Valor nutricional de suplementos concentrados para vacas leiteiras com farinha de baru em substituição ao fubá de milho

Abstract

Due to the price fluctuations of the main grains used in animal nutrition, added to the availability of baru, the possibility arises to evaluate its use in diets for dairy cows. The objective was to evaluate the nutritional value and economic viability of concentrated supplements with increasing levels (0; 25; 50; 75 and 100% of dry matter) of epicarp and baru mesocarp (BM) meal to replace cornmeal (CM). The experimental design used was completely randomized with five treatments and five replications. The supplements were formulated to be isoproteic and to meet the requirements of 50% of the net lactation energy of cows with an estimated production of 15 kg of milk/day corrected at 4% fat. The inputs used were soybean meal, FM, FB and mineral vitamin core. The bromatology was determined by the analysis of dry matter (DM), crude protein (CP), ethereal extract (EE), ash, neutral detergent (NDF) and acid (FDA) insoluble fibers, non-fibrous carbohydrates (NFC), total digestible nutrients (TDN) and in vitro dry matter digestibility (DIVMS) of inputs and experimental concentrates and the phenolic content of FB. The economic viability of the supplement was calculated according to the cost of DM and digestible DM. The similarity between the CNF levels of the supplements showed that FB has the potential to replace FM. Similarly, there was no effect (p<0.05) of replacing FM with FB on DM, ash, CP, NDF, FDA, EE, CNF and TDN contents of concentrated supplements. The FB presented 32.20 mg/100g (0.322 mg/ml) of total tannins, which allowed to estimate that the treatment with greater inclusion of FB (100%) would present an estimated concentration of 0.0073 mg/100g of total tannins in the diet. , a value below the levels related to negative effects on animals. There was a linear effect (p<0.05) of the inclusion of FB on the in vitro digestibility of DM of the concentrated supplements, with each 1% of inclusion of FB the IVDM of the supplements reduced by 0.137%. For every 25% of FB inclusion, the cost of the supplement was reduced by R$/kg 0.06; however, the increasing replacement of FM by FB does not change the chemical composition and reduces the cost of dry matter of concentrated supplements. However, supplements with greater participation of FB have lower in vitro digestibility of dry matter and higher cost of digestible dry matter, which makes it less nutritionally and financially advantageous.