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

Abstract

Objective 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. Methods 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 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. Conclusion 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.