Essential oils blend with a newly developed enzyme cocktail works synergistically to enhance feed utilization and milk production of Farafra ewes in the subtropics

The present study assessed the synergetic effects of providing oral doses of capsicum/thymus essential oils blend and exogenous fibrolytic enzymes cocktail on lactational performance of Farafra ewes. Forty ewes (39.93 ± 0.56 kg) were grouped into 4 treatments and fed: (1) a total mixed diet of concentrates, berseem hay and wheat straw (60:20:20 dry matter basis; control), (2) the control diet supplemented with 2 mL of capsicum/thymus essential oils blend (EO treatment), (3) the control diet supplemented with 4 g of enzymes cocktail (ENZ treatment), and (4) the control diet supplemented with 2 mL of capsicum/thymus essential oils blend + 4 g of enzymes cocktail (ENZEO treatment) for 12 weeks. The supplements were delivered orally to individual ewes using syringes. Compared with the control diet and without affecting (P > 0.05) feed intake, ENZ, EO, and ENZEO diets had greater digestibilities (P < 0.01) of neutral detergent fiber by 4.9, 2.6 and 6.8% and acid detergent fiber by 2.3, 2.4, and 4.5%, respectively. Supplements increased (P < 0.001) ruminal short chain fatty acids by 13.1, 13.1, and 12.2% for ENZ, EO, and ENZEO treatments, respectively, with higher (P < 0.001) acetate for ENZ and ENZEO treatments and propionate (P = 0.001) for EO and ENZEO treatments. Feeding ENZ, EO, and ENZEO treatments increased (P < 0.001) milk production by 14.5, 11.7, and 16.6% and energy corrected milk (ECM) by 19.0, 10.8, and 22.8%, respectively. Besides, ENZ and ENZEO supplements increased milk fat content by 6.8 and 8.7%, respectively. Greater (P < 0.001) milk (feed) efficiencies by 13.4, 9.8, and 15.9% as milk production/feed intake and by 18.6, 9.3, and 22.1% as ECM/feed intake were observed with ENZ, EO, and ENZEO treatments, respectively. Supplements decreased (P < 0.01) milk saturated fatty acids concentrations by 3.1, 4.6, and 3.3% and increased (P < 0.01) milk contents of unsaturated fatty acids by 7.3, 10.6, and 7.6% and total conjugated linoleic acid by 12.1, 19.0, and 13.8% for ENZ, EO, and ENZEO treatments, respectively. It is concluded that capsicum/thymus essential oils blend at 2 mL and/or enzymes cocktail at 4 g enhanced feed digestion, ruminal fermentation and milk production, composition, and nutritive value of lactating Farafra ewes. Combining exogenous enzymes with the essential oils is synergistically beneficial compared with the individual supplements.