The microbiological and chemical composition of silage over the course of fermentation in round bales relative to that of silage made from unchopped and precision-chopped herbage in laboratory silos

The composition of baled silage frequently differs from that of comparable conventional silage. A factorial experiment was conducted with three wilting treatments (0, 24 or 48 h) × three ensiling systems [unchopped grass in bales, unchopped grass in laboratory silos (LS), precision-chopped grass in LS] × six stages of ensiling to (i) confirm that the fermentation of unchopped grass in LS could be used as an adequate model for baled silage fermentation, (ii) quantify the differences between baled silage and silage made from precision-chopped herbage across a range of dry-matter contents and (c) quantify the fermentation dynamics within the various treatments. The onset of fermentation as evidenced by the accumulation of fermentation products and the decline in pH were slower ( P  < 0·05) in baled silage compared with silage made from precision-chopped herbage. Furthermore the pH ( P  < 0·001) and overall concentration of fermentation acids ( P  < 0·01) were lower while ammonia-N concentration was generally higher in baled silage, making it more conducive to the activities of Clostridia , Enterobacteria and yeast. Numbers of Enterobacteria were higher ( P  < 0·001) in baled silage in the early stages of ensilage and persisted in baled silage at the end of the storage period. The implications of a slower onset of fermentation in baled herbage are greater in farm practice, as the fermentation would be further restricted by a more extensive wilting of the herbage prior to ensiling.     

Fresh and ensiled forage plants—total composition,silage losses and the prediction of silage composition from the crop

Twenty ley and whole‐crop samples were analysed before and after ensiling to determine the proportion of dry matter (DM) that could be accounted for by the sum of 12 chemical assays for ash, ash‐excluded‐amylase‐treated neutral detergent fibre (aNDFom), starch, water‐soluble carbohydrates (WSC), pectin, crude protein (CP), CP in aNDFom (CPndf), ammonia, crude fat, phenolics, plant organic acids and liquid fermentation products (acids and alcohols). Crop components, utilized during silage fermentation and the possibility of predicting silage composition from that of the crop, were also investigated. Samples consisted of timothy and red and white clover, harvested at early and late maturities in two cuts per maturity and of whole‐crop barley, wheat and maize, harvested at early, intermediate and late stages of maturity. Ley crops were wilted to reach a DM content of approximately 400 g/kg, whereas whole crops (WC) were not wilted (151–757 g DM/kg) before ensiling. The average sum of analytes was 1022 and 981 g/kg DM for crops and silages respectively. An overall closeness to complete recovery indicates that no major plant components were missing from the analyses. Relative proportions of pectin, plant organic acids and phenolics, which are rarely analysed, were approximately 60:40:2 (w/w). Ash, aNDFom, crude fat and CP were almost completely recovered after ensiling, whereas partial metabolism reduced recoveries of starch (81%), CPndf (62%), plant organic acids (65%), pectin (64%) and WSC (29%). Only the four analytes with high silage recoveries could be reasonably well predicted from parent crop levels with mean prediction error from 0.065 for aNDFom to 0.167 for crude fat.     

Inclusion of alfalfa improves nutritive value and in vitro digestibility of various straw–grass mixed silages in Tibet

To enlarge the feed resources and enhance the utilization efficiency of straws as ruminant feed in Tibet, four kinds of local crop straws with tall fescue (Festuca arundinacea Schreb.) based on the ratio of 40/60 (fresh weight) were ensiled with four levels (0, 10%, 20% and 30% of fresh weight) of alfalfa (Medicago sativa L.), respectively. The laboratory silos (1L) were opened after 45 days of ensiling, and the fermentation characteristics, nutritive value and in vitro digestibility of the mixed silages were analysed. The silages including alfalfa had significantly (p < 0.05) or numerically (p > 0.05) higher lactic acid and crude protein contents, lactic acid bacteria counts, in vitro digestibility of dry matter, neutral detergent fibre (NDF) and acid detergent fibre (ADF), and lower NDF and ADF contents than controls. The results suggest that inclusion of alfalfa to mixtures of straws and tall fescue had favourable effects on fermentation quality and obviously improved the nutritive value and in vitro digestibility of mixed silages. This effect was most evident when the inclusion proportion of alfalfa was 30% in oat straw mixed silage.     

A comparison of in vivo and in vitro estimates of protein digestibility of native and thermally processed vegetable proteins

Research was performed to determine the suitability of the rapid multienzymatic assay for in vitro protein digestibility estimation by using a group of native and thermally processed vegetable proteins which constitute the staple foods in developing countries. The in vitro digestibility was assessed by measuring the extent to which the pH of the protein suspension dropped when treated with a multienzyme system consisting of trypsin, chymotrypsin, and peptidase for 10 min, andStreptomyces griseus protease for 10 min more. The best correlation occurred between in vivo rat protein digestibility and the pH of the protein suspension after 15 min enzymatic treatment. The response of different types of proteins to the multienzyme assay was different, and thus distinct equations were derived for the in vitro digestibility estimation of the samples assayed. The first group included nonprocessed cereal grains and oilseeds, and cereal grain-leguminous seed mixtures. The second group was formed by leguminous seeds, and the third by thermally processed cereal and oilseed products. Although highly significant correlations between in vivo and in vitro estimates for the three groups were found, important differences occurred in the group of processed samples; therefore, more research is required with these types of samples.     

The influence of grass and maize silage quality on apparent diet digestibility, metabolizable energy concentration and intake of finishing beef cattle

The effects of offering a range of grass silages and mixtures of grass and maize silages on the intake of beef cattle were studied. Four grass silages (GS1, GS2, GS3 and GS4) were used. Grass silage 1 was ensiled from a second regrowth in mid‐late September and treated with an inoculant additive. Grass silages 2, 3 and 4 were ensiled, without additive, from a primary regrowth harvested in early July, late May and mid‐June respectively. Wilting periods were 8, 30, 36 and 36 h for GS1, GS2, GS3 and GS4 respectively. Grass silages 1, 2 and 3 were precision chopped and ensiled in bunker silos, while GS4 was ensiled in round bales. The DM content (g kg^?1) and starch concentration (g kg^?1 DM) of the three maize silages (MS1, MS2 and MS3) used were 256 and 128, 256 and 184, and 402 and 328 for MS1, MS2 and MS3 respectively. Seventy‐two Charolais and Limousin cross‐bred steers were used in a changeover design with two 4‐week periods. The study consisted of sixteen treatments incorporating the four grass silages fed alone and with the three maize silages arranged as a 4 × 4 factorial design. The grass silage and maize silage mixtures were offered in a ratio of 0·60:0·40 (DM basis) once daily using individual Calan gates. All silages were offered ad libitum with 3 kg per head per day of a concentrate supplement. Dry matter and metabolizable energy (ME) intakes were highest with diets based on grass silage GS4 compared with diets containing the other grass silages. Metabolizable energy intakes of diets containing no maize silage, and those based on MS1 and MS2, were similar (P > 0·05) but lower than that of diets containing MS3. Only limited increases were found in DM and ME intakes with the inclusion of maize silage in grass silage‐based diets while offering high‐quality grass silage (assessed in terms of DM content, and fibre and N concentrations) promoted high voluntary intakes.     

Effects of tropical legume silages on intake,digestibility and performance in large and small ruminants: A review

A meta‐analysis was performed to determine the effects of feeding ruminants with tropical legume silages on intake, digestibility and performance using a data set with 218 treatments (162 containing legumes, 56 without legumes) from 62 trials. First, a regression analysis was performed for diets containing legumes. Dry‐matter intake (DMI) and digestibility decreased with increasing legume proportion, with greater effects on large compared with small ruminants. Milk yield (MY) by dairy cows was not affected by legumes. Average daily gain (ADG) by cattle was maximized with legume silage inclusion between 200 and 400 g/kg DM, but no effect appeared for small ruminants. A second analysis compared diets without legumes with diets with medium (101–400 g/kg DM) and high (401–800 g/kg DM) legume inclusion. There were no differences in DMI, MY and ADG between the medium inclusion and without legumes, but all these parameters decreased with high inclusion. Digestibility was lower in diets with legume silages than in diets without legumes, regardless of the inclusion level. Feed conversion efficiency (FCE) was highest in diets with medium inclusion and lowest with high legume inclusion. While high legume inclusion negatively affected performance, including legume silages up to 400 g/kg DM seems to enhance or at least maintain MY, ADG and FCE, despite lower intake and digestibility. The reasons for such apparent paradox remain unclear. Well‐designed studies focusing on, e.g. microbial protein synthesis, energy metabolism, protein/carbohydrates characteristics, are required to better understand the effects of tropical legumes silages on nutrients’ utilization.     

Apparent digestibility and nitrogen utilization of diets based on maize silage harvested at three stages of maturity and fed to steers

Advancing maize crop maturity is associated with changes in ear‐to‐stover ratio which may have consequences for the digestibility of the ensiled crop. The apparent digestibility and nitrogen retention of three diets (Early, Mid and Late) containing maize silages made from maize of advancing harvest date [dry matter (DM) contents of the maize silages were 273, 314 and 367 g kg^?1 for the silages in the Early, Mid and Late diets respectively], together with a protein supplement offered in sufficient quantities to make the diets isonitrogenous, were measured in six Holstein–Friesian steers in an incomplete Latin square design with four periods. Dry‐matter intake of maize silage tended to be least for the Early diet and greatest for the Medium diet (P = 0·182). Apparent digestibility of DM and organic matter did not differ between diets. Apparent digestibility of energy was lowest in the Late diet (P = 0·057) and the metabolizable energy concentrations of the three silages were calculated as 11·0, 11·1 and 10·6 MJ kg^?1 DM for the Early, Medium and Late diets respectively (P = 0·068). No differences were detected between diets in starch digestibility but the number of undamaged grains present in the faeces of animals fed the Late diet was significantly higher than with the Early and Mid diets (P = 0·006). The apparent digestibility of neutral‐detergent fibre of the diets reduced significantly as silage DM content increased (P = 0·012) with a similar trend for the apparent digestibility of acid‐detergent fibre (P = 0·078). Apparent digestibility of nitrogen (N) was similar for the Early and Mid diets, both being greater than the Late diet (P = 0·035). Nitrogen retention did not differ between diets. It was concluded that delaying harvest until the DM content is above 300 g kg^?1 can negatively affect the nutritive value of maize silage in the UK.     

Effect of a Bangladeshi home-cooking procedure on the amino acid content,trypsin inhibitor activity and in vitro digestibility of some legume seeds

Raw and cooked samples of cultivars ofLens esculenta (Lentils),Pisum sativum (peas),Phaseolus vulgaris (beans),Phaseolus aureus (navy beans)Cicer arietnum (gram), andLathyrus sativus (dhal) as well as precooked commercial products were analysed for amino acids, trypsin inhibitor activity and in vitro protein digestibility. Of the fifteen samples used in the study one lentil sample, one pea sample, two gram samples and one sample of khesari dhal were from Bangladesh, one gram sample was from Sri Lanka. The other samples were obtained either in shops in Norway or from an industrial firm. The latter were also obtained precooked and dried. The two samples obtained in shops were used with hull and dehulled.Neither cooking by a Bangladeshi household procedure nor industrial precooking and drying had any effect on the amino acid contents of the samples.Cooking and precooking reduced the trypsin inhibitor activity of the raw samples more when the original activity was high then when it was low. The inhibitor activity was similar between samples after cooking.Cooking and precooking and drying increased the in vitro protein digestibility in all samples except in the lentils in which the digestibility was reduced.In the raw samples protein digestibility was negatively correlated with the trypsin inhibitor activity.     

Nutritive value of two meadows and relationships with some vegetation traits

This study was designed to compare the evolution in nutritive value between two permanent grasslands that had different botanical composition, during 2 years (2003 and 2004), and to study the relationships between a set of vegetation and digestibility characteristics. Botanical composition, lamina proportions (LP), and in vivo organic matter digestibility (OMD) of grasslands were measured at three different times during the first growth cycle over 2 years: last week in May, third week in June and second week of July. Foliar traits [specific leaf area (SLA) and leaf dry matter content (LDMC)] were measured on grasses in the first period of both years. The LDMC and botanical composition values were used to calculate plant functional types (PFT) of the grasslands at each period. Relationships between OMD and SLA, LDMC, LP and forbs proportions (FP) were tested. Grassland rich in forbs, which was classified in PFT B, showed higher OMD in the first stage of maturity and lower OMD at the end of the cycle in 2004 than grassland rich in grasses, which was classified as PFT C. There were significant relationships between LDMC and OMD across the two first periods. There were also significant relationships between LP and OMD in the first period and between FP and OMD in the third period. The botanical composition of the grassland and consequently its PFT is an important factor explaining the evolution of the nutritive value of permanent grasslands during the first growth cycle.     

Effect of plant development during first and second growth cycle on chemical composition,condensed tannins and nutritive value of three sainfoin (Onobrychis viciifolia) varieties and lucerne

Sainfoin (Onobrychis viciifolia) is a temperate legume that contains condensed tannins (CT), i.e., polyphenols that are able to bind proteins and thus reduce protein degradation in the rumen. Few studies have investigated the relation between plant phenology, CT characteristics and nutritive value of sainfoin. In this study we investigated differences among three sainfoin varieties (Esparcette, Ambra and Villahoz) that were of different geographical origin, and which were cultivated at the same site over the course of two growth cycles and compared with a tannin‐free legume, lucerne (Aubigny). Plants were harvested on nine dates in the first and four dates in the second growth cycle. Phenological stages were analysed for leaf‐to‐whole‐plant ratio, nitrogen (N), organic matter digestibility (OMd) by the pepsin‐cellulase method, cell‐wall concentration, N solubility (solN) plus CT concentration, biological activity and structures. Leaf‐to‐whole‐plant, cell‐wall concentration, N of sainfoin and lucerne were closely related to the phenological stage. Although sainfoin developed earlier than lucerne, its pepsin‐cellulase digestibility was higher than or close to lucerne. Esparcette had the lowest OMd, N and solN and the highest CT concentration. CT concentration, proportion of prodelphinidins (PD) and mean degree of polymerization (mDP) increased with the phenological stage (or plant maturity), and these parameters were associated with lower biological activity of CT. Sainfoin varieties differed in their relationships between phenological stages, nutritional parameters and CT characteristics. The results demonstrated that sainfoin can be a valuable alternative forage legume to lucerne.     

Effect of processing on the in vitro digestibility of proteins and carbohydrates in some Indian legumes

The effect of different types of processing such as boiling, pressure cooking, puffing, frying, germination, and germination followed by cooking on the protein and carbohydrate digestibility of chickpea, horsegram and cowpea were studied in in vitro systems. In the case of chickpea, the protein digestibility was not significantly improved by any of the treatments. However, for horsegram and cowpea, improvement in protein digestibility was observed after some of the different processing treatments. Frying decreased the protein digestibility in all of the pulses. All of the treatments, except germination, caused a marked increase in in vitro carbohydrate digestibility.     

Nutritional and Antinutritional Characteristics of Seven South Indian Wild Legumes

Seeds from seven species of wild legumes of the South India were analyzed for proximate composition, mineral profiles, amino acid profiles of total seed protein, in vitro protein digestibility, and certain antinutritional factors to assess their potential as alternative sources of protein crops. The major findings of the study were as follows: crude protein ranged from 20.3 to 35.0%, crude lipid 3.1–9.6%, crude fiber 5.9–12.1%, ash 2.7–5.1%, and carbohydrates 49.2–61.8%. Minerals viz., sodium, potassium, calcium, magnesium, phosphorus, iron, copper, zinc, and manganese occurred in the range 42.9–135.9, 556.2–1639.5, 304.5–572.2, 174.9–686.7, 98.4–947.8, 3.6–16.4, 0.2–1.2, 2.0–30.0, and 1.0–3.9 mg/100 g seed flour, respectively. Profiles of amino acids of total seed proteins detected in the present study revealed that levels of valine, phenylalanine, tyrosine, isoleucine, and histidine of all the seven wild legume seed samples, threonine of Canavalia ensiformis and C. gladiata, leucine of Mucuna pruriens var. pruriens, and lysine of Cassia floribunda and C. obtusifolia were found to be higher than FAO/WHO (1991) requirement pattern. The in vitro protein digestibility of the legumes under study ranged from 63.39 to 83.32%. Antinutritional factors such as total free phenolics ranged from 0.41 to 5.96%, tannins from 0.04 to 0.60%, L-DOPA from 1.34 to 8.37% and trypsin inhibitor activity from 13.48 to 65.43 TIU/mg protein. The detected antinutritional factors probably have little nutritional significance if the seeds are properly processed.     

Effect of structure of a tropical pasture on ingestive behaviour, digestibility of diet and daily intake by grazing cattle

The effect of the structure of a tropical pasture, based on Dichanthium spp., on the ingestive behaviour, in vivo digestibility of the diet and herbage intake by eight Creole tethered heifers was studied. Two levels of nitrogen fertilizer (0 and 50 kg ha^?1) were applied to plots after each grazing cycle and there were 28 d between each of the three grazing cycles. Four heifers grazed individual subplots daily on each plot for 14 d in each of the successive grazing cycles. Simultaneous measurements of bite depth, bite mass, biting rate, short‐term intake rate and daily grazing time were made in two 4‐d periods at the end of each 14‐d period. The in vivo organic matter digestibility (OMD) and daily herbage organic matter intake (OMI, expressed on a kg LW^0·75 basis) were also measured at the same times. Relationships among pasture characteristics and ingestive behaviour were similar to those reported in other short‐term studies: pasture height was highly correlated with bite depth, bite mass and biting rate (r = 0·91, r =0·79 and r = ?0·68, respectively, P < 0·001). Pasture variables had lower correlations with grazing time and short‐term intake rate than with bite depth, bite mass and biting rate. Pasture structure was more highly correlated with OMD than OMI: leaf mass and length and also the extended tiller length were highly correlated with OMD (r = 0·77, r = 0·76 and r = 0·72, respectively, P < 0·001) whereas the crude protein concentration of the herbage was correlated with OMI and digestible OMI (r = 0·50 and r = 0·69, respectively, P < 0·001). Ingestive behaviour variables, as well as OMD, were correlated more with pasture characteristics than was OMI.     

Formulation,acceptability, chemical composition and in vitro digestibility of novel snack food and meat ball analogue

Potato purée and wheat flour were blended at ratio of 7:1 w/w with 2 parts per weight of soybean protein concentrate (SPC) and/or faba bean-protein micellar mass (PMM). Two snack foods were formulated and deep fried. Spices, onion, parsley and chicken stock were added to the aforementioned two recipes to formulate meat ball analogues. Data revealed good acceptability of all products. Moreover, they can be considered as a good source for some essential amino acids; protein (26%); lipids (20%); carbohydrates (48%) and minerals. The in vitro digestibility ranged between 61.0% and 66.9%.     

Estimation of nitrogen concentration and in vitro dry matter digestibility of herbage of warm-season grass pastures from canopy hyperspectral reflectance measurements

Remote sensing of nitrogen (N) concentration and in vitro dry matter digestibility (IVDMD) in herbage can help livestock managers make timely decisions for adjusting stocking rate and managing pastures during the grazing season. Traditional laboratory analyses of N and IVDMD are time-consuming and costly. Non-destructive measurements of canopy hyperspectral reflectance of pasture may provide a rapid and inexpensive means of estimating these measures of nutritive value. Using a portable spectroradiometer, canopy reflectance was measured in eight warm-season grass pastures in the USA in June and July in 2002 and 2003 to develop and validate algorithms for estimating N concentration and IVDMD of herbage. Nitrogen concentration of herbage was linearly correlated (r = 0·82; P < 0·001) with a ratio of reflectance in the 705- and 1685-nm wavebands (R₇₀₅/R₁₆₈₅) and IVDMD was correlated with R₇₀₅/R₅₃₅ (r = 0·74; P < 0·001). Compared with simple linear regressions of N concentration and IVDMD in herbage with two-waveband reflectance ratios, multiple regression, using maximum r² improvement, band-depth analysis with step-wise regression, and partial least-squares regression enhanced the correlation between N concentration and IVDMD of herbage and canopy reflectance values (0·81 ≤ |r| ≤ 0·90; P < 0·001). Validation of the prediction equations indicated that multiple regression only slightly improved accuracy of a model for predicting N concentration and IVDMD of herbage compared with simple linear regression of reflectance ratios. Results suggest that the N concentration and IVDMD of herbage of warm-season grass pastures can be rapidly and non-destructively estimated during the grazing season using canopy reflectance in a few narrow wavebands.     

Nutritive value of desert wormwood (Artemisia desertorum Spreng.) silage in mixture with high‐moisture maize straw

This study aimed to determine the fermentation characteristics, nutrient composition and in vitro digestibility of desert wormwood (DW, Artemisia desertorum Spreng.) silage as the sole ingredient, or mixed with high‐moisture maize (corn) straw (HMCS). Desert wormwood and HMCS were harvested and chopped (1–2 cm) then ensiled in laboratory silos (25 cm high with an internal diameter of 7·6 cm) at a density of 550 g L^?1 at room temperature for 60 days. The proportions of DW in the DW/HMCS mixtures were 1, 0·75, 0·50, 0·25 and 0, based on fresh weight. The silages were analysed for fermentation characteristics, nutrient composition and in vitro digestibility. Desert wormwood ensiled with HMCS had lower pH and acetic acid concentration and higher lactic acid concentration as the proportion of DW decreased. As the proportion of DW decreased, the crude protein concentration and the in vitro digestibility of dry matter increased and the concentrations of neutral detergent fibre, acid detergent fibre and acid detergent lignin decreased. This study has indicated that mixing HMCS with DW can improve the fermentation quality and nutrient composition of these silage mixtures.     

Phytic acid,in vitro protein digestibility,dietary fiber,and minerals of pulses as influenced by processing methods

The objective of this project was to determine the effect of various types of processing on selected nutrition related parameters of commonly consumed Indian pulses and soybean. Germination reduced the phytic acid content of chickpea and pigeonpea seeds by over 60%, and that of mung bean, urd bean, and soybean by about 40%. Fermentation reduced phytic acid contents by 26–39% in all these legumes with the exception of pigeonpea in which it was reduced by more than 50%. Autoclaving and roasting were more effective in reducing phytic acid in chickpea and pigeonpea than in urd bean, mung bean, and soybean. Germination and fermentation greatly increased the in vitro protein digestibility (IVPD). IVPD was only slightly increased by roasting and autoclaving of all legumes. Germination and fermentation also remarkably decreased the total dietary fiber (TDF) in all legumes. Autoclaving and roasting resulted in slight increases in TDF values. All the processing treatments had little effect on calcium, magnesium and iron contents.     

In vitro digestibility and calculated PER as rapid methods for the nutritional evaluation of potato protein

Protein Efficiency Ratios (PER) have been determined for hybrid potato selections by feeding flake diets to rats; more rapid and inexpensive tests are required by breeding programs which select for improved potato protein. Two more recent methods, in vitro digestibility (IVD) and calculated PER utilizing discriminant computed PER (DC-PER) and computed PER (C-PER), were studied for their potential in evaluation of the nutritional quality of potato. Albumin (A) and two subfractions, acid soluble and insoluble (ASA and AIA), were studied, as well as flakes. The average IVD for albumin was 68.9%, for ASA was 67.5% and for AIA was 77.5%. Digested proteins were identified by electrophoresis before and after enzyme treatment. The higher IVD values for AIA were probably due to the presence of protease inhibitors among the ASA proteins. IVD differences among groups of hybrids were found and a reasonable correlation (r=0.71*) of these values with flake PER values was observed. The DC-PER values ranged from 2.64 to 2.79, these values were larger than those observed in feeding trials; additional genotypes need to be studied before this method can be proposed for potato evaluation. The presence of protease inhibitors in the albumin samples is indicated, because the average IVD value of 68 increased to about 84 after the albumins were heated prior to IVD determinations.Scientific Journal Article 12,095 of the Minnesota Agricultural Experiment Station. This research was supported by a USDA/SEA Grant.     

A collaborative study of methods of protein evaluation: introductory paper

The USDA's collaborative study of methods of protein quality evaluation is introduced. It was intended primarily to provide a basis for the evaluation of possibly improved procedures for the labelling of foods as a source of dietary protein. In general, the usefulness of in vitro digestibility procedures has been confirmed, but problems remained for the in vitro evaluation of heat-damaged materials and of some types of pinto beans.     

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.