Abstract

PARRA SUESCUN, Jaime Eduardo  and  ECHAVARRIA SANCHEZ, Hernán Alonso. EFFECT OF VARIOUS LEVELS OF THREONINE: LYSINE ON PRODUCTION PARAMETERS IN FINISHING PIGS TREATED WITH RACTOPAMINE. Rev. Fac. Nac. Agron. Medellín [online]. 2008, vol.61, n.1, pp.4400-4408. ISSN 0304-2847.

To determine the effect of adding Ractopamine (RAC) and Threonine:Lysin ratio (Thr: Lys) on the productive yields,  an experiment during 28 days was made.  42 pigs of approximately 72,4± 2,3 kg were used in which the effect of two levels of RAC was evaluated (5 and 10 ppm) and three relate Thr:Lys (0,60; 0,65 and 0,70) in the diet on the consumption of daily food (CDF), the daily weight gain (DWG), daily lean fat-free tissue gain (DLFFTG), and also, the efficiency (Ef)  was expressed as DLFFTG in function of CDF. A randomized experimental block design, in a 2 x 3 factorial arrangement and a repeated-measures analysis over time were made. All the variables were measured in each animal 14 and 28 days after initiate the diet supply. The mean/animal/days values of all the variables presented interactions. In general it was observed that high levels of Rac had a better acting with low or mean levels of Thr:Lys while the low levels of Rac had better results with high levels of Thr: Lys. For this reason, differences among variables with two levels of Rac are due to nutritional handling (Thr: Lys ratio), since this factor influences the magnitude of the answer. From the productive point of view, the combination to recommend is 10 ppm of Rac and Thr: Lys 0,6.

Keywords : Ractopamine; lean tissue; threonine; lysine ratio; finishing pigs.

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