Adaptability and productivity of some warm-season pasture species in a Mediterranean environment

Warm‐season grasses and legumes have the potential to provide forage throughout the Mediterranean summer when there are high temperatures and low rainfall and when cool‐season grasses become less productive. Twenty‐nine non‐native, warm‐season pasture species (twenty‐three grasses and six legumes) were assessed for their adaptability to the coastal plain of southern Italy in terms of their productivity and nutritional quality. The investigated species were compared with two reference species widely used in a Mediterranean environment: a grass (Festuca arundinacea) and a legume (Medicago sativa). The species differed in their phenological and biological characteristics, i.e. start of vegetative resumption, first flowering and cold resistance, from each other and from the control species. From the second year after establishment, warm‐season perennial grasses had high dry‐matter (DM) yields and, in many cases, a more than adequate nutritional quality. As for legumes, the control, M. sativa gave the best results in all the investigated characters. Among the grasses, seven species (Chloris gayana, Eragrostis curvula, Panicum coloratum, Paspalum dilatatum, Pennisetum clandestinum, Sorghum almum, Sorghum spp. hybrid) had DM yields greater than the control species and had their maximum growth during the hottest period of the year, when F. arundinacea, the control grass species, was dormant. Eragrostis curvula had the highest annual DM yield (21·1 t ha^?1) and P. clandestinum provided the best combination of agronomic and yield characteristics which were similar to those of M. sativa. The seven above‐mentioned species have the potential to supply hay or grazing and contribute to broadening and stabilizing the forage production calendar in Mediterranean‐type environments.     

Effect of soya bean oil supplementation and forage type on methane production and fibre digestibility using the in vitro gas production system

We aimed to evaluate the effect of soya bean oil (SBO) supplementation with different forages on in vitro gas production kinetics, methane (CH₄) emissions and potentially digestible neutral detergent fibre (pdNDF) digestibility (IVpdNDFD). Samples of whole‐crop maize silage (MS; Zea mays), sugarcane (SC; Saccharum sp.), perennial ryegrass (RG; Lolium perenne), guinea grass (GG; Panicum maximum) and palisadegrass (PG; Brachiaria brizantha) were incubated with three concentrations of SBO (0, 30 and 60 g/kg of dry matter). The interaction between forage species and SBO inclusion affected molar proportion of acetate, acetate‐to‐propionate ratio, asymptotic gas and IVpdNDFD. Acetate‐to‐propionate ratio numerically decreased from 3.56 to 3.44 and 3.77 to 3.56 for MS and SC respectively. Soya bean oil inclusion at 60 g/kg DM decreased 21.2% and 12.9% of IVpdNDFD for MS and SC respectively. Soya bean oil increase did not affect IVpdNDFD for RG, GG and PG. Soya bean oil inclusion decreased quadratically the asymptotic gas (294–265 ml/g OM) for MS and increased linearly (275–283 ml/g OM) for GG. Lower and greater CH₄ production was observed for RG and SC respectively. Methane production decreased quadratically by SBO increase. Soya bean oil inclusion linearly decreased CH₄ concentration in total gas at 48 hr of incubation from 133 to 128 ml/L. In conclusion, MS and SC are more sensitive to adverse effects of SBO supplementation from 30 to 60 g/kg DM on rumen fermentation when compared to RG, GG and PG.     

Cattle select against the invasive grass tall fescue in heterogeneous pastures managed with prescribed fire

Tall fescue (Festuca arundinacea) is a Eurasian forage grass extensively planted in the United States. However, an endophytic fungus in tall fescue, Epichloë coenophiala, causes health problems in cattle. We predicted that cattle prefer to graze alternative forages when available. We also predicted that cattle use tall fescue more intensively in recently burned areas, as fire can increase forage quality. We tested these predictions in four diverse‐forage pastures in Iowa, comparing use by cattle of tall fescue and four alternative forages (non‐fescue cool‐season grasses, native warm‐season grasses, non‐leguminous forbs and legumes) to their availabilities at the pasture scale. We also examined how tall fescue influences the distribution of grazing at a fine scale (0.1‐m² quadrats). Tall fescue was the most abundant forage (46% of plants), but composed only 26% of grazed vegetation. In contrast, legumes composed 12% of available forage but 25% of grazed vegetation. Other forages were used in proportion to availability. At a fine scale, total grazing frequency (proportion of plants grazed) was lower in quadrats containing abundant tall fescue, and higher in quadrats with abundant warm‐season grasses. Grazing frequency of tall fescue and other cool‐season grasses was greatest in recently burned quadrats, but total grazing frequency did not increase after burning. Our results show that although cattle graze tall fescue, particularly following burns, they limit their use of this grass. Given that tall fescue is underused, creates health risks for cattle, and degrades wildlife habitat quality, it may be advisable to reduce tall fescue in pastures.     

Annual forage legumes in dryland agricultural systems of the West Asia and North Africa Regions: research achievements and future perspective

Forage legumes are vitally important to animal production in the dryland farming systems of the Mediterranean region. Of the diverse forage‐legume species adapted to the Mediterranean climate, vetches, (Vicia spp.), chicklings (Lathyrus spp.), annual medics (Medicago spp), clovers (Trifolium spp.) and species of the Lupinus, Lotus, Onobrychis, Hedysarum and Ornithopus genera are considered to be the most agronomically important and economically valuable species for the region. Adoption of perennial self‐regenerating medic (Medicago spp.) has been limited because of technical difficulties, but annual vetch (Vicia spp.) has the greatest potential as a viable animal‐feed source and a rotation crop with cereals. Some forage legumes survive harsh conditions by their unique underground growth habit, for example, V. amphicarpa and Lathyrus ciliolatus. Efforts to improve forage legumes have been based on both management/cultural factors and breeding. Research based on several long‐term barley‐ and wheat‐based rotation trials has demonstrated the viability of forage legumes, especially vetch, in the region's improved farming system. An additional benefit to such legumes is the enhancement of soil quality, that is, soil fertility, soil organic matter and soil physical properties. Thus, the development of forage legumes is essential to agricultural sustainability in the Mediterranean region and in other dryland cereal‐growing areas of the world where grazing livestock is a dominant enterprise. To build upon the considerable research conducted on forages, intensified efforts are needed to develop locally adapted forage cultivars, to provide economic assessment of forages in cropping systems and to promote technology transfer at the farm and community level.     

The choice of grass species to combat desertification in semi‐arid Kenyan rangelands is greatly influenced by their forage value for livestock

Livestock production is the main source of livelihood in the arid and semi‐arid lands in Africa. However, desertification characterized by vegetation degradation and soil erosion is a major threat to the sustainability of land‐based production systems. Native rangeland forage species Cenchrus ciliaris L. (Buffel grass/African foxtail grass), Eragrostis superba Peyr. (Maasai love grass) and Enteropogon macrostachyus (Hochst. Ex A. Rich.) Monro ex Benth. (Bush rye grass) have been used to combat desertification. The objectives of the study were to identify the best‐suited native grass species to combat desertification in a semi‐arid environment in Kenya and to identify the preferred grass species among the agropastoralists in the area. Percentage basal cover, plant densities and frequencies of the three grasses in pure stands and mixtures were estimated. Grass species preferences were through household survey and focus group discussion. Results showed a significant difference (P < 0·05) in plant densities and cover estimates: E. macrostachyus was ranked first; C. ciliaris and E. superba were ranked second and third respectively. The agropastoral farmers, however, preferred E. superba followed by C. ciliaris and E. macrostachyus, a reverse trend. These results suggest that the choice of grass species to combat desertification is influenced more by its contribution as a source of forage for livestock than its contribution for rehabilitation purposes.     

Factors affecting digestibility of temperate forages from seminatural grasslands: a review

Abstract To indicate possibilities for the use of forages from seminatural grasslands in ruminant production systems, a literature study to describe the nutritive value of those forages was carried out. In species‐rich grasslands, the digestibility of forages is usually lower than the digestibility of forages produced by grasslands used for intensive production. There is also more variation within a species‐rich sward, because of different stages of maturity of the individual species and because of likely variations in digestibility among forage species independent of stage of maturity. Moreover, the presence of dicotyledonous species may have a positive or negative effect on digestibility. In forages from seminatural grasslands, the relationship between chemical composition and digestibility differs from that of Lolium perenne, which is often used as a research standard. Therefore, predictions of the digestibility of species‐rich forage can be inaccurate. The relationship between in vivo and in vitro digestibility may also be different from the relationship that is common for L. perenne. In some cases, the in vivo digestibility is higher than the in vitro value, as calibrations are based on L. perenne. Therefore, the quality of forages from seminatural grasslands might be higher than predicted, and this may increase the scope for practical use of this kind of forage in ruminant nutrition systems.     

Diversity of condensed tannin structures affects rumen in vitro methane production in sainfoin (Onobrychis viciifolia) accessions

Sainfoin is a non‐bloating temperate forage legume with a moderate‐to‐high condensed tannin (CT) content. This study investigated whether the diversity of sainfoin accessions in terms of CT structures and contents could be related to rumen in vitro gas and methane (CH₄) production and fermentation characteristics. The aim was to identify promising accessions for future investigations. Accessions differed (P < 0·0001) in terms of total gas and CH₄ productions. Fermentation kinetics (i.e. parameters describing the shape of the gas production curve and half‐time gas production) for CH₄ production were influenced by accession (P ≤ 0·038), but not by PEG. Accession, PEG and time affected (P < 0·001) CH₄ production, but accession and PEG interaction showed only a tendency (P = 0·08). Increase in CH₄ due to PEG addition was not related to CT content. Further analysis of the relationships among multiple traits (nutritional composition, CT structure and CH₄ production) using principal component analysis (PCA) based on optimally weighted variables revealed differences among accessions. The first two principal component axes, PC1 (57·6%) and PC2 (18·4%), explained 76·0% of the total variation among accessions. Loading of biplots derived from both PCAs made it possible to establish a relationship between the ratio of prodelphinidin:procyanidin (PD:PC) tannins and CH₄ production in some accessions. The PD:PC ratio seems to be an important source of variation that is negatively related to CH₄ production. These results suggested that sainfoin accessions collected from across the world exhibited substantial variation in terms of their effects on rumen in vitro CH₄ production, revealing some promising accessions for future investigations.     

In vitro total and methane gas production as influenced by rate of nitrogen application, season of harvest and perennial ryegrass cultivar

The effects of rate of inorganic nitrogen (N) fertilization (0, 80 or 160 kg N ha^?1 per regrowth), season of harvest (regrowths 1, 2 and 3) and perennial ryegrass (Lolium perenne L.) cultivar [classified as having either a normal or elevated water soluble carbohydrate (WSC) concentration genotype] on in vitro gas production and digestibility were assessed. Increased N fertilizer application significantly decreased total gas production (TGP), methane (CH₄) production and organic matter digestibility (OMD). The results suggest that the decreases in TGP and CH₄ production were associated with a restriction in organic matter (OM) fermentation and an altered crude protein (CP) to structural carbohydrate ratio rather than a modification in the stoichiometry of fermentation. Season of harvest only significantly (P < 0·05) altered in vitro OMD and CH₄ production at 8 h, despite altering the chemical composition of the herbage. Cultivar effects on all measured in vitro parameters were not significant presumably because the elevated WSC concentration trait was not expressed strongly in the study.     

An evaluation of the hygienic quality in single‐species hays and commercial forages used in equine nutrition

Pulmonary diseases such as recurrent airway obstruction have become a major concern in the horse industry. Airborne dust, including aeroallergens from forages, is suspected to be the main factor in its aetiology. Hypothesizing that grassland flora could affect hay hygienic quality, and therefore have implications for the respiratory health of horses, we compared five single‐species hays (Trifolium repens, Lolium perenne, Alopecurus geniculatus, Poa trivialis and Holcus lanatus). Multi‐species hay from Normandy, and different commercial forages (single‐species haylage, multi‐species haylage, Crau hay and hay from Swiss mixing), chosen to represent current horse forages, were also investigated. Dust, moulds, pollens and endotoxins were different among forage types, while mycotoxins were not detected in any of the forage types. Holcus lanatus hay was the dustiest among the single‐species hays but also the least contaminated by moulds. A particular mould profile was associated with each plant species. The four commercial forages appeared to have a better hygienic quality than the multi‐species hay. Among commercial forages, the single‐species haylage was the least dusty but also the most contaminated by moulds. Overall the results suggest that the hygienic quality of equine forages could be improved by an appropriate choice of grassland species.     

The nutritive value of Prangos ferulacea

This study was conducted to determine the chemical composition and nutritive value of Prangos ferulacea, a plant found in the Mediterranean and Middle‐east regions, where it is used as animal fodder. Samples of mature plants were collected from S.E. Turkey. Metabolizable energy (ME) values were estimated from in vitro gas production measurements and from chemical composition. ME concentrations of the whole plant, leaves and stems were estimated to be 12·2, 11·9 and 12·7 MJ kg^?1 dry matter (DM) respectively, which compares favourably with high‐quality forages commonly used in ruminant feeding. The DM degradability of the whole plant, leaves and stems increased up until 48 h of in situ incubation, 866, 915 and 784 g kg^?1 DM respectively, but changed little between 48 and 72 h. In vitro DM and organic matter digestibility of the whole plant, leaves and stems were 0·769 and 0·806, 0·773 and 0·790, and 0·740 and 0·840 respectively. The results show that P. ferulacea may be regarded as a high‐energy forage, but further research is needed on its intake characteristics and the levels of animal performance that can be achieved from its inclusion in the diet.     

Effects of species richness and functional groups on chemical constituents relevant for methane yields from anaerobic digestion: results from a grassland diversity experiment

Changes in livestock production systems have led to land‐use changes and abandonment, especially of semi‐natural grassland in agriculturally less favoured regions. The generation of energy from biomass of extensive, high‐diversity grasslands can be an alternative to their abandonment, and anaerobic digestion is one possible method for converting grassland biomass into energy. However, little is known about the effects of species richness (SR) and functional groups on chemical constituents relevant for anaerobic digestion and the resulting energy potential. In this study, changes in the herbage chemical constituents that are relevant for forage quality were studied along a well‐defined diversity gradient (one to sixty species) and across different combinations of functional groups (legumes, small herbs, tall herbs and grasses). Substrate‐specific methane yield (CH_4 sub) was estimated through the concentrations of forage‐quality parameters such as crude fibre (CF), crude protein (CP), crude lipid, nitrogen‐free extract and their documented digestibility values, as well as the respective methane yields. Results show that with increasing SR, the CF increased and CP decreased, even though these effects could not be fully disentangled from the presence of grasses. These trends led to a negative effect of SR on CH_4 sub, while the area‐specific methane yield (CH_4 area = CH_4 sub × biomass yield) increased due to a strong increase in biomass with increasing SR. The CH_4 sub was increased when legumes were present, and it declined with the presence of grasses. Generally, CH_4 sub and CH_4 area varied between functional‐group monocultures and all functional‐group mixtures.     

Effect of six-weekly harvests on the yield, chemical composition and dry matter degradability of Panicum maximum and Stylosanthes hamata in Nigeria

The dry matter (DM) yield and degradability of 6‐week‐old harvests of tropical forages were measured over a season. The forages were nitrogen‐fertilized Guinea grass (Panicum maximum, NFG), unfertilized Guinea grass (UFG), Verano stylo (Stylosanthes hamata,VS), a Guinea grass–Verano stylo mixture (GSM) and Guinea grass in the grass–Verano stylo mixture (GGSM). Six‐week‐old forages were made possible through a cutting regime, which produced four harvests in the growing season. The DM yields of the forages differed significantly (P < 0·001) and showed a significant reduction (P < 0·01) across the season. Crude protein and neutral‐detergent fibre concentrations were significantly (P < 0·01) different between the forages but there was no difference between harvests. The DM degradability of the forages at all harvests were significantly (P < 0·001) different with differences in the soluble fraction (a), degradable fraction (b), potential degradability (PD) and effective degradability (ED), but rate of degradability (c) did not show any significant difference between the forages. Significant (P < 0·01) differences were found between harvests for b and PD, and for the interaction between forage and harvest for b, PD and ED but were not found for the a and c fractions. Both the PD and ED values of all the forages fell with advancing harvests. Although the 6‐week‐old harvests of forage were found not to influence the characteristic reduction in yield of tropical grasses over time, it is concluded that such a management system could be used to obtain forage of relatively high nutritive value during the growing season.     

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.     

Comparison of feed intake,body weight gain,enteric methane emission and relative abundance of rumen microbes in steers fed sainfoin and lucerne silages under western Canadian conditions

Beef cattle are major contributors of enteric methane (CH₄) emissions in Canada. Feeding forages containing condensed tannins (CT) has been suggested as a means of reducing enteric CH₄ emissions and improving production efficiency. Sainfoin (Onobrychis viciifolia) is one of the CT‐containing legumes, which has also been recognized to have several additional beneficial properties. This study compared sainfoin silage (SS) and lucerne (Medicago sativa) silage (LS) with respect to animal performance, enteric CH₄ production, abundance of selected rumen microbes and selected serum parameters in yearling steers during a Canadian winter. Sainfoin silage in our study contained approximately 12 g CT kg^?1 dry matter (DM), a level which did not adversely affect silage palatability as steers fed SS experienced higher DM intake. However, animals fed LS and SS had similar body weight gain over the course of the trial. Feeding SS resulted in lower blood urea nitrogen concentrations and relative abundance of methanogenic archaea in rumen fluid. Yet, microbial population shifts fell short of exerting significant influence on enteric CH₄ emissions. This study suggests that under western Canadian growing and animal‐rearing conditions, sainfoin is not yet competitive with lucerne forage with respect to enteric CH₄ emissions or animal productivity warranting further research and development.     

Effect of harvest time on yield and pre-harvest quality of semi-leafless grain peas (Pisum sativum L.) as whole-crop forage

The aim of the work was to study changes in the yield and nutritional characteristics of whole crop semi-leafless field pea over two growing seasons in the Po plain, Italy. Samples of two cultivars (Baccara and Sidney) were collected from flowering to grain maturity. The developmental stage, yield, dry matter (DM) content, crude protein (CP), neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL), starch, water soluble carbohydrates (WSC), gross energy (GE), organic matter digestibility (OMD) and the net energy for lactation (NE_L) were determined at each harvest. The forage characteristics were regressed on the growing degree days (GDD) with 4.4 °C as the base temperature. The DM yield increased with advancing maturity from 0.5 to 8.91 Mg ha⁻¹, while the CP decreased from 261 to 159 g kg⁻¹ DM. During the whole growth cycle the GE, OMD, NE_L and milk forage units (milk FU) were almost steady. No differences were observed between the cultivars for any of the measured parameters. At grain maturity, the crop produced over 4.0 Mg ha⁻¹ DM of grain. The CP, starch and WSC of the grain did not show any differences between the cultivars or years. The data showed that the nutritive quality of the forage of the semi-leafless grain pea harvested as a whole crop for ensiling purposes did not diminish with maturity and could help improve the self-sufficiency of dairy farms, in terms of home-grown protein forages.     

Prediction of legume silage digestibility from various laboratory methods

The potential of different laboratory methods to predict legume silage organic matter digestibility (OMD) in vivo was evaluated by using data from thirty‐three pure legume silages in seven experiments. The samples were analysed for crude protein concentration, cell wall composition, in vitro digestibility by the methods of Tilley and Terry [Journal of the British Grassland Society, 18 (1963) , 104–111; OMD_T&T], pepsin‐cellulase solubility (OMS) and gas production (OMD_GAS), and for indigestible neutral‐detergent fibre concentration in situ (INDF). The relationships between the results obtained by the laboratory methods and in vivo OMD, all expressed as ratios, were studied using linear univariate regression models with experiment as a random variable (mixed model). Legume silage digestibility could be estimated with acceptable accuracy by different in vitro methods, but not from the chemical composition of the samples. The highest accuracy in OMD prediction was found with OMS (RMSE 0·0113; R² = 0·965) followed by OMD_GAS (RMSE 0·0149; R² = 0·944), OMD_{T& T} (RMSE 0·0149; R² = 0·940) and INDF (RMSE 0·0168; R² = 0·925). The relationships between the in vitro methods and in vivo digestibility are not universal, and should be determined separately for each laboratory and type of forage. Part of the error in OMD prediction can be attributed to errors in in vivo OMD determination.     

Simulating tropical forage growth and biomass accumulation: an overview of model development and application

Crop models can aid the synthesis and application of knowledge, planning of experiments and forecasting in agricultural systems. Few studies have reviewed the uses and applications of these models for tropical forages. The purpose of this study was to review the information available in this scientific area, highlighting the main models, their applications and limitations. Several empirical models have been developed to predict the growth and biomass accumulation of tropical forages, especially for the genera Cynodon, Paspalum, Panicum and Brachiaria. Their application, however, is often location or region specific. The adaptation of mechanistic models to accurately predict biomass accumulation in tropical grasses is still limited. Recent advances have been made on the plot‐scale and farm‐scale process‐based models ALMANAC, CROPGRO Perennial Forage and agricultural production systems simulator (APSIM), with promising results. In addition, global‐scale process‐based models, such as the Century Agroecosystem Model and the Orchidee Grassland Management Model, have been tested for tropical grassland areas. A greater number of region‐specific calibrations of empirical models can enhance their use, and improved databases and model parameterizations for a wide range of tropical grasses will enable the continuous improvement of mechanistic models.     

Response of plant species composition,biomass production and biomass chemical properties to high N,P and K application rates in Dactylis glomerata‐ and Festuca arundinacea‐dominated grassland

Little is known about the immediate effect of high nitrogen (N), phosphorus (P) and potassium (K) application rates on sown grasslands cut twice per year. We asked how quickly plant species composition, biomass yield, biomass chemical properties and nutrient balance respond to N, P and K application. An experiment using unfertilized control, P, N, NP and NPK treatments was established on seven‐year‐old cut grassland in the Czech Republic in 2007 and monitored over four years. Annual application rates were 300 kg N ha^?1, 80 kg P ha^?1 and 200 kg K ha^?1. The immediate response of plant species composition to N application was recorded and was found to be different to the response over the four years of the study period. Highly productive grasses (Dactylis glomerata, Festuca arundinacea and Phleum pratense) were promoted by N application in 2008 and then retreated together with legumes (Medicago sativa, Trifolium pratense and Trifolium repens) in all N treatments where the expansion of perennial forbs (Urtica dioica and Rumex obtusifolius) and annual weeds (Galinsoga quadriradiata, Impatiens parviflora, Lamium purpureum and Stellaria media) was recorded. At the end of the experiment, Festuca rubra was the dominant grass in the control and P treatment, and species richness was lowest in all treatments with N application. Mean annual dry‐matter yield over all years was 3.5, 3.9, 5.8, 5.6 and 6.8 t ha^?1 in the control, P, N, NP and NPK treatments, respectively. Concentrations of N in the biomass ranged from 20.0 to 28.7 g kg^?1 in the P and N treatments; concentrations of P ranged from 3.2 to 3.7 g kg^?1 in the N and P treatments; and concentrations of K ranged from 24.1 to 34.0 g kg^?1 in the NP and NPK treatments. The N:P, N:K and K:P ratios did not correctly indicate the nutrient limitation of biomass production, which was primarily N‐limited, and K‐limitation was only recorded for high production levels in treatments with N applications. On the basis of the nutrient‐balance approach, the balanced annual application rates were estimated as 140 kg N ha^?1, 30 kg P ha^?1 and 100 kg K ha^?1. We concluded that high N, P and K application rates can very quickly and dramatically change species composition, biomass production and its chemical properties in sown cut grasslands. High N application rates can be detrimental for tall forage grasses and can support the spread of weedy species.     

Exploiting genetic and physiological variation of the native forage grass Trichloris crinita for revegetation in arid and semi‐arid regions: An integrative review

In arid, semi‐arid and dry subhumid regions, which represent ~ 41% of the Earth's land surface, desertification and soil degradation are very frequent, leading to low soil fertility and productivity. In these regions, revegetation with locally adapted native species may aid in ameliorating desertification processes. Trichloris crinita is a C4 perennial grass native to arid and semi‐arid regions of the American continent. Its good forage quality, drought tolerance, resistance to trampling and grazing, and rapid growth and competing aggressiveness among other native species warrant its use as forage and for revegetation purposes. In the last decades, many studies have revealed broad intraspecific genetic variation for ecophysiological, morphological, biomass production, nutritional quality (as forage) and adaptive stress response‐related traits. Also, results from field trials evaluating T. crinita genotypes as forage and for restoration of degraded areas suggest great potential for—and have encouraged—its utilization under different habitats and environmental conditions. In this integrative review, we compiled and discussed the most relevant research data regarding T. crinita, focusing on aspects and traits that influence its utilization both as forage and in rehabilitation of degraded lands. Challenges and prospects towards the improvement of this species in breeding programmes with specific goals are discussed.     

In vitro fermentation patterns and methane production of sainfoin (Onobrychis viciifolia Scop.) hay with different condensed tannin contents

Sainfoin (Onobrychis viciifolia Scop.) is a perennial legume recently reappraised for some positive characteristics leading to highly satisfactory animal performance. Sainfoin’s characteristics may be partly explained by the presence of moderate levels of condensed tannins (CTs) able to protect dietary protein from microbial degradation in the rumen. Decreased CH₄ emissions have been reported for ruminants consuming CT‐containing forage. The aim of this study was to evaluate the effects of CT content on the in vitro fermentation characteristics and kinetics and methane production of four samples of O. viciifolia cut at different phenological stages. Sainfoin hays and one sample of alfalfa hay were incubated at 39°C in anaerobiosis using the in vitro gas production technique. The chemical composition, tannin content and fermentation characteristics and kinetics of sainfoin samples were significantly affected by phenological stage. After 48 h, the CH₄ production in sainfoin hays showed a tendency to increase with the advancement of phenological stage [from 38·6 to 49·8 mL g⁻¹ of degraded organic matter (OM)]. The best period to cut sainfoin for hay making is between early and late flowering, when the forage combines high OM digestibility, low CH₄ production and more efficient microbial fermentation.