Molybdenum but not copper counteracts cysteine-induced tibial dyschondroplasia in broiler chicks

Difficulties in using soil-based methods to assess plant availability of potentially toxic elements in biochars and their feedstocks

The use of biochars in agriculture to improve soil function and carbon sequestration is expected to increase into the future. We aimed to identify the most suitable chemical extractants for the risk assessment of potentially toxic element (PTE) availability in biochars produced from a range of feedstocks, and to investigate the changes in PTE extractability that occur as a result of feedstock pyrolysis using five common extraction methods. We evaluated these methods with regard to their ability to predict PTE phytoavailability in four different biochars against metal uptake by wheat. No single extractant significantly correlated well with ≥ 4 PTEs from the 10 examined, highlighting that the availability and binding mechanism of individual PTEs differed by biochar type. Commonly used PTE extraction methods need to be reviewed for use with biochars, and that some biochars may be able to stabilise PTEs, reducing risks of contamination upon land application.

Skeletal deformities and their causes: introduction

Much has been done to characterize skeletal deformities in poultry and to identify the causes of these deformities. However, skeletal problems in poultry continue to cost poultry producers over $100 million per year. A basic understanding of bone growth and development is essential for continuous progress in solving current skeletal diseases. Although this research will be of great benefit to the poultry industry, the use of poultry models has proven valuable in studying human bone disease.

Factors influencing growth plate cartilage turnover

A number of nutrients and chemicals have now been identified as consistent inducers of tibia dyschondroplasia (TD). Thiram, Antabuse, and fusarochromanone induce TD when fed at 30 to 75 ppm. Cysteine, cystine, homocysteine, and histidine induced TD when fed at .5 to 3% of the diet. Cation: anion imbalances resulting in acidotic diets also induced TD. Even though prevention of TD induced by these chemicals and nutrients has been established, reversal of the spontaneous TD lesion has not been clearly demonstrated. Thus, the etiology of the spontaneous lesion awaits elucidation. These model systems all suggest that TD is the result of decreased growth plate cartilage degradation. Recent work has shown that increased collagen cross-links in the accumulated cartilage, which makes collagen less susceptible to degradation. Cysteine-induced TD seems to decrease growth plate collagenase activity and production. A role of growth plate macrophages in paracrine signaling of collagenase production by chondrocytes has been presented.