DIETARY PREFERENCES OF PIGLETS FOR MIXTURES OF FORMIC AND LACTIC ACIDS OR THEIR SALTS COMBINED OR NOT WITH PHOSPHORIC ACID

Weaning is a stressful process in piglets, in which the adaptation to the weaning diet is one of the most limiting factors. The palatability of the weaning diet ingredients may play a determinant role. A series of double choice trials with 180 pigs (20-25 kg BW) in 45 pens, were conducted to determine the preference of piglets, relative to a control (REF) diet, for diets containing a mixture of formic and lactic acids (FLa) or of their corresponding Ca-salts (FLs) in presence or absence of phosphoric acid (PA). Each pen (4 pigs per pen) contained two feeding hoppers; one with the REF diet and one with the test diet with one of the products being studied. Each product was tested using 9 pens in three consecutive 4d-periods, in which low (0.5%), medium (1%) and high (1.5%) inclusion rates were tested, respectively. The diets tested were: REF (control); FLa; FLs; FLa+PA and FLs+PA. Preferences were calculated as the percent contribution of the test diet to total feed intake and are presented in brackets ordered by increasing doses. The preference values were compared to the neutral value of 50% with the Student t-test and values with asterisk are significantly (P<0.05) different. Preferences for REF (48.2, 53.0, 51.3) and FLs (54.6, 46.5, 51.2) diets did not differ from 50%, whereas FLa significantly reduced feed preference (38.3*, 37.4*, 25.9*). The partial replacement of the mixtures with PA did not significantly affect preference for FLs (40.8, 43.0, 37.2), whereas it improved that for FLa particularly at the low and medium inclusion rates (49.0, 43.8, 33.9*). We conclude that the combination of lactic and formic acids but not that of their corresponding Ca-salts has a negative effect on piglet feed preference, and that it can partially be counteracted by the replacement of the acid mixture with phosphoric acid. tech.service.fad@lucta.com