Efficacy of l-glutamic acid, N,N-diacetic acid to improve the dietary trace mineral bioavailability in broilers

Abstract

Trace minerals are commonly supplemented in the diets of farmed animals in levels exceeding biological requirements, resulting in extensive fecal excretion and environmental losses. Chelation of trace metal supplements with ethylenediaminetetraacetic acid (EDTA) can mitigate effects of dietary antagonists by preserving the solubility of trace minerals. Lack of EDTA biodegradability, however, is of environmental concern. L-glutamic acid, N,N-diacetic-acid (GLDA) is a readily biodegradable chelating agent that could be used as a suitable alternative to EDTA. The latter was tested in sequential dose response experiments in broiler chickens. Study 1 compared the effect of EDTA and GLDA in broilers on supplemental zinc availability at three levels of added zinc (5, 10 and 20 ppm) fed alone or in combination with molar amounts of GLDA or EDTA equivalent to chelate the added zinc, including negative (no supplemental zinc) and positive (80 ppm added zinc) control treatments. Study 2 quantified the effect of GLDA on the availability of native trace mineral feed content in a basal diet containing no supplemental minerals and supplemented with three levels of GLDA (54, 108 and 216 ppm). In study 1, serum and tibia Zn clearly responded to the increasing doses of dietary zinc with a significant response to the presence of EDTA and GLDA (P<0.05). These results are also indicative of the equivalent nutritional properties between GLDA and EDTA. In study 2, zinc levels in serum and tibia were also increased with the addition of GLDA to a basal diet lacking supplemental trace mineral, where serum zinc levels were 60% higher at the 216 ppm inclusion level. Similar to the reported effects of EDTA, these studies demonstrate that dietary GLDA may have enhanced zinc solubility in the gastrointestinal tract and, subsequently enhanced availability for absorption, resulting in improved nutritional zinc status in zinc deficient diets. As such, GLDA can be an effective nutritional tool to reduce supplemental zinc levels in broiler diets thereby maintaining health and performance while reducing the environmental footprint of food producing animals.

Tolerance and safety evaluation of L-glutamic acid, N,N-diacetic acid as a feed additive in broiler diets

“…Inclusion of GLDA did not affect serum levels of Mn and Fe, in accordance with previous findings ( Boerboom et al, 2020 ; Boerboom et al, 2021 ). Copper levels when GLDA was fed at 10,000 mg/kg showed numerically higher values compared to the control, which can be explained by the gut integrity effects described above ( Kołodyńska, 2013 ).…”

“…A novel chelator, L-glutamic acid, N,N-diacetic acid ( GLDA ) has shown to increase the nutritional availability of Zn in broilers. In this way, it can be used as a dietary ingredient to safely reduce Zn supplementation in complete feed without compromising the Zn status of the animal, thus contributing to the reduction of environmental trace element pollution of animal production ( Kołodyńska, 2011 ; Wu et al, 2015 ; Boerboom et al, 2020 ; Boerboom et al, 2021 ). In contrast with other chelators such as EDTA, GLDA is readily biodegradable in the environment presenting a low persistence in soils and surface waters.…”

Age features and reference intervals for the concentrations of some essential and toxic elements in laying hens

“…Previous studies conducted on beef [ 18 ], and dairy cattle [ 19 ], cattle breeding, and sports horse breeding [ 20 ] confirmed this. The most common substrate for determining the primary conditions of poultry is blood [ 21 , 22 ]. However, the feather is preferred when defining an organism’s elemental status over a lengthy period with the lowest harmful effects on the organism [ 23 - 28 ].…”

Effects of Different Patterns and Sources of Trace Elements on Laying Performance, Tissue Mineral Deposition, and Fecal Excretion in Laying Hens

“…Some organs are recognized as indicators for assessing the bioavailability of specific minerals. For example, bone zinc content can be considered as a responsive criterion for Zn bioavailability [ 21 ]. Liver and kidneys are sensitive to the variation of Cu concentration.…”