Sexual difference in ascorbic acid synthesis, tissue ascorbic acid and plasma total antioxidant capacity in mature chickens.

1. An experiment was conducted with commercial White Leghorn type chickens to determine the effect of gender on tissue ascorbic acid concentration, antioxidant capacity and ascorbic acid synthesis. 2. Birds reared and maintained on litter were given a standard layer diet, without supplemental ascorbic acid, from 18 weeks of age. Tissue ascorbic acid concentration, plasma total antioxidant capacity and renal L-gulonolactone oxidase activity were measured at 30 weeks of age. 3. Females and males differed in ascorbic acid synthesis, as measured by renal L-gulonolactone oxidase activity, and tissue ascorbic acid concentration. 4. Plasma total antioxidant capacity and adrenal, gonadal, plasma and pituitary ascorbic acid concentrations were significantly higher in males, whereas ascorbic acid synthesis and splenic and thymic ascorbic acid concentrations were significantly higher in females. 5. L-Gulonolactone oxidase activity was not detected in the comb of cockerels.

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

The consequences of chronic corticosterone-induced stress (CCIS) on ascorbic acid (AsA) metabolism in chickens, an animal that syntheses the vitamin, are not known. This study was conducted to determine whether CCIS alters AsA synthesis, as measured by l-gulonolactone oxidase (GLO) activity, tissue AsA, lipid peroxides and tissue total antioxidant capacity (TAC). Stress was induced by dietary administration of corticosterone from 2 to 4 weeks of age and measurements were made at 0, 7 and 14 days post-treatment. Ascorbic acid synthesis was not influenced by CCIS but hepatic, cardiac, renal, bursal and duodenal AsA concentrations were significantly decreased and plasma TAC and uric acid concentrations were significantly elevated. Stress caused significant hepatomegaly and hepatic lipidosis but hepatic peroxides were not elevated despite the slight decrease in hepatic TAC. Tissue TAC varied in different organs. It was markedly elevated in the kidney, reduced by 49% in the spleen, and changes were not detected in the heart and duodenum even though AsA concentration was significantly decreased in all tissues. We conclude that CCIS caused a significant reduction in tissue AsA concentration but did not inhibit GLO activity. The change in AsA concentration was associated with increase, decrease or no change in TAC in tissues examined. The findings suggest that CCIS may alter AsA recycling, influx or turnover in different tissues of chickens.

Ascorbic acid biosynthesis in hens producing strong and weak eggshells.

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.

Factors affecting ascorbic acid (AsA) biosynthesis in chickens. II. Effect of dietary AsA and strain of chicken.

The present study examined the effect of supplemental ascorbic acid (AsA) and ascertained if genotype is a determinant of biosynthesis and the response of strains to dietary AsA. Slow- (Ottawa Meat Control; OMC) and fast-growing (Peterson Enhanced x Hubbard; PEH) chicks were fed 1000 mg/kg AsA from 1 to 10 weeks of age. The activity of l-gulonolactone oxidase (GLO) was used to measure biosynthesis and estimated synthetic capacity (ESC) computed. Body weight was not affected by diets and relative kidney weight decreased with age. In 1 week, dietary AsA increased plasma AsA and inhibited GLO activity with a greater reduction in OMC birds. At 10 weeks, GLO activity was depressed almost uniformly in both strains. Strain by age and diet by age interactions were detected for GLO activity and ESC with significantly greater decline in PEH birds and birds fed supplemental AsA. The results demonstrated that dietary AsA inhibited biosynthesis in meat type chickens and the response at 10 weeks was not influenced by growth rate; and the age dependent decline in biosynthesis was more pronounced in the commercial PEH birds. The result suggests that such strains may be compromised in some situations. Research using multiple dietary levels of AsA, commercial strains, and defined stressors is warranted.

Factors affecting ascorbic acid biosynthesis in chickens: III. Effect of dietary fluoride on L-gulonolactone oxidase activity and tissue ascorbic acid (AsA) concentration.

The inconsistent beneficial responses to dietary ascorbic acid (AsA) may be due to dietary factors that alter biosynthesis or tissue turnover of AsA. It has been suggested on the basis of altered tissue AsA that dietary fluoride is a determinant of biosynthesis in chickens. Fluoride may enter the food chain of poultry via industrial contamination, feed ingredients and drinking water. The goal of this study was to ascertain whether dietary fluoride at 300 mg/kg influences l-gulonolactone oxidase (GLO) activity in commercial meat-type chickens. The experimental diet was fed from day-old to 3 weeks and responses measured. Growth and feed conversion were not affected by fluoride in the diet. Dietary fluoride neither inhibited nor enhanced GLO activity nor did it increase or decrease AsA concentration in plasma, liver, kidney, adrenal gland and muscle (pectoralis major). Tissue AsA concentration in ascending order was adrenal > liver > kidney > pectoralis major > plasma. The results are consistent with that reported for the rat and calculations based on the results eliminate fluorine contamination for the inconsistent responses of immature chickens to dietary AsA.

Stability of dietary ascorbic acid and the effect of supplementation on reproductive performance of broiler breeder chickens.

1. The purpose of the study was to determine the stability of dietary ascorbic acid and the reproductive responses of broiler breeder chickens to supplemental 75 mg ascorbic acid/kg diet. 2. Six breeder flocks of 13,000 birds each were studied. Egg production, eggshell porosity, fertility, hatchability and plasma ascorbic acid were measured. 3. Storage of the diets under dry heat resulted in a linear decrease in ascorbic acid content and the rate of decline was 5-fold higher in the supplemented diet. 4. Differences were not detected between treatments in egg production, egg weight, eggshell porosity, fertility, hatchability or plasma ascorbic acid. 5. The results did not provide evidence of a beneficial reproductive response to the inclusion of ascorbic acid in commercial broiler breeder diets.

Dietary prilled fat and layer chicken performance and egg composition.

Prilled and poultry fat were fed at 2% to 58-wk-old hens and at 4% to 2-wk-old hens for 8 wk. Comparisons by dietary fat source were made within age groups for BW, feed consumption, egg production, egg weight, yolk cholesterol, and fatty acid composition, egg quality, plasma cholesterol, dietary fatty acid utilization, dietary ME, and gastrointestinal transit time of feed. Old hens fed prilled fat had lower egg weight, increased egg production, lower plasma high density lipoprotein (HDL) cholesterol (P < 0.08), and reduced energy. Young hens fed prilled fat were lighter in weight and had lower plasma total and low density and very low density lipoprotein cholesterol. Young hens fed prilled fat had a lower utilization of stearic acid (P < 0.07) but a higher utilization of linoleic acid. In both groups, prilled fat increased yolk saturated fatty acids and decreased polyunsaturated fatty acids. Gastrointestinal transit time of feed was increased by 29 to 31 min (P < 0.09) in young hens fed prilled fat.

Research note: relationship of comb color to liver appearance and fat content in Single Comb White Leghorn laying hens.

A flock of commercial Single Comb White Leghorn laying hens, diagnosed as having fatty Liver Hemorrhagic Syndrome (FLHS), was surveyed to ascertain the relationship between comb color and selected FLHS characteristics. Twenty-eight hens with and without pale combs were selected from 14 cages for paired comparisons. Hens with pale combs had a higher (P less than or equal to .05) liver score and relative liver weight than hens with normal combs. Differences were not detected in BW, comb weight, relative comb weight, liver fat and plasma estrogen concentration. In flocks diagnosed with FLHS, comb appearance is associated with a higher incidence of FLHS.

Comparison of glutathione S-transferase activity in the rat and birds: tissue distribution and rhythmicity in chicken (Gallus domesticus) liver.

1. Mature, male chickens, Bobwhite quail, and rats differed with respect to glutathione S-transferase (GST) activity in the kidney, duodenum and testis, but species differences were not observed in the liver. 2. GST activity was present in the heart, spleen, liver, duodenum, kidney, testis, cerebral cortex, cerebellum, optic tecta, and medulla oblongata of chickens with differences in tissues and breeds. 3. Renal GST activity was higher in female chickens, whereas enzyme activity in the brain was higher in males. 4. Hepatic GST activity fluctuated about a mean of 784 nmol min-1 mg protein-1 with a 12 hr periodicity which was not a feeding phenomenon. 5. The results demonstrate that GST activity occurs in diverse tissues of the chicken and Bobwhite quail with kidney greater than liver greater than duodenum greater than testis, compared to testis greater than liver greater than duodenum greater than kidney in the rat. Hepatic GST activity exhibits an ultradian periodicity.

High dietary niacinamide and performance of male poults at 16 weeks of age.

1. Male poults were fed diets with 50 and 100 mg supplemental niacinamide/kg and grown at stocking densities of 3.2 and 4.3 birds/m2 from 56 to 112 d. 2. At 50 mg/kg niacinamide high stocking density (HSD) depressed 112 d body weight and gain from 56-112d. High dietary niacinamide (100 mg/kg alleviated the growth depression under HSD but decreased body weight gain under low stocking density (LSD). 3. Dressed yield and hock width were not affected by dietary niacinamide or stocking density. 4. Dressed carcase composition was altered by stocking density. The dressed carcase of HSD birds contained 3.7% more protein and 7% less fat. 5. High dietary niacinamide tended to increase carcase protein (+2.4%) and decrease carcase fat (-4.0%).

Response of male poults to high levels of dietary niacinamide.

The response was determined of male poults to high levels of dietary niacinamide, when maintained in a stressful environment of high stocking density and high litter moisture induced by excess dietary NaCl. The experiment was designed as a factorial (2 by 2 by 2) with 70 versus 140 mg of niacinamide per kg; .3 versus 1% NaCl; 7 versus 14 birds per m2. Each treatment was assigned to 6 pens, with either 20 or 40 males per pen depending on stocking density. The calculated niacin content of the basal diet was 22 mg per kg; the experimental diets contained 92 and 162 mg of total niacin per kg. Added niacinamide at 140 mg per kg increased the body weight at 8 wk of age (3,095 versus 3,198) at .3% dietary NaCl. The response to 140 mg per kg of niacinamide was 4.6% at .3% NaCl and only 1.9% at 1% NaCl. The high level of niacinamide was ineffective in terms of alleviating the growth depression induced by a high stocking density. Treatment effects were not detected in relation to feed efficiency. The incidence of leg abnormalities was not influenced by dietary niacinamide or by litter moisture, but was aggravated by a high stocking density. The treatments did not induce ascites or macroscopic lesions in the heart or kidney. These findings demonstrated that supplemental niacinamide at 140 mg per kg, in a basal diet calculated to contain 22 mg of niacin per kg of feed, will produce a significant increase in the weight gain of male poults at 8 wk of age under praxis conditions when dietary salt is at .3%, but not at 1%.

Effects of synthesized hard water and of cadmium in the drinking water upon lipid metabolism and cholelithiasis in rabbits.

Rabbits were fed a purified ration known to result in cholelithiasis and alterations in lipid metabolism. During a 12-week experimental period, either synthesized hard water (500 mg of Ca/L and 100 mg of Mg/L) or deionized distilled water were available as drinking water, and half of each of these groups of rabbits were also given 5 mg of Cd/L of water. Hair samples taken at the beginning and end of the experiment revealed an increase in the Ca concentration in rabbits given hard water, but no increase in Cd in rabbits given this element in the water. Cadmium in the drinking water resulted in accumulations of this element in liver and kidneys, and water hardness did not influence the amount of accumulation. Liver cholesterol concentrations and the severity of cholelithiasis were less in rabbits given Cd. The hard water administration resulted in lower liver cholesterol concentrations and less cholelithiasis. These results indicate that hard water does not reduce cardiovascular disease frequency by lessening Cd accumulation, but may affect cholesterol metabolism.

Influence of norethindrone on lipid metabolism and cholelithiasis in rabbits.

Rabbits were fed a purified ration containing 15% lard and were killed and examined at 0, 4, 8, 12, and 16 weeks. One group (group II) was given (treated) norethindrone in the ration (10 mg/kg of ration). There were no treatment effects noted on hepatic weight, percentages of dry matter and ether extract in liver, and hepatic cholesterol concentrations; however, there were some changes in the hepatic fatty acid percentages at some observation times. The occurrence and severity of cholelithiasis were not influenced by the treatment, but gallstone formation was pronounced in the 2 groups (ration alone, ration with added norethindrone) by the 4th weeks. The thoracic aorta did not reveal treatment effects as to weight and percentages of dry matter and ether extract, but the aortic cholesterol concentration was greater in the nontreated group than in the group fed the ration with the added norethindrone. Increased thoracic aortic weights were noted in both groups by the 4th week. Examinations and analyses of the adipose deposits forming the kidney pads did not reveal influences of time or treatment.

Influence in rats of dietary fats during the perinatal period: effects upon brain chemistry of dams and offspring.

Female rats were fed a purified ration containing 20% fat during gestation and lactation and the offspring were fed a commercial ration after weaning. The fat content of the purified ration was butter oil, a mixture of equal parts of butter oil and lard, or safflower oil. Brains of the dams were analyzed 1 month after parturition and brains of the offspring were analyzed when they were 20 weeks of age. Brains of the dams and offspring fed the safflower oil (about 75% linoleic acid) exhibited changes if comparisons were made with those fed other fats. In the dams, the percentage of cerebral weight as related to total brain weight was increased and the dry weight percentages of the cerebrum and brainstem were increased. In the cerebrums of male and female offspring, the DNA concentrations were increased and the RNA:DNA ration were decreased.