category: feed additives
authors: suarez, j., tedó, g., roura, e. and torrallardona, d.
book/journal:journées recherche porcine, 44, 197-198
a double choice test was conducted to determine preference of diets with free l‐valine (l‐val) in pigs under different nutritional status. one hundred and eight piglets (17.5 ± 1.5 kg bw) were divided into three groups and adapted for one week to diets that were either deficient (d), adequate (a) or excessive (e) in valine (val:lys ratio; 0.63, 0.68 or 0.73, respectively). after the adaptation period, the animals were used in pairs to perform series of 2‐day double‐choice tests between diet d (without free l‐val), as reference, and three diets with increasing levels of free l‐val to provide val in excess (e1, e2 and e3; 0.73, 0.78 and 0.83 val:lys ratio; or 1.2, 1.8 and 2.4 g l‐val/kg, respectively). preference for each tested diet was expressed through its % contribution to total feed intake. preference values were analyzed considering the main effects of l‐val level (e1, e2 or e3), val status (d, a or e), and their interaction. overall, l‐val diets were preferred (58%) over diet d, independently of l‐val level. however, the effect of val status tended to be statistically significant (p<0.1) and the piglets on the d status presented higher preferences than those on the e status (p<0.05). it is concluded that, under the conditions tested, free l‐val improves feed preference independently of the dose used, and that pigs may be able to modulate this preference to compensate for their nutritional status for this amino acid.