Recent findings indicate that nutrition helps improve meat and carcass quality in modern broiler birds. A recent trial done by Novus International Inc. at the Universidad Politécnica de Madrid in Spain shows that a strategy with reduced levels of organic source of trace minerals in replacement of inorganic sources helps mitigate meat defaults and foot pad lesions while maintaining heavy broilers growth and feed efficiency.
Meat and carcass quality: multifactorial causes, impacting the whole value poultry chain
Modern broilers, particularly those of genetics with high speed of growth, can be affected by several issues regarding meat and carcass quality.
Figures 1, 2, 3:
- Woody breast, named for its hard or “wooden” appearance, is the most severe and troublesome myopathy as it significantly impacts meat texture and taste, therefore impacting consumer acceptance.
- White striping is another type of myopathy where connective tissue creates white “stripes” of variable thickness across the breast muscle, but this still affects meat quality.
- Spaghetti meat, or destructured meat, is an emerging muscular abnormality that affects the integrity of the muscle and offers a stringy, soft consistency because of the poor cohesion of the muscular fibers.
The industry has developed a rating system in which each abnormality is scored based on severity from 0 (no indication of myopathy) to 2 or 3 (severe).
The meat and carcass quality issues can occur at all stages of the bird life and have consequences at farm level (foot pad dermatitis) or slaughterhouse level (carcass and breast meat yield, skin integrity, broken bones, bruises), and till the transformation. Some of these meat quality issues can significantly impact the appearance of the meat, and while these meat quality issues do not pose any known risks to the food safety for consumers, they significantly impact producer profitability. Severe cases can result in poultry meat of lower quality, leading to additional processing costs, products downgrading and potential meat condemnations. Modern myopathies, that particularly affects breast meat quality such as wooden breast, spaghetti meat, and white striping are the main issues identified today (see figure 1). These defaults are now well described, and the causes are also better identified, although the etiology remains complex.
These myopathies are more frequent and severe for heavier birds with rapid growth. The most probable hypothesis is that broilers with higher rate of hypertrophic muscle growth, result in increased metabolic and circulatory demands leading to increased risk of accumulation of metabolic waste products, such as oxygen free radicals. The oxidative stress increases, and the accumulated highly reactive free radicals can damage DNA, RNA, proteins and lipids present in muscle cells, causing inflammation, metabolic disturbances, and eventually degeneration of the muscle fiber.
Strategies to support muscle growth
One strategy to mitigate these pains is to reduce growth rate. In this strategy, dietary restrictions, nutrient density or lysine reduction have been studied with variable successes. But by compromising the performance, this strategy is often not compatible with the goal of producing affordable meat for an increasing demand. A more intensive method is often selected to produce meat with highly efficient birds. Other strategies such as antioxidant approaches, with exogenous antioxidants, or endogenous antioxidant support through highly bioavailable trace minerals such as zinc, copper, manganese and selenium were also tested with success.
After having analyzed several studies (Kuttappan & al., 2021), conducted in both research and commercial facilities, Novus’s two-way nutritional strategy was developed: 1) support healthy muscle growth and development and 2) reduce oxidative stress in the tissue.
What are MINTREX® organic trace minerals?
These organic trace minerals include two chemically differentiated HMTBa molecules (methionine precursor) as ligands bound to the mineral. The strong bounds and protection brought by the two HMTBa molecules to the mineral allow it to reach the proper absorption site in the small intestine, providing better utilization of the mineral by the animal. This means birds are better equipped with the nutritional tools for optimal muscle growth.
Due to the biological processes involved in muscle tissue growth and oxidative stress in broilers, trace minerals have been identified for their proven positive effects on bodyweight and growth rates. Several studies indicated that highly bioavailable trace minerals such as MINTREX® could help reduce damages to broiler breast tissue due to stress or other causes up to 50%. These Organic Trace Mineral (OTM) also help in the regeneration process if damage occurs. It was then hypothesized that the same trace minerals that support healthy muscle growth could help reduce the development of abnormal tissue.
Recent data shows the effect of bis-chelated organic trace minerals
In a recent trial done at the Universidad Politécnica de Madrid (UPM), Novus tested a strategy of replacement of inorganic source of trace minerals (Zn, Cu and Mn) by a reduced level of MINTREX® highly bioavailable organic source of trace minerals on performance and quality parameters of Ross 308 broilers at 45 days of age.
324 one-day-old Ross 308 male broilers were divided in 2 groups (9 pens, 18 animals per pen) and reared for 45 days. There was a thinning of 4 birds per pen at day 28. Animals were fed iso-nutritional diets following FEDNA recommendations with feeds mainly composed of Wheat/Soybean meal, Iso Methionine. The only differences between diets were the source and the level of minerals (table 1). After 45 days, animals were slaughtered, and carcass quality was assessed. Foot Pad Dermatitis & Hook burns were scored on 240 legs by treatment using a 3 scores scale (0 normal to 2 severe) and breast quality was evaluated on 120 fillets by treatment for White Striping.
With less Zn and Mn and equal Cu from organic sources, between 1 and 45 days, animals performed numerically better on ADG (+1.5 g/d), Live Weight (+65 g) and FCR (-0.013 kg/kg).
Table 1. Source and level of trace mineral (Zn, Cu, Mn) included in the trial
Concerning carcass and meat quality, there was a significant (P <0.01) reduction of the incidence of food pad lesions (12.9% severe FPD with MINTREX® vs 24.9% for the inorganic trace minerals source) and hock burns (15.9% severe lesions with MINTREX® vs 23.7% for the inorganic trace minerals source), that leads to an indication of a better welfare for the animals and better valorization of the legs. White Striping incidence was significantly lower (P <0.01) by 2.2 pts (9.6% vs 11.8% of severe defaults for MINTREX® and inorganic trace minerals source, respectively).
In the context of increased demand for affordable meat, the poultry industry is well positioned to offer affordable products easy to prepare and having high nutritional value, if it can cope with metabolic challenges caused by modern broiler production intensification.
Recent Novus’s works (*) confirm that the use of highly bioavailable trace elements helps mitigate meat and carcass defects while maintaining the performance of the animals. This is a cost-effective way, compared to other nutritional strategies, to optimize profitability of poultry production chain.
(*) References: Kuttappan VA., Manangi M., Bekker M., Chen J., Vazquez-Añon M.2021 Nutritional Intervention Strategies Using Dietary Antioxiidants and Organic Trace Minerals to reduce the incidence of Wooden Breast and Other Carcass Quality defects in broiler birds. Front. Physiol. 12:663409 doi:10.3389/fphys.2021.663049
Aguirre L., de Juan Á., Castillo M., Peris S., Mateos G. 2021. Effects of source and level of trace minerals in the diet on growth performance and carcass quality of broilers from 1 to 45 days of age. IPPE conference, 2021