Tibia Weight Research Articles

Supplementary biotin decreases tibial bone weight, density and strength in riboflavin-deficient starter diets for turkey poults

1. Growth and skeletal responses to different dietary concentrations of riboflavin and biotin were compared in turkey poults from hatch to 21 d of age. The birds were fed on a turkey starter diet with different concentrations of supplementary riboflavin (0, 20 and 40 mg/kg) and biotin (0, 0.3 and 0.6 mg/kg) in a factorial design.2. Poults fed on diets with no supplementary riboflavin had poor gait scores, decreased times to sit and higher rates of culling compared to poults fed on the control diet (20 mg biotin and 0.3 mg riboflavin/kg diet). Histologically, riboflavin deficiency was associated with a peripheral neuropathy similar to that described previously in chicks and, unexpectedly, in growth plate abnormalities.3. Tibiae of poults fed on the control diet were larger, more dense, stronger and stiffer than the diets with no supplementary riboflavin.4. Increasing supplementary biotin in poults fed on diets with no supplementary riboflavin was associated with a decrease in tibia weight, density, strength and stiffness.5. The results demonstrated that riboflavin deficiency in fast-growing turkey poults was associated with growth retardation, growth plate disturbance and peripheral nerve dysfunction leading to an inability to walk.

Gender, caponization and exogenous estrogen effects on lipids, bone and blood characteristics in Taiwan country chickens

This study investigated gender, caponization and exogenous estrogen effects on lipids, bone and blood characteristics in Taiwan country chickens. Thirty male chickens were caponized at 8 weeks (capons); 15 capons were injected with estrogen (5 mg/bird estradiol 3-benzoate) every 2 weeks from 8 to 28 weeks, and 15 sham-operated male (shams) chickens and 15 females were selected for this trial. The results showed that the shams had lower relative abdominal and chest subcutaneous fat than females (P < 0.05). The estrogen-treated capons had greater relative abdominal and chest subcutaneous fat than shams and capons (P < 0.05), which might result from higher blood very low-density lipoproteins and triacylglycerol concentrations (P < 0.05). Caponization could dramatically increase relative abdominal fat (506%; P < 0.05). The shams had higher tibia weight and biomechanical properties, such as maximum bone strength and bending moment values than the capons (P < 0.05). Tibia biomechanical properties were reduced by estrogen treatment (P < 0.05). The females obtained the lowest biomechanical value in all treatments (P < 0.05). Histological examination revealed cavity formation in the cortical bone of estrogen-treated capons and female chickens, which suggested that estrogen reduced bone biomechanical properties by destroying its structural integrity.

Abstract 504: Muscle Regeneration is Impaired in Diabetic Mice

Background Sarcopenia is the degenerative loss of skeletal muscle mass which impaired quality of life in the elderly. On the other hand, sarcopenic obesity which is a loss of muscle and a concomitant increase in fat is reported to increase in life-style related diseases. Especially the prevalence of sarcopenia is greater in patients with type-2 diabetes mellitus (T2DM) than in non-diabetic subjects. However, the detailed mechanism of such muscle degeneration has not been well established. Here, we investigated muscle regeneration using muscle-injured models in life-style related disease mouse model such as angiotensin II overexpression mice for hypertension and obese diabetic mice for diabetes. Methods Male eight-week-old wild-type mice (C57BL6), Tsukuba hypertensive mice (transgenic mice carrying human renin and angiotensinogen genes) and T2DM mice (KKAy) were undergone intramuscular injection of cardiotoxin (Ctx) (100uL/10uM) into tibia. After two weeks, muscle were removed and stained with hematoxylin and eosin. KKAy replaced by bone marrow prepared from GFP-transgenic mice were generated by 8 Gy whole body X-ray irradiation. Results Treatment with Ctx showed increased muscle satellite cells where nucleuses were observed in the center of cells. In Tsukuba hypertensive mice, inflammatory cells were significantly accumulated in muscle compared with C57BL6, but muscle regeneration was not significantly impaired. KKAy mice exhibited impaired muscle regeneration. Tibia weight was a half in Ctx-injected KKAy compared with Ctx non-injected KKAy, and Ctx-injected and non-injected C57BL6 tibia. Moreover, remarkable fat deposition was observed in Ctx-treated muscle of KKAy. Such change was also observed in another diabetic mouse model, db/db, but not in streptozocin-induced diabetic mice. Fat deposition was remarkably increased in aged KKAy (6-month-old) compared with younger mice (8-week-old). In GFP-chimeric mice, fat tissue showed highly GFP-positive indicating that fat tissue was generated from marrow cells. Conclusion Diabetic mice showed significantly impaired muscle regeneration with fat deposition, suggesting that diabetes enhanced sarcopenic obesity possibly due to inhibitory effect of marrow cell differentiation.

Evaluation of varying levels of acid-binding capacity of diets formulated with various acidifiers on physical and histological characteristics of leg bones in broiler chickens

An experiment was conducted to investigate the effect of acid-binding capacity (ABC) and acidifiers in different basal diets on leg bones of broilers at 21 and 41 days of age. In a 3 × 2 × 2 factorial experiment, three levels of ABC (650, 800, and 950 mEq/kg), two mixes of acidifiers (fumaric acid and sodium diacetate and tartaric acid and calcium propionate), and two types of basal diet (optimal diet based on corn and suboptimal diet based on wheat–corn without enzyme) were assessed. Wheat–corn diet containing 650 mEq/kg ABC and tartaric acid caused the most density of femur, but fumaric acid resulted in the lowest density as compared with the other treatments at 21 days. The combination of fumaric acid and calcium carbonate improved bone density and ash percentage of tibia at 21 days. Tibia of chickens fed corn diet containing 650 mEq/kg ABC and fumaric acid had the highest density but with tartaric acid had the lowest density as compared with the other dietary treatments. However, the main effects and their interactions were not pronounced on weight, volume, and length of tibia at 21 days. Wheat–corn diet and 950 mEq/kg ABC significantly decreased phosphorus content of serum. However, the other factors and their interactions did not affect the phosphorus and calcium content of serum at 41 days. In histological traits of tibia, corn diet as compared with wheat–corn diet increased the height of proliferative zone but did not affect the hypertrophic and mineralized zones at 21 days. Tartaric acid as compared with fumaric acid significantly increased hypertrophic and mineralized zones but did not affect the proliferative zone at 21 days. The ABC at the level of 950 mEq/kg ABC significantly increased the height of hypertrophic zone but decreased proliferative and mineralized zones at 21 days. These factors and their interactions did not affect any zones of growth plate of tibia at 41 days.

Effect of formaldehyde inclusion on phytase efficiency in broilers

SUMMARY Phytase and formaldehyde-based additives (FBA) are routinely used in broiler nutrition. Phytases hydrolyze phytate, the storage form of P in plants, making organic sources of P more digestible by poultry; FBA are also used to decrease the incidence of Salmonella contamination in feeds. Though phytase activity recovered in the feed is the most common way to measure dietary phytase inclusion, FBA reduce the analyzed phytase activity in the feed. The objective of this trial was to evaluate the effect of a FBA on the efficiency of phytase in broilers. One-day-old chicks (n = 630) were allocated to 14 treatments in a 7 × 2 factorial arrangement of treatments consisting of a positive control formulated to meet nutrient requirements or a negative control with reduced available phosphorus and calcium. The negative control diet was supplemented with 5 different phytases according to supplier recommendations (enhanced Escherichia coli Quantum phytase at 500 U/kg; wild-type E. coli Finase EC at 500 U/kg; fungal Finase P at 500 U/kg; coated fungal Ronozyme NP at 1,500 U/kg; and a coated wild-type E.coli Phyzyme TPT at 500 U/kg) with or without inclusion of an FBA (Salmex, 3 kg/t) with 5 replicates per treatment and 9 birds per replicate. At d 20, animal performance was determined by feed intake and BW gain and mortality-corrected feed conversion was calculated. All birds were euthanized and left tibias were collected and weighed for ash and determination of Ca and P. Analyzed phytase activity of the feeds containing an enhanced E. coli and a wild-type E. coli were reduced with FBA inclusion. Body weight gain and tibia weight, ash, ash concentration, ash Ca and P, and P concentration were reduced when animals were fed a low-available P diet. Phytase supplementation improved all these response variables, regardless of FBA inclusion. In conclusion, FBA inclusion may negatively affect phytase activity recovered in the feed but has no effect on phytase effectiveness in vivo.

Genetic variability of metabolic characteristics in chickens selected for their ability to digest wheat1

Improving feed efficiency remains crucial for poultry production. Birds have previously been selected on their ability to digest their diet, as assessed by AMEn (Apparent ME corrected for 0 nitrogen). Such selection, for either a high (D+) or a low AMEn (D-), affects energy, nitrogen, lipid, and starch digestibility. The aim of this study was to establish whether selection on the digestive ability of birds modified metabolic traits. A total of 630 broiler chickens of the eighth generation of a divergent selection experiment on AMEn were used for this purpose. A balance trial was performed to determine energy, nitrogen, and phosphorus retention. Growth performance was recorded and body protein and lipid deposition assessed by breast and abdominal fat yields. Tibia development and mineralization were also studied and heat production was indirectly assessed through the measurement of body temperature during fasting and feeding. Phenotypic correlations estimated within line showed that an increased efficiency was associated to fatter birds and more solid bones in D- but not in D+ line, whereas increased consumption was associated with more solid bones in D+ but not in D- line. The heritability estimates for metabolic traits were relatively high, except for temperature traits (from 0.08 to 0.12), ranging from 0.28 to 0.56 for body composition, and from 0.38 to 0.77 for bone characteristics. Breast meat yield did not differ between the 2 lines whereas a slight increase in abdominal fat yield was observed in the high-digestion line (D+). The relative dry tibia weights and ash weights were greater in D+ birds (+6.56 and +8.06%, respectively) but the lengths and the diameters of the tibia were lower (-7.89 and -3.77%, respectively). Finally, AMEn was poorly correlated with almost all metabolic traits (ranging from -0.10 to 0.20), indicating that the ability of the animal to digest its diet is genetically independent of post-digestion metabolic traits.

The Effects of Melatonin on the Physical Properties of Bones and Egg Shells in the Laying Hen

Laying hens often experience unbalanced calcium utilization which can cause deficiencies in bone and egg mineralization. Because melatonin has been shown to affect bone mineralization in other animals, we examined whether treating hens with melatonin would affect eggshell thickness and improve skeletal performance, thereby reducing skeletal and egg shell defects. Birds were given a diet containing either low (30 µg/kg), medium (300 µg/kg), or high (3 mg/kg) concentrations of melatonin, or control feed through approximately one laying cycle. We examined the weight, length, and strength of egg, femur, tibia, and keel. Hens treated with a high concentration of melatonin showed significant strengthening in their femur and tibia, as measured by maximum force sustained and breaking force, compared to controls. Egg weights from hens treated with melatonin were significantly greater than those from hens that were not treated with melatonin. Conversely, egg shell mass of hens treated with melatonin was significantly lower than those of hens not treated with melatonin. Our data suggest that melatonin may affect the allocation of calcium to bone at the expense of egg shell mineralization.

Ascorbic acid insufficiency induces the severe defect on bone formation via the down-regulation of osteocalcin production

The L-gulono-γ-lactone oxidase gene (Gulo) encodes an essential enzyme in the synthesis of ascorbic acid from glucose. On the basis of previous findings of bone abnormalities in Gulo-/- mice under conditions of ascorbic acid insufficiency, we investigated the effect of ascorbic acid insufficiency on factors related to bone metabolism in Gulo-/- mice. Four groups of mice were raised for 4 weeks under differing conditions of ascorbic acid insufficiency, namely, wild type; ascorbic acid-sufficient Gulo-/- mice, 3-week ascorbic acid-insufficient Gulo-/- mice, and 4-week ascorbic acid-insufficient Gulo-/- mice. Four weeks of ascorbic acid insufficiency resulted in significant weight loss in Gulo-/- mice. Interestingly, average plasma osteocalcin levels were significantly decreased in Gulo-/- mice after 3 weeks of ascorbic acid insufficiency. In addition, the tibia weight in ascorbic acid-sufficient Gulo-/- mice was significantly higher than that in the other three groups. Moreover, significant decreases in trabecular bone volume near to the growth plate, as well as in trabecular bone attachment to the growth plate, were evident in 3- or 4-week ascorbic acid-insufficient Gulo-/-. In summary, ascorbic acid insufficiency in Gulo-/- mice results in severe defects in normal bone formation, which are closely related to a decrease in plasma osteocalcin levels.

Effects of dietary probiotic inclusion on performance, eggshell quality, cecal microflora composition, and tibia traits of laying hens in the late phase of production

Ninety-six White laying hens (64 weeks old) were used to investigate the effect of dietary inclusion of Bacillus subtilis on performance and eggshell quality. Hens were randomly distributed into three treatment groups and fed basal diet (control), basal diet plus 0.5 g/kg B. subtilis (Probiotic-0.5), or basal diet plus 1 g/kg B. subtilis (Probiotic-1) for 10 weeks. Probiotic-1 group exhibited the maximum (P<0.05) increase in egg production, egg weight, egg mass, eggshell weight, and eggshell thickness, compared with Probiotic-0.5 and the control groups. During the last week of the study, eggshell densities were 94.9, 88.7, and 65.6 mg/cm(2) in Probiotic-1, Probiotic-0.5, and the control group, respectively. The average unmarketable eggs were 1.3 %, 2.2 %, and 6.4 % in Probiotic-1, Probiotic-0.5, and the control group, respectively. Tibia weight, density, and ash content increased significantly. The average time required by B. subtilis to establish a significant effect was 3 weeks for Probiotic-1and 6 weeks for Probiotic-5. B. subtilis improved gut microflora balance, which has the potential to improve gut health and absorption efficiency. It should be possible to improve egg performance and eggshell quality of aged laying hens by dietary inclusion of B. subtilis, which will be of importance for farmers.

Can 2-oxoglutarate prevent changes in bone evoked by omeprazole?

ObjectiveProton-pump inhibitors, such as omeprazole, are widely used in the prevention and treatment of gastroesophageal diseases. However, an association between proton-pump inhibitors and the increased risk of bone fractures has been observed, especially in patients treated for extended periods. Conversely, 2-oxoglutarate, a precursor of hydroxyproline, the most abundant amino acid in bone collagen, counteracts the bone loss. The aim of the present study was to elucidate the influence of omeprazole on bone and investigate whether dietary 2-oxoglutarate supplementation could prevent the effects of omeprazole. MethodsEighteen male Sprague-Dawley rats were used. Rats received omeprazole in the diet and 2-oxoglutarate in the drinking water. Body and organ weights and serum concentrations of cholecystokinin and gastrin were measured. The femurs, tibias, and calvarias were collected. Histomorphometric analysis of bone and cartilage tissues was conducted. Bone densitometric and peripheral quantitative computed tomographic analyses of the femur and tibia were performed. ResultsOmeprazole decreased the femur and tibia weights, the mechanical properties of the femur, the volumetric bone density and content, the trabecular and cortical bone mineral content, the total, trabecular, and cortical bone areas, the mean cortical thickness, and the periosteal circumference of the femur. Omeprazole had a minor effect on the examined bone morphology and exerted negligible effects on the cartilage. 2-Oxoglutarate lowered the gastrin concentration. ConclusionsOmeprazole treatment exerts its effects mostly on bone mineralization and cancellous bone, adversely affecting bone properties. This adverse effect of omeprazole was not markedly abolished by 2-oxoglutaric acid, which acted as an anti-hypergastrinemic agent.

Phosphorus utilization in finishing broiler chickens: Effects of dietary calcium and microbial phytase

A decrease in dietary P, especially in finishing broilers (21 to 38 d old), is a crucial issue in poultry production from an environmental and economic point of view. Nevertheless, P must be considered together with other dietary components such as Ca and microbial phytase. Different corn and soybean meal-based diets varying in Ca [low (LCa) 0.37, medium (MCa) 0.57, and high (HCa) 0.77%], and nonphytate P [nPP; low (LnPP) 0.18 and high (HnPP) 0.32%] content were tested with and without microbial phytase [0 or 500 phytase units (FTU)/kg]. Feed intake, BW gain, bone mineralization, and mineral retention were examined in 144 Ross PM3 broilers (22 to 38 d old) reared in individual cages. Growth performance was not significantly affected by the treatments. Nevertheless, a numerical decrease of ADG and ADFI was observed in HCa-LnPP and LCa-HnPP associated with an increase of feed conversion ratio. Decreased dietary Ca reduced tibia ash content (Ca, linear: P < 0.001; quadratic: P = 0.034) and tibia ash weight for the highest level of nPP (Ca × nPP; P = 0.035). In parallel, increasing dietary Ca reduced the flow of retained P (P = 0.022) but also tibia ash weight in LnPP diets (Ca × nPP; P = 0.035). The responses of the animals in terms of tibia ash content and P retention were improved by the addition of microbial phytase especially for the lowest P diets (nPP × phytase, P = 0.021 and P = 0.009; respectively). Phytase increased dry tibia weight, bone breaking strength, and tibia diameter in broilers fed the highest Ca diets (Ca × phytase; P < 0.05). We conclude that is possible to decrease P levels in finishing broilers, if the Ca content is appropriate. Nevertheless, decreasing the dietary P and Ca cannot allow a maximization of bone mineralization, but the optimal threshold remains to be determined.

The effects of growth rate on leg morphology and tibia breaking strength, mineral density, mineral content, and bone ash in broilers

Fast-growing broilers are especially susceptible to bone abnormalities, causing major problems for broiler producers. The cortical bones of fast-growing broilers are highly porous, which may lead to leg deformities. Leg problems were investigated in 6-wk-old Arkansas randombred broilers. Body weight was measured at hatch and at 6 wk. There were 8 different settings of approximately 450 eggs each. Two subpopulations, slow-growing (SG; bottom quarter, n=511) and fast-growing (FG; top quarter, n=545), were created from a randombred population based on their growth rate from hatch until 6 wk of age. At 6 wk of age, the broilers were processed and chilled at 4°C overnight before deboning. Shank (78.27±8.06 g), drum stick (190.92±16.91 g), and thigh weights (233.88±22.66 g) of FG broilers were higher than those of SG broilers (54.39±6.86, 135.39±15.45, and 168.50±21.13 g, respectivly; P<0.001). Tibia weights (15.36±2.28 g) of FG broilers were also greater than those of SG broilers (11.23±1.81 g; P<0.001). Shank length (81.50±4.71 g) and tibia length (104.34±4.45 mm) of FG broilers were longer than those of SG broilers (71.88±4.66 and 95.98±4.85 mm, respectively; P<0.001). Shank diameter (11.59±1.60 mm) and tibia diameter (8.20±0.62 mm) of FG broilers were wider than those of SG broilers (9.45±1.74, 6.82±0.58 mm, respectively; P<0.001). Tibia breaking strength (28.42±6.37 kg) of FG broilers was higher than those of SG broiler tibia (21.81±5.89 kg; P<0.001). Tibia density and bone mineral content (0.13±0.01 g/cm2 and 1.29±0.23 g, respectively) of FG broilers were higher than those of SG broiler tibia (0.11±0.01 g/cm2 and 0.79±0.1 g; P<0.001). Tibia percentage of ash content (39.76±2.81) of FG broilers was lower than that of SG broilers (39.99±2.67; P=0.173). Fast-growing broiler bones were longer, wider, heavier, stronger, more dense, and contained more ash than SG ones. After all parameters were calculated per unit of final BW at 6 wk, tibia density and bone ash percentage of FG broilers were lower than those of SG broilers.

The influence of stocking density on broiler chicken bone quality and fluctuating asymmetry

Because broiler chickens are juvenile animals undergoing physical development, stocking density during rearing may influence this development. Some of these physical changes may cause welfare problems, for example, decreased bone quality, which may lead to fracture during catching and transport. Others do not influence welfare directly but can be used as indicators of the animal's ability to cope with its environment (e.g., fluctuating asymmetry). The present study evaluates the effect of stocking density on bone quality and fluctuating asymmetry. Birds were stocked at densities of 2.4, 5.8, 8.8, 12.1, 13.6, 15.5, 18.5, and 21.8 birds/m(2) from 1 until 39 d of age. Increased stocking density had a negative effect on some aspects of bone quality (tibia curvature and shear strength). Tibias were shorter at high density, possibly due to increased curvature. Several other bone quality aspects (tibia weight, torsion, and dyschondroplasia, and femur curvature and epiphysis shape) remained unaffected. Middle-toe length was the only character that showed a significant increase with increasing density when each character was analyzed separately. Nevertheless, a composite index of fluctuating asymmetry, which combined data on all 11 measured characters, tended to increase with stocking density. Such increased fluctuating asymmetry may indicate decreased welfare. However, one of the assumptions of fluctuating asymmetry is that the animal is subjected to the same environmental influences on both sides. This assumption may not be fulfilled when leg deformations occur, as these may lead to asymmetric changes in bone growth by altering the division of force over the 2 legs. In addition, leg deformations decrease the accuracy of bone length measurements made in a straight line. This raises some concerns on the applicability of fluctuating asymmetry measurements on broiler chicken legs, especially because stocking density did not effect the asymmetry of the head.

Effects of dietary supplementation of citric acid, copper, and microbial phytase on growth performance and mineral retention in broiler chickens fed a low available phosphorus diet

SUMMARY An experiment was conducted to study the effects of microbial phytase (PHY), citric acid (CA), and Cu proteinate supplementation in broilers (13 to 42 d of age) fed a low available P diet (0.25%) on growth performance, carcass characteristics, blood parameters, and mineral retention. A 2 × 2 × 2 factorial arrangement of treatments was used to evaluate 2 levels of PHY (0 and 750 phytase units/kg of diet), Cu (0 and 250 ppm), and CA (0 and 3%). The CA and Cu supplementation as well as their interaction significantly affected BW and BW gain (P < 0.05), with birds fed supplemental CA having better BW gain when fed the Cu-supplemented diet. A significant Cu × CA interaction (P < 0.05) was observed for tibia weight, in which CA supplementation resulted in increased tibia weight when birds were fed a diet not supplemented with Cu. Interaction effects between PHY and Cu were noted for tibia ash (P < 0.01) and tibia P (P < 0.05), with Cu + PHY supplementation being superior to the other treatments for tibia ash. However, tibia P was greater for the individual effects of both Cu and PHY compared with the combined effect of both additives. There was a significant interaction (P < 0.01) of PHY and CA supplementation with tibia ash percentage, in which the tibia ash (%) increased with combinations of PHY and CA. Supplementation with Cu also resulted in significantly lower cholesterol levels in the thigh muscle (P < 0.05) and serum of birds (P < 0.05). Regarding the main effects of microbial phytase (P < 0.01) and CA (P < 0.05), supplementation increased the P retention with both additives. Therefore, when a low available P diet is used after 13 d, supplementing these additives in the formulation should be considered.

Effects of dietary calcium formate inclusion on broiler performance, skeletal development, and gut maturation

SUMMARY Modern broilers grow much faster and more efficiently than their predecessors. Because of the rapid growth rates of broilers, particular attention must be given to the skeletal development of the bird. Calcium formate (CaFo) has been used as a calcium source in animal diets in the European Union for many years. The objective of this study was to evaluate CaFo in broiler diets as an alternative source of calcium. Four experimental groups (0.0, 0.5, 1.0, and 1.5% CaFo) were evaluated, with 10 replicate pens per treatment. Variables measured included BW, FCR, tibia weight, bone ash percentage, tibia breaking strength, and gut morphology. Many of the parameters measured were statistically similar to the calcium carbonate control treatment. However, the 1.0% CaFo treatment significantly increased tibia breaking strength and duodenal villus height when compared with the other treatments at the completion of grow out. Therefore, CaFo can serve as an alternative calcium source in broiler diets and may significantly improve skeletal development.

Effect of age and caponization on blood parameters and bone development of male native chickens in taiwan.

An experiment was carried out to determine the effect of age and caponization on the development blood and bone characteristics development in male country chickens in Taiwan. A total of two hundred 8-wk-old LRI native chicken cockerels, Taishi meat No.13 from LRI-COA, were used as experimental animals. Cockerels were surgically caponized at 8 wks of age. Twelve birds in each group were bled and dressed from 8 wks to 35 wks of age at 1 to 5 wk intervals. The results indicated that the plasma testosterone concentration was significantly (p<0.05) lower in capons after 12 wks of age (caponized treatment after 4 wks) than that of the intact males. The relative tibia weight, bone breaking strength, cortical thickness, bone ash, bone calcium, bone phosphorus and bone magnesium contents were significantly (p<0.05) higher in intact males, while capons had higher (p<0.05) plasma ionized calcium, inorganic phosphorus and alkaline phosphatase concentration. The plasma testosterone concentration, relative tibia weight, tibia length, breaking strength, cortical thickness, bone ash, calcium, and phosphorus contents of intact males chickens increased significantly (p<0.05) with the advance of age. In addition, the relative tibia weight of capons peaked at 18 wks of age, and declined at 35 wks of age. The bone ash, calcium and phosphorus content increased most after 14 wks of age in male native chickens in Taiwan. Also, tibia length and cortical thickness peaked at 22 wks of age. However, the peak of bone strength was found at 26 wks of age. These findings support the assertion that androgens can directly influence bone composition fluxes in male chickens. Caponization caused a significant increase in bone loss at 4 wks post treatment, which reflected bone cell damage, and demonstrated reductions in the relative tibia weight, breaking strength, cortical thickness, bone ash, calcium, phosphorus and magnesium contents, and increases in plasma ionized calcium, inorganic phosphorus and alkaline phosphatase concentration.

Growth Hormone Does Not Stimulate Early Healing in Rat Tendons

Growth Hormone stimulates bone growth and fracture repair. It acts mainly by increasing the systemic levels of IGF-1. Local treatment with IGF-1 appears to stimulate tendon healing. We therefore hypothesized that systemic treatment with Growth Hormone would also stimulate tendon healing. Rat Achilles tendons were transected and left to heal. 4 groups were studied. Intramuscular injections of botulinum toxin A (Botox) were used to reduce loading in 2 groups. The animals were randomized to twice daily injections of Growth Hormone (n=2×10) or saline (n=2×10), and killed after 10 days. Healing was assessed by mechanical testing. Muscle paralysis induced by Botox reduced the strength of the healing tendon by two thirds. Growth Hormone increased femoral and tibial length in the unloaded, and femoral and tibial weight in the loaded group. Body weight and muscle weight were increased in both. In contrast, there was no increase in the strength of the healing tendons, regardless of mechanical loading status. An increase in peak force of the loaded healing tendons by more than 5% could be excluded with 95% confidence. In spite of its stimulatory effects on other tissues, Growth Hormone did not appear to stimulate tendon or tendon repair.

The effect of different dietary sodium levels on blood mineral concentrations and tibia mineralization in turkeys

The objective of this study was to determine the effect of different dietary levels of sodium in diets with and without sodium chloride on mineral metabolism, including blood electrolyte levels and tibia mineralization parameters, in young turkeys (to six weeks of age). The influence of diets with a low (L), medium (M) and high (H) sodium content, at 0.34, 1.34 and 2.82 g/kg respectively, was compared. The content of chloride and potassium in turkey diets (1.7 - 5.9 and 11 g/kg, respectively) was above the recommended levels. The sodium-deficient diet L decreased the serum concentrations of sodium, chloride and phosphorus, and it increased the serum levels of calcium and magnesium in turkeys, compared with groups M and H. Relative to group L, different dietary sodium levels in groups M and H contributed to a similar increase in the body weights of birds (1.06 vs. 1.46 and 1.44 kg, p < 0.001) and in the absolute (4.60 vs. 6.83 and 6.62 g, p < 0.001) and relative tibia weight (0.42 vs. 0.46 and 0.46% body weight, p = 0.031). No significant differences were found between groups with respect to the content of ash, calcium and phosphorus in tibia dry matter. Supplemental sodium increased the bone density index (from 50.6 to 68.4 and 66.3 mg/mm in groups L, M and H, respectively, p < 0.001), the maximum bending moment (from 5.27 to 7.40 and 7.33 N/mm, p = 0.002) and the minimum breaking strength of tibia (from 0.136 to 0.191 and 0.189, p = 0.002). In conclusion, our study indicates that the applied dietary treatment with a moderate sodium level (1.34 g/kg) resulted in a rate of bird growth and tibia mineralization similar to those observed with the treatment with much higher Na content (2.82 g/kg).

One Alpha-hydroxycholecalciferol Improves Growth Performance, Tibia Quality, and Meat Color of Broilers Fed Calcium- and Phosphorus-Deficient Diets.

An experiment was conducted to evaluate the effects of one alpha-hydroxycholecalciferol (1α-OH D3) on growth performance, tibia quality, and skin and meat color in broilers fed calcium (Ca)- and phosphorus (P)-deficient corn-soybean meal diets. A total of 288 male Ross broilers, at 21 days of age, were randomly assigned to three treatments with eight cages per treatment. Three levels of 1α-OH D3 (0, 5, and 10 μg/kg) were added to a basal diet (0.50% Ca, 0.13% non-phytate phosphorus (NPP), and 0.35% total phosphorus (tP)) without vitamin D3. As a result of this study, the addition of 1α-OH D3 increased body weight gain (p<0.001), feed intake (p = 0.007), feed efficiency (p<0.001), tibia weight (p = 0.002), length (p<0.001), breaking-strength (p = 0.012), ash (p<0.001), Ca (p<0.001), and P content (p = 0.004). Dietary 1α-OH D3 enhanced breast meat yellowness (p = 0.015) and the length and weight of the small intestine of the broilers. Moreover, 1α-OH D3 decreased serum Ca concentration (p = 0.074) and breast meat redness (p = 0.010). These results indicate that the 1α-OH D3 improves growth, tibia quality, and meat color in broilers fed Ca- and P-deficient corn-soybean meal diets.

Comparison of Push‐In versus Pull‐Out Tests on Bone‐Implant Interfaces of Rabbit Tibia Dental Implant Healing Model

This study aimed to investigate whether push-in and pull-out tests measure mechanical properties of the bone-implant interface differently, and which test is more sensitive to changes over the healing period. Two identical self-threading dental implants (3.3×8.5mm) were placed in medial surface of the proximal condyles of left and right tibias of 20 rabbits (40 implants total). Five rabbits each were sacrificed after 1, 4, 8, and 12 weeks of healing. Push-in test was performed on one side's tibia implant and pull-out on the other side's implant, at a rate of 6mm/min. Primary and secondary implant stabilities and tibia weight were measured on all implants. The push-in test generated significantly higher failure load (p=.0001; 530N vs 279N), lower displacement at failure (p=.0003; 0.436mm vs 0.680mm), and higher interface stiffness (p<.0001; 1,641N/mm vs 619N/mm) than pull-out test. Failure load, stiffness, and secondary implant stability were significantly higher for longer compared with shorter healing periods, while displacement, tibia weight, and primary stability were not. Failure load and stiffness differed significantly for four healing times for the push-in but not for the pull-out test. Failure load was significantly correlated with secondary implant stability for both push-in (r=0.66) and pull-out (r=0.48) tests, but stiffness was significantly correlated with secondary stability only for the push-in test (r=0.72; pull-out test r=0.40). The push-in test appeared more sensitive than pull-out to changes in mechanical properties at bone-implant interfaces during healing in rabbit tibia model.