bluuebunny/crossref_metadata_2025 huggingface dataset:
Triticale and other small grain cereals for forage and grain in Mediterranean conditions
Authors: ROYO C. , MONTESINOS E. , MOLINA‐CANO J. L. , SERRA J.
Published: April 2006

In field experiments conducted over 2 years, triticale was compared with barley, bread wheat and oats for its dual‐purpose (forage and grain) capability.

The effect of spring forage removal on grain yield ranged from small yield increases (in the triticale and barley genotypes that otherwise lodged) to a 53% decrease, and was dependent on species, genotype, stage of development when cut, and time for recovery before grain harvest. A key factor influencing grain yield after early cutting was the number of spikes that developed.

The complete types of triticale were better than the one substituted type tested for dual purpose but, as there is variability among them, selection for good mixed aptitude is possible.

The production of the best triticale averaged over 2 years 3 t of forage DM ha‐1 (with 684 kg of crude protein ha‐1) and then 4–3 t of grain ha‐1. In this instance, neither the grain yield nor the number of spikes per plant were reduced after clipping, in spite of the fact that the shoot apices were removed.

Plant height and lodging were reduced by a forage cut. In triticale, the number of days to heading was increased even more when the cut was late, but no effect was observed in barley.
Progress in breeding interspecific hybrid ryegrasses
Authors: JONES M. LL. , HUMPHREYS M. O.
Published: April 2006

Stable hybrids were produced between tetraploid perennial and Italian ryegrasses derived from commercial varieties and germplasm introduced from European collections. Spaced plant characteristics were used to select Fl plants for the production of F2 families which were assessed in small plots for growth and quality traits. Ten of the 19 selected hybrid families were based on perennial ryegrass collected from the Zurich Uplands. The influence of this parental material in improving vegetative growth during early spring, late summer and autumn was demonstrated. Its use in improving feeding value by increasing the water‐soluble carbohydrate content of hybrids was also shown. Consequently, selected hybrid varieties based on this new genetic resource showed considerable improvements in seasonal growth and quality over the older hybrid variety Augusta and Italian ryegrass variety RvP.
Cell wall degrading enzymes for silage. 1. The fermentation of enzyme‐treated ryegrass in laboratory silos
Authors: SELMER‐OLSEN I. , HENDERSON A. R. , ROBERTSON S. , McGINN R.
Published: April 2006

The effects of two commercial cellulase/hemicellulase enzymes derived from Trichoderma reesei on silage fermentation were investigated in three laboratory‐scale experiments. In Experiment 1, perennial ryegrass (Lolium perenne) was treated with enzyme A at the rates of 0, 0·125, 0·250, 0·500 and 0·750 cm3 kg‐1. In Experiment 2, Italian ryegrass (Lolium multiflorum) was treated with the same enzyme at the rates of 0, 0·250 and 0·500 cm3 kg‐1 and with 85% formic acid (3·5 cm3 kg‐1). In Experiment 3, perennial ryegrass was ensiled untreated, with enzyme A (0·250 and 0·500 cm3 kg‐1) and with 0·200 and 0·400 cm3 kg‐1 enzyme B which also contained glucose oxidase. All silages were well preserved. In general enzyme treatment reduced pH and the contents of ammonia nitrogen, neutral detergent fibre and acid detergent fibre, whereas the contents of water‐soluble carbohydrates, acetic acid, lactic acid and ethanol were increased.
Herbage intake and liveweight gain of bulls and steers continuously stocked at fixed sward heights during autumn and spring
Authors: MORRIS S. T. , HIRSCHBERG S. W. , MICHEL A. , PARKER W. J. , McCUTCHEON S. N.
Published: April 2006

Two experiments were conducted to examine the relationship between sward surface height, herbage intake and liveweight gain in beef cattle grazed on pasture. In Experiment 1, two ‘animal types’ (18 Charolais × Angus steers and 18 Friesian bulls) were continuously grazed for 22 days during the late autumn on replicated swards maintained at sward surface heights of 6, 10 and 15 cm. Herbage intakes, assessed from the faecal concentration of chromium delivered from an intraruminal controlled release capsule and the in vitro digestibility of hand‐plucked herbage samples, were curvilinearly related to sward height (r = 0·76, p<0·0·01). Average liveweight gains were 0·02, 0·61 and 1·31 kg d‐1 (P <0·05) and increased linearly (r= 0·84, P <0·001) with sward height. The maintenance organic matter intakes of the steers and bulls, with initial mean (± s.e.) live weights of 225 ± 15 kg and 172 ± 15 kg respectively, were estimated to be 3·6 and 3·5 kg d‐1 respectively. In Experiment 2 (spring) 36 cattle, including 35 of those used in Experiment 1, were reallocated to sward heights of 5, 10 and 15 cm using the same design as for Experiment 1. Average liveweight gains were 0·94, 1·57 and 1·68kg d‐1 (p 0·05) and were curvilinearly related to sward height (r= 0·093, p <0·05). Maintenance intakes could not be reliably extimated for the cattle in Experiment 2 because few animals had liveweight gains close to zero. These trials confirm that liveweight gain in continuously grazed finishing steers and bulls increases with sward surface height to maximum of 8–10cm with spring ryegrass/white clover pastures while, in autumn, swards of 12–15cm height are required to achieve maximum performance.
Component yields and quality of binary mixtures of lucerne and perennial, Italian or short rotation hybrid ryegrass
Authors: JUNG G. A. , SHAFFER J. A.
Published: April 2006

Studies were conducted to characterize sward dynamics of lucerne (Medicago sativa L.) and perennial, Italian or short rotation hybrid rye‐grass (Lolium perenne L. and L. multiflorum Lam.) binary mixtures under hay management. Lucerne/timothy (Phleum pratense L.) mixtures were included as controls. The study was conducted on two farms in central Pennsylvania, USA on Hagerstown silt loams (fine, mixed, mesic hapludalf). Total dry matter yield, grass yield and yield of digestible dry matter were higher for tetraploid perennial and tetraploid Italian ryegrass mixtures than for timothy mixtures. Seasonal production differed for the three kinds of ryegrass. Italian ryegrass dry matter yields were higher in cuts 2 and 3 than perennial ryegrass yields. Grass yields represented 34%, 24% and 12% of total yields of the Italian, perennial or short rotation, and timothy mixtures, respectively. However, herbage in vitro dry matter digestibility of Italian was lower than that of perennial ryegrass.

The tetraploid perennial ryegrasses Grimalda and Reveille had high‐ranking N concentrations more frequently than other cultivars, while Bar‐vestra and Reveille tetraploid perennials and Bison short rotation ryegrass had high‐ranking dry matter digestibility values more frequently than the other cultivars. Perennial ryegrass cultivars and Lipo tetraploid Italian ryegrass persisted well for 4 years and produced higher yields with a lower weed content than timothy mixtures. It is concluded that perennial ryegrasses and Lipo Italian ryegrass should be recommended over timothy, as companion grasses with lucerne.
The effects of forage preservation method and proportion of concentrate on nitrogen digestion and rumen fermentation in cattle
Authors: JAAKKOLA S. , HUHTANEN P.
Published: April 2006

A 6 × 6 Latin square experiment with a 2 × 3 factorial arrangement of treatments was used to study forage preservation method and level of concentrate in a diet on organic matter (OM) and N digestion and rumen fermentation. Six bulls, each fitted with ruminal and duodenal cannulae, were given unwilted silage (S) or barndried grass (G) prepared simultaneously from the same timothy sward. The forages were fed together with 250 (L), 500 (M) or 750(H)g concentrate dry matter (DM)kg‐1 total diet DM. The concentrate consisted of barley (875 gkg‐1) and rapeseed meal (125g kg‐1). The feeding level was 80g DMkg‐1 live weight0·75.

The apparent digestibility of OM was similar for S and G diets, and increased linearly (P < 0·001) with increasing level of concentrate. The flow of microbial N at the duodenum and the apparent efficiency of microbial protein synthesis in the rumen were higher (P < 0·05) with S than with G diets. Increasing the concentrate level increased linearly (P < 0·05) the amounts of total N and microbial N at the duodenum, whereas the synthetic efficiency was not significantly affected. The mean rumen pH decreased linearly (P < 0·001) from 6·43 to 6·03 with increasing concentrate level. The molar proportion of acetate (Ac) in the rumen volatile fatty acids (VFA) showed a linear (P < 0·001) and quadratic (P < 0·01) decrease, and that of butyrate (Bu) a linear (P < 0·001) increase when the level of concentrate was increased. The proportion of propionate decreased slightly with both forages when the amount of concentrate was increased from level L to M. A further increase to level H increased propionate from 157 to 170 mmol mol‐1 of total VFA with S and from 157 to 188 mmol mol‐1 with G, the effect of concentrate level being not significant. The number of protozoa increased linearly (P < 0·001) as the level of concentrate increased. The changes in the rumen fermentation patterns during the feeding cycle were greater for S than for G diets.
Influence of growth stage and season on the energy value of fresh herbage. 1. Changes in metabolizable energy content
Authors: GIVENS D. I. , MOSS ANGELA R. , ADAMSON A. H.
Published: April 2006

The energy value and chemical composition of 70 herbages harvested over two years as either spring primary growths of increasing maturity (n= 32), summer regrowths (n= 14) or autumn regrowths of increasing maturity (n= 24) are reported. The herbages, which were dominated by perennial ryegrass, were harvested from commercial grassland on four sites in England in1986 (year 1) and 1987 (year 2). Digestibility and energy values were determined in vivo using wether sheep.

In year 1, autumn regrowths had significantly (P < 0·05) lower neutral detergent fibre concentrationsthan summer regrowths, and lignin was lower (P < 0·05) in spring than in summer herbages. In year 2, autumn herbages had significantly(P < 0·05) higher concentrations of crude protein and hemicellulose than summer and autumn herbages. Spring herbages had higher concentrations of water‐soluble carbohydrates than summer (P 0·01) and autumn (P < 0·001) herbages.

A higher (P < 0·05) metabolizable energy (ME) concentration was observed in spring compared with summer herbages in year 2 and in general there was considerably more variability in the values for the spring growths, ME content fell with increasing maturity in spring growths(0·046 and 0·035 MJ kg‐1 DM per day; years 1and 2 respectively) and this decline was 3–4 times faster than for autumn‐harvested material (0·012 and 0·017 MJ kg‐1 DM per day; years 1 and 2 respectively). In both years only immature spring herbages consistently produced ME contents in excess of 11·9 MJ kg‐1 DM.

For 15 of the herbages the proportion of gross energy intake (GEI) lost as methane was measured directly using respiration chambers. The mean methane energy loss was 0·07 of GEI (range 0·057–0·082). A commonly used publish equation for predicting methane energy loss was shown not to be appropriate, although no relationships could be established between methane energy loss and either energy digestibility in vivo or chemical composition.
Sodium fertilizer application to pasture. 2. Effects on dairy cow production and behaviour
Authors: CHIY P. C. , PHILLIPS C. J. C. , BELLO M. R.
Published: April 2006

Fifty‐four lactaling dairy cows were grazed for 24 weeks on pasture receiving 0 (Nil), 32 (Low) or 64 (High) kg Na ha‐1 yr‐1 and with (+) or without (‐) 100g NaHCO3 buffer included in a maize gluten concentrate supplement. Cattle grazed the Na‐fertilized pasture to a lower height, particularly in the High treatment. Cows grazing pasture with Na fertilizer produced more milk, and milk fat concentration increased in direct proportion to amount of Na fertilizer applied and with NaHCO3. This increase was greatest in early season. Milk protein concentration was not affected by Na fertilizer application or NaHCO3 buffer addition. Milk lactose concentration was increased by Na fertilizer application but not by NaHCO3 supplementation. Cows in the Na‐applied treatments gained more live weight but there was no effect of treatment on condition score change. Grazing time and drinking frequency increased linearly with increasing pasture Na. Ruminating time and biting rate were similar at the Low and High treatments and greater than the Nil treatment. NaHCO3, supplementation increased drinking frequency and decreased the rate of concentrate intake. Cow reproductive performance was not significantly affected by Na fertilizer application. During the residual period, cows that had previously grazed the Na‐fertilized pasture had reduced milk fat and protein contents.
A comparison of grass/white clover and grass silages offered to dairy cows as the sole feed
Authors: WILMAN D. , WILLIAMS S. P.
Published: April 2006

Two diets were compared: perennial ryegrass (Lolium perenne L.) silage and perennial ryegrass/white clover (Trifolium repens L.) silage, in each case fed ad libitum, without supplementation, to lactating dairy cows. The comparison was made with silages cut on each of four dates. The crops were wilted to a dry matter content of at least 256g kg‐1 and no additives were used.

The grass/clover silages were well preserved at all four cuts. The grass was well preserved at three cuts, but, at a May cut, the grass silage was less well preserved and less digestible than the grass/clover silage. When the May silages were fed, milk yield was higher with grass/clover than with grass. Taking the experiment as a whole, however, milk yield and composition were similar on the two diets. The grass/clover silages had a lower proportion of cell wall and their intake by dairy cows was consistently higher than that of the grass silages.

It is concluded that perennial ryegrass/white clover crops can be ensiled successfully and fed successfully, with high intake, to lactating dairy cows, but it should not be assumed that cows will give more milk than when fed equivalent all‐grass silage.
Long‐term changes of endophyte infection in tall fescue stands
Authors: SHELBY R. A. , DALRYMPLE L. W.
Published: April 2006

Pastures of tall fescue (Festuca arundinacea) presumed to be free of the endophytic fungus (Acremonium coenophialum) had increasing levels of endophyte, averaging 4% per annum over periods of 9–12 years. Similarly, replicated plots sown at four levels of initial endophyte infection increased in infection over a 4‐year period: for example, plots with a 27% initial level increased to 84%, and those with a level of 58% increased to 92% by the fourth year. Mowing plots to prevent seed formation did not affect the rate of change in infection percentage, except that plots with 0% initial endophyte began to show detectable levels in un‐mown blocks, presumably as a result of contamination by seed from adjacent infected plots. By the fourth year of the study, fescue plant densities, measured by plant counts, as well as ground cover, were significantly higher in plots with high initial endophyte level. It is proposed that the change in infection percentage was due to enhanced survival of infected plants in mixed stands where there was intense competition for available moisture in conditions of drought.
Sodium fertilizer application to pasture. 5. Effects on herbage digestibility and mineral availability in sheep
Authors: CHIY P. C. , PHILLIPS C. J. C. , AJELE C. L.
Published: April 2006

The effects of feeding herbages fertilized with 0 (nil), 32 (low), 66 (medium) or 96 (high) kg of sodium per hectare per year to sheep on herbage digestibility and mineral availability were examined. Modified acid detergent fibre (MADF), ash, magnesium (Mg) and phosphorus (P) contents were increased by the application of sodium (Na) treatments, while potassium (K), sulphur (S) and true protein (TP) contents were reduced. Dry matter (DM) and MADF intakes were increased in the low and medium treatments and DM and MADF digestibility increased in all Na‐treated herbages. The medium‐ and high‐sodium treatments increased salivary Na content and Na/K ratio and decreased K content. Blood K content was not affected by treatment. Intake, faecal output, apparent availability, urinary output and balance of Na were increased by the application of Na treatments. Potassium intake, balance, apparent retention and urinary output were increased by the low, unaffected by the medium and reduced by the high sodium treatment. The low and medium Na treatments increased the intake and apparent availability of Mg; Mg balance and apparent retention were increased by all Na treatments. Feeding the Na‐treated herbages increased intakes, apparent availability, balance and apparent retention of Ca, P and total cations.

The low and medium Na treatments increased S intake, faecal output and apparent retention. It is suggested that through increasing the balance and apparent retention of minerals, the application of sodium fertilizer to pasture will improve the mineral status of sheep, particularly at the low and medium application rates employed in this experiment.
The effect of sugar beet pulp‐based silage additives on effluent production, fermentation, in‐silo losses, silage intake and animal performance
Authors: MOORE CHARLOTTE A. , KENNEDY S. J.
Published: April 2006

First‐harvest direct‐cut, double‐chopped grass (190 and 164g DMkg−1 in Experiments 1 and 2 resptectively) was ensiled without an additive or, in Experiment 1, with 30 kg t−1 grass of an absorbent additive based on sugar beet pulp (Sweet ‘n’ Dry) or with 3·441 t−1 grass of formic acid and, in Experiment 2, with 30, 50 and 70 kg t−1 grass of Sweet ‘n’ Dry or with 50kg t−1 grass of unmolassed sugar beet pulp. The preservation and nutritive value of the silage, in‐silo losses (including silage effluent production), silage intake and animal performance of adult and growing cattle were examined.

In Experiment 1 all three silages were well preserved, although the formic acid‐treated silage displayed significantly lower pH, ammonia nitrogen (NH3N) [g kg−1 total nitrogen (TN)] and volatile fatty acids (VFAs) than the other two silages. In Experiment 2 absorbent‐treated silages displayed significantly lower pH, buffer capacity (Bc), NH3N (gkg−1 TN), CP, modified acid detergent fibre (MADF) and VFAs than untreated silage.

Treatment of grass with the absorbent additives at ensiling resulted in reduced effluent production. In Experiment 1 each kilogram of Sweet ‘n’ Dry retained approximately 11 effluent, and in Experiment 2 silages made with Sweet ‘n’ Dry applied at 70kgt−1 and sugar beet pulp applied at 50 kg t−1 produced similar volumes of effluent and each kilogram of absorbent retained 1·0 and 1·31 of effluent respectively.

In Experiment 1 sixty beef cattle [mean initial live weight (LW) 460 kg] were grouped according to LW and allocated to treatment at random. For untreated silage (unsupplemented or with 1 or 2 kg supplement head−1 day−1), absorbent‐treated silage (unsupplemented or with 1 or 2 kg supplement head−1 day−1) and formic acid‐treated silage (1 kg supplement head−1 day−1) the daily silage DM intakes were 6·12, 6·21, 6·40, 7·65, 7·45, 7·11 and 7·85 (s.e. 0·280) kg respectively, the daily liveweight gains were 0·22, 0·56, 0·81, 0·59, 0·74, 0·81 and 0·75 (s.e. 0·071) kg respectively and daily carcass gains were 0·31, 0·47, 0·67, 0·47, 0·61, 0·70 and 0·57 (s.e. 0·043) kg respectively throughout a 75‐day feeding period.

In Experiment 2, fifty‐six growing cattle (mean initial weight 312 kg) were grouped according to LW and allocated to treatment at random. For untreated silage (unsupplemented or with 1·5 kg Sweet ‘n’ Dry or 1·5 kg commercial concentrates head−1 day−1), silage treated with Sweet ‘n’ Dry at 30, 50 and 70 kg t−1 grass and silage treated with 50kg sugar beet pulp t−1 grass the daily silage DM intakes were 5·46, 5·28, 5·33, 6·21, 6·27, 6·60 and 6·62 (s.e. 0·154) kg respectively and daily liveweight gains were 0·39, 0·75, 0·81, 0·63, 0·76, 0·94 and 1·75 (s.e. 0·052) kg respectively throughout a 122‐day feeding period. In this experiment 360g kg−1 more absorbent was required when it was included at ensiling rather than offered as a supplement to untreated silage to achieve the same individual animal performance.
In vitro gas production kinetics of grass silages treated with different cell wall‐degrading enzymes
Authors: BEUVINK J. M. W. , SPOELSTRA S. F.
Published: April 2006

Grass was treated with six different cell wall‐degrading enzymes and ensiled under different conditions [dry matter (DM) content, stage of maturity]. Silage samples were dried, ground and incubated with buffered rumen fluid. Gas production was monitored over 48 h and gas production curves were fitted to a modified Gompertz equation.

In general, enzyme‐treated silages showed a shorter initial lag phase and lower maximum gas production rate, indicating that the enzymes degraded cell wall material to more rapidly fermentable components, leaving a more slowly fermentable fraction. The total amount of gas produced was not altered by enzyme treatment, but a shift towards more rapidly fermentable material was observed. These changes in gas production kinetics went hand in hand with a change in chemical composition (more degradation of neutral detergent fibre and higher production of lactic acid in the enzyme‐treated silages than in the control silages). Silages treated with enzyme preparations that did not contain cellulase did not differ from the control silages either in gas production kinetics or in chemical composition.

Wilting up to 300 g DM kg−1 had no influence on gas production kinetics, whereas wilting up to 488 g DM kg−1 resulted in a longer initial lag phase, a lower maximum rate and lower total gas production. With increased maturity, lower total amounts of gas and lower maximum rates were observed. The measurement of changes in gas production kinetics of enzyme‐treated silages compared with control silages is a useful and rapid technique for prescreening the effects of enzyme addition.
Influence of the fungal endophyte Acremonium lolii on agronomic traits of perennial ryegrass in France
Authors: RAVEL C. , CHARMET G. , BALFOURIER F.
Published: April 2006

Four sets of half‐sib families of perennial ryegrass with (E+) and without (E‐) infection with the fungal endophyte Acremonium lolii were established in spaced‐plant nurseries and trial plots in 1989 and 1990 at eight locations in France. In the nurseries, families were scored visually for six agronomic traits; in trial plots, dry matter yields or visual scores were obtained for eleven traits in the planting year and in the following two years. Significant differences between E‐and E+ families in each set were more frequent in trial plots than in nurseries, and in all cases there was a positive response to A. lolii infection. In the nurseries, the traits showing the greatest number of significant responses to infection were spring growth (3/28 comparisons) and autumn vigour (3/26 comparisons). In trial plots, E+ families had a significantly (P < 0·05) higher yield than E‐ families at three dry locations (5/7 comparisons at Clermont‐Ferrand, 3/9 at Montours, and 4/7 at Vemeuil I'Etang) in the 1989 sowings. However, in the 1990 sowings, when different families were studied, endophyte infection had no effect on yield at the driest location. Therefore it is concluded that infection of perennial ryegrass with some strains of A. lolii seems to benefit the host in stressful conditions. However, in Europe generally, climatic conditions are not often stressful for perennial ryegrass and the chances of E+ plants being favoured by either natural or artificial selection seem to be low.
The effects of separated cow slurry liquor on soil and herbage nitrogen in Phalaris arundinacea and Lolium perenne
Authors: STUDDY C. D. , MORRIS R. M. , RIDGE I.
Published: April 2006

Simulated swards of reed canary grass (Phalaris arundinacea L) and ryegrass received applications of separated cow slurry liquor in winter, at rates up to the equivalent of 500 m3ha−1. Subsequent measurement of oxidized nitrogen in the soil under the different species indicated that lower levels of soluble forms of nitrogen were found under the reed canary grass than were under the ryegrass sward. At the first harvest after liquor application, the dry weight yield of reed canary grass responded positively to increasing applications of slurry liquor, but the ryegrass sward appeared to be damaged by very high rates of application. At later harvests, yields of the two species were similar, but over the season, apparent recovery of the nitrogen applied to the swards was greater in the reed canary grass than in ryegrass, suggesting that this species could be of value in the control of losses of nutrients from livestock wastes.
Seed production in white clover (Trifolium repens L.). II. Effect of autumn defoliation on potential seed yield and seed yield components
Authors: PASUMARTY S. V. , HIGUCHI S. , MURATA T. , MATSUMURA T.
Published: April 2006

A field experiment was conducted to assess the effect of autumn defoliation treatments on inflorescence production, potential seed yield and yield components of white clover cv Makibashiro. Between 10 July and 10 October 1992, white clover swards were subjected to one of three treatments: monthly cutting to 3–4 cm (4DEF), cutting to 3–4 cm on 10 August and 10 October (2DEF), and no cutting (control). The total numbers of inflorescences and the proportion of inflorescences in different development categories were counted throughout the period of seed crop development to determine the pattern of inflorescence development and optimum harvest date. There were consistent significant differences in inflorescence density between treatments. Plots which received the 2DEF treatment produced significantly more inflorescences than did the no‐defoliation (control) and 4DEF‐treatment plots. In this particular year the optimum harvest date (date at which the proportion of ripe inflorescences and potential seed yield was highest) was 26 July, approximately 30 d after peak flowering. Defoliation treatments had no effect on optimum harvest date. However, treatments differed in potential seed yield and ripe inflorescences on this date. The 2DEF treatment gave the highest potential seed yield because there were significantly more ripe inflorescences than either the contol or 4DEF plots. Control plots produced inflorescences with more florets than the other two defoliation treatments, but the differences were not always significant. Seed number per pod was higher in inflorescences obtained from previously defoliated plots than from control plots. The 1000‐seed weight was significantly lower in inflorescences developed in 4DEF plots than those developed in 2DEF and control plots. The results are discussed in relation to the management of white clover seed crops and the importance of canopy structure and light intensity for seed production.
Effect of interval between harvests and spring‐applied fertilizer N on the growth of white clover in a mixed sward
Authors: FISHER A. , WILMAN D.
Published: April 2006

A perennial ryegrass (Lolium perenne)‐white clover (Trifollum repens) sward, that had been grazed for over 2 years, was cut at 1‐, 2‐, 3‐ or 6‐week intervals from 18 April to 28 November 1986. The effects of two rates of N application in spring, 0 and 66kg Nha−1, were compared. Clover growth was studied in three six‐week periods that began on 18 April, 18 July and 17 October respectively. Increasing the interval between cuts increased the yield of herbage without reducing the proportion of clover in the harvested herbage, but the combination of applied N and the six‐week interval was harmful to clover production. Increasing the interval between cuts tended to increase the proportion of resources allocated to stolons rather than to leaves, and to increase the weight of new dry matter (DM) per growing point rather than per m2. In the third period of the study, when the ten youngest internodes per stolon were examined separately, all ten ages of internode were found to have been affected by the cutting management. This was indicated by the positive effect of the length of the interval between cuts on the weights of N, P and K per intemode. The concentrations of N, P and K were highest in the youngest intemodes. The application of N reduced the proportion of new DM allocated to stolen rather than to leaf and it reduced the number of clover growing points per m2.
Cattle and sheep grazing effects on soil organisms, fertility and compaction in a smooth‐stalked meadowgrass‐dominant white clover sward
Authors: MURPHY W. M. , BARRETO A. D. MENA , SILMAN J. P. , DINDAL D. L.
Published: April 2006

This experiment was carried out to improve understanding of sward and soil responses to cattle and/or sheep rotational grazing of low‐input (no N fertilizer), natural swards dominated by smooth‐stalked meadowgrass (Poa pratensis) syn. Kentucky bluegrass and based on white clover (Trifolium repens). Treatments during two grazing seasons (1989–90) were: cattle grazing alone (C); cattle grazing followed by topping (CT); cattle grazing followed by sheep grazing (CS); and sheep grazing alone (S), Mean target pre‐ and post‐grazing herbage masses were 2200 and 1100 kg dry matter (DM) ha−1. Plants in sheep‐grazed swards regrew more quickly and accumulated more herbage (8·28 compared to 5·35 t DM ha−1 for cattle‐grazed swards, unadjusted for rejected area) than in other treatments. After 2 years, soil in sheep‐grazed areas contained 0·25% N, 5·7 kg available P ha−1, and 379 kg K ha−1, compared to an average of 0·19, 3·9, and 179 respectively for the same soil nutrients in cattle‐grazed treatments. Besides differences in manure distribution and sward rejection, differences in soil compaction among treatments also may have affected soil organisms and thus plant growth. After 2 years, soil bulk densities (g cc−1) were 1·37, 1·37, 1·27, and 1·12; soil penetrometer measurements (kg cm sec−1 sec−1) to 20‐cm soil depth were 9·8, 9·3, 9·5, and 6·7; soil nematodes per 100 g of soil were: 5333, 8705, 2810, and 15208; soil rotifers per 100 g soil were: 288, 242, 715, and 33; and earthworms m−2 (and their biomass (g m−2)) were 262 (205), 157 (162), 344 (409), and 294 (343) for C, CT, CS, and S treatments, respectively.
Uniformity trial with lucerne grown for fodder
Authors: HANDA D. P. , SREENATH P. R. , RAJPALI S. K.
Published: April 2006

Data on the yield of lucerne for individual cuts and the total for three cuts from a uniformity trial were analysed. It was observed that CV% values decreased with the increase in plot size, both for each cut and for total yield. The decrease was considerable up to a plot size of 8 to 16 m2. The plot shape did not show any consistent effect. Increasing the size of block resulted in increased CV values, but block shape had no consistent effect. The CV values were highest for the first cut and lowest for the second cut. A relationship between the average CV% and plot size was found. However, this relationship, or its modified form Y= a.X1−b1. X2−b2 taking into account the plot shape and considering the individual CV values, provide a good fit to the data for the cases where blocking was adopted. The coefficient of heterogeneity was less than 0·29, being lowest for first‐cut yields, followed by the total, the third cut and the second cut yields. This showed a high degree of positive correlation between yields of neighbouring plots. Blocking proved useful in increasing the efficiency of the experiment and it is suggested that block size may be kept at 8 or less plots per block. The relationship between average CV% and block size was of the from Y = a Xb. The present study suggests that, for field experiments with luceme, the plot size may be kept to a minimum that does not exceed 8 to 12 m2, in blocks of eight to nine plots with the shapes of plots and blocks being nearly square. Calculating the efficiencies of confounded factorial design and incomplete block design revealed that block size may be kept to a minimum. The recovery of interblock information was found useful and balancing may be attempted, but only, if necessary.
Some effects of applying undiluted silage effluent to grassland
Authors: BINNIE R. C. , FROST J. P.
Published: April 2006

Two small‐plot experiments were carried out to assess the influence on herbage dry matter (DM) production, chemical composition and soil fertility status of applying undiluted silage effluent at a range of application rates and intervals after a silage cut. In the first experiment, in 1990, silage effluent was applied at 25, 50, 100, 150 and 200 m3 ha−1 1, 8, 15 and 22 d after a silage cut in August. In the second experiment, in 1991, silage effluent was applied at 7, 14, 21, 28, 35, 42, 49, 75, 100, 125 and 150 m3 ha−1 1, 4, 8, 15, 22 and 29 d after silage cuts were taken from different sites in May, July and August. An untreated control and an Inorganic fertilizer treatment were incorporated in both experiments. The immediate effects of the treatments on herbage yield, chemical composition and soil nutrient status were assessed 6–8 weeks after the initial application; residual effects on herbage and soil fertility were measured at a subsequent harvest. Compared with the untreated control, herbage yield increases were obtained with increasing rates of effluent application. Although there was evidence that higher yields could be obtained from earlier applications, up to 50 m3 ha−1 of effluent could be applied up to 15 d after taking a silage cut with little damage to the sward. Delaying the timing of application, and increasing the application rate, increased the proportion of the sward which was damaged; this reached a maximum of 0·84 when the highest application rates were applied 29 d after a silage cut. The increase in the proportion of dead herbage in the sward, associated with increasing rate of effluent application, reduced the quality of the herbage harvested in Experiment I. In Experiment 2 the N, P and, in particular, the K content of the herbage increased with increasing rate of effluent application, whereas the effect on Mg content was variable with contents generally being less than 2·0 g kg−1 DM. Apparent recovery of nutrients applied in the effluent was both low and variable ranging from 0·58 to −0·03 for N, 0·10 to −0·005 for P, 0·34 to −0·02 for K and 0·21 to −0·002 for Mg over both experiments. Effluent had little effect on soil pH, whereas P and, in particular, K contents increased with increasing rate of effluent application. There was evidence that effluent had a beneficial effect on both herbage yield and chemical composition at the residual cut, the extent depending upon rate and time of effluent application.
Modelling mineral nitrogen accumulation in grazed pasture: will more nitrogen leach from fertilized grass than unfertilized grass/clover?
Authors: HUTCHINGS N. J. , KRISTENSEN I. S.
Published: April 2006

A model of herbage growth and nitrogen dynamics for grazed pasture was developed. Grazed herbage nitrogen is partitioned between animal growth, urine and faeces. After allowing for ammonia volatilization, the rate and area covered by urinary nitrogen is simulated. The fate of each day's urinary nitrogen deposition is followed separately through time. The mineral nitrogen remaining in the soil at the end of the growing season is assumed to be leached over winter. Leaching from fertilized grass only and unfertilized grass/clover pastures are compared at varying levels of dry matter (DM) production. Biological fixation is assumed to provide sufficient nitrogen to allow the grass/clover pasture to achieve the same seasonal distribution of production as the fertilized grass‐only pasture. There was a non‐linear increase in predicted leaching with increasing DM production owing to the aggregation of urinary nitrogen into urine patches. Leaching was lower from grass/clover than the grass‐only pasture and the difference increased with DM production. At levels of production common in the UK, the difference in leaching between the two pasture types was small and the spatial distribution of soil mineral nitrogen was uneven, so differences in leaching may be small and difficult to detect.
Peduncle characteristics, inflorescence survival and reproductive growth of white clover (Trifolium repens L.)
Authors: MARSHALL A. H.
Published: April 2006

Field experiments were carried out in four harvest years to compare the peduncle characteristics and reproductive growth of the small‐leaved white clover (Trifolium repens L.) cv. AberDale, selected for long and strong peduncles, with other varieties bred in the Institute of Grassland and Environmental Research (IGER). The peduncles of cv. AberDale were of larger diameter and had a greater fresh and dry weight than those of other varieties. There were also differences in structure as the peduncles of cv. AberDale had more pronounced ridges and furrows than those of cv, Menna.

Inflorescences of cv. AberDale and other varieties were tagged when in full bloom throughout the flowering period in each of the four harvest years. Generally, more inflorescences of cv. AberDale remained intact until harvest, particularly from the early tagging dates. Although there were seasonal differences, at harvest in each of the 4 years, cv. AberDale had more inflorescences and seeds per floret and a greater potential seed yield than the other varieties.

The basis of peduncle strength and effect on reproductive growth is discussed, and the implications for improving the seed yield potential of white clover varieties is considered.
The influence of autumn management and companion grass on the development of white clover over winter in mixed swards
Authors: PATTERSON J. D. , LAIDLAW A. S. , McBRIDE J.
Published: April 2006

Three experiments designed to investigate different facets of autumn management on white clover stolon development are described. The effects of defoliation interval (2, 4, 6 and 8 weeks during 16 weeks from 27 July) were investigated. The shortest interval resulted in the shortest length of stolon material per unit area but cutting interval had no effect on growing point density nor on hardiness of stolon tips evaluated in October, December and January.

Chemical grass suppressants were employed to reduce grass biomass during winter in two experiments to evaluate the influence of grass on white clover development. One experiment involved varying grass tiller density by spraying a perennial ryegrass/white clover sward in October with three rates of three chemical suppressants (Clout, Kerb and Checkmate). Although tiller and clover growing point density were inversely related in January, the overall relationship was not strong.

Clout at l·5kg a.i. ha−1 was sprayed in October on one of two subplots in each of twelve grazed grass/white clover plots that had been maintained at 7 or 9 cm from July to October then grazed to 3–4 cm with sheep. Sward height had no effect on clover population density but the shorter sward had a greater mean node number per secondary stolon branch. By March, suppressing grass resulted in more than double the stolon population density, a higher proportion of plants with tertiary and quaternary branches, and on marked stolons, five times more branches and 60% higher dry matter (DM) produced during winter but with shorter petioles compared with clover in untreated plots.

It is concluded that white clover has the capacity to branch during a mild winter and as stolon branch numbers can suffer a net loss as a result of the presence of the grass canopy, management that controls grass growth during winter should aid over‐wintering and improve persistence of white clover.
Effects of timing and intensity of defoliation on growth and development of white clover seedlings
Authors: HAYES M. J. , WILLIAMS E. D.
Published: April 2006

The effects of different defoliation regimes on the growth and development of three contrasting white clover cultivars (S184, Menna and Alice) were assessed in three experiments in the glasshouse. Experiment 1, with clover growing on its own, investigated the effects of three times of onset × two intensities of defoliation. In Experiment 2, clover was grown with grass and there were two times of onset × two heights × two frequencies of defoliation. Experiment 3, also with grass, investigated the effects of changing defoliation frequency at different intervals from sowing.

All clover cultivars responded similarly to the various treatments and there were no interactions between time of onset and subsequent defoliation regimes in Experiments 1 and 2. Without competition from grass (Experiment 1), defoliating early at the three leaf‐stage of clover decreased the number of growing points by 32% and stolon weights and lengths by 50% compared with delaying defoliation until the nine leaf‐stage. Maintaining one compared with two leaves per growing point had similar effects. Over 17 weeks undefoliated seedlings produced ten times more stolon than early defoliated or intensively defoliated seedlings. In competition with grass (Experiment 2) delaying defoliation significantly decreased all aspects of stolon growth. Seedlings growing in swards defoliated frequently and closely had most growing points whereas those defoliated infrequently had least. Stolon lengths and weights were larger for seedlings growing in swards defoliated frequently than for those defoliated infrequently at both heights of cutting. Mean weight of stolon per unit length was greater when swards were defoliated at 6 cm than at 2 cm height. Changing defoliation from every 2 weeks to every week (Experiment 3) decreased stolon growth slightly when the change was made early but increased it when the change was made late, although similar amounts of stolon were produced by seedlings continuously defoliated throughout every week and every 2 weeks.

The results are discussed in relation to the seedlings' leaf complements and growth habit; the over‐riding influence of grass competition is highlighted. The possibility of devising optimal defoliation strategies and the need to test these in the field are also outlined.
Productivity of Lotus corniculatus L. (bird's‐foot trefoil) in the UK when grown under low‐input conditions as spaced plants, monoculture swards or mixed swards
Authors: BULLARD M. J. , CRAWFORD T. J.
Published: April 2006

The dry‐matter productivity of the forage legume Lotus corniculatus (bird's‐foot trefoil) was assessed under low‐input conditions at three sites in the north of England. An initial study in 1989 and 1990 compared fourteen accessions of L corniculatus with Trifolium repens and T. pratense grown as spaced plants at two sites with contrasting soil conditions. One site represented good agricultural land, the other poor‐quality, marginal land. Yields of all species and accessions were significantly lower on the marginal site. Seasonal yields (averaged over sites) of L corniculatus cultivars averaged 52 g plant−1 and 170 g plant−1 in 1989 and 1990 respectively. General trends over both seasons were that T. repens and T. pratense yields were high but some L. corniculatus cultivars (Empire, Franco, Leo) and naturalized UK ‘aliens’ were similar to at least one Trifolium in each year. Yields from L. corniculatus ecotypes from the UK and Norway were very low in comparison with the cultivars. A largerscale study of eighteen L corniculatus, two L uliginosus, three T. repens and two T. pratense accessions was undertaken on an upland, calcareous site in 1990. Legumes were assessed in 2 m × 2 m swards as either monoculture or grass/legume mixture. Establishment and productivity of L uliginosus and T. pratense accessions were poor, with seasonal yields no greater that 50gm−2 year−1. When grown as a monoculture, L corniculatus yields were superior to both Trifolium spp., and averaged 1080 gm−2. In mixed swards, L. corniculatus constituted a higher proportion of the total dry matter yield (26% and 62% at first and second cuts, respectively) than the other legume species. It is concluded from these studies that L corniculatus is suited to marginal or free‐draining calcareous soils under low‐input conditions, and consequently has more potential for use in the UK than has previously been reported.
Leaf appearance and senescence patterns of some pasture species
Authors: CALVIERE I. , DURU M.
Published: April 2006

Five pasture species, very different in their morphological organization (four dicotyledons: Plantago lanceolata, Sanguisorba minor, Ranunculus repens, Taraxacum officinalis and one grass: Dactylis glomerata), were grown as spaced plants in pots, thus excluding competition for light, to study the proportion of senescent leaves. In May, after a 6 month period, the proportion of partially or totally senescent leaves varied from 20% to 80%. Four plant characteristics were important: leaf appearance and senescence rates, leaf lifespan and date and type of flowering. Plantago lanceolata had the longest lived foliage and the smallest proportion of senescent leaves. In contrast, Taraxacum officinalis had the most rapid leaf turnover and Dactylis glomerata had the slowest rate of leaf appearance. Sanguisorba minor and Ranunculus repens were almost identical, with intermediate leaf characteristics in all respects. These results illustrate the fact that the four characteristics studied, and not simply the species' phenology, must be taken into account in order to compare growth between species. The likelihood of these characteristics remaining the same when species are in dense sward is considered.
Effects of grazing by sheep or goats on sward composition in ryegrass/white clover pasture and on subsequent performance of weaned lambs
Authors: del POZO M. , WRIGHT I. A. , WHYTE T. K. , COLGROVE P. M.
Published: April 2006

An experiment was conducted to assess the effects of grazing a perennial ryegrass (Lolium perenne)/ white clover (Trifolium repens) sward by sheep or goats on sward composition and structure and on subsequent diet selection, herbage intake and liveweight gain by weaned lambs. From mid‐May to late July (phase 1), ewes with twin lambs or yearling Scottish Cashmere goats grazed continuously swards maintained at 4‐ or 8‐cm sward surface height. From mid‐August to the end of September (phase 2), weaned lambs continuously grazed the same swards maintained at 4 cm (treatment 4–4) or at 8 cm (treatment 8–8) or which had been allowed to increase from 4 cm to 8 cm (treatment 4–8). By the end of phase 1, swards grazed by goats had higher proportions of white clover in the whole sward (0.377 vs. 0.181; s.e.d 0.0382; P< 0.001) than those grazed by sheep, irrespective of sward height treatment. This resulted in phase 2 in a higher proportion of white clover selected (P<0.001), higher herbage intakes (P < 0.001) and higher liveweight gains (P < 0.001) by weaned lambs grazing swards previously grazed by goats compared with those previously grazed by sheep. There were higher proportions of clover present in the swards from treatment 4–8 at the beginning of phase 2 compared with the other sward height treatments and consequently weaned lambs had, on this treatment, a higher proportion of clover in their diet (P<0.001), higher herbage intakes (P<0001) and higher liveweight gains (P <0.001). It is concluded that goats can be integrated into sequential grazing systems with sheep on grass/clover swards and this can result in an increase in the proportion of clover in swards and increased sheep performance.