Water-soluble carbohydrates and in vitro digestibility of annual ryegrass (Lolium rigidum Gaudin) sown at varying densities

1995 ◽  
Vol 46 (3) ◽  
pp. 611 ◽  
Author(s):  
H Smouter ◽  
RJ Simpson ◽  
GR Pearce

An experiment is described in which the tiller density of microswards of Lolium rigidum was varied by altering planting density. The treatments were expected to alter the interplant competition for light and thus affect the concentration of water-soluble carbohydrates (WSC) of the grass swards. Swards were grown at planting densities of 100 (low density), 500 (medium density) and 5000 (high density) plants m-2. Mainly because of compensatory tillering in the low and medium density swards, all swards had equivalent dry matter yields by 13-15 days after anthesis. The concentrations of material soluble in neutral detergent (NDS) and of WSC, in particular, varied in response to the treatments, and the yield of WSC in the low density sward was 30-50% higher than in the other swards. The yield of WSC reached a maximum at anthesis in all treatments with large losses of WSC occurring as the grass senesced. Fructans were the major type of soluble carbohydrate in all plant parts (50-99% of WSC). At anthesis, the in vitro dry matter digestibility (IVDMD) of the low density sward was higher than that of the high density sward (60.7% and 54.3% respectively). When dead, whole plant IVDMD had declined to 40.8% in the low density and 37.9% in the high density sward. The higher digestibility of the low density grass sward was a result of higher digestibility in almost all component plant parts. Opportunities may exist to improve the feeding value of senescing grass pastures if mobilization of WSC can be delayed or regulated to ensure higher retention of NDS.

2002 ◽  
Vol 139 (2) ◽  
pp. 151-160 ◽  
Author(s):  
P. V. STOREHEIER ◽  
S. D. MATHIESEN ◽  
N. J. C. TYLER ◽  
I. SCHJELDERUP ◽  
M. A. OLSEN

The marginal winter pastures of reindeer and caribou (Rangifer tarandus) in Arctic and sub-Arctic areas are assumed to be nitrogen- and mineral-poor. Reindeer eat a mixed diet consisting of nitrogen-deficient lichens and a wide variety of vascular plants in winter. Some reindeer populations manage to maintain carcass mass outside the growing season and very little is known about the ability of reindeer to utilize vascular plants in this season. The chemical composition and in vitro digestibility of 17 species of vascular forage plants and one species of moss collected mid-winter from beneath the snow at an inland winter pasture in northern Norway were determined. Wintergreen parts of graminoids had a high content of crude protein (0.072–0.108 g/kg dry matter (DM)) and water-soluble carbohydrates (0.098–0.167 g/kg DM) and were highly digestible (50–65% IVDMD) compared with the withered parts of the plants (27–53% IVDMD). The digestibility of both shrubs and graminoids was inversely related to content of cellulose and lignin, but positively correlated with increasing contents of water-soluble carbohydrates. Shrubs were relatively calcium-rich (3.6–6.1 g/kg DM) while wintergreen graminoids contained up to 10.0 g/kg DM of potassium, 1.5 g/kg DM magnesium and 2.1 g/kg DM phosphorus. The present study demonstrates that the wintergreen parts of several species of vascular plants are nutritious, containing high levels of nitrogen and minerals, and that they are highly digestible to reindeer in winter. Vascular plants may, therefore, be more important to reindeer and caribou in winter than previously realized.


1979 ◽  
Vol 92 (2) ◽  
pp. 493-498 ◽  
Author(s):  
R. H. Phipps ◽  
R. F. Weller ◽  
Rosemary J. Fulford

SummaryMaize (Anjou 210), a density-sensitive genotype, was established at 5 and 15 plants/m2 and produced crops containing 50 and 26% grain respectively. Prior to ensiling, the high and low grain crops contained 6·9 and 20·4% water-soluble carbohydrates in the dry matter respectively and were reduced to 0·4 and 1·6% of the dry matter in the silage. The high grain silage contained a lower concentration of acid-detergent fibre, cellulose, lignin, cell-wall constituents and organic acids than the low grain silage. These differences were not reflected in the in vitro digestible organic matter in the dry matter values which were similar in both silages.Two groups of autumn-calving Freisian cows were offered either the high or low grain silage ad libitum as the sole forage plus an 18% crude protein concentrate during a 14-week experimental period. The cows which received the high grain silage produced significantly more milk of a significantly lower milk fat content than the cows which received the low grain silage.The increased milk production coupled with the smaller loss of water-soluble carbohydrates during ensiling show that a high grain content in forage maize is a desirable attribute. It is suggested that density tolerance should be one of the selection criteria used by plant breeders to allow crops to be established at high plant densities from which near maximum dry-matter yields could be obtained, while still containing a high proportion of grain.


1966 ◽  
Vol 66 (3) ◽  
pp. 351-357 ◽  
Author(s):  
W. Ellis Davies ◽  
G. ap Griffith ◽  
A. Ellington

The primary growth of eight varieties of three species–white clover (3), red clover (4) and lucerne (1)–was sampled at fortnightly intervals and the percentage dry matter, in vitro digestibility, crude protein, water soluble carbohydrates, P, Ca, K, Na and Mg were determined.Differences between species were nearly always significant and the general order of merit was white clover, red clover and lucerne. The exceptions were for dry-matter percentage where this order was reversed, and red clover had the lowest Na and highest Mg content.


2014 ◽  
Vol 68 (1) ◽  
pp. 65-75
Author(s):  
Soleiman Mohammadi ◽  
Reza Kas Nazani ◽  
Ayda Hosseinzadeh Mahootchi ◽  
Keiwan Ftohi

ABSTRACT In order to evaluate promising lines in terms of grain yield and water-soluble carbohydrates remobiliza-tion, an experiment with fifteen promising lines and two checks was carried out under full irrigation and terminal water stress conditions at Miyandoab Agricultural Research and Natural Resources Station. Mobilized dry matter content and remobilization percentage from shoot to grain under water deficit (177mg)(11.2%) were greater than those under well watering condition. The lowest (110 mg) and the highest (260mg) mobilized dry matter to grain were obtained for C-79-18 and C-83-15lines, respectively. Water deficit reduced grain yield of barley genotypes by 200-1600 kg/ha, and mean grain yield reduction was 800 kg/ha. Line 14 with 5.880and 5.300t/ha grain yield in favorable and water stress conditions was superior to the other lines. Under water deficit condition, line 14 had greater grain yieldby20% and 38% than the Bahman and Makouee cultivars, respectively. The results showed that greater grain yield in tolerant lines under water deficit was due to remobilization of unstructured carbohydrates from shoot to grain. Thus, it seems that selection of lines with higher translocated dry matter and contribution of pre-anthesis assimilate in grain filling under water stress, the suitable way for achieving genotypes with high grain yield under water stress condition.


2000 ◽  
Vol 80 (2) ◽  
pp. 309-313 ◽  
Author(s):  
H. T. Kunelius ◽  
K. B. McRae ◽  
S. A. E. Fillmore ◽  
G. Dürr

Late-maturing cultivars of red clover (Trifolium pratense L.) and timothy (Phleum pratense L.) may be grown in short-term rotations with other crops and harvested for hay and silage. Harvesting forage in mid-summer is often advantageous for field curing, but the quality of mature forage may be low. We studied how harvests at different developmental stages affected yield, composition of herbage, and species persistence. The late-maturing single-cut red clover cultivar Altaswede and late timothy cultivar Farol were grown alone and in combination with and without applied N. Total forage, and red clover and timothy dry matter yields, increased between the first (27 June) and third (11 July) dates of harvest. Timothy grown alone or combined with red clover and fertilized with N produced greater forage yields than red clover alone or red clover + timothy without applied N. The in vitro digestibility of dry matter declined from 670 to 625 g kg−1 and crude protein from 134 to 109 g kg−1 between 27 June and 11 July. Water soluble carbohydrates in forage were low (36–66 g kg−1) in cuts 1 and 2. Macronutrient and micronutrient concentrations were generally highest at the first date of harvest on 27 June. Nutrient concentrations in cut 2 were similar for the three harvest schedules. We conclude that growing late-maturing single-cut red clover combined with late timothy produced high yields with good nutritional quality even at advanced stages of maturity. Single-cut red clover persisted for the first production year making this combination suited for short-term rotations that involve late harvesting of the primary growth. Key words: Red clover, Trifolium pratense, timothy, Phleum pratense, composition


2005 ◽  
Vol 62 (5) ◽  
pp. 427-432 ◽  
Author(s):  
André de Faria Pedroso ◽  
Luiz Gustavo Nussio ◽  
Solidete de Fátima Paziani ◽  
Daniele Rebouças Santana Loures ◽  
Mauricio Scoton Igarasi ◽  
...  

Sugar cane silages are characterized by extensive yeast activity, alcohol production and great dry matter - DM - losses. Better knowledge of the fermentation process is fundamental to the development of efficient ensilage techniques for this forage. This study evaluates temporal changes in chemical composition, DM losses and epiphytic microflora in sugar cane silage. Mature sugar cane, variety RB835486 (12 months of vegetative growth), was hand harvested, processed in a stationary chopper and ensiled in 20-L plastic buckets provided with valves for gas release and a device for effluent collection. Laboratory silos were kept at ambient temperature and sampled after ½, 1, 2, 3, 7, 15, 45, 90, 120 and 180 days. Ethanol concentration reached 6.4% in DM after 15 days of ensilage, followed by 71% water soluble carbohydrates - WSCs - disappearance. Gas and total DM losses reached a plateau on day 45 (16% and 29% of DM, respectively). Yeast count was higher on the second day (5.05 log cfu g-1). Silage pH declined to below 4.0 on the third day. Effluent yield was negligible (20 kg t-1). DM content in the forage decreased (35% to 26%) from day 0 to day 45. The increase in ethanol concentration showed an opposite trend to WSCs and true in vitro dry matter digestibility reductions in the silage. Developing methods to control yeasts, most probably through the use of additives, will enable more efficient production of sugar cane silage by farmers.


1975 ◽  
Vol 85 (3) ◽  
pp. 455-463 ◽  
Author(s):  
E. S. Bunting

SUMMARYResults are presented from four experiments in which comparisons were made between isogenic sterile and fertile plants of maize to study the effects of grain content on yield and quality of shoot dry matter. In two experiments comparisons were made over a range of densities, extending from 5 to 25 plants/m2 in 1972 and 5 to 20 plants/m2 in 1973. The other two experiments, grown in 1974 at a density of 10 plants/m2, were sampled 30, 60 and 90 days after flowering.In 1972 and 1973 yield of shoot dry material was about 10% higher in fertile plants at the lowest density, 5 plants/m2, but grain formation had a negligible effect at higher densities. In 1974, at 10 plants/m2, the yield advantage for fertile plants was 6–7%. These results are in line with other European data, but show a much smaller effect of grain formation on shoot dry matter yield than is normally recorded in USA trials. The discrepancies probably reflect differences in environmental conditions.Absence of grain had little effect on contents of nitrogen, ash and in vitro digestible dry matter, and increased content of pepsin soluble material and hot water soluble carbohydrates. Percentage content of dry matter in the shoot was higher in fertile plants in 1973, and during the later stages of crop development in 1974.The results suggest that the importance attached to high grain content as an essential requirement for yield and quality in forage maize is exaggerated, and that the restriction of maize breeding and testing programmes to assessments of grain production, in the belief that the best grain varieties will also be best for forage, can no longer be justified in northern European countries.


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