# Effect of strategic nutrient reduction and exogenous enzyme supplementation on mineral and energy balance in growing pigs

## TL;DR

This study shows that reducing nutrients in pig diets with added enzymes improves nutrient use without harming growth.

## Contribution

Demonstrates that mineral and energy reduction with enzymes can enhance nutrient efficiency in growing pigs.

## Key findings

- Mineral reduction with enzymes did not affect daily weight gain or feed efficiency.
- Total nitrogen excretion decreased significantly with the treatment.
- Phosphorus and zinc digestibility improved with enzyme supplementation and mineral reduction.

## Abstract

This study evaluated the effects of strategic nutrient reduction in combination with exogenous enzymes (phytase, pectinase, and β-glucanase) on mineral and energy balance in growing pigs.

Twenty-four barrows (age: 97±5 days) with an average initial body weight of 49.26±0.42 kg were individually housed in metabolism crates under controlled conditions. Diets were offered for 10 days, consisting of a 5-day adaptation period followed by a 5-day total-collection balance period. Pigs were assigned to four experimental treatments: a positive control diet (PC-100) with standard levels of metabolizable energy (ME), calcium, phosphorus, and mineral premix; a negative control diet (NC-100) with the same mineral premix but reduced by 100 kcal/kg ME, 0.05% calcium, and 0.10% phosphorus, supplemented with the enzyme blend; and two additional diets based on NC-100 with a 33% (NC-67) and 66% (NC-34) reduction in the mineral premix. Productive performance, apparent fecal digestibility (AFD), nutrient retention, and energy efficiency were measured.

Results showed that mineral reduction (33% and 66% vs. the recommended level) together with exogenous enzymes did not affect daily weight gain or feed efficiency (p>0.05). However, a significant decreased total nitrogen excretion (from 13.66 to 10.72 g/day; p<0.001), and increased proportion of retained nitrogen relative to absorbed nitrogen (from 73.46% in PC-100 to 81.69% in NC-34; p = 0.0025) were observed. AFD of phosphorus improved with enzyme supplementation (up to 74.89% in NC-100; p<0.01), and zinc digestibility increased significantly with mineral premix reduction (up to 50.01% in NC-34; p<0.01). ME remained stable among treatments (p = 0.06), with average values ranging from 3,593 to 3,642 kcal/kg.

Strategic reduction of dietary minerals (33% and 66% vs. the recommended level), and energy, in combination with exogenous enzymes, improved nutrient utilization without negatively affecting short-term growth performance in growing pigs.