Pasture Legumes Research Articles

Overexpression of SgGH3.1 from Fine-Stem Stylo (Stylosanthes guianensis var. intermedia) Enhances Chilling and Cold Tolerance in Arabidopsis thaliana.

Stylosanthes (stylo) species are commercially significant tropical and subtropical forage and pasture legumes that are vulnerable to chilling and frost. However, little is known about the molecular mechanisms behind stylos’ responses to low temperature stress. Gretchen-Hagen 3 (GH3) proteins have been extensively investigated in many plant species for their roles in auxin homeostasis and abiotic stress responses, but none have been reported in stylos. SgGH3.1, a cold-responsive gene identified in a whole transcriptome profiling study of fine-stem stylo (S. guianensis var. intermedia) was further investigated for its involvement in cold stress tolerance. SgGH3.1 shared a high percentage of identity with 14 leguminous GH3 proteins, ranging from 79% to 93%. Phylogenetic analysis classified SgGH3.1 into Group Ⅱ of GH3 family, which have been proven to involve with auxins conjugation. Expression profiling revealed that SgGH3.1 responded rapidly to cold stress in stylo leaves. Overexpression of SgGH3.1 in Arabidopsis thaliana altered sensitivity to exogenous IAA, up-regulated transcription of AtCBF1-3 genes, activated physiological responses against cold stress, and enhanced chilling and cold tolerances. This is the first report of a GH3 gene in stylos, which not only validated its function in IAA homeostasis and cold responses, but also gave insight into breeding of cold-tolerant stylos.

COMPOSICIÓN BOTÁNICA Y EVALUACIÓN NUTRICIONAL IN VITRO DE PASTO KIKUYO COMPARADO CON GRAMÍNEAS DE CLIMA TEMPL

<p><strong>Background: </strong>Intensive continuous grazing of temperate grass and legume pastures has been a feeding strategy adopted in small-scale dairy systems (SSDS) in the highlands of central Mexico that reduces costs and increases profitability of farms. However, temperate grasses have low persistency due to agroclimatic and management conditions, so that pastures are invaded by kikuyu grass (<em>Cenchrus clandestinus</em>), a sub-tropical grass that may be a valuable forage resource in these systems. There are not many studies in Mexico on kikuyu grass pastures and on the relationship between botanical composition, nutritional value and ruminal fermentation parameters, important aspects for their inclusion in feeding strategies for dairy cattle. <strong>Objective: </strong> The objective was to determine the botanical composition and to assess the <em>in vitro </em>digestibility of dry matter (DM), organic matter (OM), and neutral detergent fibre (NDF), and to characterize the kinetics of <em>in vitro </em>ruminal fermentation of a pasture based on with kikuyu grass (KY) in comparison to pastures based on festulolium cv. Spring Green (FL), tall fescue cv. TF-33 (TF), and perennial ryegrass cv. Pay Day (RG), all associated with white clover. <strong>Methodology: </strong> There were four sampling periods every 14 days. On the last day of each period, five random samples in each pasture were cut to ground level to determine botanical composition by manual separation, and 200g samples from each pasture taken by simulated grazing to determine digestibilities and the <em>in vitro </em>fermentation dynamics. Statistical analyses were following a split-plot model. <strong>Results: </strong>There was a higher proportion of grasses in KY and a better <em>in vitro </em>nutritional value for RG, related to a higher content of structural carbohydrates in KY, being a subptropical grass compared to temperate pastures with lower content of cell walls. <strong>Results: </strong>There was a higher proportion (P<0.05) of live grass in KY. There were no differences (P>0.05) among pastures for <em>in vitro </em>nutritional value. There were differences (P<0.05) among pastures and periods for the insoluble fraction fermentation rate (C<sub>B</sub>) and for the interaction between pastures and periods for gas production in 4.0 h of the soluble fraction (A) and the soluble carbohydrate fermentation rate (C<sub>A</sub>), but no differences between pastures, periods or the interaction (P>0.05) for other parameters of ruminal fermentation (lag time and total gas production). <strong>Implications: </strong> Pastures of kikuyu grass associated with white clover have a similar <em>in vitro </em>nutritional value as pastures of temperate grasses representing a valuable forage resource for SSDS. <strong>Conclusion: </strong>In spite of differences in some <em>in vitro </em>ruminal fermentation parameters, the <em>in vitro </em>nutritional value of kikuyu grass pastures associated with white clover is similar to pastures based on temperate grasses with white clover.</p>

Characterization of Phytoestrogens in Medicago sativa L. and Grazing Beef Cattle.

Phytoestrogens are plant-produced bioactive secondary metabolites known to play an integral role in plant defense that frequently accumulate in times of stress and/or microbial infection. Phytoestrogens typically belong to two distinct chemical classes; flavonoids (isoflavones) and non-flavonoids (lignans and coumestans). Upon consumption by livestock, high concentrations of phytoestrogens can cause long-term disruption in reproduction due to structural similarities with mammalian estrogens and their tendency to bind estrogen receptors. Wide variation in phytoestrogen concentration has been reported in pasture legumes and corresponding silage or hay. Lucerne is a common perennial pasture legume in temperate climates, but information on phytoestrogen production or accumulation in grazing livestock is currently limited. Therefore, metabolic profiling using UHPLC-MS-QToF was performed to identify and quantitate key phytoestrogens in both fresh and dried lucerne fodder from replicated field or controlled glasshouse environments. Phytoestrogens were also profiled in the blood plasma of Angus cattle grazing field-grown lucerne. Results revealed that phytoestrogens varied quantitatively and qualitatively among selected lucerne cultivars grown under glasshouse conditions. Fresh lucerne samples contained higher concentrations of coumestans and other phytoestrogenic isoflavones than did dried samples for all cultivars profiled, with several exceeding desirable threshold levels for grazing cattle. Coumestans and isoflavones profiled in plasma of Angus heifers grazing lucerne increased significantly over a 21-day sampling period following experimental initiation. Currently, threshold concentrations for phytoestrogens in plasma are unreported. However, total phytoestrogen concentration exceeded 300 mg·kg−1 in fresh and 180 mg·kg−1 in dried samples of selected cultivars, suggesting that certain genotypes may upregulate phytoestrogen production, while others may prove suitable sources of fodder for grazing livestock.

Growth Performance and Plasma Metabolites of Grazing Beef Cattle Backgrounded on Buffel or Buffel-Desmanthus Mixed Pastures.

Simple SummaryPasture quality and digestibility decline during the dry season resulting in weight loss or marginal weight gains of grazing cattle in the seasonally dry subtropics of northern Australia. Oversowing grass with legume pastures has shown potential to improve pasture quality and cattle weight gain. This study aimed to evaluate the change in steers’ weight gain and plasma metabolites in response to grazing buffel grass pastures oversown with Desmanthus spp. (Desmanthus), a tropical legume adapted to cracking clay soils, compared to buffel-grass-only pastures. Results showed that Desmanthus at a low botanical composition had no effect on weight gain and plasma metabolites, although pasture yield and stocking rate were 443 kg/ha and 9.5% higher, respectively. Since the productivity of grazing systems depends on cattle annual weight gain and stocking rate, the practical implication of this study is that Desmanthus may improve the profitability of beef production in the dry tropics of northern Australia by improving pasture-carrying capacity with no adverse effect on cattle health status and growth performance.Dietary crude protein and dry matter digestibility are among the major factors limiting feed intake and weight gain of cattle grazing native and improved pastures in the subtropics of Northern Australia during the dry season. Incorporating a suitable legume into grasses improves pasture quality and cattle weight gain, but only a limited number of legume pastures can establish and persist in cracking clay soils. This study aimed to evaluate the effect of Desmanthus inclusion in buffel grass (Cenchrus ciliaris) pastures on the plasma metabolite profile and growth performance of grazing beef cattle during the dry season. We hypothesised that backgrounding steers on buffel grass-Desmanthus mixed pastures would elicit significant changes in plasma glucose, bilirubin, creatinine, non-esterified fatty acids and β-hydroxybutyrate, resulting in higher liveweight gains than in steers on buffel grass only pastures. Four hundred tropical composite steers were assigned to buffel grass only (n = 200) or buffel grass oversown with Desmanthus (11.5% initial sward dry matter) pastures (n = 200) and grazed for 147 days during the dry season. Desmanthus accounted for 6.2% sward dry matter at the end of grazing period. Plasma metabolites results showed that changes in β-hydroxybutyrate, creatinine, bilirubin, glucose and non-esterified fatty acids were within the expected normal range for all the steers, indicating that with or without Desmanthus inclusion in the diet of grazing steers, animal health status was not compromised. It was also evident that Desmanthus inclusion in buffel grass pastures had no impact on the plasma metabolite profile, liveweight and daily weight gain of grazing steers. Therefore, our tested hypothesis of higher changes in plasma metabolite profile and higher liveweight gains due to backgrounding on low-level buffel grass-Desmanthus mixed pastures does not hold.

Tropical grass and legume pastures may alter lamb meat physical and chemical characteristics.

The present study assessed the influence of the type of the tropical pastures on lamb body weight (BW) gain and meat quality. Fifty-four lambs were allocated to three grazing pastures: (1) AG - Aruana grass (Panicum maximum cv. IZ-5); (2) PP - pigeon pea legume (Cajanus cajan cv. Anão); and (3) CS - contiguous swards, half of the paddock with AG and half with PP. After 92days of grazing, the lambs were slaughtered. Carcasses were evaluated and the longissimus muscle was collected to determine color, lipid profile, tocopherol concentrations, and lipid oxidation. Although the pastures present differences in the characteristics of nutritional quality, the animals did not show difference in BW gain. The results show that all forage presented similar concentration of alpha-tocopherol (137 ± 14.37mgkg-1 of fresh matter), whereas total and condensed tannin contents were greater in PP, intermediate in CS, and the lowest in AG treatment (P = 0.0001). Meat α-tocopherol content was similar among treatments (P = 0.1392), with an average concentration close to the optimal level to reduce the meat oxidation. Meat from AG treatment had 45 and 25% lower n-6/n-3 ratio than meat from PP and CS treatments, respectively. The legume increases the unsaturated fatty acids and the grass can reduce the n6/n3 ratio. The level of condensed tannin concentration did show to have important effect on meat characteristics. Both tropical pastures studied can provide a high amount of alpha-tocopherol, generating a great potential to increase the concentration of this antioxidant in lamb's meat.

Nutrient excretion from cattle grazing nitrogen‐fertilized grass or grass–legume pastures

AbstractNutrient cycling via livestock excreta is an important grassland ecosystem service. This study was conducted in 2016 and 2017 and determined nutrient excretion from cattle grazing three systems: (a) N‐fertilized bahiagrass (Paspalum notatum Flüggé) overseeded with rye (Secale cereale L.) and oat (Avena sativa L.) during winter (Grass+N), (b) unfertilized bahiagrass overseeded with rye–oat–clover (Trifolium sp.) mixture (Grass+clover), and (c) rhizoma peanut (Arachis glabrata Benth.)–bahiagrass mixture overseeded with a rye–oat–clover mixture (Grass+CL+RP). Urinary volume excreted in the warm season ranged from 122 to 182 L ha−1d−1, more than double that in the cool season (56–70 L ha−1 d−1). Urinary N concentration during the warm season was greater in Grass+CL+RP compared with Grass+N (4.4 vs. 3.1 g kg−1, respectively). In addition, fecal dry matter and organic matter output was greater for Grass+N than for steers grazing Grass+CL+RP during the warm season (3.8 and 3.2 vs. 2.8 and 2.2 kg hd−1 d−1, respectively). Total annual feces excretion concentrations of P, K, Mg, and N were greater in the Grass+N than in Grass+CL+RP system. The introduction of legumes increased the proportion of N returning via urine. However, when summed across seasons, total N excretion (feces and urine) was greater in Grass+N than in Grass+CL+RP (89 vs. 71 kg ha−1 yr−1), mainly due to the greater stocking rate in the former. Grass–legume systems receiving 34 kg N ha−1 yr−1 recycled 80% of the N recycled in the grass system receiving 224 kg N ha−1 yr−1, indicating the potential of forage legumes to add N to grasslands.

Landscape position, sampling time, and tillage, but not legume species, affect labile carbon and nitrogen fractions in a 4-yr-old rejuvenated grazed pasture

Termination by tillage is one strategy used for regenerating pasture stands. Yet, research gaps exist on how tillage affects carbon (C) and nitrogen (N) forms and amounts in western Canadian soils. We measured total soil organic C (SOC), dissolved organic C (DOC), total dissolved N (TDN), light fraction organic C (LFOC) and light fraction organic N (LFON), microbial biomass C (MBC) and microbial biomass N (MBN), and inorganic N as indicators of soil organic matter (SOM) dynamics. After tillage termination in fall 2018, we sampled soils (0–10 cm; 0–15 cm) under three legume species (alfalfa, cicer milkvetch, and sainfoin) three times (spring, summer, and fall of 2019) across three landscape positions. Legume species did not affect the measured parameters. Over time, tillage affected DOC, TDN, and inorganic N. Averaged across three pasture legumes and three landscape positions, tillage increased DOC 29% by summer. Fall-applied tillage led to 59% and 33% higher TDN in the succeeding summer and fall. Inorganic N increased by 14% and 40% across landscape positions and sampling after tillage. Averaged across landscape positions, MBC decreased by 31% from spring to summer and increased by 51% from summer to fall. However, MBN increased by 53% and decreased by 5% within the same period. The seasonal fluctuations in MBC and MBN reflected variations in moisture, temperature, and substrate quality. Total SOC, LFOC, and LFON increased on the upper slopes and fall sampling time. Although single intensive tillage did not affect total SOC, several tillage operations could accelerate SOM loss and reduced total C storage over time.

Transcriptomics and metabolomics reveal the induction of flavonoid biosynthesis pathway in the interaction of Stylosanthes-Colletotrichum gloeosporioides

Colletotrichum, a hemibiotrophic fungal pathogen with a broad host range, causes a yield-limiting disease called anthracnose. Stylo (Stylosanthes) is a dominant pasture legume in tropics and subtropics, and anthracnose is one of its most destructive disease. Resistance mechanisms against anthracnose in stylo are poorly understood, thus hindering the development of resistant varieties. We performed time-resolved leaf transcriptomics, metabolomics and in vitro inhibition assay to investigate the defense responses against Colletotrichum gloeosporioides in stylo. Transcriptomics demonstrated that flavonoid biosynthetic genes were significantly induced during the infection. Consistently, metabolomics also showed the increased accumulation of flavonoid compounds. In vitro assays showed that phloretin and naringenin inhibited the mycelial growth, and apigenin, daidzein, quercetin and kaempferol suppressed conidial germination of Colletotrichum strains. Together, our results suggest that stylo plants cope with C. gloeosporioides by up-regulation of genes and compounds in flavonoid biosynthesis pathway, providing potential targets for resistance breeding.

Producción animal en pasturas de tres leguminosas asociadas con <i>Urochloa decumbens</i> en los Llanos Orientales de Colombia

In a loamy clay soil of the Colombian Altillanura, animal production of the legumes Centrosema molle accession CIAT 15160, C. macrocarpum accession CIAT 15799 and Grona heterocarpa subsp. ovalifolia (syn. Desmodium ovalifolium) cv. Maquenque, in association with Urochloa decumbens (syn. Brachiaria decumbens) cv. Decumbens, was evaluated under rotational grazing with zebu Brahman steers. The experiment was established in a native savanna area at the Carimagua Research Center of Agrosavia, in a randomized complete block design with three replications. During three years of grazing, C. molle stood out over the other legumes, due to its good forage production and ability to associate and persist with the grass, reaching 40% in the botanical composition in the first year and 24% in the third year. The highest animal liveweight (LW) gains were achieved with this legume with, on average, 760 g/animal/day in the rainy season and 500 g/animal/day in the dry season. With an average stocking rate equivalent to 800 kg LW/ha, mean annual hectare productivity of the pasture with C. molle reached 600 kg LW compared with an average of about 380 kg/ha/year obtained in the other associations and in the grass-only pasture. It is concluded that C. molle CIAT 15160 is a promising pasture legume for the region and confirming its productivity and persistence at farm level and in association with other grasses seems warranted.

Palisadegrass pastures with or without nitrogen or mixed with forage peanut grazed to a similar target canopy height. 2. Effects on animal performance, forage intake and digestion, and nitrogen metabolism

AbstractThe lack of nitrogen (N) input on pastures is the main limiting factor to increase animal performance in tropical regions. This 2.5‐year study assessed animal performance, forage intake and digestion, and N metabolism responses of three pasture treatments: (1) mixed Marandu palisadegrass—Brachiaria brizantha (Hochst. ex A. Rich.) R.D. Webster (syn. Urochloa brizantha Stapf cv. Marandu)—and forage peanut (Arachis pintoi Krapov. & W.C. Greg. cv. BRS Mandobi) pastures (GRASS + LEGUME), (2) monoculture Marandu palisadegrass pastures with 150 kg of N/ha (GRASS + N), and (3) monoculture Marandu palisadegrass without N fertilizer (GRASS). Continuous stocking with variable stocking rate was used with a target canopy height of 20 to 25 cm. The average daily gain was greatest at GRASS + N and GRASS + LEGUME (p = .081). GRASS + N pasture had greatest stocking rate and liveweight gain per area (p < .001 and p < .001, respectively), followed by GRASS + LEGUME pasture. No differences between treatments were found for the dry matter forage intake (p = .729); however, GRASS + N and GRASS + LEGUME pastures had greater crude protein and digestible organic matter intakes than GRASS pasture (p = .007 and p = .083, respectively). Greatest microbial protein synthesis and efficiency of microbial synthesis were found for GRASS + N and GRASS + LEGUME pastures (p = .016 and p = .067, respectively). Apparent efficiency of N utilization and microbial protein/CP intake ratio was greatest at GRASS + LEGUME pastures (p = .009 and p = .042, respectively). Nitrogen application or the integration of forage peanut in grass pasture increases animal performance, forage digestibility, and microbial protein synthesis.

An Improved Protocol for Agrobacterium-Mediated Transformation in Subterranean Clover (Trifolium subterraneum L.).

Subterranean clover (Trifolium subterraneum) is the most widely grown annual pasture legume in southern Australia. With the advent of advanced sequencing and genome editing technologies, a simple and efficient gene transfer protocol mediated by Agrobacterium tumefaciens was developed to overcome the hurdle of genetic manipulation in subterranean clover. In vitro tissue culture and Agrobacterium transformation play a central role in testing the link between specific genes and agronomic traits. In this paper, we investigate a variety of factors affecting the transformation in subterranean clover to increase the transformation efficiency. In vitro culture was optimised by including cefotaxime during seed sterilisation and testing the best antibiotic concentration to select recombinant explants. The concentrations for the combination of antibiotics obtained were as follows: 40 mg L−1 hygromycin, 100 mg L−1 kanamycin and 200 mg L−1 cefotaxime. Additionally, 200 mg L−1 cefotaxime increased shoot regeneration by two-fold. Different plant hormone combinations were tested to analyse the best rooting media. Roots were obtained in a medium supplemented with 1.2 µM IAA. Plasmid pH35 containing a hygromycin-resistant gene and GUS gene was inoculated into the explants with Agrobacterium tumefaciens strain AGL0 for transformation. Overall, the transformation efficiency was improved from the 1% previously reported to 5.2%, tested at explant level with Cefotaxime showing a positive effect on shooting regeneration. Other variables in addition to antibiotic and hormone combinations such as bacterial OD, time of infection and incubation temperature may be further tested to enhance the transformation even more. This improved transformation study presents an opportunity to increase the feeding value, persistence, and nutritive value of the key Australian pasture.

Arbuscular mycorrhizal fungus-mediated interspecific nutritional competition of a pasture legume and grass under drought-stress

It is widely claimed that common mycorrhizal networks (CMN) play significant roles in facilitated transfer of nutrients between plants. This experiment investigated the role of a common mycorrhizal network with a C3 legume and a C4 grass under drought-stressed conditions, and assessed whether there was an interaction between water and plant species on rhizosphere bacterial DNA community profile. Shoot biomass of Trifolium subterraneum increased by almost 150% when grown in close proximity to Panicum clandestinum when the only possible connection between their roots was via a common mycorrhizal network. Inter-species competition between T. subterraneum and P. clandestinum was observed in low-nutrient soil. The soil bacterial communities in rhizospheres of both T. subterraneum and P. clandestinum were similar. Drought-stress increased the relative abundance of Firmicutes and Actinobacteria and decreased the relative abundance of Proteobacteria, especially when plants were likely connected by a CMN. Drought-stress decreased the abundance of N-cycling genes under P. clandestinum but not under T. subterraneum. The competitiveness of T. subterraneum when grown adjacent to P. clandestinum corresponded with enhanced P acquisition and depletion of soil P under P. clandestinum for both water treatments at different times. Thus, T. subterraneum may have been more competitive due to enhanced direct P acquisition from soil under P. clandestinum rather than by direct P transfer from P. clandestinum to T. subterraneum via a common mycorrhizal network.

Palisadegrass pastures with or without nitrogen or mixed with forage peanut grazed to a similar target canopy height. 1. Effects on herbage mass, canopy structure and forage nutritive value

AbstractNitrogen (N) inputs to pasture systems coupled with grazing management strategies based on monitoring and control of canopy structure may provide conditions for greater productivity and enhanced forage nutritive value. This 2‐year study assessed canopy structure and nutritive value responses of three pasture treatments, namely, (1) mixed Marandu palisadegrass (Brachiaria brizantha [Hochst. ex A. Rich.] R.D. Webster [syn. Urochloa brizantha Stapf]) cv. Marandu and forage peanut (Arachis pintoi Krapov. & W.C. Greg.) cv. BRS Mandobi pastures without N fertilizer (GRASS + LEGUME); (2) monoculture Marandu palisadegrass pastures fertilized with 150 kg N/ha (GRASS + N); and (3) monoculture Marandu palisadegrass without N fertilizer (GRASS). Grazing management was similar across pasture treatments, using continuous stocking and a target canopy height of 20–25 cm. Herbage mass was greater in GRASS + N and GRASS + LEGUME pastures than in GRASS in summer and spring (p = .014). The leaf:stem ratio in the grass mass (p = .731) was similar between treatments. Grass crude protein (CP) and in vitro digestible dry matter (IVDDM) were greatest in the GRASS + N pasture (p < .001). Grass neutral detergent fibre (NDF) concentration was greater at GRASS and GRASS + LEGUME pastures than in GRASS + N (p < .001). Forage peanut had a greater IVDDM and CP concentration and a lower NDF concentration than Marandu palisadegrass. Nitrogen application or the presence of the legume increased green herbage mass and improved forage nutritive value in canopies with similar height.

Evaluation of cool-season binary mixtures as pasture: Herbage yield, nutritive value, and beef cattle performance

• Hybrid bromegrass-legume mixtures produced 54% more biomass than Russian wildrye-legume mixtures at Lanigan site, while biomass did not differ between mixtures at Swift Current site. • Legume contribution to total biomass was greater at Swift Current than at Lanigan site, and alfalfa contributed more to biomass than sainfoing at Lanigan site. • Crude protein tended to be greater for RWR mixtures than HBG mixtures at Lanigan site. • Beef steer gain was similar for all binary mixtures at Swift Current site, however steer gain was greater at Lanigan site for sainfoin mixtures, suggesting inclusion of legume in pasture was beneficial. • Results demonstrate that all four binary mixtures appear to be suitable for late summer and fall grazing. ABSTRACT A 3-year study (2016, 2017, and 2018) was conducted to compare the effects of alfalfa (ALF; cv. Yellowhead) (Medicago falcata L.) or sainfoin (SF; cv. AAC Mountainview) (Onobrychis viciifolia Scop.) in mixtures with either Russian wildrye (RWR; cv. Tom) (Psathyrostachys junceus [Fisch.]) or hybrid bromegrass (HBG; cv. Success) (Bromus riparius Rehm × B . inermis Leyss) on herbage dry matter yield (DMY) and nutritive value, and beef yearlings performance at two sites: Swift Current (Brown soil zone) and Lanigan (Thin Black soil zone), Saskatchewan, Canada. In 2015, in each site, sixteen 0.7-ha (in Lanigan) or 0.8-ha (in Swift Current) paddocks were established with replicated ( n = 4) ALF-HBG, ALF-RWR, SF-HBG, or SF-RWR binary mixtures. Each year in August, yearling steers (16 ± 1 month and BW = 391 ± 1.7 kg and 350 ± 0.04 kg for Swift Current and Lanigan sites, respectively) were allocated to paddocks for an average 30-d grazing trial to utilize 40–60% of available herbage. The DMY (3629 ± 154 kg/ha) did not differ ( P > 0.05) among mixtures at Swift Current. The HBG included (ALF-HBG and SF-HBG) mixtures produced 54% more ( P < 0.01) DMY than RWR included (ALF-RWR and SF-RWR) mixtures (4542 vs. 2943 kg/ha, SEM = 303) at Lanigan. Legume contribution to DMY was greater at Swift Current than at Lanigan (33.1% ± 2.1% vs. 14.0 ± 1.7%), and ALF contributed more to DMY than SF at Lanigan (18.0 vs. 10.1%). Crude protein tended ( P = 0.10) to be greater for RWR mixtures than HBG mixtures (93.5 vs. 83.4 g/kg DM for RWR and HBG mixtures, respectively) at Lanigan. The yearling steers had similar ( P = 0.25) ADG (0.78 ± 0.03 kg/d) for the treatments at Swift Current. However, at Lanigan, the animal ADG differed ( P < 0.01) with 0.88 and 0.90 kg/d for ALF-RWR and SF-RWR and 0.53 and 0.63 kg/d for ALF-HBG and SF-HBG mixtures, respectively. The HBG mixtures (ALF-HBG and SF-HBG) produced approximately 10 more grazing days (GD) (AUD/ha) than the RWR (ALF-RWR and SF-RWR) mixtures at both, Swift Current (95 vs. 88 AUD/ha, SEM = 9) and Lanigan (112 vs. 101 AUD/ha, SEM = 7) sites. Sainfoin-grass mixtures produced 8 and 3 GD less (AUD/ha) than ALF-grass mixtures at Swift Current and Lanigan, respectively. Overall, these results demonstrate that all 4 binary mixtures appear to be suitable for late summer and fall grazing to provide sufficient nutritive value and beef cattle steer performance in both soil zones of Saskatchewan, Canada.

Long-Term Growth of Alfalfa Increased Soil Organic Matter Accumulation and Nutrient Mineralization in a Semi-Arid Environment

Land use patterns and vegetation coverage in semi-arid areas of the Loess Plateau have undergone great changes due to the implementation of the “Grain for Green” project. The introduction of legume pasture species, such as alfalfa (Medicago sativa L.) and sweet clover (Melilotus officinalis L.), is one of the most efficient methods of vegetation restoration and reconstruction in this region. However, there is a need for an effective assessment of the root system distribution and its interaction with soil after long-term introduction. An experiment involving the introduction of alfalfa and sweet clover on abandoned farmlands was initiated in 2003 to assess the long-term effects. After 17 years, root and soil samples at depths of 0–20 and 20–60 cm were collected to characterize the root biomass, root carbon (C), nitrogen (N), and phosphorus (P), soil microbial biomass carbon (MBC) and nitrogen (MBN), soil organic carbon (SOC), and soil N and P. The results showed that the root biomass density of alfalfa in the 0–20 and 20–60 cm layers (63.72 and 12.27 kg m–3, respectively) were significantly higher than for sweet clover (37.43 and 8.97 kg m–3, respectively) and under natural abandonment (38.92 and 9.73 kg m–3, respectively). The SOC, total nitrogen (TN), total phosphorus (TP), available phosphorus (AP), nitrate-nitrogen (NO3–-N), MBC and MBN in the 0–20 and 20–60 cm layers were higher after alfalfa introduction compared with sweet clover introduction and natural abandonment, although the ammonia-nitrogen (NH4+-N) concentration in the 0–20 cm layer was lower. There were significantly positive correlations between root biomass density and both soil nutrients and microbial biomass, while there was a negative correlation between the soil NH4+-N and root biomass density. These results indicate that alfalfa root growth improved soil organic matter accumulation and nutrient mineralization. The accumulation and mineralization of soil nutrients also guaranteed root and microorganism growth. Therefore, it was concluded that alfalfa introduction will promote soil nutrients immobilization and mineralization and may enable sustainable land use in the semi-arid region of the Loess Plateau, China.

Evaluation of access to different legume pastures on performance and welfare of broiler chickens during dry season under tropical environment.

There have been a plethora of studies on the effects of access to runs on chickens’ welfare and behavioural repertoire with a paucity of information on the comparative advantage of various legume pasture and deep litter system. A total of 200‐day‐old unsexed Marshall Broiler chicks were weighed and assigned randomly into five experimental groups, viz. deep litter without access to run (DL), deep litter with access to Stylosanthes hamata (SH), Stylosanthes guanensis (SG), Mucuna pruriens (MP) and free run (FR) during dry season. Each treatment had 4 replicates of 10 birds. Data were collected on growth performance, behaviour, tonic immobility (TI), gait score and blood parameters. The data obtained were subjected to One‐Way Analysis of Variance in a Completely Randomized Design. Results showed that the final body weight of birds in SH was significantly higher (p ˂ .05) than those of SH, MP, FR and DL which were comparable. The feed intake of the birds of DL, SH and FR was higher than those of the other treatment groups. The feed conversion ratio (FCR) of the birds on legume pastures was lower than those without access to pasture. The birds of SH, SG and MP spent higher (p ˂ .05) time drinking, preening, dust‐bathing, spot pecking and walking standing behaviours while those in DL and FR spent more (p ˂ .05) time feeding. Generally, the gait score of the birds on the different legume pastures was similar but better than those without access to pasture. Tonic immobility of the DL birds was longer than that of FR whose duration was longer than those of the birds on the pastures. The study concluded that access to different legume pastures, particularly Stylosanthes hamata, improved the welfare of broiler chickens without adverse effect on the performance of the birds.

Root growth response of serradella species to aluminium in solution culture and soil

AbstractSerradella (Ornithopus) species are high‐quality pasture legumes that originate from the Mediterranean basin and have been increasingly used in southern Australian temperate grazing systems. They are generally regarded as tolerant of soils with low pH and, by inference, elemental toxicities such as aluminium (Al). No studies have examined the effect of high Al concentrations on the growth of French serradella (Ornithopus sativus Brot.) or newly developed cultivars of yellow serradella (O. compressus L.). Several cultivars/accessions of each species were grown in low ionic‐strength nutrient solutions at pHCa 4.5 containing a range of Al concentrations. Their susceptibility to root growth inhibition by Al was benchmarked against reference species ranging from Al‐sensitive to Al‐tolerant. Most serradella cultivars had moderate‐to‐high Al tolerance in solution culture but one yellow and two French serradella cultivars ranked alongside the Al‐sensitive reference species. A subset of cultivars and reference species were then grown in an Al‐toxic soil to test the validity of the solution culture results; these cultivars spanned the apparent range in Al sensitivity/tolerance indicated by the solution culture experiment. Variation in the relative root length achieved in Al‐toxic solution culture explained ~59% of the variation in the relative root length achieved in the acidic Al‐toxic soil. This result supports the conclusion that Al tolerance varies among serradella and that some cultivars may not thrive in soils with pHCa &lt; 4.5 and elevated extractable Al concentrations.

Pasture legumes differ in herbage production and quality throughout spring, impacting their potential role in fodder conservation and animal production

AbstractThis study reports on the herbage production and quality of a range of pasture legume species during spring, at three sites with moderate to strongly acidic soils in southern NSW, Australia. These data have enabled prediction of livestock production when legumes are conserved as silage or hay. Total herbage production, its timing and quality differed significantly between species, which generally was not predicted by the traditional metric of time to flowering. Trifolium incarnatum L., T. michelianum L., Biserrula pelecinus L., Ornithopus sativus Brot. and Hedysarum coronarium L. all maintained growth rates exceeding 200 kg DM/ha/d for 4 weeks over spring, while T. vesiculosum Savi. maintained this for 6 weeks, with a peak growth rate of 561 kg DM/ha/d. Herbage quality of all species declined over time and was greatest in species with a rapid increase in stem‐to‐leaf ratio or with weak stems, resulting in lodging. The modelling inferred that maximizing potential livestock production via fodder conservation required earlier cutting. Only the indeterminate species B. pelecinus and Ornithopus spp. increased potential liveweight gain per hectare through delayed harvesting from (probable) silage to hay‐making time.

“Summer sowing”: A successful innovation to increase the adoption of key species of annual forage legumes for agriculture in Mediterranean and temperate environments

AbstractThis paper reports on the evaluation of “summer sowing,” an innovative approach to increase the adoption of recently domesticated species of hard seeded annual legumes in Mediterranean and temperate Agriculture. The research revealed that several species of annual legumes whose seed can be readily harvested on‐farm and which possess natural hard seed dormancy, may be sown into dry soil in late summer without additional processing. These studies proved that the hard seed dormancy was broken down sufficiently in the soil over 4–6 weeks to produce robust legume pastures with more than 150 seedlings per m2 following the first winter rains, in replicated field sites established across wide agro‐ecological zones in Western Australia (WA) and New South Wales (NSW). Ornithopus sativus Brot., O. compressus L. and Trifolium spumosum L. were suitable for summer sowing based on both hard seed breakdown patterns and subsequent seedling survival in WA. While in NSW, in addition to these legumes, Biserrula pelecinus L., T. vesiculosum Savi. and T. glanduliferum Boiss. were also suitable for summer sowing. A 1.5‐ to 10‐fold increase in herbage production was achieved relative to conventionally sown T. subterraneum L. This development represents a step change in forage legume development for renovated pastures in these environments. Importantly, the experiments revealed differences in G x E effects on seedling establishment, total herbage production and seed yield in different climatic zones. The summer sowing approach is presented as a revolutionary method for pasture renovation that overcomes significant barriers to adoption.

Cryptic diversity found in Didymellaceae from Australian native legumes.

Ascochyta koolunga (Didymellaceae, Pleosporales) was first described in 2009 (as Phoma koolunga) and identified as the causal agent of Ascochyta blight of Pisum sativum (field pea) in South Australia. Since then A. koolunga has not been reported anywhere else in the world, and its origins and occurrence on other legume (Fabaceae) species remains unknown. Blight and leaf spot diseases of Australian native, pasture and naturalised legumes were studied to investigate a possible native origin of A. koolunga.Ascochyta koolunga was not detected on native, naturalised or pasture legumes that had leaf spot symptoms, in any of the studied regions in southern Australia, and only one isolate was recovered from P. sativum. However, we isolated five novel species in the Didymellaceae from leaf spots of Australian native legumes from commercial field pea regions throughout southern Australia. The novel species were classified on the basis of morphology and phylogenetic analyses of the internal transcribed spacer region and part of the RNA polymerase II subunit B gene region. Three of these species, Nothophoma garlbiwalawardasp. nov., Nothophoma naiawusp. nov. and Nothophoma ngayawangsp. nov., were isolated from Senna artemisioides. The other species described here are Epicoccum djirangnandirisp. nov. from Swainsona galegifolia and Neodidymelliopsis tinkyukukusp. nov. from Hardenbergia violacea. In addition, we report three new host-pathogen associations in Australia, namely Didymella pinodes on S. artemisioides and Vicia cracca, and D. lethalis on Lathyrus tingitanus. This is also the first report of Didymella prosopidis in Australia.