The influence of the genotype and castration of sheep on the consumption and assimilation of gross energy of individual nutrients in the feed diet

Introduction . The balance trial provided data indicating the influence of genotype and castration of ram lambs on the intake and utilization of gross energy from dietary nutrients. Methodology . For the experiment, the following groups of young animals were formed: Group I: Purebred Tsigai ram lambs; Group II: First-generation crossbred ram lambs with Edilbai breed (½ Tsigai x ½ Edilbai); Group III: Purebred castrated males (wethers) of the Tsigai breed; Group IV: Crossbred castrated males (wethers) (½ Tsigai x ½ Edilbai). Results . The influence of genotype and castration on the amount of consumed and digested gross energy from specific dietary nutrients was established, which subsequently affected its digestibility within the organism. It was found that due to the heterosis effect, the crossbred young animals in Groups II and IV outperformed their purebred counterparts in Groups I and III in terms of gross energy intake from: protein by 0.83 MJ (17.15%) and 0.77 MJ (17.23%), respectively; fat by 0.34 MJ (16.75%) and 0.30 MJ (15.79%), respectively; fiber by 1.14 MJ and 1.09 MJ (17.55%), respectively; nitrogen-free extract (NFE) by 2.10 MJ (16.87%) and 2.04 MJ (17.80%), respectively. Regarding the coefficient of digestibility of gross energy, the advantage of the crossbred groups II and IV was: protein: 1.18% and 0.68%, respectively; fat: 0.53% and 1.21%, respectively; fiber: 0.27% and 0.21%, respectively; NFE: 0.99% and 1.44%, respectively.