Orange essential oil (Citrus sinensis) as a source of limonene in sheep feed

Abstract

Three experiments will be conducted to investigate the effects of different levels of limonene present in orange essential oil (Citrus sinensis) as a feed additive on ruminal fermentation, performance of feedlot lambs and milk production and composition of ewes and performance of their lambs. In all experiments the concentration of limonene in the experimental diets will be: 100, 500 and 1000 mg of limonene/kg of DM. In addition to the treatments with limonene, a negative control (without addition of additive) and a positive control with inclusion of 25 mg/kg DM of monensin will also be evaluated, totaling 5 treatments. In the metabolism experiment (Experiment I) will be used 10 lambs, cannulated in the rumen, distributed in double Latin square 5 x 5. In this experiment the consumption and digestibility of nutrientes (DM, OM, CP, EE, NDF and NCF), nitrogen balance and rumen fermentation characteristics (pH, SCFA, N-NH3) will be measured. In the performance experiment (Experiment II) 45 lambs will be used, distributed in a randomized complete blocks design (9 blocks and 5 treatments). In this experiment the DMI, ADG, FE and ingestive behavior will be evaluated, as well as the ruminal histology and the fatty acid composition of the meat. In the lactation experiment (Experiment III) 50 ewes will be used, distributed in a randomized complete blocks design (10 blocks and 5 treatments). In this experiment will be evaluated: milk production and composition of ewes and performance of their lambs. All variables will be evaluated using the SAS MIXED Procedure (1999) and the differences will be declared significant when P < 0.05. (AU)