The quality of the locomotor system is vital to the success of poultry farming, yet lameness is a recurrent problem.
Previous studies (see dossier articles on previous pages) have shown that the most intense period of ossification is during the first four weeks of broiler life.
ossification is most intense in the first four weeks of broiler life, despite differences in levels between Ross 308 and JA strains, and between males and females. As a reminder, the necessary elements for ossification are :
- Dietary proteins ;
- Calcium and phosphorus form the mineral framework of bone tissue and give it its hardness ;
- Vitamin D3 regulates calcium/phosphorus metabolism ;
- Trace elements (copper, zinc and manganese) are cofactors for enzymes involved in ossification
The denser a bone is, the less likely its tissue is to be infected by bacteria in the bloodstream, and the less likely chickens are to develop lameness.
The aim of this experiment is to demonstrate the benefits of PROVITOS® for Ross 308 chickens in terms of end-of-batch gait quality.
Vitamin D3 undergoes two transformations to reach an active form (see diagram). Chicks under 10 days of age are unable to e ffect the first hepatic metabolism. It is therefore essential to distribute the pre-metabolized form of vitamin D3 contained in PROVITOS® , as “raw” vitamin D3 is then ineffective.
The protocol
For this study, 11 buildings of Ross 308 strain were selected. These buildings, located in Brittany, all had the same feed mill and the same production organization.
In 5 buildings, PROVITOS® was distributed according to this protocol :
No PROVITOS® was distributed in the other 6 buildings.
At 42 days, a visit was e ffected to each building. Around one hundred chickens, males only, were observed in equal numbers in 4 areas of the building. They were weighed individually and ranked according to their lameness score from 0 to 5.
45 male chickens (lame and non-lame) per building were selected for laboratory handling and measurements. A total of 500 broilers from 11 buildings, aged 42 days, were sampled in this study.
For each animal, several measurements were taken in the laboratory :
Blood samples were e ffected to analyze di fferent parameters: Calcium / Phosphorus / 25-OH-D3 levels (premetabolized form of vitamin D3).
Complete autopsies enabled us to describe the various macroscopic lesions (arthritis, fragile femur head, etc.) and classify them by score :
- 0 : no lesion
- 1 : non-infectious lesion(s)
- 2 : infectious lesion(s)
Results
Early distribution of PROVITOS®, in the form of 3 courses of treatment, increases blood levels of premetabolized vitamin D3 significantly, even at 42 days.
At the same time, blood calcium and phosphorus levels were also higher in the group of chickens receiving PROVITOS® treatments, an element favorable to ossification.
We were also able to verify that chickens fed PROVITOS® moved better than control batches. Indeed, the lameness score is very largely and significantly in favor of the PROVITOS® batches (graph 4).
Furthermore, batches of chickens supplemented with PROVITOS® showed fewer infectious lesions than control batches (graph 5).
Conclusion
In conclusion, the 3 PROVITOS® distributions (D3 to D6, D10 to D13 and D20 to D22) improved the chickens’ movement and reduced infectious lesions, particularly of the locomotor system.
We recommend PROVITOS® as part of a comprehensive program to support broiler growth.