Net energy requirements for maintenance and weight gain in male guinea pigs (Cavia porcellus) of the Peru breed

Abstract

This study aimed to estimate the net and metabolizable energy requirements for maintenance (NE_m, ME_m) and gain (NE_g, ME_g), along with the efficiencies of metabolizable energy utilization for maintenance (k_m) and weight gain (k_g), in intact male guinea pigs of the Peru breed. Sixty animals were assigned to three feeding levels: ad libitum, restricted (75 % of ad libitum intake), and maintenance (150–160 kcal DE/kg BW^0.75/day). A metabolism trial and a comparative slaughter technique were employed to determine gross energy intake (GEI), digestible energy (DE), metabolizable energy (ME), heat production (HP), and retained energy (RE). NE_m and ME_m were estimated at 100 and 149 kcal/kg EBW⁰·⁷⁵/day, respectively, with corresponding efficiencies k_m and k_g of 67 % and 48 %. The NE_g requirement increased with both body weight (BW) and daily weight gain (DWG), ranging from 15.3 to 18.7 kcal/day for 5 g DWG in animals weighing 900 to 1200 g. The NE_g ranged between 3.06 and 3.74 kcal/g of BW gained, with higher values attributed to increased fat deposition. These findings highlight the importance of considering both growth rate and body composition in energy requirement estimations. The results support the development of more accurate and tailored feeding systems for guinea pigs raised for meat production.