Panicum maximum cv. Tanzânia: climate trends and regional pasture production in Brazil

Projected change in forage production under a range of climate scenarios is important for the evaluation of the impacts of global climate change on pasture‐based livestock production systems in Brazil. We evaluated the effects of regional climate trends on Panicum maximum cv. Tanzânia production, predicted by an agro‐meteorological model considering the sum of degree days and corrected by a water availability index. Data from Brazilian weather stations (1963–2009) were considered as the current climate (baseline), and future scenarios, based on contrasting scenarios in terms of increased temperature and atmospheric CO₂ concentrations (high and low increases), were determined for 2013–2040 (2025 scenario) and for 2043–2070 (2055 scenario). Predicted baseline scenarios indicated that there are regional and seasonal variations in P. maximum production related to variation in temperature and water availability during the year. Production was lower in the Northeast region and higher in the rainforest area. Total annual production under future climate scenarios was predicted to increase by up to 20% for most of the Brazilian area, mainly due to temperature increase, according to each climate model and scenario evaluated. The highest increase in forage production is expected to be in the South, Southeast and Central‐west areas of Brazil. In these regions, future climate scenarios will not lead to changes in the seasonal production, with larger increases in productivity during the summer. Climate risk is expected to decrease, as the probability of occurrence of low forage productions will be lower. Due to the predicted increase in temperature and decrease in rainfall in the Northeast area, P. maximum production is expected to decrease, mainly when considering scenarios based on the PRECIS model for the 2055 scenario.     

Forage quality of leaf fodder from the main woody species in Iceland and its potential use for livestock in the past and present

Woody species played, and in many Nordic regions still play, a very important role in livestock feeding. However, forage quality (contents of macroelements and fibre fractions) of the leaves of common woody species is often inadequate. The aim of our study was to determine forage quality of leaves of Betula nana, Betula pubescens, Salix lanata, Salix phylicifolia and Sorbus aucuparia from Iceland and to compare it with the forage quality of the common native grass Deschampsia cespitosa and the introduced grass Alopecurus pratensis used by contemporary Icelandic farmers for forage production. Samples were collected at four localities in Iceland in late June 2013 and analysed for nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), neutral and acid‐detergent fibre and lignin concentration. Analyses were compared with the optimum range for cattle and sheep nutrition. The nutritive value of leaves of the Icelandic woody species was relatively high, and analysis showed their nutritive content satisfied both cattle and sheep nutrient requirements for N, P, K, Ca and Mg, but the relatively high content of indigestible lignin in all woody species could cause problems for livestock metabolism. Grasses were characterized by lower P, Ca and Mg, but substantially higher K concentrations, and higher N:P and K:(Mg + Ca) ratios. The forage quality of leaves of woody species increased in the order B. nana < B. pubescens < S. phylicifolia < S. aucuparia < S. lanata. Results are discussed in relation to use of leaf fodder in the past, when woody species, particularly Salix spp., are likely to have played an important role in livestock feeding.     

Effects of sheep stocking on the plant community and agricultural characteristics of upland Anthoxanthum odoratum–Geranium sylvaticum meadow in northern England

In the UK, upland hay meadows (Anthoxanthum odoratum–Geranium sylvaticum grassland) with high plant biodiversity are rare and confined to submontane areas of northern England. We report results from a 5‐year experiment to test suggestions that recent biodiversity declines were attributable to increased sheep‐stocking density and a longer spring stocking period, thus delaying the shut up date for the growth of the hay crop. Longer stocking periods and higher stocking densities decreased the forage mass at 8 July, but they increased herbage N content and digestibility, reduced plant species diversity and reduced populations and seed production of Rhinanthus minor. Compared with unstocked swards, the similarity of the vegetation to Anthoxanthum odoratum–Geranium sylvaticum grassland was reduced by 16·9% when stocking with sheep continued until 27 May each year, and by 8·3% when sward heights were maintained at 3 cm compared with 5 cm. Increased mean sward height and height of R. minor were positively correlated with accumulated temperatures. Results support suggestions that recent reductions in the nature value of these grasslands might be a consequence of high stocking densities persisting until later in the spring, carried out during a 1‐year period with warmer temperatures.     

Impact of land‐use intensity on the relationships between vegetation indices,photosynthesis and biomass of intensively and extensively managed grassland fens

Vegetation indices are widely used as model inputs and for non‐destructive estimation of biomass and photosynthesis, but there have been few validation studies of the underlying relationships. To test their applicability on temperate fens and the impact of management intensity, we investigated the relationships between normalized difference vegetation index (NDVI), leaf area index (LAI), brown and green above‐ground biomass and photosynthesis potential (PP). Only the linear relationship between NDVI and PP was management independent (R² = 0·53). LAI to PP was described by a site‐specific and negative logarithmic function (R² = 0·07–0·68). The hyperbolic relationship of LAI versus NDVI showed a high residual standard error (s.e.) of 1·71–1·84 and differed between extensive and intensive meadows. Biomass and LAI correlated poorly (R² = 0·30), with high species‐specific variability. Intensive meadows had a higher ratio of LAI to biomass than extensive grasslands. The fraction of green to total biomass versus NDVI showed considerable noise (s.e. = 0·13). These relationships were relatively weak compared with results from other ecosystems. A likely explanation could be the high amount of standing litter, which was unevenly distributed within the vegetation canopy depending on the season and on the timing of cutting events. Our results show there is high uncertainty in the application of the relationships on temperate fen meadows. For reliable estimations, management intensity needs to be taken into account and several direct measurements throughout the year are required for site‐specific correction of the relationships, especially under extensive management. Using NDVI instead of LAI could reduce uncertainty in photosynthesis models.     

Effects of Lactobacillus buchneri as a silage inoculant and as a probiotic on feed intake,apparent digestibility and ruminal fermentation and microbiology in wethers fed low‐dry‐matter whole‐crop maize silage

Lactobacillus buchneri was investigated as a silage inoculant and as a probiotic on feed intake, apparent digestibility, and ruminal fermentation and microbiology in wethers fed low‐dry‐matter (DM) whole‐crop maize silage. Maize forage (279 g/kg DM) was ensiled without inoculant (untreated) and with L. buchneri CNCM I‐4323 at 1 × 10⁵ cfu/g fresh forage (inoculated). Six cannulated wethers were arranged in a double 3 × 3 Latin square and assigned to one of three diets: (i) untreated maize silage (untreated), (ii) inoculated maize silage (inoculated), and (iii) untreated maize silage with a daily dose of L. buchneri (1 × 10⁷ cfu/g supplied silage) injected directly into the rumen (LB‐probiotic). Wethers fed the inoculated diet had a higher (p = .050) DM intake (1.30% body weight [BW]) than wethers fed untreated and LB‐probiotic diets (1.17% and 1.18% BW respectively). The relative proportion of Ruminococcus flavefaciens (proportion of total estimated rumen bacterial 16S rDNA) in the rumen of wethers fed inoculated and LB‐probiotic diets (both 0.42%) tended (p = .098) to be lower than in the untreated diet (0.83%). Lactobacillus buchneri as a silage inoculant or as a probiotic had little effect on the variables measured in wethers.     

Forage selectivity by cattle and sheep co‐grazing swards differing in plant species diversity

Interactions between sward diversity and forage selectivity of cattle and sheep managed within mixed grazing systems are not fully understood. The objective of this study was to investigate the effect of either mono‐ or co‐grazing of sheep and cattle on swards differing in botanical composition (either diverse or grass‐dominated) on the intake choices of six target forage species. Jacobs' selection index (JSI) was employed to quantify the preference for single target species in relation to their proportion in the sward. Results revealed distinct intake preferences of sheep and cattle; as expected, sheep were more selective than cattle. To a lesser extent, the sward composition had an effect on intake preferences: cattle responded to botanical composition by changing their intake preferences, but to a lesser extent than sheep. Phleum pratense was the most preferred target forage species (JSI = 0.62). Lolium perenne, Taraxacum sect. Ruderale and Trifolium repens were also highly preferred regardless of sward composition or type of grazing (JSI = 0.47, 0.32 and 0.27 respectively). Dactylis glomerata and Festuca pratensis tended to increase in abundance after grazing events in both diverse and grass‐dominated swards. Co‐grazing of cattle and sheep facilitated a more homogeneous consumption of the target forage species evaluated.     

Pyrrolizidine alkaloid production of Jacobaea aquatica and contamination of forage in meadows of Northern Austria

Jacobaea aquatica (=Senecio aquaticus, Asteraceae), marsh ragwort, grows regionally in low management intensity wet grasslands in various European countries. The plant can be regarded as a noxious weed as it contains pyrrolizidine alkaloids (PAs), which cause health problems in livestock. In the Waldviertel region of Northern Austria, marsh ragwort has established dense populations as the fertilizing and production intensity of the meadows changed during the last decades. Ragwort biomass production and alkaloid concentration in J. aquatica were recorded during three consecutive years at three sites to study the effects of two treatments: cutting twice a year either early in June plus September, or in July plus August, respectively. Six PAs (Z‐erucifoline > senecionine > integerrimine > seneciphylline > acetyl‐erucifoline and acetyl‐seneciphylline) were evaluated. The alkaloid contents were highest in July and August when 600–1,400 mg/kg dry matter (DM) total PAs occurred in most ragwort samples. Consequently, the forage can easily be contaminated with 40–80 mg/kg DM of PAs and may present a health risk for domestic animals and also affect human health as these alkaloids are transferred into milk.     

Winter grazing stockpiled native warm‐season grasses in the Southeastern United States

In the Southeastern United States, native warm‐season grasses (NWSG) are not harvested during autumn to rebuild root reserves, resulting in de facto stockpiled winter forage. Senesced NWSG forage is considered nutritionally inadequate by temperate livestock managers, but comparable forage is regularly utilized in rangeland systems. This experiment compared the forage characteristics of two NWSG pastures: switchgrass [Panicum virgatum L. (SG)] and a two species mixture of big bluestem/indiangrass [Andropogon gerardii Vitman/Sorghastrum nutans L. (BBIG)] to tall fescue [Festuca arundinacea Schreb. (TF)]. During two winter periods (January‐April), monthly samples were collected and measured for dry‐matter herbage mass (HM), crude protein (CP), in‐vitro true dry‐matter digestibility (48 hr; IVTDMD), neutral detergent fibre (NDF), NDF digestibility (dNDF) and lignin. Across sampling dates, TF provided adequate forage for low‐input animal maintenance (90.3 CP g/kg; 488 g IVTDMD/kg; 4,040 kg DM/ha), while SG had lowest nutritive values and greatest DM (21.0 g CP/kg; 366 g IVTDMD/kg; 7,670 kg DM/ha). Samples of BBIG had results intermediate to SG and TF (32.1 g CP/kg; 410 g IVTDMD/kg; 5,160 kg DM/ha). Leaf sub‐samples of NWSG indicated greater forage nutritive value compared to whole plant samples (e.g., SG: 65 vs 27 g CP/kg respectively). This indicates that selective grazing could allow superior outcomes to those expected from whole plant NWSG nutritive values. Although consistently nutritionally inferior to TF, further research could reveal strategies to make stockpiled NWSG economically useful to livestock managers.     

Soil water dynamics,herbage production and water use efficiency of three tropical grasses: Implications for use in a variable summer‐dominant rainfall environment,Australia

In the moist mid‐latitudes of eastern Australia, soil water dynamics, herbage production and water use efficiency (WUE) were monitored during 2006–2008, for five perennial pastures: digit grass (Digitaria eriantha), Rhodes grass (Chloris gayana), forest bluegrass (Bothriochloa bladhii), native grass (Bothriochloa macra and Rytidosperma bipartita dominant), lucerne (Medicago sativa); and two forage crops: oat (Avena fatua) and sorghum (Sorghum bicolor). Ground cover formed more quickly in Rhodes grass and lucerne (>70% ground cover in 120 and 175 days after sowing [DAS] respectively) than in forest bluegrass and digit grass (245 and 365 DAS respectively). Values of maximum extractable water (MEW) for Rhodes grass and lucerne were similar (180–242 mm), while values for digit grass and forest bluegrass (129–175 mm) were equal to or greater than those for native grass, and two annual forage crops (77–144 mm). Lucerne expressed the maximum root depth (1.46 m), while values for the tropical grasses (0.96–1.39 m) were greater than native grasses and forage crops (0.87–0.96 m). Native grasses (6.5–12 t DM/ha) had the lowest herbage production, which resulted in values of WUE that were significantly less than most other treatments (16–21 vs. 23–43 kg DM ha^?1 mm^?1). Digit grass (33–34 kg DM ha^?1 mm^?1) had higher WUE compared with the other tropical grasses (20–27 kg DM ha^?1 mm^?1). The data collected here suggest that a forage system comprising digit grass, lucerne and forage oat would provide high production and WUE in this environment.     

Effect of forage species and ensiling conditions on silage composition and quality and the feed choice behaviour of goats

The hypothesis was that forage species and ensiling conditions have an impact on the formation of biogenic amines and the feed choice of goats in short‐term preference trials. At ensiling, lucerne (Medicago sativa L., first cut), red clover (Trifolium pratense L., first cut) and Italian ryegrass (Lolium multiflorum Lam ., second cut) were treated differently to obtain a range of fermentation qualities. Six treatments of each forage species were prepared and included different dry‐matter concentrations, chemical and biological silage additives, and additions of soil. Silages were sampled for chemical analyses (proximate constituents, fermentation products and other volatile compounds, crude protein fractions and biogenic amines) and stored anaerobically in vacuum‐sealed plastic bags for use in preference trials (one trial for each forage species) with Saanen‐type wethers (n = 8 or 6). Each possible two‐way combination of the six silage treatments and a standard hay (n = 21 combinations) was offered for ad libitum intake for 3 hr. Data were analysed using multidimensional scaling, analysis of variance and correlation analysis between silage characteristics and dry‐matter intake (DMI). For each forage species, fermentation characteristics and crude protein fractions revealed only small differences among treatments. Although the degree of proteolysis, as measured by non‐protein nitrogen, of all silages was high, biogenic amine and butyric acid concentrations were low. The different treatments apparently had no direct influence on the formation of biogenic amines and feed choice. The preference behaviour within one forage species was strongly divergent, but DMI rankings of the three species were very similar.     

CO2 fertilization does not affect biomass production and nutritive value of a C4 tropical grass in short timeframe

Increased atmospheric carbon dioxide (CO₂) is a consequence of recent anthropogenic environmental changes, and few studies have evaluated its effects on tropical grasses used in Brazilian pastures, the main feed source for major part of ruminant livestock. This study evaluated forage production, chemical composition, in vitro total gas production and organic matter degradability of Brachiaria brizantha under contrasting CO₂ atmospheric conditions in a free air carbon dioxide enrichment (FACE) facility. The forage plants were sown in each of the 12 octagonal rings of the FACE facility: six under ambient atmospheric CO₂ concentration of approximately 390 μmol/mol, hereafter referred to as control (CON) plots, and other six rings enriched with pure CO₂ flux to achieve a target CO₂ concentration of 550 μmol/mol, hereafter called elevated CO₂ (eCO₂) plots. Soil samples were collected to determine carbon and nitrogen concentrations. After seventy days of sowing, a standardization cutting was performed and then at regular intervals of 21 days the forage was harvested (ten harvest dates) and forwarded to laboratorial analyses. Forage above‐ground biomass production (dry matter (DM): 6,143 vs. 6,554 kg/ha), as well as morphological characteristics (leaves: 71% vs. 68%; stem: 28% vs. 31%), chemical composition (crude protein: 162.9 vs. 161.8; neutral detergent fibre: 663.8 vs. 664.3; acid detergent fibre: 369.5 vs. 381; lignin: 60.1 vs. 64.1 g/kg DM; total C: 45.9 vs. 45.9; total N: 2.8 vs. 2.8; total S: 0.2% vs. 0.2%), organic matter in vitro degradability (573.5 vs. 585.3 g/kg), methane (5.7 vs. 4.3 ml/g DM) and total gas (128.3 vs. 94.5 ml/g DM) production did not differ significantly between CON and eCO₂ treatments (p > .05). The results indicated that at least under short‐term enrichment, B. brizantha was not affected by eCO₂.     

Bio‐agronomic characterization and implications on the potential use as forage of Bituminaria bituminosa and B. morisiana accessions

Perennial forage legumes may be pivotal for improving the sustainability of Mediterranean rainfed farming systems. This study summarizes the outcomes of a study aimed at characterizing morphological and agronomic traits of new germplasm of Bituminaria bituminosa and B. morisiana in Mediterranean environments. Five B. morisiana and three B. bituminosa native populations were evaluated in a small‐plot field experiment in Sardinia (Italy) and compared with seven Spanish accessions of B. bituminosa. The two Bituminaria species differed greatly in morphological traits and the beginning of the flowering stage, and remarkable variations between species were found for forage production and its seasonal distribution, seed yield and persistence. Average cumulative dry‐matter yield was higher in B. bituminosa than in B. morisiana (+7.6%; 297 vs. 276 g per plant). Average 3‐year seed production varied greatly between accessions (from 0.3 to 141 g per plant). Differences for these traits were also found between Sardinian and Spanish germplasm of B. bituminosa. Four clusters were generated by K‐means clustering. Accessions included in cluster III exhibited a positive combination of favourable forage production, high seed yield and satisfactory persistence. Nonetheless, the cluster analysis did not highlight a sharp discrimination between Bituminaria species. The overall results revealed the potential role of Sardinian accessions of B. bituminosa and B. morisiana in extending the forage season and for increased resilience of grasslands in Sardinia and other Mediterranean regions under rainfed conditions.     

Increasing the population of forage peanut in a mixed pasture by controlling the canopy height

The aim of this study was to determine a temporary strategy for increasing the legume population in an established pasture of brachiaria grass (Brachiaria brizantha) and forage peanut (Arachis pintoi). The treatments comprised four previous long‐term canopy heights (10, 20, 30 and 40 cm) from the establishment (the first 32 months after treatment initiation). From September 2014, all of the experimental units were kept at 10 cm height. The pastures were evaluated for their forage harvest, forage mass, botanical composition and stolon and tiller density. The tiller density and brachiaria grass mass were maintained in all pastures since the first season of evaluation (p > 0.10). The stolon density and legume mass were initially lesser at 30 and 40 cm than those at 10 and 20 cm, early in the experiment, but progressively increased over time. After 1 year under 10 cm height, the population and mass of legume were similar in all treatments. Therefore, reducing the canopy height to 10 cm at the beginning of the rainy season is an efficient method to increase the botanical composition of forage peanut in mixed pastures with brachiaria grass.     

Performance and blood parameters when lambs and meat‐goat kids were finished on pasture with and without whole cottonseed (Gossypium hirsutum) supplementation

We evaluated forage production patterns, weight gains and blood parameters when lambs (Ovis aries) and meat‐goat (Caprus hircus) kids were finished on a mixed sward of cocksfoot (Dactylis glomerata L.), red clover (Trifolium pratense L.) and white clover (Trifolium repens L.) with (SUP) and without (UNSUP) supplemental whole cottonseed (Gossypium hirsutum; WCS) in a replicated study. Botanical composition and energy/protein ratios of the sward varied with year and with time during the growing season. Swards had greater amounts of red clover relatively early and more cocksfoot later in the season. Suffolk (SX) lambs had the heaviest body weights, Katahdin (KA) lambs were intermediate, and meat‐goat (GX) kids were the lightest at the end of each year. Overall body weight gain followed a trend of SX > KA > GX, and WCS supplementation increased weight gain for all animals by 18%. Only in 2008 did SUP animals have higher blood urea nitrogen levels, which may indicate less efficient use of dietary nitrogen when grazing grass–legume pastures managed for high nutritive value compared with UNSUP animals. Gossypol in WCS did not affect blood packed cell volume between SUP and UNSUP lambs and meat‐goat kids. Suffolk lambs, Katahdin lambs and cross‐bred Boer meat‐goat kids finished on pasture with and without WCS supplementation produced desirable body weights for most ethnic markets in the USA.     

Optimal defoliation management of brachiaria grass–forage peanut for balanced pasture establishment

A well‐established canopy is crucial for a stable mixed grass–legume forage pasture. The aim of this study was to assess a defoliation intensity that can ensure the establishment of mixed pasture of brachiaria grass (Brachiaria brizantha) intercropped with forage peanut (Arachis pintoi). The treatments comprised four canopy heights: 10, 20, 30 and 40 cm, maintained throughout the first 3 years of pasture establishment. Canopy structure, morphogenetic and structural characteristics were measured. A block design was used with four replicates, and seasons of the year were considered using repeated measurements over time. Light interception during the experimental period was 86.3%, 95.9%, 97.6%, and 99.1% for 10, 20, 30 and 40 cm of defoliation respectively (p < .001). Competition for light in taller canopies (at 30 and 40 cm) caused etiolation of forage peanut (greater internode, petiolate and stolon lengths). This response promoted its upward growth, leading to a lower stolon density compared with 10 and 20 cm. The treatment at 10 cm displayed a predominance of forage peanut (up to 0.614), potentially compromising community stability. Overall, the 20 cm canopy height showed a desired botanical composition (from 0.20 to 0.45 of legume in forage mass) and thus was considered an ideal defoliation intensity for establishment of mixed canopies of brachiaria grass and forage peanut.     

Forage chain arrangement for sustainable livestock systems in a Mediterranean area

Mediterranean forage systems suffer from limited availability of fresh forage because of water deficits and extreme temperatures. Consequently, fresh forage is unavailable for at least 6–7 months a year, and farmers must buy feed to support livestock production. With the aim of overcoming these limitations, a 2‐year trial was conducted on three distinct sites in Sicily (at 10, 600 and 1200 m elevation) with thirty‐four varieties of forage species belonging to nine biennial/perennial and thirteen annual species. Results showed that by integrating grasses and legumes, species from environments with different climatic conditions enable the season of forage production to be extended from mid‐April to mid‐November. Quality traits of forage in different areas varied in relation to species and varieties. In general, the sown‐forage quality was better than in pastures and fallows in the same areas commonly used to feed animals. This also leads to a reduction in the use of supplementary feeds. Among the tested species, Lolium multiflorum and Medicago sativa emerged as the most promising for filling the forage‐deficit periods, and Trifolium spp. and Vicia sativa were found to be superior for increasing forage quality. The results are discussed in the context of adapting Mediterranean forage supplies for ensuring greater sustainability of livestock production in mountain, hill and plain areas. The proposed forage chain arrangement represents part of local potential adaptation to climate limitations and climate change.     

Impacts of dormancy‐regulating chemicals on innate and salinity‐induced dormancy of four forage grasses native to Arabian deserts

The effects of dormancy‐regulating chemicals (DRCs) on alleviating innate and salinity‐induced dormancy (SID) were assessed in seeds of four perennial forage grasses (Pennisetum divisum, Sporobolus spicatus, Coelachyrum brevifolium and Centropodia forsskalii). These grasses have the potential to be used for restoration or rehabilitation of degraded rangelands of the Arabian Gulf deserts. The four species showed various levels of innate dormancy. Germination of seeds stored for 2 months was not enhanced by any of the five studied DRCs in both C. brevifolium and P. divisum, but significantly improved by thiourea, fusicoccin and gibberellic acid (GA) in C. forsskalii and by thiourea, fusicoccin and nitrate in S. spicatus. Salinity had a significant negative effect on all the studied grasses. Sporobolus spicatus was more tolerant to salinity, compared with the other species. The effect of DRCs on alleviating SID depended on species. Whereas DRCs had little effect on alleviating SID in C. forsskalii and P. divisum, they greatly alleviated it in S. spicatus and C. brevifolium. Partial alleviation was observed by fusicoccin in C. brevifolium and by GA, kinetin and thiourea in C. forsskalii. Nitrate, fusicoccin and GA resulted in a complete alleviation in S. spicatus seeds in 200 mm NaCl.     

Thirty‐year variations of above‐ground net primary production and precipitation‐use efficiency of an alpine meadow in the north‐eastern Qinghai‐Tibetan Plateau

Above‐ground net primary production (ANPP) and precipitation‐use efficiency (PUE) are key factors that can clarify the response of grassland ecosystem carbon and water cycles to ongoing climate change. The variations of ANPP and PUE were analysed based on long‐term in situ observations of a species‐rich alpine meadow in the north‐eastern Qinghai‐Tibetan Plateau from 1981 to 2010. ANPP and PUE increased markedly over time. ANPP was significantly controlled by post‐growing season length (from 1 September to the end of growing season in the previous year, R² = 0·31, P < 0·01). Regression trees showed that air temperature during October of the previous year played a predominant role in ANPP annual variations. Results indicated that a strong thermal‐lagging effect on ANPP variations was present in the alpine meadow ecosystem. ANPP variations were undetectable during wet, normal and dry years (P = 0·25). Our finding supported the hypothesis that temporal site‐specific ANPP variations were less regulated by a single factor. The temporal PUE declined linearly with increasing annual precipitation, and the slope was obviously steeper than that of spatial patterns. More ANPP variability in an alpine meadow under warming conditions might occur via community transition in the north‐eastern Qinghai‐Tibetan Plateau.     

Genetic and morphological characterization of Acroceras macrum Stapf

Acroceras macrum is a warm‐season grass used for pastures, and it has high nutritive value. The scarce genetic and reproductive information about this grass is limiting its breeding for forage. The objective of this research was to determine the number of genotypes and cytotypes present in a collection established in Argentina, and to estimate the diversity of this species based on molecular markers, and morphological and agronomic characteristics. The number of genotypes among forty‐seven accessions was determined using ISSR markers. The identified genotypes were further characterized for ploidy levels. In addition, the genetic distances among them were estimated with ISSR markers. They were also propagated and planted into the field following a randomized complete block design with four replications, and a group of sixteen morphological and agronomic variables were evaluated. A total of twenty‐seven genotypes were identified in this collection; twenty‐two genotypes were tetraploid (2n = 4x = 36) and five were hexaploid (2n = 6x = 54). These two cytotypes were found clearly separated by both genetic and phenotypic characteristics. Above‐ground biomass, internode length, initial growth and number of spikelets per inflorescence were the most variable traits. The high diversity present in this collection will allow for the initiation of a breeding programme for A. macrum.     

Evaluation of yield and chemical composition of a halophyte (Suaeda glauca) and its feeding value for lambs

Suaeda glauca is a potential feedstock for ruminants in north‐east China in areas of increasing salinity. The characteristics of S. glauca pasture from June to October and effects on intake, digestion and blood metabolites in lambs given increasing proportions of S. glauca in the forage component of a mixed hay/concentrate (50/50) diet were evaluated. Harvest date had a significant effect on dry matter (DM) yield. There were significant increases in DM content, total energy, neutral detergent fibre and acid detergent fibre (ADF), but declines in leaf proportion, crude protein, total ash and sodium contents with maturity. Inclusion of 25%S. glauca hay in a diet significantly improved daily intake of DM, organic matter (OM) and energy compared with T0% and T50% groups. Supplementation at 25 or 50% significantly increased the digestibility of energy, DM, OM and ADF compared with the T0% group. Water intake, urinary excretion, water content of fresh faeces and sodium excretion from urine linearly increased with increasing S. glauca content, but potassium excretion from urine decreased. K and Mg serum contents were significantly increased compared with T0% group when S. glauca made up 50% of diet. This study indicates that S. glauca is a suitable hay when added as 25% of the lamb diet.