Adding arginine to the diets of farmed turkeys may improve gut health and weight gain, while supporting blood quality, say researchers.
An international team of researchers from Nigeria, the UK, the US and China examined the use of supplemental arginine (Arg) in the diets of turkeys. The group published its work in the journal of Livestock Science .
“This study investigated the effect of supplemental Arg on hematological indices, serum chemistry, carcass yield, gut microflora, and lymphoid organs of growing turkeys,” said the researchers.
The researchers found that the supplement reduced the amount of salmonella found in the small intestine and the enhanced the weights of some organs, they said.
“Arginine supplementation improved the hematology of finisher turkeys as indicated by increased PCV [packed cell volume], improved serum chemistry of grower and finisher turkeys as indicated by increased total serum protein, and reduced serum enzymes with appreciable improvement obtained at 0.5 g Arg/kg,” they said.
Why supplemental arginine?
The amino acid arginine is needed for maintenance, growth, immunity and reproduction, said the researchers. It is involved in the biosynthesis of several molecules and, in pigs, has been linked to the expression of fat metabolic genes, muscle growth and the reduction of body fat mass.
The amino acid also has been found to ameliorate abnormalities in the intestinal tract and ease growth depression in pigs getting a poor quality diet, they said. In poultry, it has been tied to improved growth performance in chickens and better carcass traits and breast meat yield in ducks.
It also has been linked with improved health status for humans and animals, they said.
“Remarkable changes in serum profile of amino acids that alleviated damages caused by Dextran Sulphate Sodium Colitis were reported in mice following Arg supplementation,” the researchers said. “The white blood cell concentration and heterophil count in laying hens, as well as packed cell volume (PCV), red blood cell (RBC), and hemoglobin (Hb) concentrations of broiler chickens were influenced following dietary supplementation with Arg.”
Arginine may have an important role in developing lymphoid organs and the immune system, they said. Relative weights of those organs has been found to decrease in an arginine-deficient diet.
“Daily oral administration of 500 mg Arg/kg alleviated unhealthy effects and negative impact of Eimeria tenella in chickens,” they said. “Dietary inclusion of Arg improved the proliferation of intestinal intra-epithelial lymphocytes and increased its toxicity against infectious bursal disease virus in chickens.”
Methods and materials
In the feeding trial, researchers gave one of three diets to 180 grower turkeys for a period of eight weeks, the researcher said. The diets included a control basal diet of corn and soybean meal, and that diet with 0.5 or 1.0 g Arg/kg.
Feed samples were checked for dry matter, crude fiber, crude protein, ether extract and ash, they said.
Bird hematological indices and serum chemistry was checked on days 84 and 112, they said. At the end of the feeding trial, sample birds were collected to assess body weight, carcass yield relative weight of cuts, organ weight and intestinal microflora.
At the end of the feeding trial, the feed supplement was found to have an effect on several organs and serum chemistry, said the researchers. Birds getting the larger supplement also had the highest body weight.
“Arg supplementation increased packed cell volume of finisher turkeys, improved serum chemistry of grower, and finisher turkeys as indicated by increased total serum protein, and reduced serum enzymes with appreciable improvement obtained when included at 0.5 g Arg/kg,” they said. “Arginine supplementation enhanced the relative weights of thymus, spleen, and reduced Salmonella counts in small intestine of turkeys.”
Birds getting the 0.5 supplementation had higher red blood cell, lymphocyte and basophil counts, they said.
Total serum protein, serum globulin and serum albumin grew as more Arg was added to the diet, as did the concentration of triodosterine, they said. Spleen weight grew linearly, although thymus weight was increased quadratically as more supplement was added.
The amount of salmonella found in the small intestine dropped quadratically as more of the supplement was used, said the researchers.