RESUMEN
This study aimed to test the hypothesis that peanut cake can substitute for soybean meal in the feed of ruminants on the basis of the intake, performance, digestion, and serum urea and glucose concentration in crossbred Boer × indigenous goat kids. Forty intact vaccinated and dewormed crossbred Boer × indigenous goat kids (average age = 5 mo, average BW = 15.6 ± 2.7 kg) were used. The goats were fed Tifton-85 (Cynodon dactylon) hay and concentrate mixes of corn bran, soybean meal, premix mineral, and peanut cake substituted for soybean meal at rates of 0.0%, 33.33%, 66.67%, and 100%. The animals were confined for 62 d, and the digestibility trial was performed from d 27 to 31 of confinement. Samples of orts and feces were quantified and collected from each animal during this period. On the d 32 of confinement, a blood sample was taken from animals to measure urea N and glucose. Data were analyzed with a regression model. Substitution of soybean meal with peanut cake in the diet of the animals resulted in a reduction in intake of DM (P = 0.02), CP (P = 0.03), NDF (P = 0.03), nonfiber carbohydrate (NFC; P = 0.01), and TDN (P = 0.02) and an increase in intake of ether extract (P < 0.001). The total and daily average weight gains decreased (P = 0.02) with substitution, whereas G:F was not influenced (P = 0.11). With the exception of ether extract digestibility, which increased (P < 0.001) with substitution, digestibility of DM (P = 0.13), OM (P = 0.18), CP (P = 0.54), NDF (P = 0.20), and NFC (P = 0.73) was not influenced by diets. The concentration of serum urea N was influenced quadratically by the postprandial time for treatments with 33.33%, 66.67%, and 100.00% substitution. Peanut cake is not a complete, equal substitute for soybean meal in goat feed. However, peanut cake may represent an eventual replacer able to reduce goat producers' dependence on traditional ingredients in the feed of growing goat kids.