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Green biorefineries provide novel opportunities to use the green biomass efficiently and utilize the ecosystem services provided by grasslands more widely. The effects of the inclusion of fractionated grass silage solid fraction (pulp) on feed intake, rumen fermentation, diet digestion and milk production in dairy cows were investigated. Pulp was separated from grass silage using a screw press simulating a green biorefinery. Partial removal of liquid from forage increased DM concentration from 220 to 432 g/kg and NDF from 589 to 709 g/kg DM while CP decreased from 144 to 107 g/kg DM. A feeding trial using an incomplete changeover design with 24 Nordic Red cows and two 3-week periods was conducted. The pulp replaced grass silage in the diet at 0 (P0), 25 (P25) and 50 (P50) percentage of total forage, which was fed ad libitum with 13 kg of concentrate for all treatments. The forage DM intake was highest on P25 (14.1 kg/day) while P0 and P50 did not differ from each other (13.2 and 13.0 kg/day, respectively). There were no differences between the treatments in rumen pH or ammonia N, but the proportion of acetate increased with increasing pulp inclusion. The digestibility was measured using acid insoluble ash and indigestible NDF (iNDF) as internal markers. Neither of the markers detected differences in NDF digestibility, but according to iNDF, apparent total tract organic matter digestibility decreased with increasing pulp inclusion. The cows maintained milk production at P25, but it showed some decline at P50 (energy-corrected milk at P0 and P25 was 39.8 kg/day while for P50, it was 38.5 kg/day, P = 0.056) and the milk protein yield significantly declined with higher pulp inclusion. Simultaneously, the nitrogen use efficiency in milk production increased. It seems that the fibrous grass-based fraction from a biorefinery process has potential to be used as a feed for ruminants.

International audience; It is essential to have accurate data relating sward herbage mass (HM) to voluntary dry matter intake (VDMI) and in vivo organic matter digestibility (OMDIV) across the year. This will ensure that the production performance of animals grazing differing HM swards can be accurately predicted using in vitro and in situ methods. The objectives of this experiment were to (i) determine the OMDIV and VDMI of sheep offered perennial ryegrass differing in HM throughout the growing season and (ii) evaluate in vitro gas production (IVGP) and in situ indigestible neutral detergent fibre (iNDFIS) as methods of predicting OMDIV. A 3 × 3 Latin square design was used to investigate three HM treatments. The target HM (measured > 4 cm) of perennial ryegrass for the three HM treatments was 1200 kg dry matter (DM)/ha (Low), 2500 kg DM/ha (Medium) and 4000 kg DM/ha (High). The experiment was a Latin square design repeated in three time stages (TS) in 2013 (TS1, TS2 and TS3). A 3 × 2 incomplete Latin square design was used in early spring 2014 (TS4). In TS4 the HM were lower than in the previous TS at 1000 kg DM/ha (Low), 1800 kg DM/ha (Medium) and 2500 kg DM/ha (High). Each experimental period within each TS consisted of a 6 day adaptation phase and 6 day measurement phase; with 12 Texel wether sheep used. Sheep were fed ad libitum to ensure a 10% refusal rate. The interaction between TS and HM treatment had the greatest effect on chemical composition, VDMI and OMDIV. Low HM swards had the greatest VDMI and OMDIV. For each 1000 kg DM/ha increase in HM, OMDIV was reduced by 2.3% on average. This varied from 0.9% in TS4 to 2.7% in TS3. There was no difference between HM treatments in the rate of digestion of digestible NDF using the IVGP technique. In situ indigestible NDF concentration and OMD derived from IVGP (OMDGP) were highly correlated with OMDIV (r2 = 0.901 and 0.895 respectively) and moderately correlated with digestible organic matter intake (DOMI) (r2 = 0.633 and 0.652 respectively). It can be concluded that the interaction between HM and TS will greatly affect OMDIV and VDMI. Secondly OMDIV can be predicted by both iNDFIS and OMDGP with acceptable accuracy to allow for their use in future feed evaluations.

The effects of rapeseed and soya bean expeller (SBE) supplementation on digestion and milk production responses in dairy cows were investigated in an incomplete Latin square design using five cows and four 3-week periods. The experimental diets consisted of five concentrate treatments fed at a rate of 9 kg/day: a mixture of barley and oats, which was replaced with rapeseed or SBE at two levels (CP concentration (g/kg dry matter (DM)) of 130 for the control concentrate and 180 and 230 for the two protein supplemented levels). A mixture of grass and red clover silage (1:1) was fed ad libitum and it had a CP concentration of 157 g/kg DM. Supply of nutrients to the lower tract was measured using the omasal canal sampling technique, and total digestion from total faecal collection. Protein supplementation increased omasal canal amino acid (AA) flows and plasma concentrations of AA, and was also reflected as increased milk production. However, N use efficiency (NUE) decreased with increased protein supplementation. Rapeseed expeller (RSE) tended to increase silage DM intake and elicited higher milk production responses compared with SBE and also resulted in a higher NUE. The differences between the protein supplements in nitrogen metabolism were relatively small, for example, there were no differences in the efficiency of microbial protein synthesis or omasal canal flows of nitrogenous components between them, but plasma methionine concentration was lower for soya bean-fed cows at the high CP level in particular. The lower milk protein production responses to SBE than to RSE supplementation were at least partly caused by increased silage DM and by the lower methionine supply, which may further have been amplified by the use of red clover in the basal diet. Although feed intake, diet digestion, AA supply and milk production were all consistently improved by protein supplementation, there was a simultaneous decrease in NUE. In the current study, the milk protein production increased only 9% and energy-corrected milk production by 7% when high level of protein supplementation (on average 2.9 kg DM/day) was compared with the control diet without protein supplementation showing that dairy production could be sustained at a high level even without external protein supplements, at least in the short term. The economic and environmental aspects need to be carefully evaluated when decisions about protein supplementation for dairy cows are taken.

Agroforestry, the integration of trees and agriculture, is valued as a multifunctional land use approach that balances the production of commodities (food, feed, fuel, fibre etc.) with non-commodity outputs such as environmental protection and cultural and landscape amenities. In this study, the possibilities for fodder production from a short rotation coppice of willow (Salix viminalis) used for wood chips to produce energy were investigated. The nutritional value and ensilability were assessed from first year regrowth of willow harvested on 29 June 2011 at Wakelyns Agroforestry, Suffolk, UK. The willow branches with a stem diameter less than 8 mm were manually harvested from 4 plots in two replicates. From 2 plots, another sample was prepared including leaves only. Both dried raw material and silage samples ensiled in evacuated polyethylene bags were analyzed. The crude protein concentration was relatively high in leaf + stem silage (182 g/kg dry matter (DM)) and even higher in leaf only silage (219 g/kg DM) and the fibre concentration was relatively low. However, the organic matter digestibility determined by in vitro pepsin-cellulase method was low (0.421 for leaf + stem silage and 0.511 for leaf only silage) and it cannot be considered as a suitable feed for lactating dairy cows. However, it might be suitable for other animal groups with lower energy requirements. The appearance and smell of the silage samples at opening of the vacuum plastic bags was rather pleasant with minor deteriorations (probably yeasts) visible. The extent of fermentation was low and pH high (5.79) for a rather low DM material (DM concentration 276 g/kg). The water soluble carbohydrates of the raw material (35 g/kg DM) and the residual water soluble carbohydrate concentration in silages was relatively low, which at least partly explains the restricted production of fermentation acids. The fermentation profile was heterofermentative (acetic acid dominated instead of lactic acid). The concentrations of total condensed tannins fractions were almost twice as high in the leaf only silage compared to leaf + stem silage. Although the feed values of willow were low, it may have a role in multifunctional systems, where it can provide additional values in grazing situations such as self-medication and microclimate benefits. For easy and efficient use in animal production, controlled browsing might be used; otherwise methods for harvesting and preservation need to be developed. There seems to be some scope for ensiling willow material. This work is part of an EU FP7 funded project “Sustainable organic and low input dairying” (SOLID, KBBE.2010.1.2-02). For more information on the project, see www.solidairy.eu

The objective of the present study was to evaluate the potential of pressurized hot water extracted hemicellulose fractions from various wood species as feeds for ruminants. In Experiment 1, the fermentability of several hemicellulose extracts was screened using an in vitro gas production method. The samples were extracted from spruce (Picea abies) including mainly galactoglucomannan (GGM), from birch (Betula pendula) consisting mainly of xylan and from larch (Larix sibirica) consisting mainly of arabinogalactan. The GGM and xylan samples were readily fermented by rumen microbes while arabinogalactan was not. Based on the in vitro study, GGM was chosen for an in vivo digestibility trial using sheep, where it was fed at increasing proportions of diet dry matter (0, 47, 94 and 141 g kg-1) in a Latin Square design. The in vivo organic matter digestibility of GGM was relatively low, 0.58, but PHWE extracted hemicellulose has some potential as a feed for ruminants.

Passage, breakdown and digestion rates of large and small particles were estimated using the rumen evacuation technique and total faecal collection with four lactating dairy cows in a4 ×4 Latin square experiment. Two primary growth grass (PG) and two regrowth grass (RG) silages, each harvested at two different growth stages, were fed as dietary treatments supplemented with 8.0 kg concentrate per day. Ruminal contents and faeces were divided into large (>1.25 mm; LP) and small (1.25–0.04 mm; SP) particles by wet sieving. Indigestible neutral detergent fibre (iNDF) was determined by 12-day ruminal in situ incubation followed by a neutral detergent extraction. Ruminal iNDF content of LP (LPiNDF) and SP (SP-iNDF) for both PG and RG diets increased with advancing maturity of the grass. The passage rate of SP-iNDF tended to be faster (P

Passage, comminution and digestion rates of large and small particles were estimated using a rumen evacuation technique and total faecal collection with five lactating dairy cows in a 5 × 5 Latin square experiment. Two grass and two red clover silages harvested at early and late primary growth stages and a 1:1 mixture of late harvest grass and early harvest red clover were the dietary treatments. Cows received 9.0 kg supplementary concentrate per day. Ruminal contents and faeces were divided into large (>1.25 mm) and small (1.25–0.038 mm) particles by wet sieving. Indigestible neutral detergent fibre (iNDF) was determined by 12 days ruminal in situ incubation followed by neutral detergent extraction. Plant species did not affect ruminal particle size distribution, whereas advancing forage maturity decreased the proportion of large particles for both grass and red clover silage diets. Ruminal pool size of iNDF was higher (P

Two silages were prepared from the primary growth (PG) of timothy-meadow fescue sward at early (E) and late (L) stage of growth. The subsequent regrowth (RG) areas were further harvested at early (EE and LE) and late (EL and LL) stages of growth resulting in six silages in total. The silages were fed ad libitum to 24 lactating Finnish Ayrshire cows and supplemented with 8 or 12 kg concentrate per day in a cyclic change-over experiment with four 21-day periods and 6 × 2 factorial arrangement of treatments. The quality of silages varied markedly within and between the harvests although variation was greater within PG than RG. Postponing the harvest in PG decreased silage dry matter (DM) intake by 0.48 kg and energy corrected milk yield (ECM) by 0.61 per 10 g decrease in silage D-value (concentration of digestible organic matter in DM), while responses and the range between the diets were clearly smaller when RG silages were fed. On average, ECM yield was higher when PG rather than RG silages were fed. The mean response to increased concentrate DM intake was 0.62 kg ECM using diets based on PG. The response increased with increasing growth stage of grass being 0.34 and 1.01 kg ECM / kg additional concentrate DM for E and L, respectively. The difference was mainly mediated by the differences in substitution rates (reduction in silage DM intake per increase in concentrate DM intake, kg/kg), which were 0.71 and 0.22 for E and L, respectively. The ECM response to increased concentrate allowance was on average greater when RG rather than PG silages (0.92 vs. 0.62 kg/kg concentrate) were fed. Milk production of dairy cows reflected the intake of metabolizable energy and no differences in the utilization of it were found between diets based on silages harvested from PG and RG. However, intake of RG silages was slightly lower than that of comparable PG silage, but definite reasons for that could not be identified.

The effects of increased concentrate level on milk production was assessed during two consecutive indoor feeding seasons according to a continuous randomised block design using 44 (season 1) and 47 (season 2) Finnish Ayrshire cows. Treatments allocated according to a 2×2 factorial design consisted of two concentrate levels and two protein feeding systems. Low and high concentrate feeding regimens were applied to multiparous cows as 9 and 14 kg/day during days 1–150 of lactation and 8 and 11.5 kg for days 151–224, respectively. Primiparous cows received proportionately 0.80 of that fed to multiparous cows. In order to identify the effects of concentrate energy alone, concentrates were formulated so that increases in concentrate feeding resulted in either a constant supply of concentrate crude protein (CP) (mean 1.4 kg/day) or constant intake of rapeseed meal (RSM) (mean 1.7 kg DM/day). Consequently, concentrate CP content decreased with the increasing level of concentrate. Concentrate was offered through computerised self-feeders and silage was fed ad libitum. Increasing energy intake at a constant CP level seemed to have a more negative effect on silage dry matter (DM) intake compared with feeding a constant supply of RSM. Increases in concentrate DM intake resulted in mean substitution rates of 0.48 and 0.25 for CP and RSM diets, respectively. However, the positive effect of concentrate supplementation on milk yield was independent of protein feeding strategies. Milk production increased ( P

This study examined the effects of primary growth (PG) and regrowth (RG) timothy-meadow fescue silages harvested at 2 stages of growth on feed intake, cell wall digestion and ruminal passage kinetics in lactating dairy cows. Four dairy cows equipped with rumen cannulas were used in a study designed as a 4 x 4 Latin square with 21-d periods. The experimental silages were offered ad libitum with 8 kg/d of concentrate. Ruminal digestion and passage kinetics were assessed by the rumen evacuation technique. Silages of PG were on average more digestible than RG silages. The concentration of neutral detergent fiber (NDF) and indigestible NDF (iNDF) increased and the concentration of digestible organic matter in dry matter (DM) of silages decreased with advancing maturity in PG and RG. Cows consumed more feed DM, energy, and protein and produced more milk when fed PG diets rather than RG diets. Delaying the harvest decreased DM intake and milk production in PG and RG. There were no differences between PG and RG in rumen pH, ammonia N, or total volatile fatty acid concentrations. The intake of N, omasal canal flow of total nonammonia N and microbial N, excretion of N in feces, and ruminal true digestibility of N were higher for PG than for RG diets. The efficiency of microbial N synthesis was not different between PG and RG. Intake and omasal canal flow of organic matter, NDF, and potentially digestible NDF (pdNDF) were higher in PG than in RG. Whole-diet digestibility of organic matter, NDF, or pdNDF in the rumen or in the total tract was not different between PG and RG despite the higher digestibility of PG silages measured in sheep. Rumen pool sizes of crude protein and iNDF were lower for PG diets, whereas the pool size of pdNDF was higher for PG diets than for RG diets. The rate of passage of iNDF was higher for PG diets than for RG diets, with no difference between them in rate of digestion or passage of pdNDF. The lower milk production in cows fed regrowth grass silages compared with primary growth silages could be attributed to the lower silage DM intake potential. Chemical composition of the silages, rumen fill, digestion and passage kinetics of NDF, or the ratio of protein to energy in absorbed nutrients could not explain the differences in DM intake between silages made from primary and regrowth grass.

This study examined the effects of red clover or grass silages cut at 2 stages of growth on feed intake, cell wall digestion, and ruminal passage kinetics in lactating dairy cows. Five dairy cows equipped with rumen cannulas were used in a study designed as a 5×5 Latin square with 21-d periods. Diets consisted of early-cut and late-cut grass and red clover silages and a mixture of late-cut grass and early-cut red clover silages offered ad libitum. All diets were supplemented with 9 kg/d of concentrate. Ruminal digestion and passage kinetics were assessed by the rumen evacuation technique. Apparent total-tract digestibility was determined by total fecal collection. The silage dry matter intake was highest when the mixed forage diet was fed and lowest with the early-cut red clover diet. Delaying the harvest tended to decrease DMI of grass and increase that of red clover. The intake of neutral detergent fiber (NDF) and potentially digestible NDF (pdNDF) was lower but the intake of indigestible NDF (iNDF) was higher for red clover diets than for grass diets. The rumen pool size of iNDF and the ratio of iNDF to pdNDF in the rumen contents were larger, and pool sizes of NDF and pdNDF were smaller for red clover than for grass silage diets. Outflow of iNDF and the ratio of iNDF to pdNDF in digesta entering the omasal canal were larger, and the outflow of pdNDF was smaller for red clover than for grass silage diets. The digestion rate (k d ) of pdNDF was faster for red clover diets than for grass silage diets. Delaying the harvest decreased k d for grass but increased it for red clover silage diets. Observed differences in fiber characteristics of red clover and grass silages were reflected in ruminal digestion and passage kinetics of these forages. The low intake of early-cut red clover silage could not be explained by silage digestibility, fermentation quality, or rumen fill, but was most likely related to nutritionally suboptimal composition because inclusion of moderate quality grass silage improved silage intake. Increasing the maturity of ensiled red clover does not seem to affect silage dry matter intake as consistently as that of grasses.

This study investigated the effects of plant species (red clover vs. timothy-meadow fescue) and forage maturity at primary harvest (early vs. late cut silage) on rumen fermentation, nutrient digestion, and nitrogen metabolism including omasal canal AA flow and plasma AA concentration in lactating cows. Five dairy cows equipped with rumen cannulas were used in a study designed as a 5 x 5 Latin square with 21-d periods. The diets consisted of early-cut and late-cut grass and red clover silage, respectively, and a mixture of late-cut grass and early-cut red clover silages given ad libitum with 9 kg/d of a standard concentrate. Grass silage dry matter intake tended to decrease but that of red clover silages tended to increase with advancing maturity. Milk yields were unchanged among treatments, milk protein and fat concentrations being lower for red clover than for grass silage diets. Rumen fluid pH was unchanged but volatile fatty acid and ammonia concentrations were higher for red clover than for grass silage diets. Intake of N, and omasal canal flows of total nonammonia N (NAN), microbial NAN, and dietary NAN were higher for red clover than for grass silage diets but were not affected by forage maturity. However, microbial NAN flow and amount of N excreted in the feces decreased with advancing maturity for grass diets but increased for red clover diets. Apparent ruminal N degradability of the diets was unchanged, but true ruminal N degradability decreased and efficiency of microbial synthesis increased with red clover diets compared with grass silage diets. Omasal canal flows of AA, except those for Met and Cys, were on average 20% higher for red clover than grass silage diets. Omasal canal digesta concentrations of Leu, Phe, branched-chain, and essential AA were higher but those of Met lower for red clover than for grass silage diets. Plasma AA concentrations, except for His (unchanged) and Met (lower), were higher for red clover than for grass diets. However, none of these AA-related variables were affected by forage maturity. Total digestibility of N and excretion of N in the urine were higher for red clover than for grass diets and decreased with advancing maturity. It was concluded that despite the higher total AA supply of cows fed red clover versus grass silage diets, further milk production responses on red clover diets were compromised by an inadequate supply of Met as evidenced by lower Met concentration in the AA profile of omasal digesta and plasma.