Feed efficiency in Mangalarga Marchador foals fed diet supplemented with probiotics or phytase

Abstract

The objective was to assess the effect of probiotic or phytase supplementation on dry matter intake (DMI), average daily gain (ADG) and feed conversion (FC) in 24 Mangalarga Marchador foals (16 males, 8 females), with 241.6 ± 23.2 days of age, and 216.7 ± 27.8 kg of body weight (BW). The study lasted 28 days, the first 23 days for diet and handling adaptation, and the last five days for feces collection. The basal diet consisted of Cynodon pasture and pelleted concentrate (1.2 kg/100 kg BW), as well as water and mineral salt ad libitum. Treatments groups were assigned as follows: basal diet (control); basal diet + 5 g/day of live yeast culture (109 CFU/g of S. cerevisiae); basal diet + 2 g/day of live bacteria (108 CFU/g of B. bifidum, E. faecium, L. acidophilus, L. plantarum) and yeast culture (105 CFU/g of S. cerevisiae); and basal diet + 1250 FTU/day of phytase. Pasture DMI was estimated with an external marker (LIPE™) associated with cecal in situ digestibility of dry matter. All foals were randomized, by replicated, using a 4 × 2 factorial, and results were compared using Student t-test, taking into consideration the effect of initial BW as covariate for the percentage DMI per BW. Among foals, DMI varied from 2.4 to 2.8% BW, with foals supplemented with live bacteria and yeast having lower DMI (total diet and forage). All animals had an ADG of 0.33 kg/day, and foals supplemented with live bacteria and yeast had FC 32.42 to 43.83% lower than foals supplemented with phytase or fed only basal diet. The phytase dose of 205 FTU/kg DM in the basal diet had no effects. Probiotic composed of live bacteria and yeast culture improved feed efficiency of forage and can be used as a nutritional strategy to maintain body condition in foals during the dry season.