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Stage Osborne posted an update 10 days ago
Previous work has identified an effect of hatch time on chick femur mineralization. This experiment assessed the impact of hatch time and a 24-h post-hatch unfed time period on chick bone mineralization and yolk mineral utilization. In early hatching chicks, yolk Mg, Zn, K, P, Fe, and Cu decreased by 40 to 50% over the 24-h post-hatch unfed time period, whereas yolk Ca and Na decreased by 25 to 40% (P = 0.026). Yolk Sr was intermediate, decreasing by 37%. Late hatching chicks which had been hatched for no more than 30 h had a higher femur bone ash percentage compared to early hatching chicks which had spent over a 30-hour sojourn unfed in the incubator (P = 0.013). These results indicate that removing chicks from the incubator within 30 h of their hatch is likely to benefit their femoral mineralization. During incubation, embryonic growth and development are dependent on nutrients deposited in the egg. The content of the yolk can be transferred to the embryo in 2 ways directly into the intestine via the yolk stalk or through the highly vascularized yolk sac membrane. It has been suggested that, as a result of genetic selection and improved management, the increase in posthatch growth rate and concurrently the increase in metabolic rate of broiler chickens during the last 50 yr has also increased embryonic metabolism. A higher metabolic rate during incubation would imply a lower residual yolk weight and possibly lower energy reserve for the hatchling. This might affect posthatch development and performance. This review examined scientific publications published between 1930 and 2018 to compare residual yolk weight at hatch, metabolic heat production, and yolk utilization throughout incubation. This review aimed to investigate 1) whether or not residual yolk weight and composition has been changed during the 88-yr period considered and 2) which abiotic and biotic factors affect yolk utilization in poultry during incubation and the early posthatch period. It can be concluded that 1) residual yolk weight and the total solid amount of the residual yolk at hatch seem to be decreased in the recent decades. It cannot be concluded whether the (lack of) differences between old and modern strains are due to genetic selection, changed management and incubation conditions, or moment of sampling (immediately after hatch or at pulling). It is remarkable that with the genetic progress and improved management and incubation conditions over the last 88 yr, effects on yolk utilization efficiency and embryonic metabolic heat production are limited; 2) factors specially affecting residual yolk weight at hatch include egg size and incubation temperature, whereas breeder age has more influence on nutrient composition of the residual yolk. Oral administration of antibodies is a promising strategy against various infectious diseases. Previously, it was demonstrated that passive immunization by providing hyperimmune egg yolk through the feed reduces Campylobacter jejuni colonization in broilers. Campylobacteriosis is the most commonly reported bacterial foodborne zoonosis worldwide, and poultry products are the number one origin of these bacteria for human infection. To date, no effective control measures exist to limit Campylobacter colonization in the chicken’s intestinal tract. Here, the effect of lyophilization of hyperimmune egg yolk on protection of broilers against C. jejuni was investigated. During an in vivo trial, broiler chickens were prophylactically given feed with lyophilized hyperimmune or non-immunized egg yolk powder starting from day 1 after hatch. At day 11, broilers were inoculated with C. jejuni according to a seeder model. Five days later, all broilers were euthanized and cecal content was examined for C. jejuni colonization. No decrease in C. jejuni colonization was found. The freeze-drying resulted in a 16-fold decrease of the antibody titer in the yolk powder compared to the fresh yolks, presumably caused by structural changes in the antibodies. In conclusion, applying freeze-dried hyperimmune egg yolk failed to protect broilers against C. jejuni colonization, possibly because lyophilization affected the antibodies’ functionality. Duck hepatitis A virus type 1 (DHAV) infection causes duck viral hepatitis and results in enormous loss to poultry farming industry. We reported that phosphorylated Codonopsis pilosula polysaccharide (pCPPS) inhibited DHAV genome replication. Here we further explored its underlying antiviral mechanisms. see more Autophagosomes formation is essential for the genome replication of picornaviruses. In this study, Western blot, confocal microscopy observation, and ELISA methods were performed to analyze polysaccharides’ effects on autophagy by the in vitro and in vivo experiments. Results obtained from in vitro and in vivo experiments showed that Codonopsis pilosula polysaccharide did not play a role in regulating autophagy and had no therapeutic effects on infected ducklings. However, pCPPS treatment downregulated LC3-II expression level activated by DHAV and rapamycin, indicating the inhibition of autophagosomes formation. The interdiction of autophagosomes formation resulted in the inhibition of DHAV genome replication. Further study showed that pCPPS treatment reduced the concentration of phosphatidylinositol-3-phosphate (PI3P), an important component of membrane, in cells and serum, and consequently, autophagosomes formation was downregulated. In vivo experiments also verified the therapeutic effect of pCPPS. Phosphorylated Codonopsis pilosula polysaccharide treatment increased the infected ducklings’ survival rate and alleviated hepatic injury. Our studies verified the effects of pCPPS against DHAV infection in duck embryo hepatocytes and ducklings and confirmed that phosphorylated modification enhanced the bioactivities of polysaccharides. The results also stated pCPPS’s antiviral mechanisms, provided fundamental basis for the development of new anti-DHAV agents. This study investigated the prevalence of Salmonella and the molecular typing of all isolates in a goose production chain including hatchery, farm, slaughterhouse, and market. A total of 350 Salmonella isolates was detected from 1,030 samples, and 13 serotypes were recovered. The highest Salmonella contamination frequency was observed at the hatchery, which 51.8% (188/363) of samples were Salmonella positive. S. Potsdam and S. Typhimurium were the 2 most common serotypes. S. Potsdam was most frequently found in the hatchery, while S. Typhimurium was widely distributed in the goose production chain. In general, the antibiotic resistance of Salmonella isolates is low, which isolates from the market is comparatively higher than from other production links indicating a possibility of Salmonella cross-contamination in the market. By the multilocus sequence typing (MLST) analysis, 7 different ST types were identified. ST2039 was the most common ST type, which was mostly found from S. Potsdam isolates in hatchery indicating that S.