Higher phosphate level better for bone formation

Each link in the production chain contributes to the development of a healthy broiler. This also applies to the compound feed. On a daily basis, feed industry nutritionists work to optimise the feed with the help of new insights which, among other things, can help to improve bone formation. Recent research shows that it is not the calcium, but the phosphate level that has a strong correlation with bone formation.


n nature a certain optimum often turns out to offer the best results. More is not always better. This also applies to nutrition. A diet must provide a certain balance be- tween the different nutrients in order to achieve an opti-

mum result. Sometimes it is difficult to find the right balance because one nutrient counteracts the effect of another. This applies to calcium, for example. Calcium is seen as an impor- tant building block for bone formation and, among other things, is added to the diet in the form of chalk. Chalk in- creases the pH in the stomach, where protein is then not di- gested well as a result. This in turn has a negative impact on daily growth and the feed conversion. An excessively gener- ous addition of chalk to the feed therefore leads to poorer technical results.

Bone formation Bone is formed from calcium and phosphate, among other things. Vitamin D3 plays a key role in this process. There also needs to be a certain balance between the calcium and the phosphate. In the bone (hydroxyapatite) salts of calcium and phosphate are deposited in a fixed ratio. Therefore, calcium and phosphate also need to be present in the diet in a fixed ratio. Calcium and phosphate can be added to the diet by

adding various raw materials. Chalk is a well-known source of calcium and monocalcium phosphate is an important source of calcium and phosphate. In addition to phytase, organic and other additives are also available which can influence the amount of calcium or phos- phate in the diet. The question is: what ratio of calcium and phosphate sources yields the best bone formation, while maintaining body growth? The Dutch compound feed company Gebrs. Fuite BV and the Health Center for Poultry conducted a study to find an answer to this question.

Laboratory research The study focused on bone formation in broilers in the first week of life. Chicks from 14 broiler farms (with chicks from different parent stock farms) were sent to the laboratory for monitoring research. In addition to a normal section the chicks were examined for a number of parameters that pro- vide an indication of the quality of bone formation. For exam- ple, the researchers determined the sex, weight, length of the gastrointestinal tract, the yolk residual weight, the breaking strength of the upper leg bone, the lower leg bone and the tread bone, the width of the growth plates and whether or not the femoral head broke during luxation. The levels of calcium, as well as organic and inorganic phos- phate in the blood were also analysed. In this way, the differ- ent parameters were correlated to three different types of

Table 1 – Correlations between a number of parameters that influence the number of bone abnormalities in broilers during the first week of life.

Weight Weight Calcium level Phosphate level Bone abnormalities 1.00

-0,231 0,314 -0,333

Calcium level -0,231


-0,082 -0,112

Phosphate level 0,314 -0,082

1.00 -0,222 ▶ POULTRY WORLD | No. 3, 2021

Bone abnormalities -0,333 -0,112 -0,222

1.00 31

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