Nucleoside supplements may boost poultry weight gain, performance

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Combining nucleosides in poultry feed may offer birds a boost in production, weight gain and intestinal development, say researchers.

An international team of researchers from Iran and the US examined the use of the nucleosides combinations on the production of broilers. The research had financial support from Ferdowsi University of Mashhad, Iran. The team published its findings in the journal of Animal Feed Science and Technology​​​.

“It could be hypothesized that a combination of purine and pyrimidine nucleosides has more beneficial additive effects on various biological attributes than individual nucleosides previously studied,” ​the researchers said. ​

“Therefore, the current study was conducted to evaluate the effects of various combinations of purine and pyrimidines nucleosides on growth performance, intestinal morphology and enzymes, serum biochemical indices and immune functions.”​

The researchers found that a combination of three nucleosides – adenosine, uridine and cytidine – increased bird growth and improved intestinal morphology and brush border enzymes, they said. The supplemented trial diet also improved production of IgA and the relative weight of the bursa.  

“[The trial diet] AUC could be introduced as an economically considerable additive for the poultry industry, whereas further investigations will be required to assure the proficiency of AUC under more challenging and authentic poultry farm conditions,”​ they said.

Why nucleosides?​

Nucleotides are bioactive compounds that take part in the structure of DNA and RNA, act as co-enzymes and take part in metabolic reactions, the researchers said. In pigs, they also have been found to have a role in development of the intestine and immune functioning.

Some organs, including the intestine and immune system, require exogenous sources for nucleotides, they said. And, the cellular requirement for nucleotides can increase in some conditions like during periods of limited nutrient intake, immune challenge or rapid growth.

Accordingly, nucleotides are considered “semi-essential”​ nutrients, they said.

In previous work looking at the use of supplemental yeast extract in swine feed, the additive was found to increase weight gain, limit diarrhea and improve elements of the intestine, said the researchers. In poultry diets, the supplement was linked to improved intestinal morphology and gene expression of interleukins in the small intestine but was not found to alter growth performance.

Most previous research used yeast extract as a source of nucleotides, but that supplement brings variable amounts of nucleotides and additional nutritional elements, they said. Additionally, the most absorbable version of the additive is as a nucleoside.

Feeding trial details​

In the study, 360 chicks were given one of four experimental diets for a period of 21 days, the researchers said.

The diets included a control diet of maize and soybean meal, and that diet supplemented with: 0.05% adenosine, 0.025% uridine and 0.025% cytidine (AUC); 0.05% guanosine, 0.025% uridine and 0.025% cytidine (GUC); and for the final test diet, 0.025% adenosine, 0.025% guanosine, 0.025% uridine and 0.025% cytidine (AGUC), they said.

The study used individual forms of commercially available nucleosides to generate the feed additive combinations used, they said.

Bird intake was noted on days 10 and 21, and bird weight was measured at the start and on days 10 and 21, said the researchers. The average daily gain, average feed intake and feed conversion ratio were determined.

Sample birds were collected on days 11 and 21 to provide jejune, bursa and spleen samples along with blood, they said.  

Results​

The researchers found that some diets were able to boost body weight and weight gain, the researchers said.

“The present study clearly demonstrated that combination of adenosine + uridine + cytidine could be [a] useful feed additive for improving economically important traits in broilers,”​ they said.

The AUC diet was found to increase bird body weight and average daily gain, decrease the feed conversion ratio, and improve intestinal villus height and width along with the activity of brush border enzymes, they said. “AUC significantly improved immune indices such as the relative weight of the Bursa of Fabricius and the concentration of IgA,”​ they added.

Both AUC and AGUC diets boosted high-density lipoprotein and uric acid, they said. However, the addition of dietary nucleosides did not alter cholesterol or triglyceride levels in serum.