The influence of dietary calcium and phosphorus on tibial dyschondroplasia in broiler chickens

The incidence and severity of tibial dyschondroplasia in broiler chickens were increased by feeding rations containing high levels of phosphorus relative to the level of calcium. Tibial dyschondroplasia was not eliminated by feeding a ration containing 1.5% calcium and 0.5% available phosphorus. Before typical dyschondroplasia developed, chickens fed a high level of phosphorus had uniformly thickened growth plates at 2 weeks of age. The majority of this thickening was due to an increase in the zone of proliferation, identical to that which occurs in calcium-deficiency rickets.     

High vitamin D3 requirements in broilers for bone quality and prevention of tibial dyschondroplasia and interactions with dietary calcium, available phosphorus and vitamin A

1. Two experiments were carried out to investigate responses in performance and bone compositional and structural characteristics in broilers fed diets containing 4 concentrations of vitamin D3 (5, 20, 125 and 250 microg cholecalciferol/kg) at different concentrations of calcium, available phosphorus and vitamin A. 2. In experiment 1, body weight and tibia breaking strength were maximised at 14d with 250 microg vitamin D3/kg, tibia ash was maximised with 125 microg vitamin D3/kg. A high incidence of tibial dyschondroplasia (TD) was decreased to very low levels with 125 microg vitamin D/kg. 3. At 42d, performance and bone characteristics showed no response to vitamin D3 concentrations above 20 microg/kg. 4. Dietary vitamin A within the range 2-4 to 4.5 mg retinol/kg did not show any interaction with vitamin D3 status at either age. 5. In experiment 2, responses to vitamin D3 were strongly influenced by dietary calcium/available phosphorus. With 13 g calcium and 5 g available phosphorus/kg, performance and bone characteristics responded to vitamin D3 concentrations up to 125 microg/kg but more was needed at less optimal concentrations of calcium and available phosphorus. TD incidence was minimised with 250 microg/kg. 6. This study shows that high dietary concentrations of vitamin D3 can prevent TD. It is concluded that the vitamin D3 requirement of broilers up to 14 d of age at optimal dietary calcium and available phosphorus concentrations may be in the range 35 to 50 microg/kg for cortical bone quality and up to 250 microg/kg for prevention of TD. The vitamin D3 requirement for cortical bone quality after 14 d is not higher than 20 microg/kg. These requirements are much higher than earlier estimates and may be related to higher calcium requirements of modern broiler genotypes. Current regulations limiting maximum vitamin D3 concentrations in broiler starter diets may need to be reviewed.     

Effects of dietary calcium and phosphorus on mineral retention,growth, feed efficiency and walking ability in growing turkeys

1. Large White male turkeys from a heavy commercial male-line were fed on 16 diets containing 4 concentrations of calcium (6, 10, 14 and 18 g/kg) and available phosphorus (3, 5, 7, 9 g/kg) in a 4 x 4 factorial experiment with three replicates (pens). Turkeys were weighed and food intakes recorded from 4 to 7, 8 to 10 and 11 to 13 weeks of age. 2. The diets containing 6 g/kg calcium and 5, 7 or 9 g/kg available phosphorus concentrations were associated with lower body weighs at 10 and 13 weeks of age. 3. Fewer than 6% of the turkeys had an abnormal gait at 13 weeks of age. 4. The optimum dietary concentrations were 10 g/kg of calcium and 3 g/kg of available phosphorus. It was concluded that these concentrations should be fed at least to 13 weeks of age. 5. Retentions of dietary calcium and phosphorus averaged 300 g/kg of intake. 6. Utilisation of dietary phytate ranged from 5 to 11 g/kg and it is recommended that organic phosphorus should be ignored in the formulation of diets for growing turkeys unless they are supplemented with a phytase enzyme.     

Effects of dietary calcium content and vitamin D source on skeletal properties in growing turkeys

1. The aim of the study was to investigate the effects of feeding fast growing turkeys with differentiated dietary calcium (Ca) content, and the partial replacement of vitamin D₃ in the feed with 25-hydroxycholecalciferol (25(OH)D₃), on skeletal properties.

2. One-day-old Big-6 male turkeys (n?=?1008) were randomly divided into 4 groups, and two subgroups were created within each group. The groups were differentiated with 4 levels of Ca provision in the feed, namely 85% of the National Research Council (NRC) recommendation (Group Ca₁); 95% as above (Group Ca₂); 105% as above (Group Ca₃); and 115% as above (Group Ca₄). The first subgroup received the recommended dosage of cholecalciferol (vitamin D₃ subgroup) in the feed, while in the second subgroup (Hy-D subgroup), half of the dosage of cholecalciferol was replaced with 25(OH)D₃. At the ages of 4, 8, 12 and 20 weeks, 7 turkeys from each subgroup were randomly selected and killed to obtain the right tibia for densitometric, geometric and mechanical analyses.

3. This study showed advantageous effects of increased calcium supply in the diet on skeletal system properties, that were increased and produced the most desirable traits in turkeys receiving 95%, 105% and 115% of the NRC calcium recommendation. Benefits resulting from administration of 25(OH)D₃ in the diet were also obtained in the skeletal formation of turkeys, and the most advantageous effects were present in the group receiving 105% of recommended dietary Ca.

4. Effects on the metabolic response of the skeleton of turkeys to manipulation of dietary calcium content and vitamin D₃ source were the most evident in the groups between 4 and 12 weeks of life, and demonstrated a limited ability to induce a positive influence on bone properties at advanced stages of the production cycle by alteration of these dietary factors.     

Effect of casein phosphopeptide and 25-hydroxycholecalciferol on tibial dyschondroplasia in growing broiler chickens

1. An experiment was conducted to investigate the influence of dietary casein phosphopeptides and 25-hydroxycholecalciferol on the incidence of tibial dyschondroplasia (TD) in 14-d-old commercial broiler chickens. 2. Three hundred and twenty broiler chicks (one day old) were randomly allocated to one of 4 dietary treatments. A standard broiler diet was used as the control with the three experimental treatments receiving the control diet supplemented with 10 g casein phosphopeptide/kg, 14 g casein phosphopeptide/kg or 69 microg 25-hydroxycholecalciferol/kg. 3. Those birds fed the diets supplemented with 14g casein phosphopeptide/kg or 25-hydroxycholecalciferol had a lower incidence of TD than both the control and 10g casein phosphopeptide/kg treatments when assessed grossly. 4. The body weight of birds fed the 10 g casein phosphopeptide/kg diet or the 25-hydroxycholecalciferol diet was higher than birds fed the control diet. Although not significant, the body weight of birds fed the 14 g casein phosphopeptide/kg diet was also greater than the control birds. 5. The current experiment demonstrated that both casein phosphopeptide and 25-hydroxycholecalciferol can reduce the incidence of TD in the young broiler chicken. More research is required to explain the unexpected increase in body weight described above.     

Effect of dietary selenium on the development of Fusarium-induced tibial dyschondroplasia in broiler chickens

A trial was conducted to determine the effects of dietary level of selenium on the pathogenesis of Fusarium-induced tibial dyschondroplasia (FITD) in broiler chicks, and to assess the applicability of FITD as an animal model of Kashin-Beck disease of humans. Day-old female broilers were fed diets that were deficient in selenium (0.02 ppm Se), adequate in selenium (0.15 ppm Se), or generous in selenium (0.50 ppm Se). TDP-1, the toxic component of the fungus, was administered to 15 of 26 chicks in each dietary group starting at 1 week of age and continuing until the chicks were killed at 24-30 days of age. Plasma selenium levels and hepatic glutathione peroxidase activity were significantly lower in the selenium-deficient group than in other dietary groups; these parameters were not affected by treatment with TDP-1. The mortality rate of the TDP-1-treated selenium-generous group was significantly less than that in the other TDP-1-treated groups, but there were no differences in the incidence, severity, or character of the FITD lesions among the groups. Thus, the interaction of selenium and TDP-1 did not include an effect on FITD.     

The effect of dietary protein content on calcium and phosphorus retention in the growing Iberian pig

The effects of dietary protein content (DPC) from excessive (192 g/kg DM) to marginally deficient (101 g/kg DM) upon whole-body retention of Ca and P was studied in 25 purebred Iberian pigs growing from 15 to 50 kg BW by means of a comparative slaughter experiment which included a digestibility trial. Ca and P retention related to intake remained unaffected at 0.228 ± 0.0072 and 0.184 ± 0.0052, reaching 3.64 ± 0.119 and 2.00 ± 0.057 g Ca and P per day respectively. Pigs fed on diets containing protein levels in excess of requirements had significantly higher concentrations of Ca and P (P < 0.05) in their bodies (14.41–14.99 and 7.88–8.08 g Ca and P/kg fat-free empty-body gain respectively) than those given adequate or marginally deficient amounts of dietary protein (11.80–12.72 and 6.61–7.01 g Ca and P/kg fat-free empty-body gain respectively). In a second experiment, made with 25 Iberian pigs of 21 kg initial weight, daily intakes of Ca and P to maintain zero retention were determined using five experimental diets in which the concentrations of Ca and P were varied by the addition of graded levels of Ca carbonate and inorganic phosphate to a basal diet balanced in protein-to-energy ratio (131 g CP; 13.8–14.4 MJ ME/kg DM). Growth rate and protein deposition were unaffected by the level of Ca and P in the diet and reached average values of 485 ± 15.4 and 103 ± 1.2 g/d. Increasing the dietary Ca and P levels increased the absolute amounts of Ca and P retained daily from 0.69 to 5.77 and 1.12 to 3.70 g respectively (P < 0.001). Highly significant (P < 0.001) curvilinear regressions were obtained when relating Ca and P absorption or retention (g/d) with Ca and P intake (g/d). From these equations, daily maintenance requirements of 105 and 72 mg/kg BW for Ca and P respectively were obtained. Average total net requirements of Ca and P for the Iberian pig at this stage of growth were estimated to be 5.25 and 3.10 g/d respectively, considerably lower than those reported for conventional and high-performance pig genotypes.     

Late clinical expression of lameness related to associated osteomyelitis and tibial dyschondroplasia in male breeding turkeys.

A sudden outbreak of lameness related to transport stress is described in a flock of male breeding turkeys. Most of the affected turkeys exhibited obvious unilateral leg disorders. All were affected with tibial or metatarsal dyschondroplasia with at least one lesion associated with a large focus of necrosis. By histological examinations, bone lesions showed the typical feature of osteomyelitis. The inflammatory bone lesions appeared at only single isolated sites and were always associated with obvious sequestra of dyschondroplastic retained cartilage. Osteomyelitis seems to be an unexpected acute complication of previous dyschondroplasia in relation with different breeding stress situations. The resulting pain of the associated lesions could be the main cause of clinical expression of lameness. The pathogenesis of the phenomenon remains uncertain.     

Environmental temperature and dietary protein concentrations for growing turkeys

Growing turkeys were kept at one of 4 constant temperatures (14, 17, 20 or 23 degrees C) from 10 to 15 weeks of age and given a food with one of three protein concentrations (201, 229 or 294 g/kg diet). Food intakes, food conversion ratios and breast meat yields (as a proportion of body weight) were decreased at the higher temperatures but there were no significant differences in growth. At each temperature, the turkeys given the higher dietary protein concentrations had increased body weight gains but their breast meat yields were similar. Thus the poor breast meat yields which resulted from rearing at high temperatures could not be counteracted by high dietary protein concentrations.     

Effect of age of maternal flock and strain on the incidence of tibial dyschondroplasia in growing chicks.

Two experiments were conducted to study the effects of age of the maternal flock (27 vs. 57 weeks of age at time the eggs were set) and strain of broiler chicks (Cobb 500, Ross, Arbor Acres, and Avian) on the incidence of tibial dyschondroplasia (TD) in broiler cockerels grown to 3 weeks of age. The chicks were fed a corn/soybean meal-based diet containing 3145 kcal metabolizable energy corrected for nitrogen retention (MEn)/kg, 24% protein, and 0.50% available phosphorus. Each treatment was replicated four times with eight chicks per pen. In Expt. 1, chicks from the old parent flock had significantly higher body weights (P < or = 0.05) than those from the young parent flock. There were no significant differences in feed efficiency or incidence of TD. In Expt. 2, body weights, feed efficiency, and TD were unaffected by strain.     

The inheritance of tibial dyschondroplasia in broilers

1. A breeding programme to develop a line of chickens with a high incidence of tibial dyschondroplasia (TD) from Australian broiler stock is described.

2. Despite the absence of a control flock, this programme has demonstrated that selection in a broiler population can rapidly increase the incidence of TD.

3. There was consistent circumstantial evidence of the presence of a major sex‐linked gene, the recessive allele of which is associated with an increased incidence of TD.

4. The realised heritability estimates (obtained in the absence of a control flock) consistently exceeded 1.00, suggesting the presence of an environmental trend favourable to the onset of TD over the four generations of this investigation.

5. There was a high maternal component or dominance genetic component, or both, for the inheritance of TD in the final generation, suggesting that environmental factors associated with the female parent line may influence the incidence of TD in broilers.     

肉鸡胫骨软骨发育不良研究进展

胫骨软骨发育不良(tibial dyschondroplasia,TD)是发生在多种禽类的一种发展迅速的疾病,而以快速生长的肉鸡最为普遍,给肉鸡生产带来严重的经济损失。该病以胫跗骨或跗趾骨近端生长板出现无血管的白色软骨楔为特征。本文结合国内外的最新研究成果,从临床症状、病因、病理变化、防治等方面对该病进行了综述。     

不同钙磷水平日粮对钙磷在猪体内代谢的影响

钙和磷对猪来说是2种极其重要的矿物质,具有非常重要的生理功能.钙和磷在日粮中的含量不同会对自身的代谢产生相当大的影响,为进一步了解日粮不同钙、磷水平对钙磷在猪体内代谢的影响,作者将从对钙、磷的吸收,血清中钙、磷的浓度,钙、磷在体内的存留,尿中钙、磷排出量和粪中钙、磷排出量这5个方面的影响来阐述.     

Morphogenesis of Fusarium sp-induced tibial dyschondroplasia in chickens

Tibial dyschondroplasia was induced in female broiler chicks by the incorporation of 2% Fusarium roseum "Alaska" culture into their starter ration. Chicks were placed on this diet at one day of age and maintained until they were killed at four days or one week. Proximal tibial physes were grossly thickened into cone-shaped masses of cartilage by one week of age. Microscopically, lesions were in both ages of treated chickens and were characterized by thickening of the transitional zone which was especially prominent in the center of the growth plate. This zone was unmineralized, avascular, and contained chondrocytes which were crenated and densely eosinophilic. The cartilage matrix was pale and contained some patchy eosinophilic foci. Four growth plates with tibial dyschondroplasia and four normal growth plates from each of the four-day and one-week-old age groups were evaluated based on the following parameters: number of metaphyseal vascular sprouts, distance between the proliferative/transitional junction and the tip of the metaphyseal vascular sprouts, width of the tips of the metaphyseal sprouts, distance between tips of adjacent metaphyseal vascular sprouts, and number of perforating vessels in the proliferative zone. The distance between the proliferative/transitional junction and the metaphyseal sprout tips was greatly increased (p less than 0.01) in the affected four-day and one-week-old chickens compared to age-matched controls.(ABSTRACT TRUNCATED AT 250 WORDS)     

Influence of dietary phosphorus concentration on the digestibility of phosphorus in monocalcium phosphate by growing pigs

An experiment was conducted to test the hypothesis that the dietary inclusion rate of P does not influence the digestibility of P. The experiment was conducted at 4 experiment stations where the same protocol was followed. A total of 60 growing pigs (initial BW: 22.22 +/- 2.13 kg) were allotted to 6 dietary treatments with 10 replications per treatment. All pigs were placed in metabolism cages that allowed for the total, but separate, collection of urine and fecal materials. Six diets were formulated. The basal diet was based on corn (54.2%), soybean meal (20%), and cornstarch. No inorganic P was used, and the total concentration of P in the basal diet was calculated to be 0.29%. Five additional diets were formulated by adding monocalcium phosphate (MCP) in increments of 0.34% to the basal diet and thereby creating diets that were calculated to contain 0.36, 0.43, 0.50, 0.57, and 0.64% total P, respectively. Ground limestone was also added to these diets to maintain a calculated Ca:P ratio of 1.2:1. The balances of Ca and P and the apparent total tract digestibility (ATTD) of Ca and P were calculated for each diet. The contribution of P from the basal diet was then subtracted from the MCP-containing diets to calculate the balance and ATTD for P in MCP. Results of the experiment showed that the absorption and retention of both Ca and P increased (linear, P < 0.001) with increasing concentrations of Ca and P in the diet. The ATTD for Ca ranged from 62.3 to 66.8% and was not influenced by the dietary concentration of Ca. However, the ATTD for P increased from 38.4 to 65.2% as increasing levels of MCP were added to the diet (linear, P < 0.001). Increasing P intake from MCP increased (linear, P < 0.001) the excretion of P in the feces, but the quantity of P that was absorbed and retained also increased (linear, P < 0.001) as more P from MCP was added to the diet. When measured as a percentage of P intake, P retention was not influenced by the dietary P concentration. The ATTD for P in MCP ranged from 79.5 to 88.5% and was not affected by the concentration of P in the diet. Results of this experiment demonstrated that the digestibility and absorption of P from MCP are not influenced by the dietary concentration of P.     

Effects of dietary chloride and magnesium on the incidence of tibial dyschondroplasia in chickens fed on Chinese practical diets.

1. The effects of varying the concentrations of dietary magnesium and chloride on the performance, incidence of tibial dyschondroplasia and tissue element contents of broilers fed on Chinese practical maize soya-bean meal diets was assessed. 2. Two concentrations of dietary chloride (1.5 and 3.5 g/kg) and 3 of dietary magnesium (2.0, 4.0 and 6.0 g/kg) were used to form 6 dietary treatments for a 21-d experimental period. 3. Results from this study indicated that the dietary ingredients of maize and soya-bean meals produced in the northeast of China may predispose or influence the susceptibility of chickens to tibial dyschondroplasia. 4. High dietary chloride induces a high incidence of tibial dyschondroplasia (P less than 0.05) which could be ameliorated by dietary magnesium supplementation. 5. Dietary magnesium plays an anti-rachitic role by improving the deposition of copper and zinc in the bone tissue. 6. Supplementation with magnesium to 4.0 g/kg is recommended for broiler diets in northeast China.     

Modeling the fate of dietary phosphorus in the digestive tract of growing pigs

Environmental effects of excess P from manure and the soaring price of phosphates are major issues in pig production. To optimize P utilization, it is crucial to improve our capacity to predict the amount of P absorbed, while taking into account the main factors of variation. Mathematical modeling can represent the complexity of the processes and interactions in determining the digestive utilization of P in growing pigs. This paper describes and evaluates a model developed to simulate the fate of the dietary forms of P in the digestive tract of growing pigs, with particular emphasis on the effect of dietary Ca and exogenous phytase on P digestive utilization. The model consists of 3 compartments associated with specific anatomical sections: stomach, proximal small intestine, and distal small intestine. The main metabolic processes occurring in these sections are, respectively, P solubilization/insolubilization and phytate P hydrolysis, and P absorption and P insolubilization. Model parameters governing these flows were derived from in vitro and in vivo literature data. The sensitivity analysis revealed that the model was stable within a large range of model parameter values (±1.5 SD). The model was able to predict the efficacy of Aspergillus niger microbial phytase in accordance with literature values, as well as the decreased efficacy of plant phytase compared with microbial phytase. The prediction capabilities of the model were assessed by comparing actual and simulated P and Ca apparent total-tract digestibility (ATTD) based on published pig data not used for model development. Prediction of P digestibility across 66 experiments and 281 observations was adequate [P ATTD observed = 0.24 (SE, 0.943) + 0.98 (SE, 0.0196) × P ATTD predicted; R(2), 0.90; disturbance error (ED), 96.5%], whereas prediction of Ca digestibility across 47 experiments and 193 observations was less accurate (Ca ATTD observed = 11.1 + 0.75 × Ca ATTD predicted; R(2), 0.78; ED, 20.4%). A lack of agreement between experimental and simulated Ca digestibility was found. This model is, therefore, useful in evaluating P digestibility for different feedstuffs and feeding strategies. It can also be used to provide insight for improving dietary P utilization, especially from plant sources, by quantifying the effect of the mean sources of variation affecting P utilization.     

Effects of dietary calcium, available phosphorus and vitamin D on growth rate, food utilisation, plasma and bone constituents and calcium and phosphorus retention of commercial broiler strains

1. The effects of different dietary concentrations of calcium (Ca), available phosphorus (AP) and vitamin D (D) on 5- to 16-day growth performance, and aspects of calcium and phosphorus (P) metabolism of chickens from three commercial strains were studied in two experiments. 2. Increasing dietary Ca reduced weight gain, tibia Ca and P content and increased plasma total Ca, Ca consumption and excretion, whilst dietary Ca at 32 g/kg increased tibia Ca:P ratio, plasma ionized calcium and reduced plasma P, tibia ash, P excretion, excreta moisture and Ca retention. 3. Increasing dietary AP reduced plasma total and ionized Ca and excreta moisture and increased P consumption and excretion, plasma P and tibia ash. 4. The addition of vitamin D increased plasma total and ionized Ca, tibia Ca:P ratio and reduced plasma sodium and P concentrations. 5. Strains differed in their tibia contents of Ca and Ca:P ratios, in response to Ca, AP and vitamin D diets whilst they differed in Ca excretion and excreta moisture caused by feeding either dietary Ca or AP. 6. It was concluded that dietary Ca, AP, vitamin D and strain of broiler chickens influenced the metabolism of Ca and P and that, as a consequence, the tolerance to high dietary Ca. A lean strain of chickens tolerated high dietary calcium better than its fat counterparts.     

The development of tibial dyschondroplasia in broiler chickens.

Two strains of broiler chickens selected for a high and a low incidence of tibial dyschondroplasia were fed a standard broiler starter ration with and without added chloride. Development of tibial dyschondroplasia was studied by radiography and serial necropsies. Lesions of tibial dyschondroplasia were mild in the low-incidence strain, regardless of ratio. The defect was more severe in the high-incidence strain and most severe in those birds fed the high-chloride ration. An abnormal thickening of the growth plate was apparent in the high-incidence strain as early as 2 weeks of age and became progressively more severe with age. No significant differences were noted in serum calcium, phosphorus, alkaline phosphatase, pCO2, or bone ash between strains of birds or between birds of the same strain fed different rations. Birds fed the high-chloride ration had a higher serum chloride and a lower serum bicarbonate and blood pH than birds on the standard ration.