摘要:

AbstractTwo 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−1for 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 feedi

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1989.tb01934.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractTwo 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−1DM 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−1for 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−1and carcass gains were 0·27, 0·35 and 0·26±0·026 kg d−1for the untreated, formic acid‐treated and inoculant‐treated silages respecti

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1989.tb01935.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractA randomized‐block experiment was carried out to evaluate a bacterial inoculant, based on a single strain of the organismLactobacillus 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−1and the inoculant at a rate of 3 g mixed in 31 water t−1(1 × 106colony forming units (g grass)−1). The dry matter and water‐soluble carbohydrate contents of the grass at ensiling were 165 g kg−1and 18·9 g kg−1respectively. For a period of 84 d, the three silages were offeredad libitumand 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−1and 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−1and 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 sil

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1989.tb01936.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractSilages were prepared in late September from a mixed crop of perennial ryegrass and white clover with low dry matter and high nitrogen content. Six different treatments were used during ensiling; addition of either molassed sugar beet pulp or rolled barley, at 50 kg and 25 kg (t fresh grass)−1, formic acid at 51 t−1and no additive (control).All silages were well fermented with low levels of ammonia and pH. The addition of rolled barley or sugar beet pulp increased the dry matter content of the silages incrementally and appeared to assist the retention of nitrogen in the silage.Dry matter intakes of silages with 50 kg of barley or sugar beet pulp tonne−1were similar to the control silage when fed to wether sheep but at 25 kg t−1, dry matter intake increased by 0·15 with barley and 0·04 with sugar beet pulp compared to the control. The digestibility of dry matter (DM) and organic matter (OM) were significantly higher than the control for silages treated with formic acid or high levels of barley and sugar beet pulp whereas neutral‐detergent fibre (NDF) digestibility did not appear to be significantly affected.All treated silages had a significantly higher metabolizable energy (ME) content than the control, and additions of barley or sugar beet increased the ME content. The ME intakes of all treated silages were also significantly greater than those of the control, and the formic acid‐treated and low barley silages were the highest. This appeared to be associated with significantly higher energy digestibility and DM intake.Addition of rolled barley during ensilage resulted in greater nitrogen intake, availability and retention compared to additions of sugar beet pulp. The higher retention with barley silages was associated with a significantly lower proportional loss of absorbed nitrogen in urine, which indicated a more efficient utilization of nitrogen.These differences require further study to determine the mechanisms involved in the interactions between the energy source and herbage protein, both during fermentation and

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1989.tb01937.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractA straw/concentrate mixture was offered to set‐stocked dairy cows over a 24‐week period. The cows were offered grazed herbage only (G), or grazed herbage with a straw/concentrate supplement offered either for 45 min after each milking (B), or overnight (P). The overnight treatment involved housing the cows between afternoon and morning milking. The straw/concentrate mixture contained 0·33 long barley straw, 0·28 barley, 0·12 soya bean meal, 0·25 molaferm and 0·02 minerals. During the first 8 weeks of the experiment an average of 2·25 kg of concentrate were fed, and from weeks 9–24, 2·0 kg of concentrate were fed.The feeding of the straw/concentrate mixture led to a decrease in estimated herbage dry matter (DM) intake, particularly for treatment P. Estimated total DM intakes were increased throughout the experiment by offering the straw/concentrate mixture. However, total metabolizable energy (ME) intakes were only increased in mid‐and late season.Milk yield was higher in early season for treatment G; 28·1 kg d−1compared to 26·8 kg d−1and 25·5 kg d−1for treatments B and P respectively. In late season the cows in treatment G had lower milk yields; 13·3 kg d−1compared to 15·5 kg d−1and 16·8 kg d−1for treatments B and P respectively. Milk fat content was increased in early season in treatment P, and milk protein content tended to be reduced throughout the experiment for cows offered the straw/concentrate mixture overnight. Over the whole experiment there were no dif

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1989.tb01938.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractThe seasonal patterns of dry‐matter (DM) production by swards of Norwegian grasses originating from high latitudes>61°N (Dactylis glomerataHattfjelldal,Phleum pratenseEngmo andPoa pratensisLeikra) were compared over 2 years (1986 and 1987) with those of grasses developed at lower latitudes, 52°N (Dactylis glomerataCambria,Phleum pratenseMotim andLolium perennePerma) at a lowland site in southwest Scotland (55.5°N, altitude 45 m). In each year, there was a significant enhancement of the DM production of the high‐latitude varieties ofDactylis glomerata, Phleum pratenseandPoa pratensisat harvests during May and June, although the lower latitude grasses gave a higher proportion of annual production than the Norwegian grasses in April and from September onwards. These findings are compatible with the observed stimulation of DM production of high‐latitude grasses by daylength extension under controlled conditions. However, since the stimulation of DM production did not occur until the normal peak of production in May and June, it served to accentuate the skewed distribution of production in Scotland, rather than to improve production earlier in the season. Since the total annual DM production was significantly lower for the high‐latitude grasses in general at the lowland site, there does not appear to be a clear role for these grasses in UK a

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1989.tb01939.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractChanges in stubble carbohydrate content during the regrowth of ryegrass (Lolium perenneL.) grown under hydroponic conditions at two nitrogen levels were studied as a function of time by high‐performance liquid chromatography. Experimental data showed that regrowth at a non‐limiting nitrogen level (1·0 mol m−3NH4NO3) involved two different physiological periods. The first occurred during the first 6 d and was characterized by the mobilization of 60 to 90% of the soluble carbohydrates (i.e. glucose, fructose, sucrose, oligofructans and polyfructans). During the second period (6.28 d of regrowth) carbohydrate contents rose to the values observed prior to cutting (20% of dry matter at the 28th d of regrowth).The effect of low nitrogen conditions (0·2 mol m−3NH4NO3) was observed only during the second phase. Plants regrown in a nitrogen‐starved medium accumulated 2·3‐fold more polyfructans than plants regrown in a non‐limiting nitrogen medium. Their fructose and glucose contents remained at 2% of dry matter from the end of the first phase of mobilization.The experimental results are interpreted and discussed in terms of the existence of two distinct fructan sy

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1989.tb01940.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractSeeds of perennial ryegrass were sown by hand in micro‐plots. Six treatment factors were applied, in all combinations, totalling thirty‐two treatments. The factors were (a) firm vs light compaction of the seedbed, (b) 1 cm vs 2·5 cm sowing depth, (c) fertilizer applied to seedbed vs no fertilizer, (d) fungicides applied to the seed and seedbed vs no fungicide, (e) pesticide applied to seedbed vs no pesticide, and (f) soil kept moist after sowing vs soil kept dry after sowing. Overall, seedling emergence was increased by moist soil (18%), fungicides (16%) and by sowing at 1 cm depth (8%). In dry soil, fungicides increased emergence by 32% but had no effect in moist soil.In other experiments, micro‐plots were sown at monthly intervals, from April to October. Seeds were either treated with benomyl + captan (3 g + 3 g a.i. (kg seed)−1) or not treated, and the plots were either covered to keep the soil dry, or uncovered. Seedling emergence on uncovered plots was increased significantly, by 16–28%, at the May, June, July and August sowings, when soil temperatures were at their highest and soil moisture contents at their lowest. On covered plots fungicides significantly increased emergence at the June sowing only, by 16%. The reasons for this anomaly are

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1989.tb01941.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractPerennial ryegrasses showing genetic differences in water‐soluble carbohydrate content (WSC) were assessed for dry matter digestibility (DMD), crude protein (CP) and dry matter production (DM) in both spaced plant and small plot trials. Among 100 accessions grown as spaced plants there appeared to be more genetic variation for WSC than for DMD or CP. In both spaced plants and plots, WSC was consistently positively correlated with DMD, negatively correlated with CP and showed little correlation with DM. Correlations between CP and DMD were rather inconsistent and some negative correlations were obtained between CP and DM, suggesting that environmental effects, particularly with regard to nitrogen availability, affected CP more than WSC content. It was concluded that there is considerable potential for using ryegrasses with high WSC contents to develop varieties with improved feeding value without sacrificing productio

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1989.tb01942.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractComparative sheep production from Aurora (very early‐flowering), Meltra (late‐flowering tetraploid) and Aberystwyth S23 (late‐flowering) perennial ryegrass (Lolium perenneL.) varieties was assessed as both grass‐only (200 kg N ha−1) and grass‐white clover (Trifolium repensL.) (75 kg N ha−1) swards under continuous stocking management. Beulah Speckled Face ewes and their Suffolk cross lambs were used from late April to mid‐July. From late July to early November only lambs grazed the pastures.Mean (1985–87) total annual lamb production per hectare from Aurora and Meltra was 16% and 13% more than that from S23. The magnitude of the differences between these varieties and S23 declined from the first to the third year. Aurora gave 29% more lamb output per hectare than S23 in 1985 but only 10% more in 1987, while the advantage of Meltra over S23 fell from 19% in 1985 to 6% in 1987. Seasonal lamb production per hectare varied between the grasses, especially during spring when lamb output from Aurora was 43% and 22% more than that from S23 and Meltra respectively, with that from the tetraploid being 17% higher than that from S23.It is concluded that the superior spring output from Aurora offers the farmer the opportunity to reduce his dependence on bought‐in feedstuffs, hence improving the efficiency and profitability of lamb produc

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1989.tb01943.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY