The most common way of using the crop-livestock integration system in subtropical regions is cultivating soybeans or corn during the summer and temperate pastures in the winter. The objective of this study was to evaluate different beef cattle finishing systems in an area of crop-livestock integration. The inclusion of legumes and supplementation on black oat (Avena strigosa Schreb) and ryegrass pastures (Lolium multiflorum L.) were evaluated. Data from three years of research (2017, 2018 and 2020) were evaluated. Thus, 54 steers (18 per year) were used, with initial age of 22 ± 3 months and 413.08 ± 4.56 kg of initial live weight. They were randomly divided into nine paddocks of 0.7 hectares. The experimental design was randomized blocks with three replicates (paddock with two animals). Supplementation provided greater carrying capacity (1406.0 vs. 1269.6 kg/ha), average daily weight gain (1.4 vs. 1.1 kg/day), and, consequently, greater gain per area (384.5 vs. 302 kg BW/ha). Animals that received energy supplementation presented higher slaughter weight (536 vs. 510 kg), weight (287.1 and 286.2 vs. 266.2 and 265.3 kg), and hot (53.6 vs. 52.1%) and cold (53.4 vs. 52%) carcass yield, as well as higher fat content in the carcass (265 vs. 234 g/kg). The legume in the pasture did not affect the performance or characteristics of the animal carcasses. The supplementation increased the performance and carcass parameters, but did not influence the qualitative characteristics of the meat. In addition to individual performance, supplementation increased the pasture's carrying capacity, improving the system's productivity.

The purpose of this experiment was to evaluate the contribution of epiphytic microbiota on alfalfa (AL), oat (OT), and red clover (RC) to ensiling characteristics and bacterial community diversity of oat. With the irradiation of γ-ray, sterile OT (~233 g/kg dry matter (DM)) was inoculated by sterile water (STOT), epiphytic microbiota from OT (OTOT), AL (OTAL) and RC (OTRC), respectively. Triplicate silage-bags for each treatment were sampled after different days (1, 3, 7, 15, 30 and 60) of fermentation, respectively. Similar chemical compositions were found between fresh oat and STOT. Lower (P < 0.05) contents of ammonia nitrogen (NH3-N) and higher (P < 0.05) accumulation of lactic acid were found in OTAL compared with OTRC and OTOT on day 3. The greatest (P < 0.05) NH3-N, acetic acid concentrations and pH and the lowest (P < 0.05) concentration of lactic acid were found in OTRC on day 60. After 3 days of ensiling, Lactobacillus accounted for a big proportion in OTAL and OTOT, and Hafnia-Obesumbacterium was predominant in OTRC. The bacterial communities in OTAL and OTOT had lower (P < 0.05) abundances of ‘Genetic Information Processing’ than OTRC after 3 days. Overall, the composition, diversity, and activity of epiphytic microbiota can notably influence the ensiling characteristics of forage oat. The lactic acid bacteria (hetero-fermentative type) and Enterobacteriaceae species played an important role in producing ethanol contents during the ensiling of forage oat.

This study aimed to examine and compare the effectiveness of a novel spray-dried inoculant and a commercial freeze-dried additive on the fermentation quality, aerobic stability and bacterial population of vetch-oat silage. An entirely random design used a 3 × 4 factorial arrangement of treatments, with and without lactic acid bacteria (LAB) inoculants and four fermentation periods. Physicochemical parameters, microbiological counts and 16S rRNA gene sequencing analysis on Nanopore MinION were conducted to characterize the ensiling process. Both LAB inoculants increased dry matter, crude protein, lactic, acetic and propionic acid contents, while reducing pH, neutral detergent fibre, ammonia nitrogen/total nitrogen and ethanol concentrations compared to the control group. Overall, the native inoculant decreased the cell load of coliforms, yeasts and moulds. In addition, bio-inoculants enhanced the aerobic stability of vetch-oat intercrops. After ensiling, bacterial alpha diversity decreased noticeably; inoculation reduced the number of observed operational taxonomic units and the Shannon and Simpson indices. Notably, the relative abundance of Lactobacillus in the control group was lower than in treated silages, while the relative values of Staphylococcus increased sharply in the uninoculated group. In conclusion, the native strains showed promise for usage as a bio-inoculant in the ensiling of vetch-oat at a mixture rate of 1:1, producing an immediate impact as well as a favourable effect on the post-opening phase. This represents the first report on 16S rRNA gene-based nanopore metagenomics applied to the bacterial analysis of vetch-oat silage, providing a microbiological insight where native and commercial strains dominate the natural epiphytic community.

Adoption of cover crops in arid agroecosystems has been slow due to concerns regarding limited water resources and possible soil moisture depletion. In irrigated organic systems, potential ecosystem services from cover crops also must be considered in light of the concerns for water conservation. A constructive balance could be achieved with fall-sown small grain cover crops; however, their impacts on irrigated organic systems are poorly understood. Our first objective was to determine the ability of fall-sown small grains [cereal rye (Secale cereale L), winter wheat (Triticum aestivum L.), barley (Hordeum vulgare L.) and oat (Avena sativa L.)] to suppress winter weeds in an irrigated, organic transition field in the southwestern USA. Small grains were planted following the legume sesbania (Sesbania exaltata (Raf.) Rydb. ex A.W. Hill) during Fall 2012 and Fall 2013. In Spring 2013 and 2014, weed densities and biomass were determined within each cover crop treatment and compared against unplanted controls. Results indicated that both barley and oat were effective in suppressing winter weeds. Our second objective was to compare weed suppression and soil moisture levels among seven barley varieties developed in the western United States. Barley varieties (‘Arivat’, ‘Hayes Beardless’, ‘P919’, ‘Robust’, ‘UC603’, ‘UC937’, ‘Washford Beardless’) were fall-sown in replicated strip plots in Fall 2016. Weed densities were measured in Spring 2017 and volumetric soil moisture near the soil surface (5.1 cm depth) was measured at time intervals beginning in December 2016 and ending in March 2017. With the exception of ‘UC937’, barley varieties caused marked reductions in weed density in comparison with the unplanted control. Soil moisture content for the unplanted control was consistently lower than soil moisture contents for barley plots. Barley variety did not influence volumetric soil moisture. During the 2017–2018 growing season, we re-examined three barley varieties considered most amenable to the cropping system requirements (‘Robust’, ‘UC603’, ‘P919’), and these varieties were again found to support few weeds (≤ 5.0 weeds m−2). We conclude that several organically certified barley varieties could fill the need for a ‘non-thirsty’ cover crop that suppresses winter weeds in irrigated organic systems in the southwestern United States.

Management strategies such as nitrogen (N) topdressing and clipping can be used to optimize a cover crop for the dual purpose of soil cover and forage. The present study tested oat (Avena sativa) for a holistic provision of soil cover and forage under various levels of clipping frequency and N topdressing. Effects on root and above-ground biomass, acid detergent fiber, neutral detergent fiber, and crude protein (CP) were evaluated. Clipping frequency had four levels, namely clipped only at termination (C1), clipped at 28 days after emergence (DAE) and termination (C2), clipped at 28, 42 DAE, and termination (C3), and clipped at 28, 42, 56 DAE, and termination (C4). Nitrogen topdressing had two levels, namely with (N1) and without (N0) the recommended N topdressing. Increasing clipping frequency reduced the root and aerial biomass and did not affect the forage quality harvested before termination. However, N topdressing increased biomass and CP content across the clipping frequencies. Results suggest clipping thrice combined with N topdressing (C4 + N1) provides the best option to satisfy both soil cover and livestock demands. The treatment (C4 + N1) gave > 2 t ha−1 of biomass during the growing period and 6 t ha−1 at termination which can be used for livestock forage and soil cover, respectively. Clipping thrice without N topdressing (C4 + N0) was the best option for resource-constrained farmers.

Factorial experiments were carried out on spring- and winter-sown oat crops in Ireland in 2016–2019 to identify plant responses in yield formation and grain filling procedures. Two cultivars (Husky and Keely), three seed rates (250, 350 and 450 seeds/m2), six applied nitrogen (N) rates (40, 70, 100, 130, 160 and 190 kg N/ha) with a plant growth regulator (PGR) were examined in spring and winter sowings, using the same cultivars at five rates of applied N (80, 110, 140, 170 and 200 kg N/ha). The applied N rate and seed rate significantly (P < 0.05) modified the yield components determining grains/m2 in spring- and winter-sown crops with increases in panicle number of key importance. Increases were also observed in the proportion of primary grain by weight (0.9–1.6%) and number (0.7–1.4%) ratios in spring-sown crops in response to applied N rate, with winter-sown crops exhibiting a more consistent pattern of grain fill. Seed rate and PGR application had minor effects on yield components and panicle conformation. Grain fill procedures played an important role in the maximization of grain yield under seasonal conditions. Significant positive correlations were observed between the number of aborted grain sites and yield under drought conditions (0.22), with negative associations observed in near-optimal conditions (−0.22 to −0.41). Agronomic effects on grain site abortion were minimal in comparison with seasonal effects. In seasons characterized by cool, consistent conditions, grain yield was maximized by the utilization of all available grain sites. Where assimilate shortages were encountered during grain fill the abortion of grains sites was positively associated with grain yield.

Replacing tillage with cover crops (CC) for weed management in corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] systems with mechanical weed control has many soil health benefits but in the western Corn Belt, CC establishment after harvest is hampered by cold temperatures, limited labor and few compatible CC species. Spring-planted CC may be an alternative, but information is lacking on suitable CC species. Our objective was to evaluate four spring-planted CC with respect to biomass production and weed suppression, concurrent with CC growth and post-termination. Cover crop species tested were oat (Avena sativa L.), barley (Hordeum vulgare L.), brown mustard [Brassica juncea (L.) Czern.] and yellow mustard (Brassica hirta Moench). They were compared to no-CC treatments that were either tilled pre- and post-planting of soybean (no-CC tilled) or not tilled at all (no-CC weedy). CC were planted in late March to early April, terminated 52–59 days later using an undercutter, and soybean was planted within a week. The experiment had a randomized complete block design with four replications and was repeated for 3 years. Mustards and small grains produced similar amounts of biomass (1.54 Mg ha−1) but mustard biomass production was more consistent (0.85–2.72 Mg ha−1) than that of the small grains (0.35–3.81 Mg ha−1). Relative to the no-CC weedy treatment, mustards suppressed concurrent weed biomass in two out of 3 years, by 31–97%, and small grains suppressed concurrent weed biomass in only 1 year, by 98%.

Six weeks after soybean planting, small grains suppressed weed biomass in one out of 3 years, by 79% relative to the no-CC weedy treatment, but mustards did not provide significant weed suppression. The no-CC tilled treatment suppressed weeds each year relative to the no-CC weedy treatment, on average 87%. The ineffective weed control by CC reduced soybean biomass by about 50% six weeks after planting. While spring-planted CC have the potential for pre-plant weed control, they do not provide adequate early season weed suppression for soybean.

Oat (Avena spp. L.) intercropped with common vetch (Vicia sativa L.) has shown high forage yield and crude protein content (CP) in rainfed Mediterranean environments of Greece. The objective was to study the oat genotypic interactions for yield, quality and agronomic traits of four oat accessions (cv. Flega and lines B2, B3 and B4) grown as intercrops with a common vetch cultivar (Pegasus) and as monocrops without or with nitrogen (N) supplementation (100 kg N/ha). In all mixtures, the land equivalent ratio exceeded the unit indicating that there was a yield advantage. Intercrops produced, on average, 5.0% less dry matter (DM) and 38.9% more crude protein yield (CPY) compared to monocropped oats with N fertilization and 3.4% more DM and 75.5% more CPY compared to monocropped oats without N fertilization. The DM, CP and quality differences between the intercropped and monocropped oats were attributed to oats by vetch cultivar interactions. The oat B2 intercropped was the shortest, the latest flowering and the less vigorous early in the season, a trait that allowed common vetch to dominate in the intercrop (vetch participation 770 g/kg). The high vetch fragment in the intercrop contributed to high CP, CPY, acid detergent lignin, total digestible nutrients, relative feeding value, relative forage quality, net energy for lactation and to low neutral detergent fibre, acid detergent fibre and hemicellulose. The replacement value index indicated that the intercrop was 21% more economically viable in comparison to the fertilized monocrop.

Using legumes in forage mixes can help decrease the use of nitrogen fertilizers and possibly increase the nutritive value of pasture. The aim of the current study was to determine animal production and behavioural and ingestion parameters by evaluating the production and nutritive value of Aruana grass (Panicum maximum ‘Aruana’) intercropped with forage peanut (Arachis pintoi ‘Amarillo’) or fertilized with nitrogen. The treatments were N200 (200 kg N/ha per season – summer and winter), 100N + PE (100 kg N/ha per season plus pasture mixture with forage peanut) and N100 (100 kg N/ha per season). The presence of forage peanut in the pasture did not replace nitrogen fertilization as the pasture fertilized with 200 kg of nitrogen had a greater leaf/stem ratio (0.66 v. 0.54), stocking rate (2600 v. 2290 kg live weight/ha), average daily gain (0.880 v. 0.700 kg/day) and live weight gain (LWG) (652 v. 468 kg/ha) during summer. During winter, no effect of increased nitrogen fertilization on pasture and animal production was observed. In the total study period (summer + winter), a greater LWG (897 v. 741 kg/ha) occurred when a higher quantity of nitrogen (N200) was placed in the pasture compared to the insertion of forage peanuts in the system.

A semi- and high-density apple and peach orchard was established at Blacksburg, VA. Starting 1 yr after transplanting, tree rows were treated with paraquat, 2,4-D, or amitrole plus simazine for 4 yr. Thereafter, diuron, simazine, or terbacil was applied in conjunction with paraquat or glyphosate. During the 12th growing season, young trees planted between existing trees failed to make proper growth. Oat bioassay of soils collected from treated rows revealed that the tree row topsoil (0 to 7.5 cm) produced less oat biomass than did deeper row soils (to 30 cm) or soils of corresponding depths from adjacent non-treated tall fescue sod alleyways. Poor growth of trees may have been related to other factors (competition from older trees, drought conditions, etc.) since herbicide residues in the upper 7.5 cm would have little effect on tree roots below this depth. After 3 yr the trees developed normally. Tree rows became heavily infested with weeds 1 yr following cessation of 23 yr of consecutive herbicide treatments.

The response of several spring wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), and oat (Avena sativa L.) cultivars to preemergence and postemergence applications of chlorsulfuron (tested under code number DPX-4189) {2-chloro-N-[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)aminocarbonyl] benzenesulfonamide} was evaluated in the field and greenhouse in 1979. In greenhouse experiments, ‘Butte’ spring wheat was less susceptible than six other spring wheat cultivars to chlorsulfuron at 1.0 kg/ha applied preemergence or postemergence. ‘Morex’, ‘Conquest’, and ‘Bonanza’ barley cultivars were less susceptible than six other barley cultivars to preemergence chlorsulfuron, but barley cultivars were similar in response to postemergence chlorsulfuron. The eight oat cultivars responded similarly to preemergence and postemergence chlorsulfuron at 1.0 kg/ha. Data from two field experiments, which included evaluation of durum wheat [Triticum durum (Desf.)] cultivars, indicated that the four small grains had adequate tolerance to postemergence chlorsulfuron at 0.125 and 0.25 kg/ha, except that durum wheat grain yield was reduced by 0.25 kg/ha at the Rosemount location. No differential cultivar responses to chlorsulfuron occurred among the small grains in the field.

In growth room studies, POST applications of fenoxaprop-ethyl at 50 g ai ha−1 at the four- to five-leaf stage of development were non-toxic to barnyardgrass, large crabgrass, and yellow foxtail. POST applications of fenchlorazole-ethyl at 12.5 or 25.0 g ai ha−1 were also nontoxic to these same three species. However, when the two chemicals were applied in combination at the above rates they were toxic to all three species, indicating a synergistic interaction in all three species. In additional studies, a sensitive biotype of wild oat was severely injured by fenoxaprop-ethyl at 50 g ai ha−1 and a resistant biotype of wild oat was only slightly injured by fenoxaprop-ethyl at rates as high as 800 g ai ha−1. However, no significant interactions were observed between fenoxaprop-ethyl and fenchlorazole-ethyl in either of these wild oat biotypes.

A field study was undertaken to investigate the influence of different management strategies on rigid ryegrass plant density and seedbank dynamics over 4 yr. Even though weed seedbank declined by 86% after oaten hay in year 1, the residual seedbank enabled rigid ryegrass to reinfest field peas the next year, and the population rebounded sharply when weed control relied solely on PPI trifluralin. However, use of POST clethodim followed by crop-topping for seed-set prevention of rigid ryegrass in field pea was highly effective and caused a further decline in the weed seedbank. Integration of effective management tactics over 3 yr significantly reduced rigid ryegrass weed and spike density (90 and 81%) in the final year of the 4-yr cropping sequence. Use of oaten hay in year 1, followed by effective weed control in field pea and wheat crops, depleted the high initial seedbank (4,820 seeds m−2) to moderate levels (< 200 seeds m−2) within 3 yr. Effective weed-management treatments depleted the rigid ryegrass seedbank, reduced in-crop weed infestation, and returned higher grain yields and profitability. The results of this study clearly show that large rigid ryegrass populations can be managed effectively without reducing crop productivity and profitability provided multiyear weed-management programs are implemented effectively.

Dormant dehusked Avena sativa L. (cv. Moyencourt) caryopses germinated easily at 10°C, but their germination was poor at 25 and 30°C. Ethanol overcame their dormancy and allowed germination at the last two temperatures when given continuously at concentrations ranging from 50 to 200 mm, or at higher concentrations at the beginning of imbibition. Ethanol also promoted germination in hypoxia. Other alcohols which were good substrates for alcohol dehydrogenase (ADH: EC 1.1.1.1), such as butanol-1, propanol-1 and 2-propen-1-ol, had the same stimulatory effect as ethanol, whereas alcohols which could not be oxidized by ADH (propanol-2 and methanol) did not improve germination. Salicylhydroxamic acid (SHAM) did not alter the stimulation of germination induced by ethanol, but 4-methylpyrazole (4-MP, an inhibitor of ADH) completely abolished this stimulation. The improvement of germination by alcohols which were good substrates for ADH was always associated with an increase in oxygen uptake by caryopses, whereas alcohols which were not ADH substrates did not enhance respiration. The stimulation of oxygen uptake induced by ethanol resulted in a decrease in CO2/O2 ratio and was suppressed by 4-MP, but ATP level in embryos was not modified until after the germination of caryopses. All the results obtained seem to demonstrate that the stimulatory action of ethanol on germination of dormant oat caryopses requires its metabolism through ADH and involves an activation of glycolysis and the Krebs cycle.

Oat is promoted as a low-glycaemic index food. Our aim was to measure the effect of the fat content of oat in glycaemia and insulinaemia and compare it with the effect of wheat. The study design was a double-blind, randomised cross-over study with four treatment segments. Eight healthy males attended four study sessions in which porridge made from four different raw materials was consumed: rolled oat (O), defatted rolled oat (DO), rolled whole wheat (W) or rolled whole wheat with added oat fat (WF). Available carbohydrate content was analysed enzymatically, and was adjusted to 50 g in each test meal. Fat content per meal was either 6·1 g (O, WF) or approximately 1·9 g (W, DO). Venous plasma glucose, insulin and triacylglycerol concentrations were measured at 0, 30, 60, 90, 120 and 180 min. All products caused a rapid increase in glucose with a peak at 30 min, where W and WF were significantly higher than O (0 = 0·006). Also insulin peaked at 30 min (no differences). A 4·2 g difference in fat content between O and DO or W and WF did not result in any significant differences in their glycaemia or insulinaemia. W and O did not differ in their overall glycaemic or insulinaemic responses. The removal of two-thirds of oat fat did not affect the postprandial plasma triacylglycerol concentration. The present study shows that neither the glycaemic nor the insulinaemic response to rolled oat is affected by the fat content, and that rolled wheat differed from rolled oat in terms of peak glucose concentration only.

Wistar rats (ten per group) were fed either an oat-free control diet or a dietary fibre-rich test diet containing 500 g oat-based products/kg for 6 weeks. The oat-based products, containing 4–128 g/kg resistant starch, 30–92 g/kg β-glucan and 122–304 g/kg total dietary fibre, were oat flour extrudate, flour/Novelose (commercial resistant starch) extrudate (80:20 w/w), oat bran, bran/Novelose extrudate (80:20 w/w) and autoclaved oat flour. Serum total cholesterol decreased in the groups fed flour, flour/Novelose and bran/Novelose (P<0·05). In most of the test groups, count numbers of bifidobacteria were higher (P<0·001) and of coliforms were lower (P<0·05). The mass of the caecum walls and contents was greater in groups fed Novelose- and bran-containing diets (P<0·005). In all the test groups, pH values were lower in the intestinal contents (P<0·001), and caecal concentrations of acetate (P<0·001), propionate (P<0·05), butyrate (P<0·005) and total SCFA (P<0·001) were higher. The lowest concentrations of steroids were found in rats fed the autoclaved flour. In the other test groups, more bile acids appeared in the caecal (P<0·001) and colonic contents (P<0·005), as well as in the faeces, at week 6 (P<0·001). The highest bile acid excretion was found after feeding bran-containing diets. In the intestinal contents of all the test groups, more primary bile acids (P<0·001) appeared than in the control group. The excretion of steroids increased within the experimental period. Using extrusion technology, dietary fibre-rich oat-based products, which have beneficial physiological effects in rats, can be produced. Oat flour and bran are excellent sources for the preparation of directly edible oat products. Their nutritional properties can be further improved by the addition of resistant starch.