%) was the most frequent lesion linked to infectious disease, whereas airsacculitis, pericarditis, perihepatitis, and salpingitis occurred in 18.5%, 3.5%, 3.8% and 17%, respectively. Yolksacculitis occurred in 15.6% of the broilers, whilst pericarditis, perihepatitis and peritonitis were diagnosed in 9.7%, 7.1% and 9.1%, respectively. WGS revealed a diverse population where ST95 dominated the population retrieved from broiler breeders, whereas ST10 was highly prevalent among broilers. Both lineages could be isolated from extraintestinal sites of birds without lesions indicative of infection. In general, the genetic diversity within flocks was comparable to the diversity between farms, and the overall occurrence of resistance markers was low. In conclusion, a comprehensive insight into lesions associated with background mortality is presented, together with a vast diversity of E. coli isolated from extraintestinal sites during a non-outbreak situation.