Utilization of alkaline hydrogen peroxide-treated wheat straw-alfalfa combinations by ruminants

Several experiments were conducted to determine the effects of feeding combinations of alkaline hydrogen peroxide-treated wheat straw (AHP-WS) and alfalfa on nutrient intake and digestibility and ruminal characteristics of both mature sheep (experiments 1 and 2) and growing dairy heifers (experiment 3). Additionally, the effect of feeding combinations of these two forages on in situ digestion kinetics of both AHP-WS and alfalfa was examined (experiment 4). Diets in all experiments consisted of an 80:20 forage:concentrate ratio on a dry matter (DM) basis. Dietary designations were based on DM ratios of AHP-WS:alfalfa. For example, diet 53:27 contained 53% AHP-WS and 27% alfalfa.When combinations of the forages were offered for ad libitum intakes (experiments 1 and 3), significant (P $<$.05) positive associative effects were noted for organic matter intake (OMI). In experiment 1, OMI was approximately 15% higher when combinations of the forages were fed than when either forage was fed separately. In experiment 3 the greatest increase in OMI occurred when the lowest level of alfalfa was added (diet 53:27). Organic matter intake increased 14% when comparing diet 53:27 to diet 80:0. Total tract digestibility (TTD) of OM (as a % of OMI) was unaffected by diet averaging 69 and 64% for experiments 1 and 3, respectively.When combinations of the forages were fed at restricted levels of intake (experiment 2), modest positive associative effects were noted for TTD of OM. Additionally, in situ data from experiment 4 confirmed the hypothesis that feeding combinations of the two forages would result in a ruminal environment more suitable to fiber degradation. Rates of disappearance of DM, neutral detergent fiber (NDF), and some hemicellulose neutral monosaccharides were greater for both AHP-WS and alfalfa when incubated in animals fed combinations of the two forages than when incubated in animals fed either forage alone.The results of experiments 2 and 4 suggest that TTD of OM should have been improved when combinations of the forages were fed in experiments 1 and 3. However, under ad libitum feeding conditions, while intake of digestible nutrients is improved when combinations of AHP-WS and alfalfa are fed, ruminal flow dynamics are such that TTD of OM remains unaffected.U of I OnlyETDs are only available to UIUC Users without author permissio