Browsing by Author "West, Charles P. (TTU)"
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Item Comparison of acid-detergent lignin, alkaline-peroxide lignin, and acid-detergent insoluble ash as internal markers for predicting fecal output and digestibility by cattle offered bermudagrass hays of varying nutrient composition(2014) Kanani, Juvenal; Philipp, Dirk; Coffey, Kenneth P.; Kegley, Elizabeth B.; West, Charles P. (TTU); Gadberry, Shane; Jennings, John; Young, Ashley N.; Rhein, Robert T.Background: The potential for acid-detergent insoluble ash (ADIA), alkaline-peroxide lignin (APL), and acid-detergent lignin (ADL) to predict fecal output (FO) and dry matter digestibility (DMD) by cattle offered bermudagrass [Cynodon dactylon (L.) Pers.] hays of different qualities was evaluated. Eight ruminally cannulated cows (594 ± 35.5 kg) were allocated randomly to 4 hay diets: low (L), medium low (ML), medium high (MH), and high (H) crude protein (CP) concentration (79, 111, 131, and 164 g CP/kg on a DM basis, respectively). Diets were offered in 3 periods with 2 diet replicates per period and were rotated across cows between periods. Cows were individually fed 20 g DM/kg of body weight in equal feedings at 08:00 and 16:00 h for a 10-d adaptation followed by a 5-d total fecal collection. Actual DM intake (DMI), DMD, and FO were determined based on hay offered, ort, and feces excreted. These components were then analyzed for ADL, APL, and ADIA concentration to determine marker recovery and marker-based estimates of FO and DMD.Results: Forage DMI was affected by diet (P = 0.02), and DMI from MH and H was greater (P < 0.05) than from L. Apparent DMD tended (P = 0.08) to differ among diets while FO (P = 0.20) was not affected by diet treatments. Average ADL recovery (1.16) was greater (P < 0.05) than that of ADIA (1.03) and APL (1.06), but ADIA and APL did not differ (P = 0.42). Estimates of FO and DMD derived using APL and ADIA were not different (P ≥ 0.05) from total fecal collection while those using ADL differed (P < 0.05). There was no diet by marker interaction (P ≥ 0.22) for either FO or DMD.Conclusion: Acid-detergent insoluble ash and APL accurately predicted FO and DMD of cattle fed bermudagrass hay of varying nutrient composition. These internal markers may facilitate studies involving large numbers of animals and forages. Results from such studies may be used to develop improved equations to predict energy values of forages based on the relationship of dietary components to digestibility across a wide range of forages. © 2014 Kanani et al.; licensee BioMed Central Ltd.Item Diurnal variation in fecal concentrations of acid-detergent insoluble ash and alkaline-peroxide lignin from cattle fed bermudagrass hays of varying nutrient content(2015) Kanani, Juvenal; Philipp, Dirk; Coffey, Kenneth P.; Kegley, Elizabeth B.; West, Charles P. (TTU); Gadberry, Shane; Jennings, John; Young, Ashley N.; Rhein, Robert T.Background: The effect of time of fecal sampling on the accuracy of acid-detergent insoluble ash (ADIA) and alkaline-peroxide lignin (APL) for the prediction of fecal output (FO) in cattle was evaluated. Eight ruminally cannulated cows (594 ± 35.5 kg) were allocated randomly to 4 bermudagrass [Cynodon dactylon (L.) Pers.] hay diets markedly different in crude protein concentration (79-164 g/kg) with 2 replicates per diet for 3 periods. Cows were offered hay individually at 20 g DM/kg of body weight daily in equal feedings at 08:00 and 16:00 h for a 10-d adaptation period followed by 5-d of total fecal collection. Fecal grab samples also were taken each day during the fecal collection period at 06:00, 12:00, 18:00, and 24:00 h either directly from the rectum or from freshly voided feces. Samples were composited within cow and time across the 5 d total fecal collection period. Additionally, forage, ort, and fecal samples were analyzed for concentrations of APL and ADIA. Results: Fecal concentrations of ADIA and APL were not affected by sampling time (P≥0.22), even though diet affected (P < 0.01) fecal ADIA and APL concentrations. There were no diet × sampling time interactions (P≥0.60). Estimates of FO and dry matter digestibility (DMD) from ADIA and APL were not affected (P≥0.16) by sampling time or the diet × sampling time interaction (P≥0.74). Estimates of FO and DMD from markers from different sampling times or all different combinations of sampling time were not different (P≥0.72) from those of total collection among internal markers. Conclusion: Little variation in concentrations of ADIA and APL in daily fecal excretion across time increases flexibility in fecal grab sampling schedules for predicting FO and DMD.Item Dominant species as biological indicators to predict the changes of trace element in different types of rangeland(2022) Ning, Jiao; Liu, Shengsheng; Chang, Shenghua; Chen, Xianjiang; West, Charles P. (TTU); Hou, FujiangAlpine meadow, typical steppe and desert are globally important rangeland ecosystems. However, the seasonal variations in concentrations of trace elements, which are important nutrients for grazing livestock, are unclear in these types of rangeland and it is difficult to prevent disorders in grazing livestock caused by trace element excesses and deficiencies. In order to identify which forage species might serve as indicators of the trace element status of livestock forage, we investigated the seasonal trends in Fe, Mn, Cu, and Zn concentrations in the plant communities and dominant species from diverse rangeland types in northwest China in relation to livestock sufficiency levels. The trace element concentrations in the plant communities changed significantly with the season, with the highest Cu, Mn and Zn concentrations and the lowest Fe and Mn concentrations detected in spring and summer, respectively. The seasonal mean temperature, seasonal precipitation, and above-ground biomass significantly negatively correlated with the seasonal variation of Fe and Mn concentrations in the plant community. However, there was almost no significant correlation between these factors and the seasonal Cu and Zn concentrations. The plant concentrations of Fe and Mn were much higher than the recommended levels for livestock in all rangeland types, but the concentrations of Cu in the alpine meadow and the Zn concentrations in all the rangelands barely met the nutritional requirements for animal growth. Based on these deficiencies, we suggest that some forage species could be used as biological indicators to predict changes in the concentrations of trace elements. A decrease in the relative biomass of Kobresia capillifolia and Kobresia humilis in alpine meadows implies a decrease in the levels of Cu in the plant community. A decrease in the relative biomass of K. humilis in alpine meadows, an increase in Stipa bungeana in typical steppes and an increase in Nitraria tangutorum and Salsola passertine in desert rangelands lead to decreased concentrations of Zn in the plant community.Item Effect of Long-Term Semiarid Pasture Management on Soil Hydraulic and Thermal Properties(2023) Kharel, Geeta (TTU); Dhakal, Madhav (TTU); Deb, Sanjit K. (TTU); Slaughter, Lindsey C. (TTU); Simpson, Catherine (TTU); West, Charles P. (TTU)Semiarid pasture management strategies can affect soil hydraulic and thermal properties that determine water fluxes and storage, and heat flow in unsaturated soils. We evaluated long-term (>10 years) perennial and annual semiarid pasture system effects on saturated hydraulic conductivity (ks), soil water retention curves (SWRCs), soil water thresholds (i.e., volumetric water content (θv) at saturation, field capacity (FC), and permanent wilting point (PWP); plant available water (PAW)), thermal conductivity (λ), and diffusivity (Dt) within the 0–20 cm soil depth. Forage systems included: Old World bluestem (Bothriochloa bladhii) + legumes (predominantly alfalfa (Medicago sativa)) (OWB-legume), native grass-mix (native), alfalfa + tall wheatgrass (Thinopyrum ponticum) (alfalfa-TW), and annual grass-mix (annual) pastures on a clay loam soil; and native, teff (Eragrostis tef), OWB-grazed, and OWB-ungrazed pastures on a sandy clay loam soil. The perennial OWB-legume and native pastures had increased soil organic matter (SOM) and reduced bulk density (ρb), improving ks, soil water thresholds, λ, and Dt, compared to annual teff and alfalfa-TW (P < 0.05). Soil λ, but not Dt, increased with increasing θv. Grazed pastures decreased ks and water retention compared to other treatments (P < 0.05), yet did not affect λ and Dt (P > 0.05), likely due to higher ρb and contact between particles. Greater λ and Dt at saturation and PWP in perennial versus annual pastures may be attributed to differing SOM and ρb, and some a priori differences in soil texture. Overall, our results suggest that perennial pasture systems are more beneficial than annual systems for soil water storage and heat movement in semiarid regions.Item Effects of irrigation rates on cotton yield as affected by soil physical properties and topography in the southern high plains(2021) Neupane, Jasmine (TTU); Guo, Wenxuan (TTU); West, Charles P. (TTU); Zhang, Fangyuan (TTU); Lin, Zhe (TTU)Lack of precipitation and groundwater for irrigation limits crop production in semi-arid regions, such as the Southern High Plains (SHP). Advanced technologies, such as variable rate irrigation (VRI), can conserve water and improve water use efficiency for sustainable agriculture. However, the adoption of VRI is hindered by the lack of on-farm research focusing on the feasibility of VRI. The objective of this study was to assess the effect of irrigation rates on cotton yield as affected by soil physical properties and topography in the Southern High Plains. This study was conducted in two fields within a 194-ha commercially managed farm in Hale County, Texas, in 2017. An irrigation treatment with three rates was implemented in a randomized complete block design with two replications as separate blocks in each field. A total of 230 composite soil samples were collected from the farm in spring 2017 and analyzed for texture. Information on apparent soil electrical conductivity (ECa), elevation, and final yield were collected from the fields. A statistical model showed that the effect of irrigation rates on cotton yield depended on its interaction with soil physical properties and topography. For example, areas with slope >2% and sand content >50% had no significant response to higher irrigation rates. This model suggests that applying irrigation amounts based on the yield response can be a basis for VRI. This study provides valuable information for site-specific irrigation to optimize crop production in fields with significant variability in soil physical properties and topography.Item Simulating the feasibility of dual use switchgrass on cow-calf operations(2021) Popp, Michael P.; Ashworth, Amanda J.; West, Charles P. (TTU)Meeting biorefineries’ demands for lignocellulosic biomass will require sourcing feed-stock without affecting the food or animal-feed supply. A decision-aid model can assess the dual use of switchgrass (Panicum virgatum L.) to maintain animal production while providing biomass. We simulated a mixed-farm operation with 156 ha of hay+pasture, 96 beef cows (Bos spp.), and poultry (Gallus gallus L.) production wherein the hay land was converted to switchgrass for dual use as biomass and forage. The cow-calf simulator tracked changes in forage and cattle production, economic returns, and net greenhouse gas (GHG) emissions. Dual use of switchgrass consisted of harvesting the first cutting (mid-June) for hay and the second cutting (October-November) for bio-mass. Dual use required a modest increase in fertilizer application and supplementing cows with corn grain to meet nutritional requirements. Converting hay land to dual-use switchgrass produced 122 Mg of switchgrass, reduced net GHG emissions for autumn-and spring-calving operations by 3.4 and 3.6%, respectively, and increased the farm profit by approximately $1,500 when priced at $50 Mg−1 regardless of the calving season. This simulation provided evidence that conversion of hay lands (in a beef cow-calf and poultry farm) to dual-use switchgrass can avoid displacing food pro-duction, while supplying bioenergy feedstock and reducing climate-forcing gases.Item Soil health within transitions from irrigation to limited irrigation and dryland management(2022) Bhandari, Krishna B. (TTU); Acosta-Martínez, Veronica; Pérez-Guzmán, Lumarie; West, Charles P. (TTU)The decline in groundwater supply in the Texas High Plains is forcing some growers to convert center-pivot irrigated cropland to dryland production. Transitioning toward reduced water input can lead to declines in soil health. We assessed short-term changes in soil health indicators in two transition scenarios: (a) from high irrigation method to low irrigation method (center pivot to subsurface drip) and (b) from high irrigation method to dryland (center pivot to dryland), in comparison to continuous center-pivot management. We monitored changes in chemical and biological indicators in four fields for each transition scenario and in three pivot-irrigated fields. There were declines in soil water content, potassium (K), sodium (Na), and soil organic carbon with transition from irrigation to reduced irrigation and dryland. Severe drought in the final year revealed reduced amounts of multi-enzyme activities, total ester-linked fatty acid methyl ester (EL-FAME), and total fungi. Transitioning to low water-input management in this environment complicates efforts to maintain microbial components of soil health. Longer-term comparisons are needed to detect slow changes in soil health indicators on producers’ fields.Item Teff grass for continuous stocking in the Southern High Plains by growing beef steers receiving protein supplements(2021) Sugg, Joel D. (TTU); Sarturi, Jhones O. (TTU); West, Charles P. (TTU); Ballou, Michael A. (TTU); Henry, Darren D. (TTU)This experiment evaluated forage quality, total nutrient yield, water footprint, and growth performance of beef steers receiving protein supplements while grazing Teff grass [‘Tiffany’Eragrostis tef (Zucc.) Trotter] over two consecutive growing seasons. Each year, four 2.66-ha irrigated paddocks (experimental units) were stocked with crossbred beef steers (n = 5 per paddock, initial BW = 289 ± 30 for yr 1; and n = 6, initial BW = 286 ± 23 for yr 2) in a randomized complete block design and stocked continuously for 63 d. Daily supplements [0.45 kg/d of cottonseed meal (Control) enough to avoid a negative ruminal N balance; and 0.50% mean paddock BW animal-daily (approximately 1.65 kg) of sorghum-dried distillers grains plus solubles, (DDGS)] were randomly assigned to two paddocks each. Supplement did not influence forage neutral detergent fiber (NDF), acid detergent fiber, crude protein, or in vitro true digestibility (P ≥ 0.54), except for a tendency (P = 0.08) for a numerical increase in NDF content of paddocks with steers that received DDGS supplementation. Paddock nutrient-yields were similar (P ≥ 0.43) between supplement treatments. Supplementation with DDGS produced greater (P = 0.01) cattle shrunk average daily gain (ADG). Predicted teff dry matter intake (DMI), net energy for maintenance (NEm), and growth (NEg) (P ≤ 0.03) were greater with cattle offered Control treatment. Predicted total DMI was similar (P = 0.14) although predicted dietary NEm, NEg, gain:feed, and total BW gain were greater (P ≤ 0.02) with DDGS. Predicted forage intake was greater (P ≤ 0.05) for cattle offered Control treatment. Teff nutrients remaining on d 56 were similar (P = 0.33) between treatments. Water footprint for total production of forage nutrient components did not differ (P ≥ 0.12) by treatments. Nutrient yield and water use efficiency of continuously stocked teff grass was not affected by supplemental regimen. Using DDGS as a supplement may increase BW gain through increased nutrient utilization without hindering teff nutrient production on a continuous stocking system.