Effects of herbal choline as a replacement for choline chloride on myopathy, locomotor system, and hepatic health of broilers

The objective of this study was to evaluate the effects of replacing choline chloride with a plant source of choline on the locomotor system, liver health, and development of breast myopathies in broilers aged 1-42 days of age. We allocated 1,120 one-day-old Cobb broilers to four treatment groups and fed them commercial diets based on corn and soybean meal. The treatments included choline in the form of 1,800.00 mg/kg choline chloride; 1,350.00 mg/kg choline chloride + 450.00 mg/kg herbal choline; 900.00 mg/kg choline chloride + 900.00 mg/kg herbal choline; and 1,000.00 mg/kg herbal choline. Each treatment group had eight replications. Throughout the experiment, gait score, footpad dermatitis, hock burn, and leg deformities (valgus and varus) were evaluated in the birds at 28 and 35 days of age. After slaughter, parameters such as breast myopathies, tibial dyschondroplasia score, and histological slides of the pectoral muscle, liver, and proximal tibial epiphysis were assessed. The results demonstrated good hepatic and locomotor health in the broilers, as no classical signs of choline deficiency were observed. Statistical analyses indicated no significant differences between treatments in terms of liver and locomotor health, suggesting that broilers fed diets supplemented with the plant source did not experience choline deficiency. Additionally, no statistically significant differences were found between treatments regarding breast myopathies. Overall, the tested choline plant source can effectively replace choline chloride in broiler diets.(AU)

Dietary supplementation with glycosaminoglycans reduces locomotor problems in broiler chickens.

This study aimed to assess the influence of glycosaminoglycan (chondroitin and glucosamine sulfates) supplementation in the diet on the performance and incidence of locomotor problems in broiler chickens. A completely randomized design was carried out in a 3 × 3 factorial scheme (3 levels of chondroitin sulfate -0, 0.05, and 0.10%; and 3 levels of glucosamine sulfate -0, 0.15, and 0.30%). Each treatment was composed of 6 replications of 30 broilers each. The performance of broilers (average weight, weight gain, feed intake, feed conversion, and productive viability) was assessed at 7, 21, 35, and 42 d of age, whereas the gait score, valgus and varus deviations, femoral degeneration, and tibial dyschondroplasia were assessed at 21 and 42 d of age. Increasing levels of glucosamine sulfate inclusion linearly increased the weight gain from 1 to 35 and from 1 to 42 d of age of broilers (P = 0.047 and P = 0.039, respectively), frequency of broilers with no femoral degeneration in the right and left femurs, and the proliferating cartilage area of proximal epiphysis at 42 d of age (P = 0.014, P < 0.0001, and P = 0.028, respectively). The increasing inclusion of chondroitin and glucosamine sulfates led to an increase in the frequency of broilers on the gait score scale 0 (P = 0.007 and P = 0.0001, respectively) and frequency of broilers with no valgus and varus deviations (P = 0.014 and P = 0.0002, respectively) also at 42 d of age. Thus, chondroitin and glucosamine sulfates can be used in the diet of broiler chickens to reduce their locomotor problems.

The Investigation of the Relationship Between HSP-27 Release and Oxidative DNA Damage in Broiler Chickens with Tibial Dyschondroplasia by Using Histopathological and Immunohistochemical Methods

Tibial dyschondroplasia (TD) is a skeletal disorder that occurs in the proximal metaphyses of tibiotarsus and sometimes tarsometatarsus, resulting in the development of avascularized and non-mineralized abnormal cartilage and causing significant economic loss. In this study, we aimed to show the histopathological changes and the relationship between the release of Heat-Shock Protein 27 (HSP-27) and oxidative DNA damage in broiler chickens with tibial dyschondroplasia, using histopathologic and immunohistochemical methods. Our study material consisted of totally 20 animals out of 42 days old 205 Ross 308 broiler chickens, 10 with TD lesions and 10 healthy control subjects. Tissue samples taken from animals performed necropsy was exposed to routine tissue follow-up. Macroscopically, unilateral and bilateral thickening and swelling were observed in the growth plates of tibiotarsal joints of the broiler chickens diagnosed with tibial dyscondroplasia. Histopathologic examination of the tibiotarsal joints of broiler chickens affected by TD revealed an increase in the number of immature chondrocytes, as well as deficiencies in vascularization and calcification. In the immunohistochemical study; HSP-27 and 8-OHDG release was positive in the chondrocytes located on the Proliferative Zone, Maturation Zone and Hypertrophic Zone. However, the positivity was the most profound in the PZ and MZ, while less in the HZ chondrocytes. As a result; we demonstrated by immunohistochemical methods that the increase in the HSP-27 release is parallel to the increase in 8-OHDG release in TD lesioned areas and this may be related to oxidative stress.(AU)

The Investigation of the Relationship Between HSP-27 Release and Oxidative DNA Damage in Broiler Chickens with Tibial Dyschondroplasia by Using Histopathological and Immunohistochemical Methods

Tibial dyschondroplasia (TD) is a skeletal disorder that occurs in the proximal metaphyses of tibiotarsus and sometimes tarsometatarsus, resulting in the development of avascularized and non-mineralized abnormal cartilage and causing significant economic loss. In this study, we aimed to show the histopathological changes and the relationship between the release of Heat-Shock Protein 27 (HSP-27) and oxidative DNA damage in broiler chickens with tibial dyschondroplasia, using histopathologic and immunohistochemical methods. Our study material consisted of totally 20 animals out of 42 days old 205 Ross 308 broiler chickens, 10 with TD lesions and 10 healthy control subjects. Tissue samples taken from animals performed necropsy was exposed to routine tissue follow-up. Macroscopically, unilateral and bilateral thickening and swelling were observed in the growth plates of tibiotarsal joints of the broiler chickens diagnosed with tibial dyscondroplasia. Histopathologic examination of the tibiotarsal joints of broiler chickens affected by TD revealed an increase in the number of immature chondrocytes, as well as deficiencies in vascularization and calcification. In the immunohistochemical study; HSP-27 and 8-OHDG release was positive in the chondrocytes located on the Proliferative Zone, Maturation Zone and Hypertrophic Zone. However, the positivity was the most profound in the PZ and MZ, while less in the HZ chondrocytes. As a result; we demonstrated by immunohistochemical methods that the increase in the HSP-27 release is parallel to the increase in 8-OHDG release in TD lesioned areas and this may be related to oxidative stress.

Tibia bone integrity in broilers subjected to cyclic heat stress / Integridade óssea de tíbias de frangos de corte submetidos ao estresse cíclico de calor

Macroscopic and microscopic changes in the epiphyseal region of the tibia were recorded in the 42nd day of life of broilers subjected to one-hour heat stress in different rearing phases. The treatments comprised both broilers reared under room temperature and humidity conditions from the 1st to the 42nd day of life (control) and broilers subjected to heat stress from the 16th to the 21st, from the 22nd to the 42nd, and from the 16th to the 42nd day of life. The adopted design was completely randomized with six replicates; 35 broilers were used in each experimental unit. Fragments from the epiphyseal region were extracted and sectioned lengthwise for macro and microscopic analyses. Data on tibia lesion scores were analyzed by Kruskal Wallis test at 5%. The one-hour cyclic heat stress did not change the morphologic integrity in the epiphyseal region of the tibia in the different treatments. Broilers subjected to one-hour cyclic heat stress did not develop lesions that suggested tibial dyschondroplasia, regardless of the rearing phase.(AU)

Foram estudadas alterações macroscópicas e microscópicas na região epifisária da tíbia no 42º dia de frangos de corte submetidos ao estresse cíclico de calor por uma hora em diferentes fases de criação. Os tratamentos compreenderam aves criadas em condições naturais de temperatura e umidade relativa do primeiro ao 42º dia de idade (controle), ou estressadas por calor do 16º ao 21º dia, do 22º ao 42º dia e do 16º ao 42º dia. O delineamento utilizado foi o inteiramente casualizado com seis repetições sendo 35 aves por unidade experimental. Para análises macro e microscópicas da tíbia, fragmentos da região epifisária foram extraídos e seccionados longitudinalmente. Os dados de escores de lesões tibiais foram analisados pelo teste de Kruskall Wallis a 5%. O estresse cíclico por calor por uma hora não alterou a integridade morfológica da região epifisária da tíbia nos diferentes tratamentos. Frangos de corte submetidos por uma hora diária ao estresse de calor não desenvolvem lesões sugestivas de discondroplasia tibial independente da fase de criação.(AU)

Tibia bone integrity in broilers subjected to cyclic heat stress / Integridade óssea de tíbias de frangos de corte submetidos ao estresse cíclico de calor

Macroscopic and microscopic changes in the epiphyseal region of the tibia were recorded in the 42nd day of life of broilers subjected to one-hour heat stress in different rearing phases. The treatments comprised both broilers reared under room temperature and humidity conditions from the 1st to the 42nd day of life (control) and broilers subjected to heat stress from the 16th to the 21st, from the 22nd to the 42nd, and from the 16th to the 42nd day of life. The adopted design was completely randomized with six replicates; 35 broilers were used in each experimental unit. Fragments from the epiphyseal region were extracted and sectioned lengthwise for macro and microscopic analyses. Data on tibia lesion scores were analyzed by Kruskal Wallis test at 5%. The one-hour cyclic heat stress did not change the morphologic integrity in the epiphyseal region of the tibia in the different treatments. Broilers subjected to one-hour cyclic heat stress did not develop lesions that suggested tibial dyschondroplasia, regardless of the rearing phase.

Foram estudadas alterações macroscópicas e microscópicas na região epifisária da tíbia no 42º dia de frangos de corte submetidos ao estresse cíclico de calor por uma hora em diferentes fases de criação. Os tratamentos compreenderam aves criadas em condições naturais de temperatura e umidade relativa do primeiro ao 42º dia de idade (controle), ou estressadas por calor do 16º ao 21º dia, do 22º ao 42º dia e do 16º ao 42º dia. O delineamento utilizado foi o inteiramente casualizado com seis repetições sendo 35 aves por unidade experimental. Para análises macro e microscópicas da tíbia, fragmentos da região epifisária foram extraídos e seccionados longitudinalmente. Os dados de escores de lesões tibiais foram analisados pelo teste de Kruskall Wallis a 5%. O estresse cíclico por calor por uma hora não alterou a integridade morfológica da região epifisária da tíbia nos diferentes tratamentos. Frangos de corte submetidos por uma hora diária ao estresse de calor não desenvolvem lesões sugestivas de discondroplasia tibial independente da fase de criação.

Photogrammetry: a non-invasive and objective method for detecting locomotion problems in broiler chickens

Locomotion problems in broiler chickens can cause economic losses of up to 40% of the total revenues due to carcass condemnation and downgrading at processing. Leg disorders, such as femoral lesions, tibial dyschondroplasia, and spondylolisthesis, substantially impact the welfare of chickens as these disorders can prevent birds from reaching the feeders and drinkers, thus reducing feed and water intake. The most important issues related to broiler welfare reported in the last two decades are their growing sensitivity to metabolic and locomotion problems due to the fast growth rates and inactivity. Traditional methods for the determination of gait score include the manual scoring of animal behavior in the broiler house. Recorded video images can also be used for manual scoring of chicken gait score. However, scoring of some animal-based information by human experts and manual methods remain difficult, time consuming and expensive when implemented at farm level. In an effort to objectively detect leg disorders, this study aimed at validating the photogrammetry technique as a non-invasive method for identifying locomotion problems in broilers. Photogrammetry allows determining the geometric properties of broilers from digital photos that are processed and analyzed using a computer software. Results obtained using photogrammetry were tested for their correlation with those obtained by accepted methodologies, including gait score and macroscopic examination of femoral degeneration and tibial dyschondroplasia. The photogrammetry results agreed with the results of the afore mentioned accepted methods.(AU)

Photogrammetry: a non-invasive and objective method for detecting locomotion problems in broiler chickens

Locomotion problems in broiler chickens can cause economic losses of up to 40% of the total revenues due to carcass condemnation and downgrading at processing. Leg disorders, such as femoral lesions, tibial dyschondroplasia, and spondylolisthesis, substantially impact the welfare of chickens as these disorders can prevent birds from reaching the feeders and drinkers, thus reducing feed and water intake. The most important issues related to broiler welfare reported in the last two decades are their growing sensitivity to metabolic and locomotion problems due to the fast growth rates and inactivity. Traditional methods for the determination of gait score include the manual scoring of animal behavior in the broiler house. Recorded video images can also be used for manual scoring of chicken gait score. However, scoring of some animal-based information by human experts and manual methods remain difficult, time consuming and expensive when implemented at farm level. In an effort to objectively detect leg disorders, this study aimed at validating the photogrammetry technique as a non-invasive method for identifying locomotion problems in broilers. Photogrammetry allows determining the geometric properties of broilers from digital photos that are processed and analyzed using a computer software. Results obtained using photogrammetry were tested for their correlation with those obtained by accepted methodologies, including gait score and macroscopic examination of femoral degeneration and tibial dyschondroplasia. The photogrammetry results agreed with the results of the afore mentioned accepted methods.

Bone characteristics of broilers supplemented with vitamin D

Vitamin D is added to broiler diets to supply its physiological requirement for bone formation. The fast growth rate of modern broilers is often associated with poor bone formation. Increasing vitamin D supplementation levels and the use of more available sources have applied to try to prevent leg problems, to increase carcass yield, and to improve the performance of broilers. The present study evaluated three vitamin D supplementation levels (1) 3,500 IU (control); (2) control + 1,954 IU of 25-hydroxycholecalciferol; and (3) control + 3,500 IU of vitamin D in broiler diets supplied up to 21 days of age. The objective was to investigate if the vitamin D levels above the recommendations could reduce leg problems in broilers. In this experiment, a total of 1,296 one-day-old male and female Cobb(r) 500 broilers were used. A 2 x 3 factorial arrangement was applied, consisting of two sexes and three vitamin D levels. No difference was found between the levels of vitamin D (p > 0.05), the performance of males or females, the gait score, the valgus and varus incidence, the tibial dyschondroplasia incidence, the occurance of femoral degeneration, the bone colorimetric, and the carcass yield. Parts yield differences were found (p > 0.05), except for liver and intestine yields. We concluded that the lowest tested vitamin D level (3,500 IU per kilogram of feed) added to the diet was the best choice in terms of cost/benefit to help minimizing leg problems in broilers.(AU)

Bone characteristics of broilers supplemented with vitamin D

Vitamin D is added to broiler diets to supply its physiological requirement for bone formation. The fast growth rate of modern broilers is often associated with poor bone formation. Increasing vitamin D supplementation levels and the use of more available sources have applied to try to prevent leg problems, to increase carcass yield, and to improve the performance of broilers. The present study evaluated three vitamin D supplementation levels (1) 3,500 IU (control); (2) control + 1,954 IU of 25-hydroxycholecalciferol; and (3) control + 3,500 IU of vitamin D in broiler diets supplied up to 21 days of age. The objective was to investigate if the vitamin D levels above the recommendations could reduce leg problems in broilers. In this experiment, a total of 1,296 one-day-old male and female Cobb(r) 500 broilers were used. A 2 x 3 factorial arrangement was applied, consisting of two sexes and three vitamin D levels. No difference was found between the levels of vitamin D (p > 0.05), the performance of males or females, the gait score, the valgus and varus incidence, the tibial dyschondroplasia incidence, the occurance of femoral degeneration, the bone colorimetric, and the carcass yield. Parts yield differences were found (p > 0.05), except for liver and intestine yields. We concluded that the lowest tested vitamin D level (3,500 IU per kilogram of feed) added to the diet was the best choice in terms of cost/benefit to help minimizing leg problems in broilers.

Avaliação do desenvolvimento da discondroplasia tibial em frangos de corte submetidos à dieta com 25 hidroxicolecalciferol / Evaluation of tibial dyschondroplasia development in broiler chickens fed diets containing 25 hydroxicolecalciferol

Este trabalho teve como objetivo avaliar o desenvolvimento da discondroplasia tibial (DT) em frangos de corte de 1 ae fontes de vitamina D (1250UI D3/kg sem 25-(OH)D3; 1250UI D3/kg com 69mg 25-(OH)D3/ton e 3000UI D3/kg com 69mg 25-(OH)D3/ton) e dois tratamentos controles com níveis de cálcio e fósforo com 3000UI D3/kg sem 25-(OH)D3 e 3000UI D3/kg com 69mg 25-(OH)D3/ton de ração. Foram avaliadas características ósseas. No período de 1 a 21 dias, os resultados indicaram que as concentrações de cálcio e fósforo nas tíbias não foram influenciadas pelos tratamentos e que o consumo de ração foi superior para os tratamentos que compõem o fatorial. A resistência óssea também não foi influenciada pelos tratamentos e a análise histológica não evidenciou lesões características de DT. Conclui-se que, nas condições experimentais da presente pesquisa, o desenvolvimento de DT não foi observado.

This research was carried out to evaluate the development of tibial dyschondroplasia (TD) in broilers from 1 to 21 days. Four hundred forty day-old male chickens, from broiler breeders aged 60-62 weeks, were randomly distributed in a 3x3+2 factorial arrangement, resulting in 11 treatments with four replicates of 10 birds each. The factors evaluated were: bird strains (Ross 308, Cobb 500, and Hybro), levels and sources of vitamin D (1250UI D3/kg without 25-(OH)D3; 1250UI D3/kg with 69mg 25-(OH)D3/ton, and 3000UI D3/kg with 69mg 25-(OH)D3/ton), and two control treatments containing calcium and phosphorus levels with 3000UI D3/kg without 25-(OH)D3 and 3000UI D3/kg with 69mg 25- (OH)D3/ton of feed. Bone characteristics were evaluated. From 1 to 21 days, the results showed that bone calcium and phosphorus concentrations were not influenced by the treatments, however, feed intake was higher for factorial than control treatments. Bone breaking resistance was not influenced by the treatments and there were no typical lesions of TD. In conclusion, it was not observed TD development in broilers from 1 to 21 days according to experimental procedures of this research.(AU)

Avaliação do desenvolvimento da discondroplasia tibial em frangos de corte submetidos à dieta com 25 hidroxicolecalciferol / Evaluation of tibial dyschondroplasia development in broiler chickens fed diets containing 25 hydroxicolecalciferol

Este trabalho teve como objetivo avaliar o desenvolvimento da discondroplasia tibial (DT) em frangos de corte de 1 ae fontes de vitamina D (1250UI D3/kg sem 25-(OH)D3; 1250UI D3/kg com 69mg 25-(OH)D3/ton e 3000UI D3/kg com 69mg 25-(OH)D3/ton) e dois tratamentos controles com níveis de cálcio e fósforo com 3000UI D3/kg sem 25-(OH)D3 e 3000UI D3/kg com 69mg 25-(OH)D3/ton de ração. Foram avaliadas características ósseas. No período de 1 a 21 dias, os resultados indicaram que as concentrações de cálcio e fósforo nas tíbias não foram influenciadas pelos tratamentos e que o consumo de ração foi superior para os tratamentos que compõem o fatorial. A resistência óssea também não foi influenciada pelos tratamentos e a análise histológica não evidenciou lesões características de DT. Conclui-se que, nas condições experimentais da presente pesquisa, o desenvolvimento de DT não foi observado.

This research was carried out to evaluate the development of tibial dyschondroplasia (TD) in broilers from 1 to 21 days. Four hundred forty day-old male chickens, from broiler breeders aged 60-62 weeks, were randomly distributed in a 3x3+2 factorial arrangement, resulting in 11 treatments with four replicates of 10 birds each. The factors evaluated were: bird strains (Ross 308, Cobb 500, and Hybro), levels and sources of vitamin D (1250UI D3/kg without 25-(OH)D3; 1250UI D3/kg with 69mg 25-(OH)D3/ton, and 3000UI D3/kg with 69mg 25-(OH)D3/ton), and two control treatments containing calcium and phosphorus levels with 3000UI D3/kg without 25-(OH)D3 and 3000UI D3/kg with 69mg 25- (OH)D3/ton of feed. Bone characteristics were evaluated. From 1 to 21 days, the results showed that bone calcium and phosphorus concentrations were not influenced by the treatments, however, feed intake was higher for factorial than control treatments. Bone breaking resistance was not influenced by the treatments and there were no typical lesions of TD. In conclusion, it was not observed TD development in broilers from 1 to 21 days according to experimental procedures of this research.

Expressão da caderina na discondroplasia tibial / Cadherin expression in the tibial dyschondroplasia

By immunohistochemistry the expression of a pan-cadherin antibody that recognizes a wide variety of cadherins in chondrocytes from normal and tibial dyschondroplasia (TD) growth plates was compared. Surprisingly, an upregulated expression that was not expected in TD lesion chondrocytes was observed. The reason for this apparent upregulation is not clear. The increased expression may simply be due to the particular phenotype of lesion chondrocytes, and cadherin may be involved in apoptosis of chondrocytes of TD lesion. Another possibility, is that a low level of calcium in the lesion may be responsible for the observed upregulation. The results of the present study suggest that the formation of the dyschondroplastic lesion is not merely due to the impaired terminal differentiation of lesion chondrocytes and that other mechanisms are probably involved in TD etiology. Further studies will be necessary to provide insight into the precise nature of the condition.(AU)

Comparison of techniques for tibial dyschondroplasia assessment in broiler chickens

This study was carried out at Faculdade de Medicina Veterinária e Zootecnia, Universidade Estadual Paulista, Botucatu, SP, Brazil, with the objective of evaluating the efficacy of four techniques in the assessment of tibial dyschondroplasia lesions in broiler chickens. Four hundred Cobb male chicks were reared from 1 to 39 days of age. At 39 days, forty birds were selected and tibial dyschondroplasia status was assessed by four different techniques: evaluation using the lixiscope, macroscopic examination, histological examination and bone mineral density assessment using optical radiographic densitometry. The efficacy of each technique to assess dyschondroplasia lesions in the tibial growth plate was determined in comparison to histology, which was considered to be 100% efficient. The correlation results between lixiscope analysis and histology were poor. Macroscopic scores and densitometry readings were highly correlated with histology scores, and it is considered that these techniques reliably reproduce the status of the growth plate.

Comparison of techniques for tibial dyschondroplasia assessment in broiler chickens

This study was carried out at Faculdade de Medicina Veterinária e Zootecnia, Universidade Estadual Paulista, Botucatu, SP, Brazil, with the objective of evaluating the efficacy of four techniques in the assessment of tibial dyschondroplasia lesions in broiler chickens. Four hundred Cobb male chicks were reared from 1 to 39 days of age. At 39 days, forty birds were selected and tibial dyschondroplasia status was assessed by four different techniques: evaluation using the lixiscope, macroscopic examination, histological examination and bone mineral density assessment using optical radiographic densitometry. The efficacy of each technique to assess dyschondroplasia lesions in the tibial growth plate was determined in comparison to histology, which was considered to be 100% efficient. The correlation results between lixiscope analysis and histology were poor. Macroscopic scores and densitometry readings were highly correlated with histology scores, and it is considered that these techniques reliably reproduce the status of the growth plate.

Tibial dyschondroplasia and bone mineral density

This study was carried out at Faculdade de Medicina Veterinária e Zootecnia, UNESP, Botucatu-SP, Brazil. The aim was to establish the normal values of bone mineral density (BMD) expressed in millimeters of aluminum in the tibia of broiler chickens using optical densitometry of radiographs. Four hundred Cobb male chicks were reared from 1 to 40 days of age, when 40 of them were selected and the right femur-tibia articulation was radiographed. Radiographs were taken with the X-ray equipment calibrated for 45 kvp and 3.2 mAs and a focus-to-film distance of 90 cm. An aluminum phantom ASTM-6063 consisting of 20 ladder steps with graduate density was placed parallel to the area to be radiographed and used as a densitometry reference standard. Radiograph images were analyzed using the software ATHENA - SIA. The proximal growth plate of the right tibia epiphysis was used as the standard reading region. The inclination axis of the reading window was 0 and the window was 10 mm high and 40-45 mm wide, depending on the bone size. Optical densitometry values of the radiographs ranged from 1.46 to 1.77 mmAl, and the coefficient of variation was 9.93%. It was concluded that densitometry values beyond the range established in the present study might indicate the presence of bone alteration in the tibia of broilers.

Tibial dyschondroplasia and bone mineral density

This study was carried out at Faculdade de Medicina Veterinária e Zootecnia, UNESP, Botucatu-SP, Brazil. The aim was to establish the normal values of bone mineral density (BMD) expressed in millimeters of aluminum in the tibia of broiler chickens using optical densitometry of radiographs. Four hundred Cobb male chicks were reared from 1 to 40 days of age, when 40 of them were selected and the right femur-tibia articulation was radiographed. Radiographs were taken with the X-ray equipment calibrated for 45 kvp and 3.2 mAs and a focus-to-film distance of 90 cm. An aluminum phantom ASTM-6063 consisting of 20 ladder steps with graduate density was placed parallel to the area to be radiographed and used as a densitometry reference standard. Radiograph images were analyzed using the software ATHENA - SIA. The proximal growth plate of the right tibia epiphysis was used as the standard reading region. The inclination axis of the reading window was 0 and the window was 10 mm high and 40-45 mm wide, depending on the bone size. Optical densitometry values of the radiographs ranged from 1.46 to 1.77 mmAl, and the coefficient of variation was 9.93%. It was concluded that densitometry values beyond the range established in the present study might indicate the presence of bone alteration in the tibia of broilers.

Discondroplasia tibial: mecanismos de lesão e controle

Tibial dyschondroplasia is attributed to an asynchrony of chondrocytes differentiation with the appearance of a layer of pre-hypertrophic chondrocytes and a non-calcified cartilage in the proximal growth plate in the tibia which is resistant to vascular invasion. It has been also proposed that in the tibial dyschondroplasia, the final step of calcification does not occur due to the effector of some genes, involved in the calcification mechanism in the growth plate, present their chemical and biological properties disrupted and does not express. Thus, the study of the mechanisms and biomolecules and minerals involved in the tibial dyschondroplasia process might contribute to the better knowledge of this disease and to stablish strategies of prevention and treatment.

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.

Discondroplasia tibial: mecanismos de lesão e controle

Tibial dyschondroplasia is attributed to an asynchrony of chondrocytes differentiation with the appearance of a layer of pre-hypertrophic chondrocytes and a non-calcified cartilage in the proximal growth plate in the tibia which is resistant to vascular invasion. It has been also proposed that in the tibial dyschondroplasia, the final step of calcification does not occur due to the effector of some genes, involved in the calcification mechanism in the growth plate, present their chemical and biological properties disrupted and does not express. Thus, the study of the mechanisms and biomolecules and minerals involved in the tibial dyschondroplasia process might contribute to the better knowledge of this disease and to stablish strategies of prevention and treatment.

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.

Toxina T-2 e alterações do crescimento endocondral em frangos de corte

The ability of T-2 toxin from Fusarium sporotrichioides Sherb in corn culture to induce epiphyseal plate lesions in broiler chicks was tested. One group of day-old male broiler chickens (Hubbard) fed ad libitum balanced diet in which all corn was replaced by T-2 toxin (2.64mg/kg) contaminated autoclaved corn. Another group received the same diet with mycotoxin free corn, and was used as control. All groups were observed for 7, 14 and 21 days. Despite the different periods and amounts of ingested T-2 (estimated in 0.3 to 1.9 mg/kg), the tibia of treated animals presented defective maturation and poor differentiation of chondrocytes, severe vascular lesions and anomalous cartilage vascular invasion and retarded cartilage erosion with a picture similar to that of early tibial dyschondroplasia. The results indicated that the T-2 toxin produced by Fusarium sporotrichioides Sherb could induce tibial dyschondroplasia in broiler chickens.

Foi testada a habilidade da toxina T-2, produzida por Fusarium sporotrichioides Sherb e veiculada por milho experimentalmente contaminado, em induzir alterações da placa epifisária proximal do tibiotarso de frangos de corte. Pintos de um dia, todos machos e da linhagem Hubbard, foram alimentados com ração básica a base de milho e soja, na qual todo o milho foi substituído por milho contaminado, contendo exclusivamente T-2 na quantidade de 2,64mg/kg. Um outro grupo alimentado com milho não contaminado serviu como testemunha e ambos foram observados por três períodos (7, 14 e 21 dias). Independente do período e da quantidade de T-2 ingerida (0,3 a 1,9 mg/kg), o tibiotarso dos animais tratados mostrou maturação e diferenciação defectivas de condrócitos, lesões vasculares e penetração vascular da cartilagem, todas similares às da discondroplasia tibial. Conclui-se que a toxina T-2 oriunda de Fusarium sporotrichioides Sherb é capaz de induzir lesões básicas e iniciais da discondroplasia tibial em frangos de corte.