Pre- and post-natal hepatic glucose phosphorylation in chicks (Gallus domesticus)

Supply organ development of young broilers in response to increased carbohydrates and amino acids in the starter period

The growth of broiler chickens is marked by high fluctuations, varying nutrient requirement, early growth is characterized by high allometric growth rates of supply organs, which if underdeveloped, can impede nutrient efficiency and growth of demand organs like muscle and skeleton. This study aimed to investigate the impact of carbohydrate- and amino-acid-rich diets on the development of supply organs in broiler chickens. Four dietary treatments were used in a 2 × 2 factorial arrangement of treatments with apparent metabolizable energy (AME) at 2 levels (low: 2,750 kcal/kg and high: 3,050 kcal/kg) and standardized ileal digestible (SID) lysine at 2 levels (low: 1.0% and high: 1.2%) in the starter diets. Feed intake (FI) and BW gain were measured weekly; dissections were conducted at d 4 and d 11 to determine supply organ weights. Allometric growth of the liver was higher (P < 0.001) in the high AME and low lysine group compared to the other groups. For the pancreas, the highest (P < 0.001) allometric growth rate was in the high lysine groups. The small intestines responded differently; the duodenum had the highest (P < 0.001) allometric growth rate in the high AME groups and the jejunum in the low lysine groups, whereas the ileum showed an effect of diet density. For performance, high AME from carbohydrates, via maize starch, had a negative effect (P < 0.001) on FI and BW gain. High lysine had a positive effect (P < 0.001) on BW gain and FI, and high lysine alleviated part of the detrimental effect of high AME from carbohydrates. This effect was visible from d 0 to d 11, and persisted till the end of the trial on d 35. In conclusion, feeding a diet with a high AME from carbohydrates has negative consequences for the development of the supply organs of broilers.

Development of breast muscle parameters, glycogen reserves, and myogenic gene expression in goslings during pre- and post-hatching periods

This study aimed to better understand the development patterns of breast muscle and glycogen reserves in goslings during pre- and post-hatching periods. The timepoints for sampling were embryonic days 23 and 27 of hatching and days 1, 4, and 7 post hatching. We found that the body weight of goslings increased with age. The small intestine developed with age and remained reasonably constant on day 4 post hatching. The breast muscle development decreased with age and stayed relatively stable on day 1 post hatching. The diameter of myofiber increased prior to hatching and then decreased while hatching. The development patterns of breast muscle glycogen reserves were similar to the diameter of myofiber. In contrast, the contents of liver glycogen began to decrease before hatching and then increased rapidly after hatching. Moreover, the expression of Myf-5 increased with age. The expression of MSTN was maintained at high levels prior to hatching, dropped immediately after hatching, and then gradually increased with age. Additionally, we also observed that the glycogen content in the breast muscle was positively correlated with the diameter of the myofiber. The liver glycogen content was positively correlated to the relative weight of the breast muscle, the diameter of the myofiber, and the breast muscle glycogen content. The development pattern of the myofiber was synchronized with the change in the MSTN/Myf-5 ratio. This study provided a profile to understand the development patterns of breast muscle, glycogen reserves, and myogenic gene expression in goslings, which was beneficial to understanding the characteristics of energy reserves during the early life of goslings.

Effects of in ovo injection of carbohydrates on somatic characteristics and liver nutrient profiles of broiler embryos and hatchlings

Effects of the in ovo injection of commercial diluent supplemented with dextrin or with dextrin in combination with various other carbohydrates on the somatic characteristics and liver nutrient profiles of Ross × Ross 708 broiler embryos and chicks were investigated. Results include information concerning the gluconeogenic energy status of the liver before and after hatch. Eggs containing live embryos were injected in the amnion on d 18 of incubation using an automated multiple-egg injector for the delivery of the following carbohydrates dissolved in 0.4 mL of commercial diluent: 1) 6.25% glucose and 18.75% dextrin; 2) 6.25% sucrose and 18.75% dextrin; 3) 6.25% maltose and 18.75% dextrin; and 4) 25% dextrin. Also, a noninjected control and a 0.4-mL diluent-injected control were included. Body weight relative to set egg weight on d 19 of incubation (E19) was increased by the injection of all carbohydrate solutions, and on the day of hatch was increased by the injection of diluent, sucrose and dextrin, and maltose and dextrin solutions. Hatchability of the fertilized eggs, residual yolk sac weight, and liver weight were not affected by any injection treatment; however, as compared with the 0.4 mL diluent-injected group, all of the supplementary carbohydrates, except for the glucose and dextrin combination group, increased liver glycogen and glucose concentrations on E19. Furthermore, all carbohydrates, except for the 25% dextrin treatment, decreased liver fat concentration on E19. From E19 to the day of hatch, liver glycogen concentrations dropped dramatically from an average of 3.2 to 0.6%. Despite treatment differences observed on E19 for liver glycogen, glucose, and fat concentrations, these differences were lost by the day of hatch. Nevertheless, liver glycogen and glucose concentrations were positively correlated on the day of hatch. In conclusion, the in ovo injection of various supplemental carbohydrates dissolved in 0.4 mL of commercial diluent altered the liver nutrient profile of Ross × Ross 708 broiler embryos before hatch. However, the subsequent pattern of energy utilization during the hatching process modified these effects.