Tacoma-Fogal, Rink2024-04-052024-04-052023-08TacomaFogal_cornellgrad_0058F_13950http://dissertations.umi.com/cornellgrad:13950https://hdl.handle.net/1813/114775102 pagesForage quality plays a critical role in the overall health, productivity, and performance of ruminants driving production efficiency, improving profitability, and sustainability. Tools to measure forage quality are numerous and ones that will be discussed in this dissertation include evaluating different meadow fescue (Festuca pratensis Huds.) cultivars, handheld near-infrared spectrometry, and apparent digestibility as influenced by fecal mass. We evaluated the effect of meadow fescue (MF) grass cultivars insterseeded with alfalfa on grass proportion and nutritive value on commercial dairy farms in New York State. To achieve high-quality alfalfa-grass forage, a seeding rate of 1.1 kg hectare-1 for most of the MF cultivars resulted in optimal grass proportion of 20-30%. The tetraploid MF cultivars had lower neutral detergent fiber (NDF) and higher invitro true digestibility (IVTD) compared to other cultivars. Additional tools to improve forage quality involved the use of hand-held near-infrared spectrometry technology. Optimal grass proportions in alfalfa-grass mixtures range between 20 to 30%, creating an opportunity for calibration development to enable hand-held NIR spectrometers to estimate grass proportion in fresh alfalfa-grass mixtures. Model predictive capability for estimating grass content in alfalfa-grass mixtures yielded an R2 of 0.83 and a ratio of performance to deviation (RPD) of 2.6 when a sliding scanning technique versus a stationary technique was used. In addition, a modified fractionation method used to quantify bacterial mass in human fecal matter was evaluated as a method to determine bacterial mass in ruminant feces. The procedure was designed to separate the undigested feed fraction from the bacterial fraction, however, microscopic assessment revealed fibrous feed residue contamination in the bacterial pellet from sheep fecal samples. Alternative methods were performed to estimate the microbial mass in sheep feces. True digestibility was examined from sheep on either high corn grain or high soy hull diets. Results suggested differences in diet NDF level affects fecal microbial mass.enDigestibilityFecal compositionForage compositionForage qualityMethod developmentdissertation or thesishttps://doi.org/10.7298/pgc8-8272