ALBERT

Notes: 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.

Notes: A randomized-block experiment was carried out to evaluate a bacterial inoculant, based on a single strain of the organism Lactobacillus plantarum, as a silage additive. The inoculant-treated silage was compared with untreated and formic acid-treated silages. The three silages were harvested from a perennial ryegrass sward on 30 September and 1 October, 1985 using two double-chop forage harvesters. Formic acid (850 g kg−1) was applied at a rate of 31t−1 and the inoculant at a rate of 3 g mixed in 31 water t−1 (1 × 106 colony forming units (g grass)−1). The dry matter and water-soluble carbohydrate contents of the grass at ensiling were 165 g kg−1 and 18·9 g kg−1 respectively. For a period of 84 d, the three silages were offered ad libitum and supplemented with three concentrates in a 3 × 3 factorial design to 63 male cattle which were initially 15 weeks old and 128 kg live weight. The three concentrates were (1) barley (115 g crude protein (CP) (kg DM)−1), (2) barley/soyabean meal (207 g CP (kg DM)−1) and (3) barley/fish meal (200 g CP (kg DM)−1); each was offered at a mean rate of 1·7 kg d−1. For the untreated, formic acid-treated and inoculant-treated silages respectively, ammonia-N concentrations were 162, 91 and 176±60 g (kg total N)−1; pH's were 4·48, 3·89 and 4·45±0·046; butyric acid contents were 12·1, 1·3and 16·6g(kg DM)−1; metabolizable energy contents were 12·4, 12·2 and 1·23±0·29 MJ (kg DM)−1; silage DM intakes were 2·28, 2·49 and 2·44±0·037 kg d−1 and liveweight gains were 0·90, 0·95 and 0·97±0·023 kg d−1. For the barley, barley/soyabean meal and barley/fishmeal supplements respectively, silage DM intakes were 2·29, 2·43 and 2·49 ± 0·037 kg d−1 and liveweight gains were 0·87,0·97 and 0·99 ±0·023 kg d−1. There were no significant interactions between silage type and the supplement offered. It is concluded that silage fermentation and metabolizable energy contents were similar for the untreated and inoculant-treated silages but that silage dry matter intake and liveweight gain were significantly greater for the inoculant-treated than for the untreated silage. Further work is needed to elucidate the mode of action of this type of silage additive.

Notes: An experiment was carried out during 1984 to study the effect of treating grass at ensiling with three commercially available inoculant-type additives (H/M Inoculant, Grass Sile and Siron), formic acid (850 g kg−1; Add-F) or no additive on grass preservation, in-silo loss, intake and animal performance. Primary growth grass ensiled from 28–29 May into concrete-walled covered silos was of high dry matter (DM, 234 g kg−1), water-soluble carbohydrate content (WSC. 212 g kg DM−1) and digestibility (MADF, 250 g kg DM−1).The untreated silage displayed good preservation and with the exception of the Sirontreated silage which showed significantly lower buffering capacity (Be) and volatile fatty acid (VFA) contents than the untreated silage, the application of inoculant-type additives did not improve silage preservation or decrease in-silo DM losses. The formic acid-treated silage displayed significantly lower Be, water-soluble carbohydrate, ash, ammonia nitrogen (g kg total N−1) and lactate contents than the untreated silage.After a 133 d storage period, silages were offered to finishing beef cattle for an 84-d period. Cattle offered the silages displayed similar and non-significant daily DM intakes, daily liveweight gains, dressing proportions and daily carcass gains. From this experiment it appears unlikely that any of the additives evaluated will improve animal performance relative to a well-preserved untreated silage.

Notes: Five experiments were carried out in the years 1980-1983 and 1986 to study the effect of treating grass at ensiling with sulphuric acid (850 g kg−1) and formic acid (850 g kg−1) additives alone, and in mixtures with or without formalin on the preservation of grass, in vivo digestibility in sheep, in-silo loss, intake and performance of finishing cattle.Primary growth grass was ensiled in experiments 1 (3–4 June 1980), 2 (12-15 June 1981) and 3 (31 May-2 June 1982), primary regrowth grass in experiment 4 (1-2 August 1983) and secondary regrowth grass in experiment 5 (7-10 October 1986). During the ensiling period within each experiment, approximately 60 t of unwilted, double-chopped, additive-treated or untreated grass was packed into covered concrete-walled 60-t capacity silos. The dry matter (DM) contents of the ensiled grass in experiments 1, 2 and 5 ranged from 155-180 g kg−1 and were lower than those recorded in experiments 3 and 4 (214 g kg−1). With the exception of grass ensiled in experiment 2, where water-soluble carbohydrate (WSC) contents were low, at 104 g kg−1 DM, grass in all other experiments contained relatively high WSC contents ranging from 140-154 g kg−1 DM.In experiments 1, 3 and 4 all silages were well-preserved. However, in experiment 2 the 450 g kg−1 sulphuric acid-treated and formic acid-treated silages displayed significantly lower pH, buffering capacity (Bc) and ammonia nitrogen contents than the untreated silage. In experiment 5, the sulphuric acid-treated and formic acid-treated silages displayed significantly lower pH, Bc, ammonia nitrogen, butyrate and volatile fatty acid (VFA) contents than the untreated silage.Each of the silages was offered daily with various levels of a supplementary concentrate for approximately 70-d periods to twelve animals of mixed breed in experiments 1, 3, 4 and 5 and to fifteen animals in experiment 2. All animals weighed between 380-470 kg at the start of the experiments.In experiments 1, 2 and 3 there were no significant differences between silages for any of the intake or animal performance parameters. In experiment 4, cattle fed the formic acid-treated silage displayed significantly higher silage DM intakes and daily liveweight gains than those fed the sulphuric acid-treated and untreated silages; in experiment 5, cattle fed the formic acid-treated silage displayed significantly higher silage DM intakes than those fed the untreated silage. It was concluded that formic acid was a more effective silage additive than sulphuric acid.Increasing the level of supplementation significantly decreased silage DM intakes in cattle in experiments 3 and 4, and significantly increased daily liveweight gains and daily carcass in cattle in experiments 1, 3 and 4.

Notes: Two 2×2 factorial experiments are described in which a bacterial inoculant being developed as a silage additive and containing a strain of Lacto-bacillus plantarum (Ecosyl, ICI plc) was evaluated at two harvests (18 July and 30 September 1985) of two swards (perennial ryegrass and permanent pasture) in difficult ensiling conditions. On each occasion erbage was ensiled with and without inoculant using two 0·5–t capacity steel tower silos per treatment. The contents of the two replicate silos per treatment were combined for feeding to cross-bred wethers in digestibility and metabolizable energy (ME) partition studies.Overall, inoculated herbage declined in pH post-harvest at a faster rate than control herbage (p〈0·001) and three out of the four inoculated silages had lower pH, ammonia-N, acetate and alcohol and higher residual soluble carbohydrate content (p〈0·001) than control. Significantly higher digestibility of nutrients (P〈0·05) was found in three of the inoculant-treated silages and these also had significantly higher ME values than control (P〈0·001), (10·58 and 8·77 MJ kg tol DM−1 for the treated and untreated silages respectively). The use of inoculant on herbage of only moderate ensiling potential therefore, produced significant improvements in fermentation quality and feeding value over control.

Notes: Two 2×3 factorial design experiments were conducted during 1985 to compare the effect of treating grass at ensiling with a silage inoculant (Imperial Chemical Industries plc) or formic acid with an untreated control, on fermentation, in-silo losses, intake and performance of finishing cattle.In experiment 1, three covered concrete-walled silos were each filled with approximately 70 t of primary growth, unwilted herbage at each of two cutting dates, 20–21 May (early harvest) and 3 June 1985 (late harvest). In experiment 2, the above procedure was repeated for second regrowth grass with two cutting dates, 30 September-1 October (early harvest) and 16–21 October 1985 (late harvest). The water-soluble carbohydrate (WSC) contents of the herbage were low in both, being 130–160 and 121–137 g kg−1 DM for the first and second experiments respectively. In both experiments the formic acid-treated silages attained lower temperatures than the inoculant-treated and untreated silages. At both harvests in experiment 1 the pH, ammonia nitrogen (NH3N) and volatile fatty acid (VFA) contents of the inoculant-treated and formic acid-treated silages were significantly lower than those in the untreated silage. However, at the early harvest in experiment 2 the pH and NH3N contents of the inoculant-treated silage were significantly higher than those in the two other silages. At the late harvest in experiment 2 the inoculant-treated and the formic acid-treated silages had significantly lower pH and VFA contents than the untreated silage.After 126 d and 98 d storage periods in experiments 1 and 2 respectively, each of the six silages was offered to twelve 475 kg steers throughout a 70-d period (experiment I) and a 63-d period (experiment 2). In experiment 1 there were no significant effects of additive on silage DM intake, liveweight gain or carcass gain with the mean carcass gains being 0·49, 0·51 and 0·52±0·024 kg d−1 for the untreated, formic acid-treated and inoculant-treated silages respectively. In experiment 2 the mean silage DM intakes were 6·34, 7·33 and 6·60±0·151 kg d−1 and carcass gains were 0·27, 0·35 and 0·26±0·026 kg d−1 for the untreated, formic acid-treated and inoculant-treated silages respectively, formic acid treatment thus gave the most consistent results.

Notes: Neutron depolarization measurements have been used to show that ferromagnetic domains exist in a-FexZr100−x alloys for 90≤x≤93, and that these domains are not affected by the ordering of transverse spin components at Txy. Domain sizes decrease from 1.1 μm at x=90, to 0.08 μm by x=93. Measurements in an applied field set an upper limit of ∼50 nm for correlations in the transverse components. By contrast, a-Fe90Sc10 shows no evidence of ferromagnetic order and is confirmed to be a spin glass. Measurements on deuterium-loaded samples show that all of the a-Fe–Zr and a-Fe–Sc alloys studied here are ferromagnetic with Tc's in the range 380–400 K, and domains ∼1 μm in size. © 1996 American Institute of Physics.

Notes: Eight field-plot experiments were carried out on established grassland swards between 1984 and 1988 to examine the effects of date and rate of application of calcium ammonium nitrate (CAN) on herbage dry matter (DM) yield and apparent efficiency of nitrogen (N) use at first-cut silage.CAN application significantly increased (P 〈0 ·001) the mean yields of herbage and N uptakes by herbage in all experiments. Herbage yields were similar (P 〉 0·05) with N rates of 100 kg ha−1, 125 kg ha−1 or 150 kg ha−1 in five experiments but in the other three there were increases above 100 kg ha−1. Date of N application had a significant effect on DM yield in three experiments; this effect was inconsistent for both single and split dressings. Lower production was associated with reduced uptake of N, a trend that primarily reflected lower DM yields and not wide herbage N content variation.It is concluded that selection of the date on which to apply fertilizer N in early spring to obtain optimum herbage yields at first-cut silage often required little precision. The use of fertilizer N rates 〉100 kg ha−1 should be questioned where there are likely to be appreciable quantities of available N derived from non-fertilizer sources.