The influence of ascorbic acid on the occurrence of tibial dyschondroplasia in young broiler chickens

Effects of angel wings on morphological and histological characteristics of White Roman geese

This study aims to determine the effects of normal and angel wing on morphological and histological characteristics of white Roman geese. Angel wing is a torsion of a wing at the carpometacarpus all the way down to the end, stretching outward away from the body lateral. In this study, 30 geese were raised for observing the whole appearance, including stretched wings and morphologies of defeathered wings at 14 wk old. A group of 30 goslings was raised to observe the feature of conformation development of wing bones from 4 to 8 wk old by X-ray photography. The results show that normal wing on angles of the metacarpals and radioulnar bones has a trend greater than the angel wing group (P = 0.927) at the age of 10 wk. According to 64-slice images of computerized tomography scanner on a group of 10-wk-old geese, the interstice at the carpus joint of the angel wing was larger than that of the normal wing. The slight to moderate dilated space of the carpometacarpal joint was found in the angel wing group. In conclusion, the angel wing is torqued outward away from the body laterals at the carpometacarpus and has a slight to moderate dilated space in the carpometacarpal joint. The normal wing geese exhibited an angel that is 9.24% greater than those of angel wing geese at the age of 14 wk (130 vs. 118.5°).

Discondroplasia tibial: mecanismos de lesão e controle

A discondroplasia tibial (DT) é atribuída a uma assincronia no processo de diferenciação dos condrócitos, levando à formação de uma camada de condrócitos pré-hipertróficos e de uma cartilagem na tíbia proximal que não é calcificada, mas é resistente à invasão vascular. Além disso, tem sido proposto que, na discondroplasia tíbial, a etapa final do processo de calcificação não ocorre devido ao fato de que os efetores de alguns genes, relacionados com o mecanismo de calcificação do disco de crescimento podem apresentar algumas de suas propriedades químicas ou biológicas alteradas e/ou não serem expressos. Nesse sentido, a compreensão do mecanismo de ação e o papel das biomoléculas e dos minerais relacionados com a discondroplasia tibial poderão contribuir para o conhecimento de doenças do tecido ósseo e estabelecer estratégias de prevenção e tratamento.

Nutrition and skeletal problems in poultry

Several excellent reviews regarding nutrition and skeletal disorders have appeared in the last 20 yr. This review will cover several areas of vitamin D research, the area of feed deprivation, and bone abnormalities, because there has been considerable interest in these areas during the past 10 yr. Studies indicate that the quantitative requirement for cholecalciferol (D3) for broiler chickens is much greater than previously thought. Ascorbic acid may play a role in stimulating 1-hydroxylation of 25-hydroxycholecalciferol [25-(OH)D3], but the evidence is not clear under exactly what conditions this relationship is important in practical prevention of tibial dyschondroplasia. Studies indicate that dietary supplementation with 1,25-dihydroxycholecalciferol [1,25(OH)2D3] will reduce the incidence of tibial dyschondroplasia in three different strains of broilers bred to develop a high incidence of the disease. But it did not prevent the disease totally in the strains, unless high enough levels of 1,25-(OH)2D3 were fed to reduce growth rate. These studies indicate that these high tibial dyschondroplasia strains have a defect(s) in vitamin D metabolism. Studies continue to elucidate the role of ultraviolet light in preventing leg abnormalities. Only a few studies have been conducted on the efficacy of various vitamin D3 derivatives to prevent tibial dyschondroplasia. Feed deprivation continues to be an intriguing method of preventing tibial dyschondroplasia, and examination of exactly how this prevents the bone abnormality could open avenues for explaining the disease.

Recycling dead hens by enzyme or sodium hydroxide pretreatment and fermentation

This study was conducted to evaluate the recycling of whole dead hens into feed ingredients by enzyme or sodium hydroxide pretreatment and fermentation. Evaluation criteria included nutrient preservation, pathogenic microorganism elimination, and assays of nutritional quality. The pH levels of enzyme- and NaOH-treated hen carcasses decreased from 6.01 and 7.66 to 4.18 and 4.24, respectively, during the 21-d fermentation. Hydrogen sulfide levels were not detected on Days 1 and 3 from the enzyme treatment; however, high levels (800 ppm) were measured from the NaOH treatments. By Day 21, H2S levels of both treatments had decreased to 78 ppm. The control, enzyme, and NaOH treatments before fermentation contained high levels of Escherichia coli and Staphylococcus aureus; however, after fermentation, these potential pathogens were eliminated in the enzyme and NaOH treatments. Levels of CP, EE, and ash of the control product were higher than either the enzyme or NaOH treatment. NaOH reduced pepsin digestibility by 11% compared to the enzyme treatment. In a bioassay, the chicks fed control autoclaved hen meal (CHM) had higher (P < 0.05) feed intake, weight gain, protein efficiency ratio (PER), and net protein ratio (NPR) than enzyme-treated, fermented, and autoclaved hen meal (EHM) or NaOH-treated, fermented, and autoclaved hen meal (NHM). However, the AMEn of the CHM and EHM were higher than the NHM (P < 0.05) when evaluated using mature cockerels. These results indicated that fermentation processing of dead hens reduced the concentration of some nutrients and depressed growth performance when hen meals were fed to young chicks.

Nutritional value of enzyme- or sodium hydroxide-treated feathers from dead hens

Two feather digestion processes to remove the feathers from the carcasses of dead hens were evaluated for their impact on the nutritional quality of the resulting feather meal. There were three treatments: control (untreated feathers), a feather-digesting enzyme, and NaOH treatment. Both enzyme- and NaOH-treated feathers were easily separated from the hen carcasses. The CP level of enzyme-treated feathers after autoclaving (49.90%) was significantly less than the control and NaOH-treated feathers (94.48 and 87.31%, respectively) because of elevated ether extract levels resulting from skin and abdominal fat release during the 12-h enzyme incubation. Before autoclaving, pepsin digestibilities of enzyme- and NaOH-treated feathers were significantly higher than the control. However, after autoclaving, no significant difference was found in pepsin digestibility between the control and enzyme treatments or control and NaOH treatments. The typical limiting amino acids, methionine, lysine, and histidine, in feathers were present at greater levels in the resulting enzyme-feather meal (E-FM) compared with the NaOH-feather meal (N-FM) or control-feather meal (C-FM) on a percentage of CP basis. Cystine levels, however, were significantly lower in the E-FM and N-FM compared with that of the C-FM. In chick bioassays, no significant differences were found in protein efficiency ratio (PER) and net protein ratio (NPR) among C-FM, E-FM, and N-FM. The AMEn of E-FM (4.52 kcal/g) was significantly higher than the C-FM (3.58) or N-FM (2.79). These findings indicated that although enzyme treatment could improve the nutritional quality of feathers from dead hens, NaOH treatment was a more rapid means of separating feathers from the carcass.

Effects of ascorbic acid and 1,25-dihydroxycholecalciferol on alkaline phosphatase and tibial dyschondroplasia in broiler chickens

1. The effects of graded amounts of dietary ascorbic acid with or without 10 micrograms/kg dietary 1,25-dihydroxycholecalciferol on performance, blood and bone variables were measured in broiler chicks. 2. 1,25-Dihydroxycholecalciferol prevented the tibial dyschondroplasia and rickets caused by feeding a low calcium diet. Gain:food was decreased, but body weight was not affected by feeding 10 micrograms/kg 1,25-dihydroxycholecalciferol. Phytate phosphorus retention was increased by dietary 1,25-dihydroxycholecalciferol. 3. Dietary ascorbic acid did not influence the incidence of tibial dyschondroplasia, but did reduce the incidence of rickets at a dietary concentration of 250 mg/kg. Gain:food was increased when 250 or 500 mg ascorbic acid/kg diet were added along with 10 micrograms/kg 1,25-dihydroxycholecalciferol in one of two experiments. 4. Alkaline phosphatase activity and plasma 1,25-dihydroxycholecalciferol were not affected by the dietary treatments. Plasma 25-hydroxycholecalciferol concentration was decreased by dietary 1,25-dihydroxycholecalciferol. 5. Ascorbic acid had no synergistic effects with 1,25-dihydroxycholecalciferol on the blood and bone variables investigated in broiler chickens at the dietary concentrations of 1,25-dihydroxycholecalciferol used in this work.

Influence of large doses of ascorbic acid on performance, plasma calcium, bone characteristics, and eggshell quality in broilers and Leghorn hens

Four experiments were conducted using broilers (Experiments 1 and 2) or White Leghorn hens (Experiments 3 and 4) to determine the effects of large doses of dietary ascorbic acid on performance, plasma concentration of total and ionic calcium, bone characteristics, and eggshell quality. A total of 564 male broilers were fed diets containing ascorbic acid (ranging from 0 to 3,000 ppm) from 3 to 7 wk of age. Weight gain and feed conversion were measured, and blood plasma was analyzed for total and ionic calcium. Leg bones (femur, tibia, and metatarsus) were analyzed for bone mineral content, density, and breaking strength. In Experiments 3 and 4, a total of 484 Leghorn hens were fed diets containing ascorbic acid (ranging from 0 to 3,000 ppm) for 4 wk. Egg weight and specific gravity were determined, and plasma and tibiae were analyzed as in Experiments 1 and 2. Results of the broiler experiment (Experiment 2) indicated that plasma ionic calcium was significantly increased (P < .05) in ascorbic-acid-treated birds. Among leg bones examined, femur strength was improved by 16% in birds fed 2,000 ppm of ascorbic acid (Experiment 2). Other bone characteristics were not affected. In the layer experiments (Experiments 3 and 4), egg weight increased up to 5% and egg specific gravity was improved in hens fed 2,000 or 3,000 ppm of ascorbic acid, which also had increased calcium in the blood. Results suggest that large doses of ascorbic acid in the diet influence calcium metabolism, affecting bone and eggshell mineralization in chickens.

Development of a serum-free system to study the effect of growth hormone and insulinlike growth factor-I on cultured postembryonic growth plate chondrocytes

We have developed a serum-free system to culture postembryonic growth plate chondrocytes while maintaining some important phenotypic characteristics of their tissue of origin. This serum-free medium was as effective as medium containing 10% newborn bovine serum (NBS) for recovering the cells from enzymatic isolation. Surface secretory activity of chondrocytes cultured in monolayer, assessed through scanning electron microscopy, was also comparable to cells grown in medium containing serum. The effects of growth hormone (GH) and insulinlike growth factor-I (IGF-I) were also studied using the serum-free medium. GH had no effect on cell density and morphology of the cells compared to the control without the hormone. In contrast, chondrocytes grown in medium containing IGF-I had a marked increase in cell density after 3 days and presented similar morphologic characteristics to cells grown in the presence of NBS. The growth factors required for proliferation of chondrocytes cultured in the serum-free medium are IGF-I and fibroblast growth factor (100 ng/ml, respectively). Addition of ascorbic acid to the serum-free medium (0 to 50 micrograms/ml) produced a dose-dependent decrease in cell proliferation. This medium should provide a useful tool for studying the effects of different growth factors/hormones in the regulation of longitudinal bone growth and their interactions.

Effect of vitamin C, environmental temperature, chlortetracycline, and vitamin D3 on the development of tibial dyschondroplasia in chickens

Seven experiments were conducted to test the influence of dietary supplementary ascorbic acid on the development of tibial dyschondroplasia in broiler chickens. Ascorbic acid supplementation significantly reduced the incidence and number of birds with a large mass of cartilage in the tibia in the first experiment but not in the two subsequent experiments. Because environmental temperature, microbial infection, and vitamin D3 status had been reported in the literature to influence ascorbic acid metabolism in the chicken, experiments were conducted to see if these variables could influence supplemental ascorbic acid effects on development of tibial dyschondroplasia. Results of the experiments indicated that none of these factors influenced the effect of ascorbic acid on the development of tibial dyschondroplasia. The presence of vitamin D3 in the diet significantly influences the incidence of this disorder.