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Precise information about carbohydrates and proteins in relation to their utilization in the rumen is useful for the breeding purposes of perennial ryegrass cultivars used for animal nutrition. The objective of the current study was to evaluate 20 diploid perennial ryegrass accessions from the intermediary heading stage. The ruminal kinetics of different carbohydrate and protein fractions of grasses and legumes are important for forage breeding programs. The Cornell Net Carbohydrate and Protein System (CNCPS) was used to provide such information. Accession-based variation can be observed after considering dynamic degradation processes. Variation among the 20 accessions was observed. Ruminally digested (RDC) and undigested (UDC) carbohydrate and ruminally degraded (RDP) and undegraded (UDP) protein contents, total carbohydrate and total protein contents, and carbohydrate and protein fractions for the first cut and annual averages show significant differences. Although the variation was smaller for the protein fractions, the calculated usable protein content (uCP, sum of UDP and amount of synthesized microbial protein in the rumen) in the small intestine is mainly influenced by decreasing the neutral detergent fiber (NDF) and increasing the sugar content among cultivars. Carbohydrate and protein fractionation is suitable for characterizing perennial grass accessions as it uses parameters relevant to ruminant nutrition, allowing a step forward in forage plant breeding for forage quality. To conclude, using parameters related to ruminal degradation kinetics should favor the selection of accessions with higher amounts of ruminally digested carbohydrates (RDC). The selection of accessions based on protein quality (proportion of UDP) is less favorable for achieving a higher usable protein content. [ABSTRACT FROM AUTHOR]

Systematic measurement of pasture biomass (kg DM/ha) is crucial for optimising pasture utilisation and increasing dairy farm profitability. On-farm pasture monitoring can be conducted using various sensors, but calibrations are necessary to convert the measured variable into pasture biomass. In this study, we conducted three experiments in New South Wales (Australia) to evaluate the use of the rising plate meter (RPM), pasture reader (PR), unmanned aerial vehicles (UAV) and satellites as pasture monitoring tools. We tested various calibration methods that can improve the accuracy of the estimations and be implemented more easily on-farm. The results indicate that UAV and satellite-derived reflectance indices (e.g., Normalised Difference Vegetation Index) can be indirectly calibrated with height measurements obtained from an RPM or PR. Height measurements can be then converted into pasture biomass ideally by conducting site-specific sporadic calibrations cuts. For satellites, using the average of the entire paddock, root mean square error (RMSE) = 226 kg DM/ha for kikuyu (Pennisetum clandestinum Hochst. ex Chiov) and 347 kg DM/ha for ryegrass (Lolium multiflorum L.) is as effective as but easier than matching NDVI pixels with height measurement using a Global Navigation Satellite System (RMSE = 227 kg DM/ha for kikuyu and 406 kg DM/ha for ryegrass). For situations where no satellite images are available for the same date, the average of all images available within a range of up to four days from the day ground measurements were taken could be used (RMSE = 225 kg DM/ha for kikuyu and 402 kg DM/ha for ryegrass). These methodologies aim to develop more practical and easier-to-implement calibrations to improve the accuracy of the predictive models in commercial farms. However, more research is still needed to test these hypotheses under extended periods, locations, and pasture species. [ABSTRACT FROM AUTHOR]

Fibrous forage and biomass crops such as grass and maize are used at large scale as feed for ruminants and feedstock for biogas production. These crops are typically harvested by chopping them in small particles which are light and suitable for partial pneumatic conveying, where the particle trajectory is determined by their aerodynamic properties. While the aerodynamic properties of many grains have been studied, no reports were found for perennial ryegrass. Chopped ryegrass samples of leaf blades and stems were collected in the fields. After imaging the fresh harvested particles to quantify their size and surface area, their terminal velocity was measured with the fluidised-bed method. The relationship between the mass, projected area and moisture content of the stems and blades with their terminal velocities were modelled. In line with theory, mass and moisture content was positively correlated with terminal velocity, while projected area was negatively correlated with it. Smaller terminal velocities were observed for the blades (1.75 m s−1) compared to the stems (4.44 m s−1). The drag coefficients of grass particles were calculated, and for blades it was negatively correlated with the particle Reynold's number lying within Newton's regime (103 < Re < 3 × 105), whilst no significant correlation was found for stems. The average drag coefficient of blades (0.75) was larger than stems (0.54). No significant effect (p-value <0.01) of moisture content on the drag coefficient of grass particles was observed. This confirms that the drag coefficient is a shape parameter, related to formation of airstreams around the particle. • Aerodynamic properties of ryegrass were quantified in a wind tunnel. • The terminal velocity of grass blades was 61% smaller than that of stems. • Terminal velocities can be predicted from mass, area and moisture content (R2 = 0.77). • Grass particles' drag coefficient was calculated and compared to similar materials. • The drag coefficient of grass blades was 39% larger than that of stems. [ABSTRACT FROM AUTHOR]

Perennial ryegrass (PRG, Lolium perenne L.) breeding effort in New Zealand (NZ) has increased since c. 1990, resulting in greater functional trait diversity (e.g. heading date, ploidy, and associated Epichloë endophyte strain) in commercial products. This study quantified the variation, associations and interactions in dry matter (DM) yield, nutritive value and persistence‐related traits among commercial cultivar‐endophyte combinations released between 1973 and 2012, as a basis for assessing gains in value being delivered to the pasture‐based livestock industries. Twenty‐four or 28 combinations were compared over 3 years in two trials in each of two regions: Waikato in northern NZ (dryland), and Canterbury in central eastern South Island (irrigated). Cultivar‐endophyte combinations were sown in mixtures with white clover, and pastures were intensively grazed 8–11 times per year by dairy cows. Principal Component Analysis identified 4 distinct clusters for the DM yield variables and for metabolisable energy (ME) content in each of the four trials. A broadly‐adapted group of three late‐season flowering, AR37‐infected diploids with NZ and Spanish breeding backgrounds dominated the highest‐yielding clusters. Tetraploids dominated the high ME content clusters. Interactions with region were observed throughout the data set: the strongest of these was driven by endophyte strain effects in Waikato. High‐yielding cultivar‐endophyte combinations in these trials were also generally high‐yielding in the standard cultivar merit testing system operated in New Zealand, as interpreted via the DairyNZ Forage Value Index. However, alignment was poorer for medium‐ and lower‐yielding cultivar‐endophyte combinations. Several implications for forage evaluation methods and end‐user industries are identified. [ABSTRACT FROM AUTHOR]

A process of plant recovery after drought cessation is a complex trait which has not been fully recognized. The most important organ associated with this phenomenon in monocots, including forage grasses, is the crown tissue located between shoots and roots. The crown tissue is a meristematic crossroads for metabolites and other compounds between these two plant organs. Here, for the first time, we present a metabolomic and lipidomic study focused on the crown tissue under drought and recovery in forage grasses, important for agriculture in European temperate regions. The plant materials involve high (HDT) and low drought-tolerant (LDT) genotypes of Festuca arundinacea , and Lolium multiflorum/F. arundinacea introgression forms. The obtained results clearly demonstrated that remodeling patterns of the primary metabolome and lipidome in the crown under drought and recovery were different between HDT and LDT plants. Furthermore, HDT plants accumulated higher contents of primary metabolites under drought in the crown tissue, especially carbohydrates which could function as osmoprotectants and storage materials. On the other hand, LDT plants characterized by higher membranes damage under drought, simultaneously accumulated membrane phospholipids in the crown and possessed the capacity to recover their metabolic functions after stress cessation to the levels observed in HDT plants. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate forage mass, morphological, and chemical composition of diploids and tetraploids Italian ryegrass cultivars in hydromorphic soil. Eight ryegrass cultivars were evaluated in a two-years completely randomised trial with four plots per cultivar. Forage production was recorded, and samples were collected to evaluate morphological and chemical composition. The contrasts methodology was used to verify differences between diploid and tetraploid cultivars. Compared to tetraploids, the diploids had the greatest number of cuts and the largest accumulation of forage in the second year, highlighting the better adaptation of cultivars in hydromorphic soils. Tetraploid ryegrass increased leaves and reduced stem and inflorescence proportion relative to diploid ryegrass. Tetraploid cultivars had lower DM, organic matter, and acid detergent fibre content than diploid cultivars. However, there was no significant difference between cultivars associated with their ploidy for the neutral detergent fibre and estimated total digestible nutrients. Additionally, only in the second year, tetraploid had lower crude protein content than diploid ones. Tetraploid ryegrass showed be less tolerant to periods of water stress due to flooding, characteristic of hydromorphic soils, resulting in less forage production than diploid ryegrass. [ABSTRACT FROM AUTHOR]

This study was carried out with the aim of determining the effect of forage plants belonging to different families on herbage quality and yield with different mixing ratios (Berseem clover:Italian ryegrass; 100:0%, 80:20%, 60:40%, 40:60%, 20:80% and 0:100%). In the study, plant height, green herbage and dry herbage yields, clover ratios in green herbage and dry herbage, crude protein ratio and yield, acid detergent fiber (ADF), neutral detergent fiber (NDF), digestible dry matter (DDM), dry matter intake (DMI) rates and relative feed value (RFV) were investigated in Derya variety of berseem clover (Trifolium alexandrinum L.) belonging to Eastern Mediterranean Agricultural Research Institute and Elif variety of Italian ryegrass (Lolium multiflorum Lam.) obtained from Aegean Agricultural Research Institute. The experiment was carried out with 4 replications according to the randomized blocks trial design in the summer term of 2020 in Bahçekapi village of Elazig city center. According to the study findings; the average green herbage yield of mixtures was found to be 3784.9 kg da-1, dry herbage yield was 1210.8 kg da-1, and crude protein yield was 146.6 kg da-1. Crude protein, acid detergent fiber (ADF), neutral detergent fiber (NDF), digestible dry matter (DDM), dry matter intake (DMI) ratios and relative feed value (RFV) of the mixtures were determined as 12.04%, 35.7%, 50.9%, 61.0%, 2.36%, and 112.15, respectively. As a result of this study; it was determined that the most suitable mixture ratios in terms of dry herbage, green herbage and crude protein yields and crude protein ratio were 80% Berseem clover + 20% Italian ryegrass and 60% Berseem clover + 40% Italian ryegrass mixtures in Elazig ecological conditions. It was observed that the dry herbage, green herbage and crude protein yields and crude protein ratios were higher in the plots where the Berseem clover was more concentrated in the mixtures. [ABSTRACT FROM AUTHOR]

Legume-based forage plant mixtures are known to increase biomass production over the mixture species grown as pure stands (overyielding), which has partly been attributed to enhanced nitrogen availability by legumes. However, the relative importance of underlying processes of these positive diversity effects and their drivers are not fully understood. Here we assessed if outcome and causes of diversity effects depend on the legume-species genetic identity. Over five years, we cultivated different white clover (Trifolium repens) populations, a grass and forb species in pure stands and clover-based mixtures and recorded biomass yield. Complementarity and selection effects of mixtures and relative yields of mixture species were calculated based on both unfertilized and nitrogen-fertilized non-leguminous pure stands. Results showed that the clover population altered the overall strength of diversity effects as well as the direction and magnitude of their temporal trends, at least for the grass component of mixtures. Differences in diversity effects between clover populations diminished when fertilized instead of unfertilized non-leguminous pure stands were considered. Hence, a part of these differences likely results from dissimilar effects of clover populations on nitrogen availability. The findings reveal the possibility to improve overyielding of legume-based forage plant mixtures by decisions on legume-species genetic identity. [ABSTRACT FROM AUTHOR]

Dairy heifers developed in certified organic programs, especially those utilizing pasture-based management schemes, have lower rates of gain than heifers raised in nonorganic confinement production systems in temperate climates, such as in the Intermountain West region of the United States. This study investigates the effects that different forages in a rotational grazing system have on development of organically raised Jersey heifers. Over 3 years, 210 yearling Jersey heifers were randomly assigned to one of 9 treatments, including a conventional confinement control where animals were fed a total mixed ration or one of 8 pasture treatments: Cache Meadow bromegrass (Bromus riparius Rehmann), QuickDraw orchard grass (Dactylis glomerata L.), Amazon perennial ryegrass (Lolium perenne L.), or Fawn tall fescue (Schendonorus arundinaceus [Schreb.] Dumort) and each individual grass interseeded with birdsfoot trefoil (Lotus corniculatus L., BFT). Each treatment had 3 blocks/yr over the 3-yr period, with each block having a 0.4 ha pasture of each treatment. Every 35 d, over a 105-d period, heifers were weighed and measured for hip height, and blood samples were collected to determine serum insulin-like growth factor-1 and blood urea nitrogen concentrations. Fecal egg counts were also assessed. Heifer body weight (BW), blood urea nitrogen, and insulin-like growth factor-1 concentrations were affected by treatment when analyzed over time. Heifers on grass-BFT pastures had increased BW compared with heifers on monoculture grass pastures. Heifers receiving a total mixed ration or perennial ryegrass+BFT had increased BW gain over the 105-d period compared with heifers grazing tall fescue+BFT, orchard grass, perennial ryegrass, meadow bromegrass, or tall fescue. Individually for all grass species, heifers grazing +BFT pastures had greater ending BW and weight gain than heifers grazing the respective grass monocultures. Furthermore, weight gain for heifers on perennial ryegrass+BFT, meadow bromegrass+BFT, and orchard grass+BFT were not different from those on a total mixed ration. Heifers grazing grass-BFT pastures had increased blood urea nitrogen compared with heifers grazing monoculture grass pastures. Heifer hip height and fecal egg counts were not affected by treatment. These results show that the addition of BFT to organic pasture improves growth of grazing replacement heifers. Economic analyses also demonstrate that interseeding grass pastures with BFT results in an increased economic return compared with grazing monoculture grass pastures. Grass pastures interseeded with BFT may be a sustainable option to achieve adequate growth of Jersey heifers raised in an organic pasture scenario in a temperate climate. [ABSTRACT FROM AUTHOR]

Sandy soil is typically poor in organic matter. When areas with sandy soil are used for pasture prior to soybean cultivation, the availability of nitrogen (N) for plants is limited even further. Our objective was to evaluate if inoculation combined with N fertilization increases N content in the soil and N supply to soybean plants in post-pasture and post-soybean areas. Four experiments were conducted in degraded post-pasture and post-soybean areas in a sandy soil (Rhodustult), between 2016 and 2018, in Brazil. Treatments used a combination of inoculant (zero, 4, 8 and 12 rates ha−1) and mineral N (0, 25, 50, and 100 kg ha−1) with four replicates. It was using the soybean cultivar TMG 7062 IPRO. The post-soybean area had higher N content in the soil than the post-pasture area; 33, 32, and 21% for total N, microbial biomass nitrogen (MBN), and inorganic nitrogen (IN), respectively. Soybean shoots from the post-soybean area also had greater accumulations of N (86 kg ha−1 of N). Increased N fertilization linearly raised levels of N in the soil (total N, MBN, and IN). In both areas, the effect of inoculation was restricted by the increase of total N in the soil. Inoculation combined with moderate rates of N in soybeans (50 kg ha−1) increased levels of N in the soil and N supply to plants in post-pasture areas. In post-soybean areas, inoculation alone fulfilled the N soybean need. [ABSTRACT FROM AUTHOR]

We evaluated Italian ryegrass (Lolium multiflorum Lam.) establishment in a factorial of grazing intensity (intense, moderate, moderate‐light, light, and no grazing, with target average sward heights of 10, 20, 30, and 40 cm in the grazed plots) and additional seeding (self‐seeding with or without additional seeding) in an integrated soybean‐beef cattle system in southern Brazil. Grazing treatments were imposed in winter (June–July) and followed by a direct‐seeded soybean crop (November). The establishment was quantified prior to the stocking periods in 2017 and 2018, corresponding to self‐seeding from 2016 and 2017. Intense grazing impaired ryegrass re‐establishment, resulting in larger individual plants (0.54 vs. 0.15 g dry matter plant−1) but lower population density (57 vs. 1,355 plants m−2) than in the other treatments. Additional broadcast ryegrass seeding did not fully compensate for the reduced natural reseeding in this treatment. The addition of seeds under intense grazing increased plant population density to values comparable to moderate grazing intensities but reduced individual plant mass, limiting herbage mass attained by the end of the pasture establishment phase. Contrastingly, the various combinations of individual plant mass and population density were sufficient to maintain herbage masses in moderate to light grazing intensities that were comparable to that in the ungrazed treatment, regardless of seed addition (63 vs. 180 g DM m−2 for intense grazing vs. the average of other treatments over the whole establishment phase). Moderate grazing, e.g., target sward heights of 20 cm or greater, is necessary to achieve a system that can sustain itself without seed addition. [ABSTRACT FROM AUTHOR]

The aim of current study was to determine silage quality traits of leafy “L” and semi-leafy “SL” forage pea varieties (Pisum arvense L) and annual ryegrass “R” (Lolium multiflorum var. westervoldicum L.) mixtures (100:0, 80:20, 60:40, 40:60, 20:80 and 0:100%). The harvested materials were chopped in size of 2 cm, and they filled into vacuum bags, and then let for fermentation at 25±2 oC for 45 days. In this study; dry matter, pH, crude protein, crude ash, some organic acids, acid detergent fiber (ADF), neutral detergent fiber (NDF), potassium (K), phosphorus (P), calcium (Ca), magnesium (Mg) and cobalt (Co) contents were determined. The highest crude protein content was determined sole forage pea silages (16.31% and 15.73%) and 80L+20R% (15.58%) mixture. According to the Flieg score, leaf forage pea (97.51) and 80L+20R% (99.19) silages have the highest value and, they were in very good quality class. ADF and NDF content of silages ranged between 25.87-30.24% and 34.55-45.53%, respectively. The highest lactic acid was determined in 100R% (4.448%), 80L+20R% (4.250%), 40L+60R% (3.523%) and 20L+80R% (3.885%). The mineral content of silages were at a level to meet the needs of the livestock. As a result, it was determined that the mixture of leafy forage pea and ryegrass 80+20% silage was better in terms of silage quality. [ABSTRACT FROM AUTHOR]

Aims: An Italian ryegrass cultivar (Lolium multiflorum Lam. cv. Bb2067), selected and bred for increased leaf magnesium (Mg) concentration in the 1970s, reduced the incidence of hypomagnesaemia in sheep under experimental grazings. Here, we report evidence from archival experiments showing that cv. Bb2067 had consistently greater Mg concentrations at multiple sites. We also aimed to quantify variation in leaf Mg concentration among modern perennial ryegrass (Lolium perenne L.), hybrid ryegrass (Lolium perenne × multiflorum), and tall fescue (Festuca arundinacea Shreb.) cultivars. Methods: Data are reported from unpublished 1980s field-plot experiments for cv. Bb2067 and contemporaneous reference cultivars, sown at two UK locations in 1983 and 1984, and from 397 cultivars of modern forage grass in 13 UK-based breeding experiments sampled in spring 2013. Results: Across sites, years and cuts, cv. Bb2067 had a consistently greater leaf Mg concentration and lower potassium (K) concentration and forage tetany index (FTI) than reference cultivars in the 1980s experiments. Seasonal variation in leaf Mg and K concentrations and FTI were observed in the 1980s experiments, with K concentrations being generally greatest and Mg concentrations smallest in spring. Among modern forage grasses, there was large variation in leaf Mg concentration (up to 6.3-fold) and FTI (up to 2.1-fold), both within and between species, which varied independently of yield. Among a subset of hybrid ryegrass cultivars, there is evidence that the high Mg trait is already present in some modern breeding lines, albeit previously unreported. Conclusions: The variation in leaf Mg concentration and FTI among old and new cultivars shows there is considerable potential to breed forages with improved mineral quality to improve livestock health, potentially without compromising yield or other nutritional traits. [ABSTRACT FROM AUTHOR]

During the past 20 years, there has been a contraction in the New Zealand Thoroughbred industry and, to a lesser extent, within the Standardbred industry. These changes have seen an increasing proportion of the market being associated with fewer larger commercial farms. Many of these farms manage their own mares, and the mares and foals of several clients. This, in turn, has increased the similarity of the management of breeding and young stock within New Zealand. The temperate climate allows the majority of the management of breeding and young stock to be pasture based. The predominant pasture is ryegrass-clover mix that has been demonstrated to provide adequate nutrition for growth and development. The temperate climate also permits management of horses at pasture year round, which is proposed to stimulate development of the musculoskeletal system. Apart from a brief period during weaning, most young stock remain at pasture from birth until the start of yearling preparation. Free access to pasture exercise provides the opportunity to stimulate the musculoskeletal system for the future challenges as a racehorse. The export focus of many of the equine industries heavily influences the management decisions. Despite the availability of good-quality pasture post-weaning, many foals receive up to 50% of the daily dietary energy requirement as concentrates, possibly reflecting the emphasis on early sales as yearlings and the drive to optimise growth. The observations of drench resistance of common internal parasites presents an emerging problem for pasture-based production systems. Alarge proportion of the Thoroughbred foal crop is exported as yearlings or ready to run 2-year-olds. There is an increasing trend for Standardbreds to be sold as yearlings and this has resulted in changes in the management of Standardbred young stock. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to conduct a pathological study to identify and collect ecotypes of Lolium perenne as a function of germplasm in the process of improvement "in situ" and "ex situ" in the Danube Meadow, Protected Areas of Mehedinţi County and the Western Plain of Timiș County. A study is performed on areas (altitudes, types of meadows) where the species Lolium perenne is present with accompanying vegetation and biogeomorphological characterization. The collection field for the study is made at the Lovrin Agricultural Research Station, where the biological development of the collected material is followed. The study of Lolium perenne species is performed by determining the ecological indices and biodiversity and performing the analysis of plant-soil quality of the soils in the collected area. Productive characteristics of Lolium perenne as a cultivated species and productive / breeding potential for use as feed, seed production, quality of green hay mass, net lactation energy and evolution of crude protein content. Seed yield is a measure of the total marketable seed recovered from the harvesting and processing of a seed crop. An economic level of seed yield is vital for the successful production and marketing of any forage plant. However, seed yield in perennial ryegrass, as in other fodder plants, has received less attention from plant breeders than feed production and quality, as these species are mainly used as fodder.Lolium perenne seed production is still low, uncertain and little is known about the production capacity of seeds of different varieties. The delimitation of the area with the help of satellite maps and the description of the area studied through the administrative and geographical description but also from the point of view of the meadows that make it up. Description of the plant associations from which the biological material of Lolium perenne was taken. [ABSTRACT FROM AUTHOR]

Field indicators of forage nutritive value could help farmers with rapid management decisions to optimize timing and intensity of grazing and meet objectives regarding animal nutrition. The objective of this research was to evaluate the likely relationships among leaf blade nutritive value, herbage mass and leaf stage of pasture regrowth under different growing seasons and residual sward heights. Experiments were performed on perennial ryegrass (Lolium perenne L.) and tall fescue (Festuca arundinacea Schreb.) pastures during spring and summer of 2016. In both pastures, three residual sward height treatments (3, 6 and 12 cm) were imposed on plots arranged in a split plot design, replicated in three blocks. Sward plots were harvested 5–6 times at intervals spaced 7–10 days apart to measure herbage mass, plant morphology, neutral detergent fibre (NDF), and the 24‐hr in vitro digestibility of NDF (NDFD) and dry matter (DMD) of leaf blades. Pastures showed strong (R2:.62 to.70), but variable, negative relationships between NDFD and herbage mass that varied with the rate at which pasture grew in each season of experimentation. Although there was a consistent NDFD decline as leaf stage of regrowth progressed (R2:.75 to.97), the NDFD also decreased as residual sward height increased, most notably in tall fescue. Additionally, findings indicate that the greater leaf length plasticity of tall fescue compared to residual sward heights may offer opportunities to manage both post‐ and pre‐grazing targets to achieve tall fescue forages with a similar high nutritive value as perennial ryegrass. However, the evaluation of this hypothesis at the farm level and its impacts on animal intake and performance warrants further careful investigations. [ABSTRACT FROM AUTHOR]

This experiment investigated the feasibility of using herb-clover mixes to enable early weaning of lambs at ∼60 days of age. Over two years, twin lambs weighing more than 16 kg were allocated to three treatments: ryegrass pastures until 90 days-of-age, herb-clover mix until 90 days-of-age or weaned at ∼60 days of age onto herb-clover mix. In 2014, lambs offered the herb-clover mix, weaned at 60 or 90 days, were heavier at 90 days than lambs grazing on pasture with their dams. In 2015, lambs that weaned early onto the herb-clover mix were lighter at the same age as lambs that remained with their dam, but they still achieved a commercial weight. Ewes weaned early were heavier at weaning than ewes suckling lambs on ryegrass pasture in both years. Under some conditions, early weaning of lambs onto a herb-clover mix can be an effective alternative to conventional weaning on ryegrass pasture. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the effect of different grassland renovation methods on the Lolium sp. productivity during rainy and dry seasons in the high tropic of the Nariño department. Materials and Methods: The essay was conducted between January and August, 2018. Two experiments were established in the Pasto and Sapuyes municipalities. An experimental design of complete randomized blocks was used, with five treatments and three replicas (T1: farmer's conventional management; T2: grassland renovator; T3: harrowing twice; T4: rigid chisel plow once, harrowing once and subsoiling once; T5: vibratory chisel plow once and harrowing once). The variables cover percentage, height, green forage and dry matter yield, were evaluated. For the statistical analysis, the software R V 3.5.1 was used. Variance analysis and Tukey's test were carried out for comparison among means (p < 0,05). Results: In the rainy season, in the Pasto locality, the variable plant height showed significant differences among treatments (p < 0,001). T5 showed the highest value (38 cm). In turn, significant differences were found in the green matter and dry matter yield among treatments, T3 being the one with the best performance (16,2 and 2,6 t ha-1, respectively). In the Sapuyes locality, T1 reached the best results for the variables cover percentage, plant height, green forage and dry matter yield (96,0 %; 67,5 cm; 34,2 t ha-1 and 4,19 t ha-1, respectively). In the dry season, in the Sapuyes locality, the variable green forage yield showed significant differences among treatments, T1 being the most outstanding one (21,1 t ha-1). Conclusions: During the rainy and dry seasons, T3 reached the best values in green forage and dry matter yield for the Pasto locality; while for Sapuyes, T1 showed the best values. [ABSTRACT FROM AUTHOR]

The excretion of urinary nitrogen (N), one of the most important environmental contaminants from livestock systems, is highly correlated with milk urea N content. The objective of this research was to evaluate the use of different types of corn supplementation on milk urea N in grazing dairy cows. Twelve Holstein × Jersey lactating dairy cows were divided into six uniform groups according to milk production, lactation stage and live weight. Treatments were compared according to a 3 × 3 replicated Latin square experimental design, with three periods of seventeen days (twelve days to adaptation and five to measurements). The experimental treatments were exclusively grazing (G); grazing + supplementation with 4.2 kg DM of corn silage (CS) and grazing + supplementation with 3.2 kg DM of ground corn (GC). The pasture used was annual ryegrass (Lolium multiflorum L.) and white oats (Avena sativa L.). The milk protein production increased 65 g/day in the GC treatment group compared to the G and CS groups. The supplemented dairy cows showed lower milk urea N (-2.8 mg/dL) than unsupplemented cows, but the N utilization efficiency (g N output in milk/g N intake) did not change between treatments (average = 0.26). Additionally, there was a relationship between milk and plasma urea nitrogen concentrations (R² = 0.64). In conclusion, for dairy cows grazing annual temperate pastures, corn ground supplementation increased milk protein production and reduced the excretion of milk urea N, whereas corn silage reduced the excretion of milk urea N without affecting milk protein production. [ABSTRACT FROM AUTHOR]

Meadow fescue (Festuca pratensis Huds.) is one of the most important forage grasses in temperate regions. It is a diploid (2n = 14) outbreeding species that belongs to the genus Festuca. Together with Lolium perenne , they are the most important genera of forage grasses. Meadow fescue has very high quality of yield with good winter survival and persistency. However, extensive genomic resources for meadow fescue have not become available so far. To address this lack of comprehensive publicly available datasets, we have developed functionally annotated draft genome sequences of two meadow fescue genotypes, 'HF7/2' and 'B14/16', and constructed the platform ForageGrassBase, available at http://foragegrass.org/ , for data visualization, download and querying. This is the first open-access platform that provides extensive genomic resources related to this forage grass species. The current database provides the most up-to-date draft genome sequence along with structural and functional annotations for genes that can be accessed using Genome Browser (GBrowse), along with comparative genomic alignments to Arabidopsis , L. perenne , barley, rice, Brachypodium and maize genomes. We have integrated homologous search tool BLAST also for the users to analyze their data. Combined, GBrowse, BLAST and downloadable data gives a user-friendly access to meadow fescue genomic resources. To our knowledge, ForageGrassBase is the first genome database dedicated to forage grasses. The current forage grass database provides valuable resources for a range of research fields related to meadow fescue and other forage crop species, as well as for plant research communities in general. The genome database can be accessed at http://foragegrass.org. [ABSTRACT FROM AUTHOR]

The aim of the present research was to compare milk fatty acid composition of cows grazing perennial ryegrass–white clover pasture (RGWC), with that of cows grazing alternative forages of chicory or plantain. Fifty-four cows, balanced for milk solids, days in milk and bodyweight, were divided evenly into replicated groups of six cows/group. Cows grazing chicory or plantain had similar estimated dry-matter intake (17.7 kg DM/cow.day) and milk-solid (MS) yield (1.93 kg MS/cow.day), which were greater (P < 0.05) than for cows grazing RGWC (15.6 kg DM/cow.day and 1.65 kg MS/cow.day). Milk produced from cows grazing chicory or plantain contained greater proportions of omega-3 fatty acids (FA) than that from cows on RGWC (P < 0.01), despite lower omega-3 FA in herbage. RGWC increased the percentage of conjugated linoleic and vaccenic acids in milk compared with those of milk produced from herbs (P < 0.01). This reflects the greater percentage of α-linolenic acid in RGWC (P ≤ 0.02) than in forage herbs. The changes in FA profile from the herbage to the milk suggests less biohydrogenation in cows grazing the herbs. Forage herbs demonstrated the potential benefit to alter milk FA composition, while increasing milk production. Milk fatty acid profile has implications on human health, processing quality and storage characteristics of milk products. This research compared milk fatty acid composition of cows grazing perennial ryegrass–white clover pasture with that of cows grazing herbs chicory or plantain. Forage herbs demonstrated the potential benefit to alter milk fatty acid composition, while increasing milk production. [ABSTRACT FROM AUTHOR]

Defoliation often has little effect on the percent plant root length colonised by arbuscular mycorrhizal (AM) fungi, and this has been interpreted as a lack of support for the carbon limitation hypothesis. We performed an experiment with three levels of repeated defoliation (none, every 3 weeks and weekly) of Lolium rigidum growing in pasture soil, and assessed colonisation of roots by naturally occurring AM fungi over 4 months in the glasshouse. Surprisingly, the percent root length colonised by AM fungi increased with defoliation. We also assessed root mass and the length of colonised root to obtain an estimate of the quantity of mycorrhizal root. As expected, both root mass and length of mycorrhizal root decreased with defoliation, as did soluble sugars in the roots. Thus, increasing the frequency of defoliation reduced mycorrhizas consistent with the carbon-limitation hypothesis. Such a decline in mass of mycorrhizal root could contribute to reducing soil biological fertility in pastures over time. [ABSTRACT FROM AUTHOR]

Small-scale dairy systems contribute to ameliorate rural poverty and to local milk supply. Their sustainability is limited by high feeding costs, mainly from purchased concentrates (CC); whereas a higher reliance on quality forage may improve profitability; but high stocking rates may justify high CC use. The objective of this work was to assess the productive and economic response by grazing dairy cows to levels of CC under grazing of ryegrass--white clover pastures under high stocking rate (4 cows/ha). Six Holstein milking cows were replicated assigned 3 X 3 Latin Square arrangements. Daily milk yield and composition were recorded, and feed intake estimated from utilised metabolizable energy. Treatments were: T1= 1.0 kg T6= 3.0 kg and T6= 6.0 kg concentrate/cow/d. There were significant differences (P<0.05) for milk yield, with T6 having higher yields than T1 and T3. There were no significant differences in milk protein or fat content among treatments (P>0.05). Herbage intake was significantly (P<0.05) lower in T6, with no differences (P>0.05) between T1 and T3. There were no differences in margins over feeding costs, but feeding cost per kg of milk was 2.2 times higher in T6 compared to T1, and margin per kilo of milk was 26 % higher in T1 than T6. Although milk yields are higher with T6, T1 and T3 require less expenditures and margins are similar. Supplementation may alleviate high grazing pressure that deteriorates pastures, ensuring the long-term sustainability of small-scale dairy farming systems. [ABSTRACT FROM AUTHOR]

Nitrogen fertilization is a major input cost of forage production, and alternatives that maintain yield and nutritive value would be advantageous. A 3‐yr study was conducted to evaluate forage nutritive value and clover proportion when N fertilizer was replaced partially with interseeded clovers (Trifolium spp.) or protein supplements for stocker cattle grazing annual ryegrass (Lolium multiflorum Lam.). Nitrogen delivery methods with or without monensin included annual ryegrass fertilized with 112 kg N ha−1 in split application (NFERT), and other methods that received 56 kg N ha−1, including annual ryegrass interseeded with crimson clover (CC, Trifolium incarnatum L.) or arrowleaf clover (AC, Trifolium vesiculosum Savi), or grazing cattle supplemented with distillers dried grains plus solubles at a rate of 0.65% body weight daily (DDGS) or whole cottonseed (Gossypium hirsutum L.) at the rate of 0.65% body weight daily (WCS). Clover proportion was greater (P = 0.003) for CC than AC across all 3 yr of the study, and CC was more (P = 0.003) abundant when monensin was fed. Year affected forage in vitro true digestibility (IVTD, P < 0.001) and crude protein (CP, P < 0.001) concentration such that IVTD and CP were greatest in Year 3, intermediate in Year 2, and least in Year 1. Forage degradable intake protein (DIP) concentration was affected by N delivery method (P < 0.001) and year (P < 0.001) such that CC was less than NFERT, DDGS, WCS, and AC, and Year 1 was greatest, Year 2 was intermediate, and Year 3 was the least. Results are interpreted to mean that year affected forage nutritive value more than did N delivery method. [ABSTRACT FROM AUTHOR]

Ryegrass (Lolium perenne L.) is a putative turf and forage plant characterized as mainly outcrossing in which the extent of self‐fertilization and its consequences has not been investigated. In this study, selfed and half‐sib family seeds were obtained from ten clonally propagated ryegrass plants among which two were endophyte‐free (EF) and eight were endophyte‐infected (EI). Then, 20 seed populations plus two commercial varieties of Speedy and Vigor were sown and evaluated in a biennial experiment for their turf and forage characteristics. Selfing caused significant inbreeding depression for plant fresh and dry weight and leaf length and width in the first year for both EI and EF genotypes. In the second year, only leaf length remained depressed among these characters. Also, for the most growth, turf and reproductive traits, EI populations showed less depression. The presence of endophyte in self‐pollinated populations made an increasing effect for the number of seed per spike and days to heading, although seed weight was reduced. Some of the populations derived from self‐pollination and infected with fungal endophyte including S9 and S10 were even superior to the two commercial varieties in terms of both seed production and turf characteristics. However, for seed‐related characteristics including number of spikes per plant, seed weight and seed yield, EF populations including Speedy and Vigor were more reproductive than EI populations. It is concluded that selfing may increase the discrimination between EI and EF ryegrass plants because endophyte infection may mitigate the negative consequences of inbreeding depression in prone populations. [ABSTRACT FROM AUTHOR]

One of the challenges of modern grassland systems is to minimize nitrogen (N) fertilization without negatively affecting the forage yield. Therefore, critical N dilution curves (Nc = acW−b) have been developed in different species to improve N fertilization management. The aim of this study was to validate a critical N dilution curve for hybrid ryegrasses. Two field experiments were conducted in southern Chile. Treatments were the factorial combination of two hybrid ryegrasses (Shogun and Trojan cultivars) and seven N fertilization rates (0, 50, 100, 200, 350, 525 and 700 kg N/ha). Factors were arranged in a split‐plot design, where forage species were assigned to main plots and N rates to subplots that were randomized into four blocks. A wide range in forage yield and plant N concentration was observed (yield: 0.16 and 3.9 Mg DM/ha and N: 1.6% and 5.1%). The variations in these traits were principally explained by the N levels and harvest times. Relative yield responses of both cultivars were significantly (p < 0.001, R2 = 0.81–0.87) related to the nitrogen nutrition index (NNI) calculated with different critical N dilution curves. However, the NNI calculated with N dilution curves from annual ryegrass best described the relative yield response of hybrid ryegrass. Therefore, this validated critical N dilution curve (%Nc = 4.1W−0.38) will serve as a useful diagnosis tool for improving the N fertilization management of grazing systems for hybrid ryegrasses. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine the leaf tissue flows in Italian ryegrass (Lolium multiflorum Lam.), in different phenological stages, grazed by lambs, and managed under three herbage allowances (6, 9 and 12 kg DM/100 kg body weight under rotational stocking method. The experimental design was completely randomized, with repeated measures arrangement. Forage allowances determined similar growth and intake flows, actual and potential utilization efficiencies of grass and they were different in the phenological stages of Italian ryegrass. The intake of leaf blade, as a percentage of body weight, was higher in the 12% herbage allowance. Considering leaf tissue flows, Italian ryegrass can be managed in forage allowances that vary between 6 and 12 kg DM/100 kg body weight. [ABSTRACT FROM AUTHOR]

Time of urine application on mineral N (Nmin) leaching from a pumice soil was tested. Artificial urine (600 kg N ha−1) was applied in early June or late July to small plots after removing a kale/swede crop or to ryegrass/white clover. Mineral N leached in the first winter (measured by porous cups, 600 mm deep) was similar under pasture or ex-forage crop: 185 vs. 60 kg N ha−1for June or July urine, with 170–300 kg N ha−1remaining in the soil (0–600 mm) at the end of drainage. Additionally, 54–118 kg N ha−1leached in the second winter. In total, later application decreased Nmin leaching by 35–40%. Application of the process inhibitor dicyandiamide increased soil Nmin levels in the post forage crop site for the early urine application but had no effect in the late-applied urine treatment. There was no significant effect on N leaching. [ABSTRACT FROM PUBLISHER]

Keeping lambs with their dams and providing concentrate supplement for weaned lambs are two strategies used in lamb meat production systems on pasture that may affect the way that lambs explore, select, and ingest the forage while grazing. Thus, this study aimed to evaluate the selection and intake of forage by ewes and lambs using the continuous bite monitoring method in two pasture-based production systems: non-weaned and non-supplemented lambs (NW); and weaned lambs supplemented with concentrate (WS). Continuous bite monitoring is based on a bite-coding grid that allows the estimation of bite mass, intake rate, selection of plant species and plant parts by grazing animals. Two experiments were carried out during September–November of two subsequent years on a mixed pasture of black oat (Avena strigosa Schreb.) and annual ryegrass (Lolium multiflorum Lam.) established over a perennial Tifton 85 (Cynodon spp.) pasture. On the second year, a third treatment including only the dams of weaned lambs – dry ewes – was also evaluated. In the WS system, lambs were supplemented with concentrate feed at 2% of body weight (BW)/day on a dry matter (DM) basis. Both experiments lasted 46 days, and a continuous stocking management with the forage allowance maintained at 16% BW in DM/day for all treatments. There was a high degree of variability on botanical and morphological composition of forage that was ingested by lambs and ewes, with ranges of 3–14 and 8–11 bite categories for NW lambs and ewes, respectively; 12–15 bite categories for WS lambs, and 8 bite categories for dry ewes. There was similarity between the forage ingested by lambs and ewes in the NW system, except for inflorescences of black oat and annual ryegrass, that were ingested in greater proportions by ewes. WS lambs ingested the most diverse forage diet, which appeared to explore the superior strata of pasture (above 10–15 cm of height) more frequently, and grazed inflorescences and senescent material in higher proportions than NW lambs. Dry ewes showed higher intake of Paspalum spp., Kikuyu grass and other voluntary species and weeds compared to NW ewes. These results suggest that the production system affects the way that lambs explore the pasture and compose their forage diet, with WS lambs ingesting the most diverse diet. The increased intake of inflorescence and, eventually, voluntary species and weeds may be a strategy used by lactating and dry ewes to extend the vegetative stage of high-quality forage species and reduce the population of low-quality plant species on pasture. • Weaning and concentrate supplementation effects on forage intake was studied. • Bite-coding grid was applied to estimate the forage diet composed by ewes and lambs. • Non-weaned lambs and their dams composed similar forage diets on grazing. • The most diversified forage diet was ingested by weaned and supplemented lambs. [ABSTRACT FROM AUTHOR]

Annual ryegrass (Lolium multiflorumLam.) is a highly nutritive, fast-growing, C3 cool-season annual forage. Blast or gray leaf spot is a fungal disease of ryegrass caused byMagnaporthe orygae(anamporphPyricularia oryzae). The disease kills seedlings as well as adult plants. Blast-resistant annual ryegrass cultivars are not available at present. Therefore, identifying sources of resistance and developing blast-resistant germplasm are priorities to circumvent the devastating disease. Incorporation of germplasm screening in a breeding program requires an efficient, low-cost, and high-throughput evaluation system. Screening methods reported in literature lack both efficiency and throughput capabilities suitable for breeding. The aims in this work were to develop a low-cost, high-throughput phenotyping system, and to screen the annual ryegrass National Plant Germplasm System (NPGS) collection with a highly aggressive, newly isolatedM. oryzaestrain from naturally infected annual ryegrass plants, which was named MoGA1. Host specificity was tested on four species in addition to annual ryegrass. Extensive damage was caused to perennial ryegrass (Lolium perenneL.) and tall fescue (Lolium arundinaceum(Schreb.) Darbysh), whereas rice (Oryza sativaL.) and orchard grass (Dactylis glomerataL.) exhibited a hypersensitivity response and resisted the infection, suggesting that pathogenicity of the strain was limited to theLoliumgenus. A portable low-cost, high-throughput screening system capable of screening 1,536 plants per unit was developed and used to screen 138 ryegrass accessions with MoGA1. Two accessions showed resistance to the pathogen and produced seed. These two entries can be used to incorporate blast resistance in annual ryegrass germplasm. [ABSTRACT FROM PUBLISHER]

Background: Genomic selection (GS) has become a commonly used technology in animal breeding. In crops, it is expected to significantly improve the genetic gains per unit of time. So far, its implementation in plant breeding has been mainly investigated in species farmed as homogeneous varieties. Concerning crops farmed in family pools, only a few theoretical studies are currently available. Here, we test the opportunity to implement GS in breeding of perennial ryegrass, using real data from a forage breeding program. Heading date was chosen as a model trait, due to its high heritability and ease of assessment. Genome Wide Association analysis was performed to uncover the genetic architecture of the trait. Then, Genomic Prediction (GP) models were tested and prediction accuracy was compared to the one obtained in traditional Marker Assisted Selection (MAS) methods. Results: Several markers were significantly associated with heading date, some locating within or proximal to genes with a well-established role in floral regulation. GP models gave very high accuracies, which were significantly better than those obtained through traditional MAS. Accuracies were higher when predictions were made from related families and from larger training populations, whereas predicting from unrelated families caused the variance of the estimated breeding values to be biased downwards. Conclusions: We have demonstrated that there are good perspectives for GS implementation in perennial ryegrass breeding, and that problems resulting from low linkage disequilibrium (LD) can be reduced by the presence of structure and related families in the breeding population. While comprehensive Genome Wide Association analysis is difficult in species with extremely low LD, we did identify variants proximal to genes with a known role in flowering time (e.g. CONSTANS and Phytochrome C). [ABSTRACT FROM AUTHOR]

Seven forage types (diploid and tetraploid perennial ryegrass, Italian ryegrass and hybrid ryegrass, a low-input mixture of perennial ryegrass, cocksfoot, timothy and meadow fescue, a mixture of perennial ryegrass and white clover, and monoculture of red clover) were sown in late July 2004. Each received one of four rates of dairy cattle slurry in three annual applications by trailing shoe, which supplied average nitrogen (N) inputs of 0·0, 114·9, 204·8 and 301·2 kg N ha−1 annum−1. Treatments were cut either three or four times annually over four years. Average dry-matter yield ( DM) response to slurry N was 15·6 kg DM kg−1 N. Lowest recovery of slurry N was in the second application each year (after first cut). The data suggest that slurry applied to Italian ryegrass, and also to swards containing legumes on soils with high phosphorus content, will produce a lower DM response to slurry N and result in a lower slurry N recovery than on swards of perennial ryegrass or cocksfoot-dominant low-input mixtures. Apparent recovery of slurry N was low at the second cut, especially when first-cut yields had been high. To maximize slurry N recovery, application to regrowths with potentially slow rates of growth or high legume content should be avoided. [ABSTRACT FROM AUTHOR]

The objectives of this study were to examine long-term effects of feeding forage rape (Brassica napus L.) on methane yields (g methane per kg of feed dry matter intake), and to propose mechanisms that may be responsible for lower emissions from lambs fed forage rape compared to perennial ryegrass (Lolium perenne L.). The lambs were fed fresh winter forage rape or ryegrass as their sole diet for 15 weeks. Methane yields were measured using open circuit respiration chambers, and were 22-30% smaller from forage rape than from ryegrass (averages of 13.6 g versus 19.5 g after 7 weeks, and 17.8 g versus 22.9 g after 15 weeks). The difference therefore persisted consistently for at least 3 months. The smaller methane yields from forage rape were not related to nitrate or sulfate in the feed, which might act as alternative electron acceptors, or to the levels of the potential inhibitors glucosinolates and S-methyl L-cysteine sulfoxide. Ruminal microbial communities in forage rape-fed lambs were different from those in ryegrass-fed lambs, with greater proportions of potentially propionate-forming bacteria, and were consistent with less hydrogen and hence less methane being produced during fermentation. The molar proportions of ruminal acetate were smaller and those of propionate were greater in forage rape-fed lambs, consistent with the larger propionate-forming populations and less hydrogen production. Forage rape contained more readily fermentable carbohydrates and less structural carbohydrates than ryegrass, and was more rapidly degraded in the rumen, which might favour this fermentation profile. The ruminal pH was lower in forage rape-fed lambs, which might inhibit methanogenic activity, shifting the rumen fermentation to more propionate and less hydrogen and methane. The significance of these two mechanisms remains to be investigated. The results suggest that forage rape is a potential methane mitigation tool in pastoral-based sheep production systems. [ABSTRACT FROM AUTHOR]

• Overexpression TaMBF1c improved thermotolerance of perennial ryegrass. • Thermotolerance of transgenic perennial ryegrass associated with elevated antioxidative capacity. • MBF1c offers a strategy to develop cool-season turfgrass/forage plants to cope with the challenges of higher temperature. High temperature is one of the major threats to global crop production, especially the C 3 plant species, such as a widely used forage/turfgrass, perennial ryegrass. MBF1c gene belongs to group II of the highly conserved multiprotein bridging factor1 (MBF1) family, and it has been reported to be involved in various plant abiotic stresses, in particular, heat stress. In the study, a wheat MBF1c (TaMBF1c) was overexpressed in perennial ryegrass, and physiological parameters including antioxidant enzyme activities were investigated under both control (16/22 °C, n/d) and high temperature (42 °C) treatments for 24 and 48 h. The results found that the ectopic expression of TaMBF1c improved thermotolerance of perennial ryegrass, demonstrated by lower leaf electrolyte leakage and lipid peroxidation, better water status, higher chlorophyll content (SPAD index), and net photosynthetic rate under high temperature, while there was no difference between wild type and transgenic perennial ryegrass plants under control condition. The enhanced stress tolerance of transgenic perennial ryegrass was, at least partially associated with its elevated antioxidative capacity under stress. The findings confirmed that MBF1c could confer thermotolerance in C 3 perennial grass species, which offers an additional strategy to develop cool-season turfgrass/forage plants to cope with the challenges of higher temperature and more frequent heat waves due to global warming. [ABSTRACT FROM AUTHOR]

Abstract: After 14 years under conventional plough tillage (CT) or conservation minimum tillage (MT), the soil available Al, Fe, Mn, Cu, and Zn (0–5, 5–15, and 15–30cm layers) and their plant uptake were evaluated during two years in a ryegrass-maize forage rotation in NW Spain (temperate–humid region). The three-way ANOVA showed that trace element concentrations in soil were mainly influenced by sampling date, followed by soil depth and tillage system (35–73%, 7–58%, and 3–11% of variance explained, respectively). Excepting for Fe (CT) and Al (CT and MT), the elemental concentrations decreased with depth, the stratification being stronger under MT. For soil available Al, Fe, Mn, and Cu, the concentrations were higher in CT than in MT (5–15 and 15–30cm layers) or were not affected by tillage system (0–5cm). In contrast, the available Zn contents were higher in MT than CT at the soil surface and did not differ in deeper layers. The concentration of Al, Fe, and Cu in crops was not influenced by tillage system, which explains 22% of Mn variance in maize (CT>MT in the more humid year) and 18% of Zn variance in ryegrass (MT>CT in both years). However, in the summer crop (maize) the concentrations of Fe, Mn, and Zn tended to be higher in MT than in CT under drought conditions, while the opposite was true in the year without water limitation. Therefore, under the studied conditions of climate, soil, tillage, and crop rotation, little influence of tillage system on crop nutritive value would be expected. To minimize the potential deficiency of Zn (maize) and Cu (maize and ryegrass) on crop yields the inclusion of these micro-nutrients in fertilization schedule is recommended, as well as liming to alleviate Al toxicity on maize crops. [Copyright &y& Elsevier]

The objective of this study, which was part of a larger grazing-systems experiment, was to investigate the cumulative impact of three levels of grazing intensity on sward production, utilization and structural characteristics. Pastures were grazed by rotational stocking with Holstein- Friesian dairy cows from 10 February to 18 November 2009. Target post-grazing heights were 4·5 to 5 cm (high; H), 4 to 4·5 cm (intermediate; I) and 3·5 to 4 cm (low; L). Detailed sward measurement were undertaken on 0·08 of each farmlet area. There were no significant treatment differences in herbage accumulated or in herbage harvested [mean 11·3 and 11·2 t dry matter ( DM) ha−1 respectively]. Above the 3·5 cm horizon, H, I and L swards had 0·56, 0·62 and 0·67 of DM as leaf and 0·30, 0·23 and 0·21 of DM as stem respectively. As grazing severity increased, tiller density of grass species other than perennial ryegrass ( PRG) decreased (from 3,350 to 2,780 and to 1771 tillers m−2 for H, I and L paddocks respectively) and the rejected area decreased (from 0·27 to 0·20 and to 0·10 for H, I and L paddocks respectively). These results indicate the importance of grazing management practice on sward structure and quality and endorse the concept of increased grazing severity as a strategy to maintain high-quality grass throughout the grazing season. The findings are presented in the context of the need for intensive dairy production systems to provide greater quantities of high-quality pasture over an extended grazing season, in response to policy changes with the abolition of EU milk quotas. [ABSTRACT FROM AUTHOR]

Characterization of grass fibre is important in assessing its potential for industrial fibre applications. Stem and leaf sections were sampled from triplicate field plots of two grass species, perennial ryegrass ( PRG) and tall fescue at three dates (monthly from 12 May) in the primary growth, and were used to (a) isolate individual fibre cells and (b) prepare transverse sections. Microscopy and image analysis software were used to determine the length and width of individual fibre cells and the proportion of lignified fibre in stem and leaf transverse sections. The length and width of individual fibre cells were greater ( P < 0·001) in stem than in leaf sections, while individual fibre cell length was greater ( P < 0·01) for tall fescue than PRG. Harvest date and grass species had little effect ( P > 0·05) on the proportion of lignified fibre in the transverse-sectional area. However, there was a greater ( P < 0·001) proportion of lignified fibre in the transverse-sectional area of grass stems than leaves, with tall fescue having a greater ( P < 0·05) stem and leaf transverse-sectional area and area of lignified fibre in transverse section than PRG. Tall fescue harvested at a later stage of growth, with higher proportions of stem than leaf tissue, may be more suitable for industrial fibre applications. [ABSTRACT FROM AUTHOR]

Perennial ryegrass ( Lolium perenne L.) infected with a novel endophyte ( AR37 or AR1), Wild-type endophyte or no endophyte (Nil) was sown with white clover ( Trifolium repens L.) in autumn 2005. The pastures were rotationally grazed by dairy cows from 2005-2009. Annual dry matter ( DM) yield did not differ but AR37 pastures had a higher ryegrass tiller density, especially after the 2008 summer drought (+130%), and less white clover than did AR1 pastures. Concentrations of alkaloids produced by the Wild-type association (lolitrem B, ergovaline) followed the same seasonal trends as did the AR37 alkaloids (epoxy-janthitrems) but summer drought reduced concentrations of lolitrem B and epoxy-janthitrems to less than half the mid-summer (February) peak concentrations in the other years. Insect pests were monitored annually between 2006 and 2009. Tiller damage by Argentine stem weevil ( Listronotus bonariensis (Kuschel)) was significantly reduced by all endophyte treatments. African black beetle ( Heteronychus arator (F.)) populations in soil samples increased during the experiment with Nil > AR1 > Wild-type = AR37. Root aphid ( Aploneura lentisci (Pass.)) infestations followed the pattern AR1 > Nil > Wild-type = AR37. A lower pest pressure from all insect pests in AR37 pastures is likely to have contributed to this treatment having the highest ryegrass tiller densities. [ABSTRACT FROM AUTHOR]

Perennial ryegrass ( Lolium perenne L.) and Italian ryegrass ( Lolium multiflorum Lam.) are important temperate forage grasses which are closely related, generating fertile interspecific hybrids. All groups are represented by multiple cultivars in the commercial pasture seeds market. Due to the close taxonomic relationship between the two species, differentiation based on morphophysiological criteria is not always readily achievable. In addition, an obligate outbreeding reproductive habit produces high levels of individual heterozygosity and intrapopulation diversity, which presents problems for discrimination between cultivars. Molecular genetic marker polymorphism provides an effective means of addressing these challenges. An iterative process of resequencing from loci distributed across the perennial ryegrass genome was used to identify single nucleotide polymorphism (SNP) markers, which were then validated and formatted in a highly multiplexed (384-plex) assay system. SNP genotyping was then performed across samples of 48-192 individuals from a total of 27 ryegrass cultivars (19 of perennial ryegrass, seven of Italian ryegrass and one hybrid cultivar). SNP markers from perennial ryegrass exhibited a high level of transfer to Italian ryegrass. Data analysis permitted quantification of intra- and inter-species diversity, as well as discrimination between cultivars within each species, including diploid and autotetraploid cultivars of perennial ryegrass. Lower levels of SNP-based diversity were detected in Italian ryegrass than in perennial ryegrass. A neighbour-joining tree based on genetic distance analysis located a hybrid cultivar to an intermediate position between the two species-specific cultivar groups. The resulting catalogue of ryegrass cultivars will provide support for the processes of cultivar accreditation and quality assurance. [ABSTRACT FROM AUTHOR]

Forages and herbs are composed of leaves and stems that have different drying times, and this complicates the management of product quality. Since their separation during drying could be made by an air stream, an evaluation of some aerodynamic properties of the components in relation to moisture content was made. Terminal velocity, unit density, and projected area of the components of white clover and ryegrass were tested. A test stand was used to determine terminal velocity, immersion was used for the unit density, and photography was used for the projected area. Terminal velocity was in the range 1.0 to 2.0 for clover leaves and 2.0 to 4.0 for clover stems and ryegrass, and Reynolds number was in the range 1000 to 5000 for clover leaves and 5000 to 35,000 for clover stems and ryegrass. The results showed better separation of components at high moisture contents. [ABSTRACT FROM AUTHOR]

Grazing sward structure can influence animal performance in forage-only and forage plus concentrate-based production systems. The objective was to determine the effects of pre-grazing herbage mass (PGHM), postgrazing sward height (PGSH) and indoor finishing diet on performance of weaned, spring-born beef steers. Steers (n = 96, ca. 12 months of age, 396 ± 20.1 kg) previously fed grass silage only over the first winter, were assigned to one of twelve grazing groups, balanced for live weight. Grazing groups were randomly assigned to a two PGHM (1500 or 2500 kg DM/ha) × two PGSH (4 or 6 cm) factorial arrangement of treatments (n = 3 groups/treatment). Steers rotationally grazed Lolium perenne-dominant swards (not mechanically topped) for 222 days. Steers were then accommodated indoors and offered grass silage only (SO) or grass silage + 3.8 kg concentrate DM/head daily (SC) for a 146 day finishing period. Data were analysed using the mixed procedure of SAS with terms for PGHM, PGSH, finishing diet and their interactions in the model. Grazed herbage intake was unaffected by PGHM but was greater for PGSH-6 than PGSH-4 (6.94 vs. 6.18 kg DM/day; P < 0.001). Steer average daily gain at pasture was greater for PGHM-1500 than PGHM-2500 (0.65 vs. 0.60 kg; P < 0.05) and for PGSH-6 than PGSH-4 (0.70 vs. 0.55 kg; P < 0.001). After indoor finishing, carcass weight was unaffected by PGHM, but was heavier for PGSH-6 than PGSH-4 (386 vs. 367 kg; P < 0.01); carcass traits were unaffected by PGHM or PGSH. Carcasses were heavier (+43 kg), fatter (P < 0.001) and more conformed (P < 0.01) for SC than SO. In conclusion, both PGHM-2500 and PGSH-4 restricted animal growth at pasture; however, following an indoor finishing period, carcass weight did not differ between PGHM, but was heavier for PGSH-6 than PGSH-4. [ABSTRACT FROM AUTHOR]

The objectives were to determine the effect of in utero and early-life dietary exposure to a diverse diet or a perennial ryegrass (Lolium perenne L.) diet on grazing behavior and dietary neophobia of lambs ~3.5 months post-weaning (weaned at 6 weeks of age). Sixty-four Coopworth lambs (152.5 ± 1.4 d of age; mean ± SEM,) were used. Sixteen lambs had previous in utero exposure to the diverse diet (INDIV) and another 16 had in utero and early life (from birth to weaning at 42 ± 2 d of age) exposure to the diverse diet (ELDIV) of ryegrass, red clover (Trifolium pratense L.), plantain (Plantago lanceolata L.), chicory (Cichorium intybus L.), and alfalfa (Medicago sativa L.). Sixteen lambs had only in utero exposure to ryegrass (INRYE) and the other 16 had early life exposure to ryegrass (ELRYE). Lambs were randomly allocated to one of 16 paddocks (n = 4 per treatment) with 4 lambs per paddock. All paddocks contained equal areas of spatially separated strips of red clover, chicory, alfalfa, plantain, and ryegrass, of which arrangement within the paddock was randomized. Every 5 min from 0620 to 2105 h, trained observers recorded the behavior (grazing, idle, and ruminating) and the location (pasture species) of each lamb. The INRYE and ELRYE lambs tended to (P ≤ 0.10) and spent more time (P < 0.05) grazing within ryegrass than their diverse treatment counterparts, respectively. The ELRYE treatment spent longer grazing in ryegrass, a product of increasing bout number within ryegrass (P < 0.05) and the INRYE treatment had longer bouts within ryegrass compared with their diverse treatment counterparts. Further, the INRYE and INDIV treatments spent less time grazing ryegrass than the other treatments (P < 0.05). The ELDIV and ELRYE treatments in general had a reduced latency to graze pasture species compared to the other treatments. Further, all lambs ate a mix of the forages offered. Exposure in utero and early in life affected the preferences of lambs exposed to diverse species after weaning. Such effects were still seen ~3.5 months after weaning and differences between treatments were more prominent in lambs exposed in the early life treatment group compared with the in utero treatments. Exposure to ryegrass in utero and early in life exposure pre-disposed animals to prefer ryegrass later in life, while diverse diet exposure appeared to reduce dietary neophobic behavior. • In utero and early life dietary exposure alter partial preference in later life. • In utero and early life dietary exposure to diverse diets reduce dietary neophobia. • Ryegrass only experienced lambs spent longer grazing ryegrass than diverse lambs. • All lambs selected a diverse diet rather than comprise a diet of a single forage. [ABSTRACT FROM AUTHOR]

Tall fescue [Lolium arundinaceum (Schreb.) Darbysh. syn. Festuca arundinacea Schreb.] and perennial ryegrass (Lolium perenne L.) are impor-tant perennial forage grasses utilized throughout the moderate- to high-rainfall temperate zones of the world. These grasses have coevolved with symbiotic fungal endophytes (Epichloe/Neotyphodium spp.) that can impart bioactive properties and environmental stress tolerance to the grass compared with endophyte-free individuals. These endophytes have proven to be very important in pastoral agriculture in the United States, New Zealand, and Australia, where forage grasses are the principal feed for grazing ruminants. In this review, we describe the biology of these grass-endophyte associations and implications for the livestock indus-tries that are dependent on these forages. Endophyte alkaloid production is put in context with endophyte diversity, and we illustrate how this has facilitated uti-lization of grasses infected with different endophyte strains that reduce livestock toxicity issues. Utilization of tall fescue and use of perennial ryegrass in the United States, New Zealand, and Australia are compared, and management strategies focused predominantly on the success of endophyte-infected perennial ryegrass in New Zealand and Australia are discussed. In addition, we consider the impact of grass-endophyte associations on the sustainability of pasture ecosystems and their likely response to future changes in climate. [ABSTRACT FROM AUTHOR]

Genomic selection ( GS) is a powerful method for exploitation of DNA sequence polymorphisms in breeding improvement, through the prediction of breeding values based on all markers distributed genome-wide. Forage grasses and legumes provide important targets for GS implementation, as many key traits are difficult or expensive to assess, and are measured late in the breeding cycle. Generic attributes of forage breeding programmes are described, along with status of genomic resources for a representative species group (ryegrasses). Two schemes for implementing GS in ryegrass breeding are described. The first requires relatively little modification of current schemes, but could lead to significant reductions in operating cost. The second scheme would allow two rounds of selection for key agronomic traits within a time period previously required for a single round, potentially leading to doubling of genetic gain rate, but requires a purpose-designed reference population. In both schemes, the limited extent of linkage disequilibrium ( LD), which is the major challenge for GS implementation in ryegrass breeding, is addressed. The strategies also incorporate recent advances in DNA sequencing technology to minimize costs. [ABSTRACT FROM AUTHOR]

Morphogenetic and structural characteristics of Italian ryegrass (Lolium multiflorum Lam.), utilized by female lambs and managed with different forage masses (FM) were studied. The experimental design was completely randomized, with two area replications and three treatments, consisting of forage masses: "High", "Mean" and "Low", corresponding to 1,800-2,000; 1,400-1,600 and 1,000-1,200kg ha'1 of dry matter (DM), respectively. The grazing method was continuous with variable stocking rate. Data were subjected to correlation analysis and polynomial regression. Pseudo stem's height and length of the intact and defoliated leaf blades and number of senescent leaves of Italian ryegrass increased linearly with the increase of forage mass. Number of green leaves was adjusted to the quadratic regression model, number of leaves in elongation and tiller population density did not adjust to any regression model. Management of Italian ryegrass with forage masses between 1,100 and 1,800kg ha'of DM did not cause changes in its morphogenetic characteristics, but causes differences in the structural characteristics of the canopy. When managed with 1,460kg ha 'of DM, tillers of Italian ryegrass maintain greater number of green leaves. Meanwhile, when managed with 1,800kg ha 'of DM it has a higher number of leaf blades in senescence, and leaves with greater length. [ABSTRACT FROM AUTHOR]

The herbs chicory ( C ichorium intybus L.) and plantain ( P lantago lanceolata L.) are increasingly popular summer forage cropping options for dairy producers. However, the impact of different establishment methods on their productivity is largely unknown. Four establishment methods for chicory and plantain crops sown into non-cultivated ryegrass pastures in spring were compared. Establishment methods included direct-drilling or broadcasting seed into existing pastures, with or without herbicide application before sowing in a 2 × 2 factorial design. It was hypothesized that plant establishment and growth would be enhanced by spraying to kill existing ryegrass pasture and direct-drilling herbs ( Spray and Drill, SD) compared with broadcasting seed with no herbicide application ( Unsprayed and Broadcast, UB). This hypothesis was supported with an additional 2·1-2·3 t DM ha−1 grown over 201 d from swards established by SD, compared with swards established by UB. The SD method also increased the plant density of the herbs and reduced the proportion of weed species. Spraying and direct drilling is more expensive than broadcasting seed with no herbicide application, but the increase in yield means that extra feed can be supplied at less than half the cost of purchasing the equivalent amount of feed. Therefore, for optimal economic outcomes, chicory and plantain swards should be established by applying herbicide to existing pasture and direct-drilling seed. [ABSTRACT FROM AUTHOR]

An assessment of genetic improvement in turf-type perennial ryegrass was performed at a network of six locations. A comparison was made of the turf performances of five natural populations, five forage-type cultivars used for turf seeding until the 1980s and 31 turf-type cultivars released from 1974 to 2004. Populations and cultivars were also compared in two spaced-plant experiments and in two seed-yield trials. Trait regressions on registration year of turf-type cultivars showed that breeding had been highly successful in improving the turf aesthetic merit (from +8·8 to +12·5% per decade according to seasons), wear tolerance (+5·4% per decade) and crown-rust resistance (+8·9% per decade) and in lessening the turf height increase rate (−0·43 mm day−1 per decade). Turf winter greenness had been marginally improved, whereas summer greenness and seed yield had not been significantly changed. A multivariate analysis provided evidence that turf density and fineness played a major role in the visual assessment of turf aesthetic merit and that wear tolerance was closely associated with turf density. Conflicting trait associations may have precluded improvements in turf ground-cover 3 months after sowing, turf winter greenness and turf persistency. [ABSTRACT FROM AUTHOR]