Ascorbic acid biosynthesis in hens producing strong and weak eggshells

Abstract

1. An experiment was conducted with two strains of layers to ascertain whether the reduction in eggshell strength occurring at the end of the production cycle is the result of reduced ascorbic acid biosynthesis. 2. Hens producing strong and weak eggshells were identified within each strain and egg production, egg weight, per cent shell, shell surface density, plasma, adrenal and hepatic ascorbic acid and renal L-gulonolactone oxidase activity were measured. 3. The strains differed in ascorbic acid synthesis, as measured by L-gulonolactone oxidase activity, and tissue ascorbic acid concentration. 4. Comparison of results from birds producing eggs of similar weight but markedly different in shell strength detected neither a shell strength group x strain interaction nor an effect of shell strength group on plasma and hepatic ascorbic acid and activity of L-gulonolactone oxidase. 5. The results did not support the hypothesis that tissue ascorbate and ascorbic acid biosynthesis are reduced in old hens producing weak eggshells.

Bombyx mori can synthesize ascorbic acid through the l‐gulose pathway to varying degrees depending on developmental stage

“…Lower vertebrates, such as fish, amphibians, and reptiles, synthesize VC only in their kidneys (Dabrowski et al, 1994). Mammals synthesize VC in the liver (Ikeda et al, 1997; Maurice et al, 2004). Enzymatic activity of GULO, which synthesizes AsA, has also been detected in the brain of Lungfish (Ching et al, 2014), but no other reports have indicated that additional species synthesize VC in the brain.…”

Strategies to Combat Heat Stress in Broiler Chickens: Unveiling the Roles of Selenium, Vitamin E and Vitamin C

“…In the research conducted by Doba et al [30], the antioxidant activity of vitamin E increased in the presence of vitamin C through reducing tocopheroxy radicals back to their active form of vitamin E. Emerging literature revealed that adult poultry are capable of synthesizing vitamin C to meet their requirements in normal conditions. However, it has been found that their requirements increase during stress, and several studies have reported the beneficial effects of the dietary supplementation of poultry feed with ascorbic acid [17,31]. Dietary supplementation with vitamin C limited and alleviated stress metabolic signs, improved performance, enhanced immunological status and reduced mortality.…”

“…In fact, chickens are confronted with three different ranges of temperature zones-the comfort zone, critical zone and upper critical zone. In the comfort zone (18-25 • C), chickens can maintain their body temperature with minimum effort, while in the critical zone (26)(27)(28)(29)(30)(31)(32)(33)(34)(35) • C), maintaining body temperature requires the help of physical heat regulation. Furthermore, in the upper critical zone (higher than 35 • C), chickens cannot dissipate their body's heat and physiological disorders appear following multi-organ dysfunction, resulting in death [4] (Figure 1).…”

Effect of chronic oxidative/corticosterone‐induced stress on ascorbic acid metabolism and total antioxidant capacity in chickens (Gallus gallus domesticus)

“…In chickens, plasma uric acid (PUA) and leucocyte oxidative activity are inversely related (Simoyi et al., 2002) but in vitamin E‐deficient chicks PUA is not indicative of plasma oxidative stress (Fuhrmann et al., 1998). Furthermore, dietary AsA reduces synthesis by feedback inhibition (Hooper et al., 2002), and numerous factors like age, breed, strain and gender influence the activity of avian l ‐gulonolactone oxidase (GLO), the rate‐limiting enzyme in the pathway (Hooper et al., 2000; Maurice et al., 2004). These factors and others could account for the unequivocal responses of chickens to dietary AsA (Kesharvarz, 1996; Creel et al., 2001) under defined conditions.…”