Effect of a commercial product containing canthaxanthin for in ovo feeding to broiler embryos on hatchability, chick quality, oxidation status, and performance

Ethoxyquin attenuates enteric oxidative stress and inflammation by promoting cytokine expressions and symbiotic microbiota in heat-stressed broilers

Intestinal oxidative stress in broilers is produced by chronic heat stress (HS) and has a negative impact on poultry performance as it induces intestinal inflammation and promotes the invasion of gram-negative bacteria, such as bacterial lipopolysaccharide (LPS). Therefore, dietary inclusion of the antioxidant compound, ethoxyquin (EQ), could improve enteric antioxidant capacity, immune responses, and the epithelial barrier, and maintain the symbiotic gut microbiota community. To investigate the effects of EQ supplementation on alleviating enteric oxidative stress in heat-stressed broilers, 200 one-day-old male Ross 308 broilers were randomly assigned to 4 groups (n = 50 chicks/group; n = 10 chicks/replicate) and fed a basal diet supplemented with 0 (CT), 50 (EQ-50), 100 (EQ-100), and 200 (EQ-200) mg EQ/ kg-1 for 5 wk. The chicks were raised in floor pens inside the broiler farm at a temperature and humidity index (THI) of 29 from d 21 to d 35. Growth performance traits, relative organ index, hepatic antioxidant enzymes, serum immunity, total adenylate, and cytokine activities were improved in the EQ-50 group (linear or quadratic P < 0.05), promoting the relative mRNA expression of cytokine gene-related anti-inflammatory and growth factors. A distinct microbial community colonised the gut microbiota in the EQ-50 group, with a high relative abundance of Lactobacillus, Ligilactobacillus, Limosilactobacillus, Pediococcus, Blautia, and Faecalibacterium compared to the other groups. Dietary supplementation with 50 mg EQ/ kg-1 for 5 wk attenuates enteric oxidative stress and intestinal inflammation by enhancing serum immune and cytokine content (IgG, IL-6, and TGF-β,) and symbiotic microbiota in heat-stressed broilers. EQ promotes the expression of Hsp70, SOD2, GPx 4, IL-6, and IGF-1 cytokine gene-related anti-inflammatory and growth factors in heat-stressed hepatic broilers. Collectively, EQ-50 could be a suitable feed supplement for attenuating enteric oxidative stress and intestinal inflammation, thereby promoting the productivity of heat-stressed broilers.

Dietary Canthaxanthin Supplementation Promotes the Laying Rate and Follicular Development of Huaixiang Hens

Canthaxanthin(CX) is a ketocarotenoid, which is widely used in poultry production as a lipophilic antioxidant. Huaixiang chickens are a local breed in China famous for their excellent meat quality; improving their laying rate via nutritional regulation has attracted extensive attention. The aim of this study was to evaluate the effects of dietary CX on the laying rate and follicular development in Huaixiang hens. A total of 180 Huaixiang hens were randomly divided into five groups with six replicates, and six chickens per replication. The control group (CON) were fed a basal diet, and the treatment group (NT) were fed a basal diet supplemented with 4, 6, 8 and 10 mg/kg CX. All chickens were 26 weeks old, living at an average environmental temperature of 25 ± 2 °C with a relative humidity of 65-75%. The results showed that supplementing the CX improved the laying rate and large white follicles (LWF) number (p < 0.05) and increased the concentration of reproductive hormones (LH, FSH, E2 and Prog) (p < 0.05), and the basal diet supplemented with 6 mg/kg CX worked best. Moreover, CX could increase the activities of antioxidant enzymes SOD and GSH-Px (p < 0.05) and reduce the content of the lipid peroxidation product MDA in Huaixiang chickens (p < 0.05); again, 6 mg/kg CX was best. In conclusion, dietary CX had positive effects on the laying rate, ovarian structure, reproductive hormone secretion, follicle development, and the antioxidant capacity of Huaixiang hens, and 6 mg/kg CX was recommended to be added to the diet of Huaixiang chickens.

Bibliographical Mapping of Research into the Relationship between In Ovo Injection Practice and Hatchability in Poultry

Recent advances in poultry practice have produced new tools enabling the poultry industry to increase productivity. Aiming at increasing production quality, varying protocols of in ovo injection facilitate the introduction of exogenous substances into the egg to complement the nutrients that support embryonic development up to hatching, which are already available in the internal and external compartments. Due to embryonic sensitivity, adding any substance into the egg can be either advantageous or disadvantageous for embryonic survival and can influence hatch rates. Thus, understanding the relationship between poultry practices and production rates is the first step towards successful commercial application. This review aims to assess the influence on hatch rates of injecting different substances in ovo, including effects on embryo and chick health parameters where these are reported. Bibliographic mappings of co-authorship of citations, co-occurrence of keywords, and bibliographic coupling based on the in ovo injection technique and hatchability parameters were also performed. Using the Scopus database, 242 papers were retrieved, reviewed, and submitted for bibliographic mapping using the VOSviewer^® software. This review provides a broad overview of just over 38 years' research on the subject, revealing that studies have significantly increased and peaked in 2020, being produced primarily by US researchers and published primarily in the journal Poultry Science. It also reveals that despite negative reports relating to some substances in the embryo, in ovo delivery of substances may possibly change the poultry industry for the better in terms of production rates (hatchability) and/or poultry health.

Results of hatching and rearing broiler chickens in different incubation systems

Hatchery efficiency is based on hatchability and the number of salable chicks. The hatchery sector has been seeking new alternatives to optimize production rates, including the use of different systems (multistage [MS] or single-stage [SS] machines) to improve incubation conditions. The present study aimed to compare results for hatchability, chick quality, and broiler performance of chicks from 2 incubator systems—MS and SS. The experimental design for hatchability, hatch window, egg weight loss, and chick performance variables was completely randomized with 2 treatments (MS and SS). Performance variables were analyzed as a 2 x 2 factorial arrangement (incubator type x chick sex). Egg weight loss between incubation and transfer was higher for eggs incubated in MS (P < 0.05). Hatchability was higher for eggs incubated in SS (P < 0.05), and chicks in SS had a longer hatch window (P < 0.05). Embryo diagnosis revealed higher final mortality for embryos incubated in MS (P < 0.05), as well as higher percentages of alive and dead pipped and cracked eggs (P < 0.05). Physical quality was better for chicks from SS (P < 0.05). There was no interaction between the studied factors for performance results (P > 0.05). Incubator type did not affect broiler performance for any of the studied ages (P > 0.05), whereas male broilers had better performance than females (P < 0.05). The SS incubation system proved better than the MS system at meeting embryo requirements during embryo development, with better hatching rates and chick quality, although performance variables were not influenced by incubation type.