04242nab a2200325 i 4500 BR-BrBNA 20250422224942.0 250422b2020 bl.ar|pooa||| 00| 0 eng | BR-BrBNA eng L02 5214 Cruz, Antonio Ariclezio Carlos Véras, Antonia Sherlânea Chaves Oliveira, Júlio César Vieira de Santos, Djalma Cordeiro dos Chagas, Juana Catarina Cariri Neves, Maria Luciana Menezes Wanderley Monteiro, Carolina Corrêa de Figueiredo Ferreira, Marcelo de Andrade ABSTRACT - This study was performed to identify the ideal amount of concentrate required for a diet based on cactus cladodes, sugarcane, and urea used to feed heifers. Twenty Girolando heifers (160±8.39 kg) were randomly distributed into four experimental treatments with 0, 0.40, 0.80, or 1.20 kg day−1 of concentrate. The basal diet contained [on dry matter (DM) basis] 38.1% sugarcane, 56.5% cactus cladodes [Opuntia stricta (Haw). Haw.], 0.5% common salt, 1.1% mineral mixture, and 3.8% urea plus ammonium sulfate. The concentrate contained [on DM basis] 87% corn meal and 13% soybean meal. The basal diet and the concentrate were formulated to provide 13% crude protein (CP). The intake of DM (4.34-4.96 kg day−1), organic matter (3.96- 4.98 kg day−1), CP (0.57-0.64 kg day−1), non-fibrous carbohydrates (2.20-2.61 kg day−1), and metabolizable energy (10.3-12.4 Mcal day−1) increased linearly with concentrate amount. Final body weight (196-224 kg), total body weight gain (36.9-61.2 kg), and average daily body weight gain (0.51-0.85 kg day−1) increased linearly with concentrate amount. The nitrogen balance was positive and increased linearly (54.8-62.3 g day−1) with concentrate amount. Based on the data, we recommend supplying six-monthold Girolando heifers (160 kg body weight) 1.20 kg concentrate day−1 added to a diet based on sugarcane and cactus cladodes plus urea for better productive and economic performance. Keywords: cactaceous, energy supplementation, non-protein nitrogen, reproduction, Publicação on-line; 27 ref.; 6 tables; Sumaries (En) ABSTRACT - This study was performed to identify the ideal amount of concentrate required for a diet based on cactus cladodes, sugarcane, and urea used to feed heifers. Twenty Girolando heifers (160±8.39 kg) were randomly distributed into four experimental treatments with 0, 0.40, 0.80, or 1.20 kg day−1 of concentrate. The basal diet contained [on dry matter (DM) basis] 38.1% sugarcane, 56.5% cactus cladodes [Opuntia stricta (Haw). Haw.], 0.5% common salt, 1.1% mineral mixture, and 3.8% urea plus ammonium sulfate. The concentrate contained [on DM basis] 87% corn meal and 13% soybean meal. The basal diet and the concentrate were formulated to provide 13% crude protein (CP). The intake of DM (4.34-4.96 kg day−1), organic matter (3.96- 4.98 kg day−1), CP (0.57-0.64 kg day−1), non-fibrous carbohydrates (2.20-2.61 kg day−1), and metabolizable energy (10.3-12.4 Mcal day−1) increased linearly with concentrate amount. Final body weight (196-224 kg), total body weight gain (36.9-61.2 kg), and average daily body weight gain (0.51-0.85 kg day−1) increased linearly with concentrate amount. The nitrogen balance was positive and increased linearly (54.8-62.3 g day−1) with concentrate amount. Based on the data, we recommend supplying six-monthold Girolando heifers (160 kg body weight) 1.20 kg concentrate day−1 added to a diet based on sugarcane and cactus cladodes plus urea for better productive and economic performance. Keywords: cactaceous, energy supplementation, non-protein nitrogen, reproduction, NOVILHO LEITEIRO DIETA MATÉRIA SECA SUPLEMENTO ALIMENTAR 3545 317600 Viçosa-MG Sociedade Brasileira de Zootecnia 1997 2024-4310 Revista Brasileira de Zootecnia (Brazil) 1516-3598 v. 49 p. 1-8; (2020) BR2025000633 https://www.scielo.br/j/rbz/a/3Ry4PZBfXd6fxQTMRdwLqzr/?format=pdf&lang=en ANA 331151 331151