Twelve steers, fitted with rumen canulae were used in a 4 x 4 Latin square design to examine the impact of the direct fed microbial Propionibacteria acidipropionici (PA) on rumen fermentation characteristics. All steers were housed together in one pen equipped with GrowSafe feed intake monitoring stations and one Greenfeed system used to estimate in vivo methane production. Steers were fed a corn silage-based diet throughout the experiment. Treatments consisted of PA administered at: 1) 0.0; 2) 1.0 x 108; 3)1.0 x 109; and 4) 1.0 x 1010 CFU∙animal-1∙day-1. Treatments were administered directly into the rumen as a single bolus dose daily. On day 7 and 14 of each period, rumen fluid was collected from each steer 2 h post treatment administration for VFA analysis and for determining in vitro fermentation characteristics. Following a 14d washout period, animal treatments were switched, and the experiment repeated. Data were analyzed as a 4 x 4 Latin square design. In vivo propionic acid molar proportions (25.4 vs 23.6±0.24) and total VFA concentrations (125.2 vs 121.3±1.87) were greater (P < 0.05) in steers receiving PA compared with controls. In vitro DM disappearance (P < 0.05; 63.3% vs 59.2%±1.12) and total VFA (P < 0.05; 147.9 vs 145.2±1.76) were greater and methane (ml/g DMD) lesser (P < 0.04; 13.1 vs 15.6±0.11) in fermentation vessels incubated with rumen fluid from animals receiving PA compared with controls. Dry matter disappearance (P < 0.03) and propionic acid (P < 0.04) increased linearly as dose of PA increased. In vitro Total VFA tended (P < 0.08) to increase linearly and methane production tended (P < 0.09) to decrease quadratically in response PA dose. In vivo methane production was similar across treatments. In conclusion, PA addition improved in vivo and in vitro rumen fermentation characteristics.

As our global agriculture landscape continues to change it has become more important than ever to find sustainable alternatives to feed livestock. Hempseed and its derivatives may provide alternative sources of nutrients for inclusion in livestock diets, however, due to the paucity of research on hemp and its byproducts, there is no authorization of the inclusion of these products in food animal diets. We hypothesized that the digestibility and use of hempseed meal would be similar to other livestock protein sources. Forty Western White-Faced wethers were used in a completely randomized block design with 5 treatments. These treatments included diets formulated to be near isonitrogenous with 0, 5, 10, 15, or 20% of diet DM as hemp seed meal, primarily as a substitute for dried distillers grains with solubles. Wethers were fed the diets individually for 90 d, which was followed by a 5 d balance trial with a total collection of urine and feces. There were no differences in DM intake (P = 0.44) or average daily gain (P= .16) between treatments. There were no differences in DM digestibility (P = 0.86) or N digestibility (P = 0.29) between treatments, although there was a slight increase in P digestibility as hemp meal inclusion increased until it represented 15% of the dietary DM (P = 0.02). There were no differences in the digestibility of Ca (P=0.44), Mg (P = 0.10), K (P = 0.85), or Na (P = 0.54). There were no differences in urinary N excretion (P=0.33) or urinary urea excretion (P=0.34) between treatments. Additionally, blood chemistry constituents were also not affected by treatment (P ≥ 0.10). Based on these data, it is concluded that hemp seed meal is a comparable protein supplement for sheep with no identified deleterious effects.