Modern poultry production has solved several challenges from the past, such as leg problems and ascites, and now the focus is on solving myopathies in poultry, Dr. Alejandro Corzo of Aviagen said during his presentation on "Chicken breast myopathies" at the Poultry Seminar in Spanish at the International Production and Processing Expo (IPPE) on January 30.
Chicken breast myopathies have gained importance since 2012, so Aviagen has focused on using genetic selection to solve them, he said.
There are three main breast myopathies:
- white striping
- stringy spongy
- wooden breast
Wooden breast is the most common. In wooden breast, muscular fibers display great variations, with hypercontracted fibers and connective tissue that gives the hardness characteristic, along with low vascularity, among other things.
Although wooden breast does not represent a public health problem, it is a meat quality problem.
To solve it, there have been several strategies. One of them is to make selections of brothers and sisters of good pedigrees at the processing plant, which involves both tactile and quantitative evaluations with equipment devices. Selections of live animals are also made by palpation in the pectoralis major muscle to detect the different levels of myopathies and to evaluate the breast firmness.
However, the selected candidates must still be good at feed conversion and other characteristics.
When will the changes be seen?
Alejandro Corzo makes it clear that the problem of breat myopathies will not be reduced to zero, but that by the middle of 2018 a reduction in between 10 and 15 percent is expected, and then a slightly more gradual reduction between four and six years more.
Other evaluations and strategies
Dr. Corzo explained that Aviagen has made a series of evaluations. They have detected that there is more wooden breast as the bird grows. That is, the longer it takes for the chicken to get to market, the more likely there is to be more wooden breast.
In this way, while genetic improvement comes, he mentioned the following strategies that have been studied to help solve the problem:
- Quantitative restriction: with a feed restriction of 5 percent and 10 percent with respect to the previous day of ad lib feed consumption, the gain decreases slightly, but myopathies are reduced between 43 and 57 percent. When Aviagen tested a 5 percent restriction at the starting phase and then left birds ad lib, incidence worsened.
- Qualitative restriction: decreasing digestible lysine content in different phases, but the other amino acids remained the same. Lysine restriction caused white striping to decrease.
- Antioxidant supplementation: the supplementation of oxidized fats with antioxidants such as ethoxyquin, vitamin C and E, and ethoxyquin + vitamin C and E caused myopathies to be reduced by almost half, either alone or together. On the other hand, oxidized fat increased incidence of wooden breast.
- Phytase: the different doses of this enzyme gave a very slight numerical response. With phytase superdose, no increases in wooden breast were observed, although there were no improvements. In other studies, there were significant differences in favor of phytase. Apparently, inositol can act in breast muscle.
- Other compounds: guanidinoacetic acid, arginine:lysine ratio, variations in anticoccidial programs, selenium and organic minerals, have been studied, but without conclusive results.
