Avaliação nutricional de fenos de estilosantes e de alfafa em equinos

Abstract

This study was carried out to evaluate the intake, nutrient digestibility, body weight gain, the intake by LIPE® marker of diets composed by concentrate and legume hay fed foals. Additionally, evaluate the nutritional value and kinetics of legumes hays digestion. Treatments were: lucerne hay (LUC) (Medicago sativa), stylo hay Campo Grande (CG) (20% Stylosanthes macrocephala and 80% Stylosanthes capitata) and stylo hay Mineirão (M) (Stylosanthes guianensis cv. Mineirão) in natura and predigested. At the first assay, were used 15 foals with 160 Kg BW, weaned with 165 days. After weaning the foals remained 30 days in a Cynodon spp. paddock fed ration twice a day, until start the assay. The dry matter intake estimative was 30g of DM/Kg BW. From total intake calculated animals were fed 40% of concentrate meal and 60% of roughage as hay. Design was entirely randomized with three treatments and five replicates. The faecal estimation, the nutrient digestibility values and the dry matter intake of hays and the total diet, were calculated by LIPE® marker methodology. Was made a predigestion trial of hays. The residue generated was used in two others assays, one in situ and other in vitro. The design used for in situ procedure was entirely randomized in factorial 3x8 arrangement. As incubation site one crossbreed horse fitted at caecum was used. The third assay evaluated hays in natura and predigested by gas production technique, which used as experimental design a split-plot randomized blocs with 3 repetitions. As inoculums donors 3 crossbreed horses fitted at right dorsal colon were used. There was no difference (P>0.05) between LUC and CG stylo hay intake. There was less M stylo hay intake (P>0.05) than LUC intake. The weightgain values between treatments did not differ. There was no difference (P>0.05) on body weight gain of foals fed experimental diet composed by LUC, CG and M, with daily mean values of 0.58; 0.54 and 0.47 Kg/day,respectively. There was no difference (P>0.05) between real consumption compared with observed by LIPE®. There was no difference among nutrient digestibility coefficients (P>0.05) from different diets. The potential degradable fraction of DM was higher for LUC, CG and M, with values of 53.1; 45.7 e 43.2%, respectively. The degradation rate followed the same order, with values of 15; 14.2 e 13.3%h-1. The effective protein degradability was higher for CG hay. No difference was observed (P<0.05) among NDF caecal in situ degradation of predigested hays evaluated. The maximum gas production at 48 hours was the same between LUC and CG hay as in natura as predigested. Less final gas production (P<0.05) was observed on M hay into both apresentationforms. Campo Grande hay can be used as alternative roughage, as intake was similar to Lucerne hay. The intake estimate through LIPE® marker is satisfactory for equines. Digested legume hays do not adjust to usually applied models for gas production. The CG hay present higher effective protein degradability. LUC and CG hay as in natura as predigested demonstrate the same final potencial of gas production. The predigestion influences gas production profile