Maintenance and Growth Requirements in Male Dorper × Santa Ines Lambs

• Published in: Frontiers in veterinary science 2021-06, Vol.8, p.676956-676956
• Main Authors: Mendes, Marcilio S., Souza, Jocely G., Herbster, Caio Julio L., Brito Neto, Antonio S., Silva, Luciano P., Rodrigues, João Paulo P., Marcondes, Marcos I., Oliveira, Ronaldo L., Bezerra, Leilson R., Pereira, Elzania S.
• Format: Article
• Language: English
• Subjects: crossbreed sheep; efficiency; energy; protein; Veterinary Science; warm areas
• ISSN: 2297-1769; 2297-1769
• DOI: 10.3389/fvets.2021.676956

The aim of this study was to estimate the energy and protein requirements for maintenance and growth of lambs. A total of 35 crossbreed Dorper × Santa Ines lambs [31 ± 1.28 kg of initial body weight (BW) and 4 months old] were distributed in a completely randomized design with three treatments groups ( ad libitum , 30 and 60% of feed restriction). Five lambs were slaughtered at the beginning of the experimental trial as a reference group to estimate the initial empty BW (EBW) and body composition. When the animals of the ad libitum treatment reached a BW average of 47.2 kg, at day 84 of trial, all lambs were slaughtered. The feed restriction promoted reduction in body fat ( P < 0.001) and energy concentration ( P < 0.001), while protein showed a quadratic response ( P = 0.05). The equations obtained for NEg and NPg requirements were 0.2984 × EBW 0.75 × EBWG 0.8069 and 248.617 × EBW −0.15546 , respectively. The net energy (NEm) and protein (NPm) for maintenance were 71.00 kcal/kg EBW 0.75 /day and 1.76 g/kg EBW 0.75 /day, respectively. In conclusion, the NEg and NPg requirement for lambs with 30 kg of BW and 200 g of average daily gain (ADG) were 0.736 Mcal/day and 24.38 g/day, respectively. Our findings indicate that the NEm for crossbreed Dorper × Santa Ines lambs is similar to those recommended by the international committees; however, we support the hypothesis that the requirements for gain are lower.