ABSTRACT The objective of this study was to evaluate the effect of a mixture of direct-fed microbials (DFM), yeast, and digestive enzymes on animal performance in feedlot cattle, as well as digestibility when finishing feedlot cattle. Thirty crossbreed (Charolais × Beefmaster) steers averaging 15 months old and 321.83±3.73 kg of initial body weight were used. Animals were randomly assigned to one of two treatment groups: control (basal diet) and a mixture of DFM, yeast, and digestive enzymes (basal diet + 30 g of the mixture). Each group contained fifteen experimental units. Animals were fed individually twice a day, and dry matter intake (DMI) was recorded daily. Body weights were recorded initially and subsequently at 28-day intervals for a total of 140 days to evaluate average daily gain (ADG). The gain:feed ratio (G:F) was also calculated per period. Dry matter digestibility, crude protein (CPD), and neutral detergent fiber (NDFD) were evaluated in the finishing phase. Ten steers per treatment were randomly selected for digestibility evaluations. Insoluble acid detergent fiber was used to calculate apparent digestibility. A completely randomized design with measurements repeated over time was used to evaluate animal performance, and a completely randomized design was used to evaluate apparent digestibility. No effect of treatment was observed for DMI. At the end of the trial, differences for ADG were found between treatments, with higher values in control than the treatment group. However, no effect for G:F was found. Dry matter digestibility, CPD, and NDFD were similar between treatments. The addition of the mixture of DFM, yeast, and digestive enzymes as a feed supplement in the diet of feedlot cattle does not improve animal performance and nutrient digestibility.

ABSTRACT The objective of this study was to evaluate the effect of three levels of cull pinto beans (CPB) on animal performance, energy balance, and digestibility of hair ewes during pregnancy-lactation. One hundred and sixty-eight Pelibuey ewes were used (105 multiparous and 63 primiparous). Seven ewes of each type were randomly assigned to each of the 24 pens. Then, the twenty-four pens were randomly assigned to one of three treatments. Treatments were assigned on DM basis at: 0 g kg−1 of CPB in the supplement; 250 g kg−1 of CPB in the supplement; and 500 g kg−1 of CPB in the supplement. Data was analyzed by using the PROC MIXED of SAS. Lamb birth and weaning weight were also evaluated with the GLM procedure of SAS. All variables were analyzed as a completely randomized design. No differences among treatments were observed for body weight, body condition score, non-esterified fatty acids, and body weaning weight. During late pregnancy, dry matter intake was different among treatments, but it was similar during lactation. Body birth weight was different among treatments and showed a quadratic effect. At day 30 of lactation, a treatment effect was found for digestibility of dry matter (DM). At the end of lactation, digestibility of crude protein was different among treatments. In day 60 of lactation, differences among treatments were found for digestibility of neutral detergent fiber. Due to equal ewe performance among treatments of CPB and its low cost, its use is recommended in hair ewe feeding for these productive stages: 500 g kg−1 DM of the supplement during pregnancy and 400 g kg−1 DM during lactation.

The objective of this research was to evaluate the inclusion of two qualities of Mexican oregano oil (MOO) in broiler diets on broiler weight, feed intake, feed efficiency, average daily gain, and water intake. The qualities were MOO1 (4% thymol, 60% carvacrol) and MOO2 (40% thymol, 20% carvacrol). Nine treatments were prepared by the combinations of MOO1 + MOO2 (0, 400, and 800 mg kg−1; added per kg of feed) respectively: 0+0, 0+400, 0+800, 400+0, 400+400, 400+800, 800+0, 800+400, and 800+800. Eighteen chicks per treatment were divided in a completely randomized design into nine cages. Broiler weights were altered by the treatments at 21 d, when 400+400 had the highest weight, and on day 39, when the greatest weight was seen in broilers on treatments 800+0 and 800+400. Feed intake was affected by treatment on day 39, with broilers on 800+0 exhibiting the highest values. Water intake was influenced by the treatments on days 14, 21, 35, and 39, when 0+0 represented the lowest. Feed efficiency was altered by the treatments on days 14, 28, 35, and 39, whereas average daily gain was affected from days 14 to 39. Supplementation of Mexican oregano oil has beneficial effects on broiler weight, feed efficiency, average daily gain, and feed and water intakes. Combinations of thymol and carvacrol levels have varying effects on these parameters. The higher relative body weights of groups 400+0, 800+0, and 800+400 suggest positive market value effects of these combinations of Mexican oregano oil.