Effects of dietary microalgae on bone strength of white pullets.

Figure 1: Effects of dietary microalgae on bone strength of white pullets.

World Poultry reports on testing at animal nutrition company Alltech that compared chicken feed formulas, using algae as a variable, to determine how nutrition, management, and environmental factors can have an impact on bone strength and quality.

Leg disorders such as angular bone deformities and Tibial Dyschondroplasia have become common in broilers attributing to poor growth, high mortality rates and increased carcass condemnation and downgrading at slaughter. It is estimated that up to 2% of broiler flocks are lost due to lameness, costing the industry approximately $4 billion globally. In addition, 6% of broilers develop skeletal abnormalities such as Osteoporosis.

Osteoporosis in laying hens is a condition that involves the progressive loss of structural bone during the laying period. This bone loss results in increased bone fragility and susceptibility to fracture, with fracture incidences of up to 30% over the laying period and depopulation not uncommon under commercial conditions. This has become a chief welfare issue facing the egg production industry in Europe and many other areas.

Bone is made up of two components: the organic matrix and the inorganic matrix. A fibrous protein called collagen is the main component of the organic matrix, while crystals of calcium phosphate make up the bulk of the inorganic matrix. The overall bone strength is determined by how each component makes up the entire structure. Because of these basic understandings of bone tissue make up, researchers have conventionally focused on minerals such as calcium and phosphorus and vitamins such as vitamin D in the past decades to improve bone strength in poultry. In recent studies, research scientists have taken a new approach in assessing the effect of fatty acids on bone strength.

Effects of dietary microalgae on bone strength of broiler chicks.

Figure 2: Effects of dietary microalgae on bone strength of broiler chicks.

Two studies were conducted in the poultry research laboratory of Alltech University of Kentucky Nutrition Research Alliance. The results clearly demonstrated that dietary supplementation of dehydrated whole cell microalgae (All-G Rich previously termed Alltech SP1) that contains 64% fat and 16% DHA significantly increased bone strength of growing chicks.

For Study One, dietary treatments consisted of feeding a corn-soybean meal control diet alone or supplemented with 1.0 or 2.0% microalgae. Bone samples including tibia and humerus were taken at weeks 10 and 17 respectively from one bird per pen. The breaking strength of tibia bone sampled at week 10 and humerus bone sampled at week 17 increased significantly by dietary supplementation of microalgae. (Figure 1)

Study Two used broiler chicks with dietary treatments of corn-soybean meal control diet without supplementation of microalgae or supplemented with 0.5, 1.0 or 2.0% microalgae. At day 19 bone samples were collected from one chick per pen for the analysis of bone breaking strength. Humerus breaking strength of chicks fed diets containing 1 to 2% microalgae was significantly higher than that of chicks fed diets containing no or 0.5% microalgae. (Figure 2)

Having weak bones is a very common disease, not only for poultry and animal production but also in humans. Studies suggest that approximately one in two women and up to one in four men aged 50 and older will break a bone due to bone weakness. Osteoporosis is responsible for approximately $19 billion in human health related costs every year. Based on the results from these poultry studies, essential fatty acid DHA may be another key factor, among many other known factors, to prevent the development of osteoporosis in humans and animals.

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