RESUMEN
Neutral detergent fiber (NDF) and acid detergent fiber (ADF) composition have been shown to predict in vitro true digestibility (IVTD), in vitro NDF digestibility (IVNDFD), and in vitro ADF digestibility (IVADFD) in ruminants. This study's objective was to estimate in vitro digestibility measures within the DaisyII incubator using equine fecal inoculum from feedstuff NDF and ADF composition. Analyzed feedstuffs included alfalfa hay (Medicago sativa), Coastal Bermudagrass hay, soybean meal, rice bran, hempseed meal, and Bluebonnet® Equilene® Pellets. Data were analyzed using Akaike's information criterion (AIC) within the R Statistical Program©. The highest ranked model for IVTD was the interaction of NDF and ADF: 10003.32 - 0.2904 × NDF - 0.4220 × ADF - 0.0010 × NDF × ADF (Adjusted R2 = 0.959 and AICc = 474.97). Sample IVNDFD was moderately predicted by ADF: 855.15 - 1.5183 × ADF (Adjusted R2 = 0.749 and AICc = 560.82). Feedstuff ADF produced the highest ranked model for IVNDFD: 881.91 - 1.5952 × ADF (Adj. R2 = 0.835 and AICc = 541.33). These results indicate the effectiveness of using feedstuff NDF and ADF composition to predict IVTD, IVNDFD, and IVADFD within equine fecal inoculum. The findings of this study provide better understanding of feedstuff digestibility using equine fecal inoculum, but more research is warranted for validation of the models and the potential impact in vivo.
RESUMEN
With greater availability of hemp (Cannabis sativa L.) due to recent legislation, hempseed meal (HSM) should be evaluated as a potential feedstuff for livestock. The study objective was to evaluate the palatability of HSM in horses. Trial 1 used a modified 3 × 3 Latin Square design utilizing three geldings and three mares. Feeding periods (6d) consisted of two feedings/d with a washout phase (3d) before each treatment phase (3d). During treatment, horses were offered soybean meal pellets (SBM), rice bran pellets (RBP), or beet pulp pellets (BPP) in one bucket (500 g) and HSM in a second bucket (500 g) each feeding. In Trial 2, six geldings were offered 1 kg of HSM pellets over two 5-minute periods, 1 hour apart each day, with 1kg of Coastal Bermudagrass hay between offerings. Consumption of HSM in Trial 1 was greater than SBM (P = .005) and BPP (P < .001) but not different from RBP (P = .19). Consumption of HSM increased with each subsequent period (P < .001). In Trial 2, intake of HSM on d1, d2, and d3 were less than d6 (P < .05). Hay consumption was greater on d1 and d2 than d6 (P < .01). Hay consumption and HSM intake were not correlated (R2 = 0.001). These findings indicate that HSM may be similar in palatability to RBP and more palatable than SBM and BPP. Consumption of HSM increases over time, but is not impacted by hay consumption. In equine rations, HSM may serve as an acceptable replacement to more common feedstuffs.