Effect of meat meal and animal fat adition as sources of protein and energy by-pass in multinutritional blocks on the voluntary intake and digestibility in lambs eating low quality hays

In order to evaluate the effect of the adition of energy and protein by-pass in multinutritional blocks (MNB) on the digestibility and voluntary intake of the fractions of the ration, a trial was carried out using 20 overcrossing lambs (15 - 20 kg liveweight). Two levels of meat meal and 2 levels of animal fat were evaluated, in a factorial treatment arrangement and a total randomized design. Animals were housed in metabolics stalls and assigned to four treatments: T0: hay of Cenchrus ciliaris ad libitum + mineral mixed; T1: hay ad libitum + blocks with 8% of animal fat, ad libitum; T2: hay ad libitum + blocks with 8% of animal fat + 12% of meat meal ad libitum; T3: hay ad libitum + blocks ad libitum and T4: hay ad libitum + blocks with 12% of meat meal ad libitum. The hay intake (HI), relative intake of hay (RIH), WINE intake (BI), relative intake of MNB (RIB), dry matter intake (DMI), relative intake of DM (RIDM), organic matter intake (OMI), relative intake of OM (RIOM), the DM digestibility (DMD), and OM digestibility (OMD) were analized. Level of animal fat affected significantly to RIOM (P < 0.01), to HI, RIH, RIDM, OMI (P < 0.05) and DMI (P < 0.10). Values obtained for HI, RIH, BI, RIB, DMI, RIDM, OMI and RIOM were: 264, 241, 305 and 313 g/animal/d; 1.64, 1.69, 1.99 and 2.07 % LW; 291, 250, 304 and 259 g/animal/d; 1.78, 1.77, 1.93 and 1.75 % LW; 555, 514, 609 and 572 g/animal/d; 3.42, 3.46, 3.92 and 3.83 % LW; 467, 405, 511 and 476 g/animal/d and 2.88, 2.85, 3.30 and 3.18 % LW for T1, T2, T3 and T4, respectively. Level of meat meal affected significantly to DMD (P < 0.05) and OMD (P < 0.01), with values for both variables of: 49.06, 36.65, 53.09 and 44.26 % and 52.9, 41.28, 54.71 and 45.54 % for T1, T2, T3 y T4, respectively.