RESEARCH NEWS STORY：Advancing the Development of Low-Protein (LP) Feed for Chicken Meat Production

RESEARCH NEWS STORY

 October 24, 2024　　　　　

 Advancing the Development of Low-Protein (LP) Feed for Chicken Meat Production

 An LP diet supplemented with essential amino acids may reduce the environmental impact of poultry farming without compromising meat production

Feeding chickens a low-protein (LP) diet has shown notable reduction the environmental impact of poultry farming. However, this diet negatively impacts muscle mass, consequently affecting meat production. In this study, researchers explore the effects of supplementing an LP diet with amino acids, the building blocks of proteins. Results reveal the mechanism behind how AA supplementation offsets the negative effects of an LP diet in chickens.

 Chicken is one of the most widely consumed meats worldwide, and global food demands have steadily been growing over time, making poultry farming a thriving industry. However, raising chickens for meat has also contributed to global warming, mainly as a result of increased nitrogen excretion and ammonia emissions. Feeding broiler chickens (chickens bred and raised for meat production) a low-protein (LP) diet can be a solution to alleviate the environmental impact of chicken meat production since it has the potential to reduce nitrogen emissions.

However, the downside of using an LP diet is that it negatively affects the growth performance of broiler chicks, measured by factors like weight gain and the feed conversion ratio, which is the efficiency with which the chickens convert their feed intake into mass. Studies have shown that to ensure that there is no loss of growth performance, LP diets can be supplemented with amino acids (AAs), which are the building blocks of proteins. However, how AA supplementation helps alleviate the negative effects of an LP diet, is not clearly understood.

Now, in a study published online on May 9, 2024 in The Journal of Poultry Science, Dr. Kazuhisa Honda, Editor-in-Chief, Japan Poultry Science Association, and Professor, Graduate School of Agriculture at Kobe University, Japan examined the mechanisms underlying the impact of AA supplementation on broiler chickens that were fed an LP diet. Explaining further about their endeavor, Dr. Honda says, “Throughout the world, protein crisis is a serious problem in the animal industry. Secondly, global warming as a result of meat production has added to these concerns worldwide. By applying our results and utilizing LP feed, we hope to reduce N₂O emissions in the environment.”

First, the researchers fed three groups of broiler chicks with different types of food—a standard recommended diet, an LP diet with 15% reduced protein content, and an LP diet supplemented with AAs. To see how these diets affected growth performance, they monitored parameters like feed intake and weight gain till the chicks were 35 days old.

Chicks fed an LP diet showed a significant decrease in body weight as well as breast and leg muscle weight, compared to those that were on a standard diet. However, none of these effects were observed in chicks fed an LP diet supplemented with AAs, indicating that AA supplementation was able to mitigate the negative effects of an LP diet.

To explore these findings further, they looked closely at various genes that are involved in muscle synthesis and degradation. Real-time polymerase chain reaction analyses—a technique that detects the amplification of DNA molecules in real time—were used to examine the extent to which these genes were ‘expressed’ in different muscles. Surprisingly, the results showed that the impact of the LP diet was different in the breast muscle (pectoralis major) and the leg muscle (biceps femoris).

Pectoralis major of chicks on an LP diet was found to have an increased expression of the gene LC3B (microtubule-associated protein 1 light chain 3 isoform B). However, in the biceps femoris muscle of the thighs, increased expression of the genes atrogin-1, MuRF-1 (muscle RING-finger protein-1), and MyoD (myoblast determination protein 1) was observed. While different muscle groups showed distinct gene expression patterns, all the identified genes are involved in protein degradation, suggesting that an LP diet induces proteolysis in muscles. Moreover, no differences were found in gene expression between chicks fed a standard diet and those fed the AA- supplemented LP diet.

These results not only provide an explanation for the reduced growth performance with the LP diet, but also indicate that AA supplementation alleviates these effects differently in different muscle groups.

These findings have major implications for the poultry industry. As Dr. Honda explains, “Our results will contribute to the development of LP feed for broiler chickens, which is still a major challenge in developing countries.” By doing so, it opens doors for the increased use of LP feed, which means lower animal production costs in the future. Moreover, these findings also address important concerns around global warming and the environmental impacts on the poultry industry.

The researchers are hopeful that utilizing an LP feed with AA supplementation can reduce nitrogen emissions to the environment, promising a more sustainable and eco-friendly future for meat production!

Reference

Additional information for EurekAlert

Image title: Understanding the Effects of Amino Acid (AA) Supplementation on a Low-Protein (LP) Diet in Broiler Chicks
Image caption: The poultry industry is faced with issues like protein crisis and global warming. Researchers from Japan Poultry Science Association and Kobe University have now found that in broiler chicks, supplementation with essential AAs alleviated the negative effects of an LP diet on growth performance.
Image credit: Kazuhisa Honda, Japan Poultry Science Association
License type: Original content
Usage restrictions: Cannot be reused without permission

About Dr. Kazuhisa Honda from the Japan Poultry Science Association

Dr. Kazuhisa Honda is a member and the Editor-in-Chief of the Japan Poultry Science Association. He is also a Professor at the Graduate School of Agricultural Science in the Department of Bioresource Science, Kobe University, Japan. He has published approximately 89 papers in the field of zoological science and animal production science and amassed over 1,000 citations for his work. He is currently the Director of the Japan Poultry Society and Editorial Committee Chair for the Japanese Society of Poultry Science. His skills and expertise span topics like cholesterol, lipid metabolism, adipose tissue, triglycerides, and nutrition.

Media Contact
Kazuhisa Honda
E-mail: honda@tiger.kobe-u.ac.jp
Web: https://jpn-psa.jp/en/home-en/