This study is aiming to the mathematically characterization of the growth pattern of Iberian pig (50 % Duroc) born at the end of the year and raised outdoor from 70 to 365 days of age. Repeated measurements of individual body weight and back fat thickness, and feed consumption per batch were carried out under field conditions. Two experimental batches were used: A (91 males and 95 females) and B (56 males and 60 females). The feeding programme determined the growth pattern and included 4 phases characterised by the feed and the amount of feed provided: 1) ad libitum "growth transition/adaptation" feed for "potential growth" between 24 and 98 days of age; 2 and 3) "Growth" and "Fattening I" feed, restricted to 2.5 % and 2.0 % of their body weight, respectively, for "slow growth", between 98 and 303 days of age; 4) ad libitum "Fattening II" feed for "compensatory growth", between 303 and 352 days of age. The result of the main parameters calculated by the adjustment of the pattern was: 1) growth equations: 218 kg of PV at maturity, 0.00977 of precocity, 162.49 days of age at maximum gain; 2) metabolisable energy consumption equations a (119229.75), b (6.76), c (1.01); 3) kg of feed provided in phases 2 and 3: 2.47 % and 2.0 % of body weight, respectively. It is concluded that, under the production conditions of the trial, the proposed methodology adjusted the growth and feeding pattern allowing the design of feeding strategies that increase efficiency.

Usero‑Alonso G, López‑Moya JA, Gil‑Rueda F, Redondo BI, Ramis‑Vidal G, Muñoz‑Luna A (2023). Determinación del patrón de crecimiento en cerdo ibérico (50 % Duroc) criado en régimen extensivo desde los 70 a los 365 días de edad. ITEA‑Información Técnica Económica Agraria 119(3): 270-287. https://doi.org/10.12706/itea.2023.007