Aspartic protease supplementation enhancing the performance, carcass characteristics, nutrient digestibility and economic viability, without changing blood parameters and salivary cortisol of pigs.

Aiming to study the performance, carcass characteristics, nutrient digestibility, blood parameters, salivary cortisol levels, and economic viability of pigs administered aspartic protease, a total of 135 pigs were housed in pens in a randomized block design, divided into five treatments with nine replications. The experimental diets were positive control (PC), basic diet with a 5.0% reduction in protein and amino acid requirements; negative control (NC) with a 7.5% reduction in protein and amino acid requirements; NC + 100 g/mT of aspartic protease (NC100); NC + 150 g/mT of aspartic protease (NC150); and NC + 200 g/mT of neutral serine protease (NC200). The inclusion of protease, independently of the source and amount, increased the average daily weight gain (P < 0.05) of animals compared with the control treatments (PC and NC), improved feed conversion (P < 0.05) in early stages, and improved diet digestibility (P < 0.05) compared with the PC. Treatment with NC150 and NC200 resulted in greater carcass weights (P < 0.05) than treatment with the PC. NC100 led to a greater carcass yield than PC (P < 0.05), and NC150 resulted in a greater loin eye area than PC (P < 0.05). No differences (P > 0.05) in the blood parameters or salivary cortisol levels were found. Regarding economic viability, proteases increased the profitability, with NC150 leading to the best results. Thus, the use of aspartic proteases is recommended to improve performance and further facilitate pork production.

Evaluation of a Phytogenic Compound with Minerals as a Possible Alternative to Ractopamine for Finishing Pigs.

The objective of this work was to evaluate the effect of a phytogenic compound for pigs in the growing and finishing phases as a possible substitute for ractopamine. A total of 140 pigs with an average initial weight of 48.8 kg ± 5.9 kg were used, distributed in a randomized block design, in a 3 × 2 factorial scheme (control diet (CONT), diet with inclusion of 2.5 kg per ton of a phytogenic compound (PC), and diet with 10 ppm of ractopamine (RAC), and two sexes: gilts and barrows), distributed in eight pens per treatment. The performance parameters were measured, and, at the end of the experimental period, the animals were slaughtered for carcass characteristics and pork quality analysis. The animals consuming RAC showed a better feed conversion, 4% improvement in relation to the group with the PC (p < 0.05). For daily weight gain, the animals supplemented with the PC showed 4.46% lower gain compared to RAC, and 3% greater gain compared to the CONT (p < 0.05). The animals that consumed the PC showed 5.6% lower shear force of the pork (p < 0.05) in relation to the CONT group and 29% lower in relation to the RAC group. The TBARS value presented a significant difference (p < 0.05), the CONTT group was 29% higher than the RAC, and the PC was 15.5% higher than the RAC. For chroma, the pork of the RAC group was 14% lower than the CONTT group and 10.3% less than the PC. There was no significant difference for the carcass parameters. It was concluded that the pigs in the ractopamine group presented the best performance; however, the phytogenic compound can be used against ractopamine's restriction because it improves daily weight gain and promotes a softer and less pale meat when compared with ractopamine.