# The Effect of Chelated Trace Mineral Supplementation in the Form of Proteinates on Broiler Performance Parameters and Mineral Excretion: A Meta-Analysis

## TL;DR

This study shows that replacing inorganic minerals with chelated proteinates in broiler diets improves growth and reduces mineral waste and carbon emissions.

## Contribution

The novelty lies in demonstrating through meta-analysis that proteinate trace minerals enhance broiler performance and sustainability compared to inorganic minerals.

## Key findings

- Replacing inorganic minerals with proteinates reduced feed intake and improved growth metrics in broilers.
- Mineral excretion of Cu, Fe, Mn, and Zn decreased significantly with proteinate use.
- Proteinate inclusion lowered carbon footprint by 3.5% in broiler production.

## Abstract

This work assessed the effect of incorporating chelated trace minerals in the form of proteinates, in place of inorganic trace minerals, on broiler performance parameters such as total feed intake, average daily feed intake, body weight gain, average daily gain, final body weight, feed conversion ratio and mortality. Two separate meta-analyses were carried out: one assessed the effect of replacing inorganics with levels of proteinates ranging from low to equivalent inorganic levels and the second evaluated the effect of replacing inorganics with proteinates at reduced (50–80%) levels only. Evaluation of mineral excretion levels (Cu, Fe, Mn and Zn), indicative of mineral absorption and bioavailability, was also carried out, as this not only impacts bird health and performance but also environmental parameters such as soil health. Sustainability was assessed using a life cycle assessment, focused on the carbon footprint of broiler production, incorporating changes in feed usage, weight gain, mortality rate, and days to slaughter. Results demonstrated that inclusion of chelated trace minerals in specific proteinate forms positively impacted these key parameters, with lower mineral excretion observed for all minerals selected, fewer carcass losses due to mortality, lower feed intake, higher body weight and average daily gain, and lower feed conversion ratio.

Comprehensive Meta-Analysis (CMA) software, using data from 64 global studies (288 dietary assessments, 194,356 broilers) evaluated the effects of substituting inorganic trace minerals (ITM) with proteinate trace minerals (PTM) in broiler diets at various inclusion levels. Replacing ITM with PTM at equivalent (100%) or reduced (11–80%) levels improved performance metrics, showing reduced total feed intake (FI) (−6 g/bird), lower average daily feed intake (ADFI) (−0.43 g/bird), higher average daily gain (ADG) (+0.36g), greater body weight gain (BWG) (+4.29 g/bird), higher final body weight (BW) (+7.50 g/bird), improved feed conversion ratio (FCR) (−1.26%), and lower mortality (−10.95%), all significant (p < 0.05). Median mineral inclusion reductions of 40% Cu, 59.82% Fe, 41.41% Mn, and 34.67% Zn had no adverse effects, instead enhancing outcomes. Across 17 studies (25,144 broilers, 85 dietary assessments), mineral excretion decreased significantly with PTM versus ITM by 16% Cu, 14% Fe, 21% Mn, and 15% Zn (p < 0.001). When PTM replaced ITM at 50–80% inclusion, further benefits were observed, including lower total FI (−7 g/bird), lower ADFI (−1.07 g/bird), higher ADG (+1.67), higher BWG (+2.65 g/bird), lower FCR (−4.50%) and lower mortality (−11.09%) with mineral inclusion reductions of 17% Cu, 42.16% Fe, 42.89% Mn, and 50% Zn. Meta-regression identified significant influences (p < 0.05) from study variables such as strain, study duration, and region. Life cycle assessment modelling demonstrated PTM inclusion lowered gross carbon emissions by 3.5% and lower emission intensities per unit live weight of both feed use and overall lifecycle by 4.5% and 4.1%, respectively on diets of high and low soybean meal inclusion. Overall, replacing ITM with PTM in broiler diets can promote production performance of broilers and lower mineral excretion levels while contributing to a lower CFP.