Manipulation of the feeding value of senescing annual ryegrass (Lolium rigidum Gaud.) with imazethapyr and glyphosate

1993 ◽  
Vol 44 (7) ◽  
pp. 1653
Author(s):  
MC Crawford ◽  
RJ Simpson

The effect of applying imazethapyr [(RS)-5-ethyl-2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin- 2-y1)nicotinic acid] on the in vitro dry matter digestibility (IVDMD) of annual ryegrass was studied and compared with the effects of glyphosate [N-(phosphonomethyl)glycine] . Application of imazethapyr 20 days before anthesis delayed loss of digestible dry matter (DDM) more effectively than when applied at anthesis or 8 days after anthesis. Digestibility of the stems of ryegrass when measured at anthesis was 57.9% and 61.9% for 50 g (a.i.) ha-1 and 100 g (a.i.) ha-1 of imazethapyr, respectively, compared with 50.4% for the control. Application of either imazethapyr or glyphosate decreased dry matter yield initially, mainly because growth of seed heads was reduced. Both glyphosate- and imazethapyr-treated plants produced secondary tillers. In the case of the imazethapyr-treated plants, yield forgone as a result of herbicide treatment was recovered through the production of secondary tillers and because seed head yield were not suppressed to the same extent as in the gylphosate-treated plants. When applied 20 days before anthesis, both herbicides maintained stem IVDMD at 54-60% for up to 42 days after spraying, whereas IVDMD of stems in the control declined. The IVDMD of leaf sheaths was intermediate between that of stems and leaf blades and was improved by herbicide treatment. The IVDMD of leaf blades was unaffected by herbicide treatment. Herbicide treatments 20 days before anthesis therefore delayed loss of DDWI from the vegetative part of the sward for up to 22 days after anthesis. By comparison, in the untreated sward, DDM was lost at a rate of 34.4 kg per ha per day. The total DDM of swards (including seed heads) in all treatments did not differ.

2002 ◽  
Vol 42 (2) ◽  
pp. 111 ◽  
Author(s):  
R. Stanton ◽  
J. Piltz ◽  
J. Pratley ◽  
A. Kaiser ◽  
D. Hudson ◽  
...  

A trial was conducted to investigate the survival and digestibility of annual ryegrass (ARG) seed (Lolium rigidum L.) eaten by sheep and cattle. Sheep (n= 8) and cattle (n = 8) were fed a basal diet containing 1:1 lucerne chaff:oaten chaff with (ARG) or without (control) the inclusion of 20% total dry matter of annual ryegrass seed in a changeover design. Intake was restricted to 17 g/kg liveweight. Digestibility of the control diet was lower (P<0.01) for sheep than cattle. Annual ryegrass seed was present (P<0.01) in the faeces of both sheep and cattle within 24 h of first ingestion. Some 10.8 and 32.8% of seed ingested was excreted by sheep and cattle respectively, with 3.9% (sheep) and 11.9% (cattle) remaining germinable. Annual ryegrass seed continued to be excreted by both sheep and cattle up to 5 days after removal from the diet. Dry matter digestibility of the annual ryegrass diet was 53% in cattle.


Author(s):  
Janet H. Woodward ◽  
D. E. Akin

Silicon (Si) is distributed throughout plant tissues, but its role in forages has not been clarified. Although Si has been suggested as an antiquality factor which limits the digestibility of structural carbohydrates, other research indicates that its presence in plants does not affect digestibility. We employed x-ray microanalysis to evaluate Si as an antiquality factor at specific sites of two cultivars of bermuda grass (Cynodon dactvlon (L.) Pers.). “Coastal” and “Tifton-78” were chosen for this study because previous work in our lab has shown that, although these two grasses are similar ultrastructurally, they differ in in vitro dry matter digestibility and in percent composition of Si.Two millimeter leaf sections of Tifton-7 8 (Tift-7 8) and Coastal (CBG) were incubated for 72 hr in 2.5% (w/v) cellulase in 0.05 M sodium acetate buffer, pH 5.0. For controls, sections were incubated in the sodium acetate buffer or were not treated.


Crop Science ◽  
1986 ◽  
Vol 26 (6) ◽  
pp. 1123-1126 ◽  
Author(s):  
N. J. Ehlke ◽  
M. D. Casler ◽  
P. N. Drolsom ◽  
J. S. Shenk

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 879
Author(s):  
Seong-Shin Lee ◽  
Jeong-Seok Choi ◽  
Dimas Hand Vidya Paradhipta ◽  
Young-Ho Joo ◽  
Hyuk-Jun Lee ◽  
...  

This research was conducted to determine the effects of selected inoculant on the silage with different wilting times. The ryes were unwilted or wilted for 12 h. Each rye forage was ensiled for 100 d in quadruplicate with commercial inoculant (Lactobacillus plantarum sp.; LPT) or selected inoculant (Lactobacillus brevis 100D8 and Leuconostoc holzapfelii 5H4 at 1:1 ratio; MIX). In vitro dry matter digestibility and in vitro neutral detergent fiber digestibility were highest in the unwilted MIX silages (p < 0.05), and the concentration of ruminal acetate was increased in MIX silages (p < 0.001; 61.4% vs. 60.3%) by the increase of neutral detergent fiber digestibility. The concentration of ruminal ammonia-N was increased in wilted silages (p < 0.001; 34.8% vs. 21.1%). The yeast count was lower in the MIX silages than in the LPT silages (p < 0.05) due to a higher concentration of acetate in MIX silages (p < 0.05). Aerobic stability was highest in the wilted MIX silages (p < 0.05). In conclusion, the MIX inoculation increased aerobic stability and improved fiber digestibility. As a result of the wilting process, ammonia-N in silage decreased but ruminal ammonia-N increased. Notably, the wilted silage with applied mixed inoculant had the highest aerobic stability.


1988 ◽  
Vol 68 (3) ◽  
pp. 787-799 ◽  
Author(s):  
V. GIRARD ◽  
G. DUPUIS

In view of the large variation found in plant cell wall digestibilities with ruminants, an attempt was made to group 124 feeds into different lignification classes (clusters) on the basis of chemical characteristics. Each feed cluster was described using a structural coefficient [Formula: see text] that related the potentially digestible fiber (PDF, %) to the ratio between lignin and cell wall volume. The optimum number of clusters was determined iteratively by performing a regression of the apparent digestibility of dry matter at maintenance level (DDM1, %) against the PDF and cell soluble (SOL, %) contents of feeds. The [Formula: see text] coefficients varied from 0.05 (grains, N = 13) to 1.85 (corn silage, N = 3) and increased with the maturity of the grasses from 0.88 (legumes, vegetative cool season grasses, N = 26) to 1.33 (mature, cool season grasses, N = 19). Predicted PDF were closely correlated (r > 0.9, P < 0.01) to in vitro cell wall disappearances (IVCWD). Apparently digestible cell wall in four grasses and four legumes increased linearly with 96-h IVCWD and standard error (SE) was similar to the SE of predicted apparent digestible SOL from SOL concentrations. Assuming that similarity between SE could be also observed in larger samples, PDF and SOL were used in summative equations to predict apparent dry matter digestibility. DDM1 discounted for intake (DDM1 – 4, %) was regressed against SOL and PDF concentrations of 87 feeds:[Formula: see text]with ds and df, the true digestibilities of SOL and PDF. Estimates of ds and df were 0.98 and 0.95 for a zero-production (maintenance) level of intake, and 0.91 and 0.79 for an intake level four times maintenance. Since the true digestibility of the PDF component was only 4% – 13% lower than that of the cell soluble component, the concentration of PDF in cell wall was the major determinant in the variation in apparent digestibility of forages. Key words: lignin, neutral detergent fiber, true digestibility, cluster analysis, feeds


1973 ◽  
Vol 13 (62) ◽  
pp. 245 ◽  
Author(s):  
MN McLeod

The dry matter digestibility measured in vitro and the levels of nitrogen, phosphorus and ash were determined on the leaves from mature trees of twenty-one species growing in two arboreta in southeastern Queensland and known to be grazed by animals. Most of the leaf samples had digestibilities in the lower range (68 per cent samples < 50 per cent D.M.D.) and low ash levels (65 per cent samples < 7 per cent ash). Nitrogen levels were satisfactory (86 per cent samples in range 1.5-3.0 per cent N) but the level of phosphorus tended to be low (84 per cent samples < 0.20 per cent P). Statistically significant variation between individual trees and seasons was found with some species.


1975 ◽  
Vol 15 (73) ◽  
pp. 211 ◽  
Author(s):  
TH Stobbs

Yield and nutritive value of three summer annual forages, hybrid forage sorghum (Sorghum spp. hybrid cv. Zulu), bulrush millet (Pennisetum typhoides cv. Tamworth) and white panicum millet (Echinochloa crusgalli var. edulis) were determined in three experiments. Uninterrupted growth was measured every 2 weeks between 4 and 12 weeks after sowing, and leaf, stem and inflorescence components analysed for nitrogen, phosphorus, calcium, magnesium, sodium and potassium and dry matter digestibility by an in vitro technique. The value of 10-week-old herbage, from crops grown with 50 kg ha-1 N, was determined by grazing with 18 Jersey cows and by feeding chopped material to 12 cows indoors. White panicum was the lowest yielding forage (up to 6,360 kg ha-1 at 10 weeks) but contained the highest concentration of nitrogen, phosphorus, calcium and magnesium in both leaf and stem fractions at all stages of growth. After 10 weeks growth this feed contained a high proportion of seed and was eaten in arger quantities than zulu sorghum or bulrush millet. Cows grazing white panicum produced the highestr lmilk yields (6.5 and 7.1 kg cow-1 day-1 indoors and grazed) and milk from these cows contained a highe solids-not-fat and protein content than milk from cows fed bulrush millet or sorghum. Zulu sorghum was highest yielding (1 1,240 kg ha-1 at 12 weeks in experiment 1 and 81 50 kg ha-1 at 10 weeks in experiment 2). With advancing maturity stem content increased (>80 per cent from 8 weeks onwards) and the nitrogen content of both leaf and stem fractions rapidly declined to sub-optimum levels. Milk production of cows feeding on zulu sorghum was low, averaging 4.7 and 6.0 kg cow-1 day-1 for indoor and grazing experiments. Bulrush millet produced high forage yields with a higher leaf content than zulu sorghum and milk yields were higher. Butterfat content of milk from cows feeding on bulrush millet was lower than when cows were fed the other forages. It was concluded that these three forages are capable of providing a large bulk of feed but their feeding value at a semi-mature stage of growth is similar to perennial tropical pastures.


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