Dry matter intake in ruminants as a function of forage quality: preliminary research - Four Chianina heifers and six Appennine wethers were fed four different types of local hay: natural meadow (PS), Italian raygrass (LO) and two types of lucerne hay (M1, M2) during eight-day ad libitum trials. OM, the apparent energy digestibility coefficient and the nutritive value of each forage were estimated. In both species DMI values (g/kg LW0.75) for the lucerne hays were higher than those obtained for the other two types of hay (101.2 and 98.8 vs 78.7 and 78.3 in heifers; 83.6 and 75.1 vs 56.0 and 55.2 in wethers). The minimum and maximum NDF intake values (%LW) were 1.01-1.16 in heifers and 1.24-1.38 in wethers. The minimum and maximum ADF intake values (% LW) were 0.72-0.80 in heifers and 0.85-1.05 in wethers. DMI, chemical composition and OM digestibility were all highly correlate (P<0.001). the OMD, ADF, NDF and CF correlation coefficients ere the highest and were influenced by the botanical species and the number of samples. This factor may also explain the positive correlation coefficients between ADL content and DMI and between ADL and OMD. Multiple regression equations were calculated in both species to estimate DMI and Milk Feed Unit intake (using the chemical composition of forages as independent variables). The R2 varied between 0.67 and 0.88 higher in heifers than in wethers; RSD values were relatively high.
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