The digestibility and the nitrogen, phosphorus and ash contents of the leaves of some Australian trees and shrubs

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.

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


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.


1987 ◽  
Vol 67 (2) ◽  
pp. 557-562 ◽  
Author(s):  
E. V. VALDES ◽  
R. B. HUNTER ◽  
G. E. JONES

A comparison of two near infrared (NIRA) calibrations (C1 and C2) for the prediction of in vitro dry matter digestibility (IVDM) in whole-plant corn (WPC) was conducted. C1 consisted of 40 WPC samples collected from four locations across Ontario (Brucefield, London, Guelph and Elora). C2 consisted of 90 samples and included the above locations plus Pakenham and Winchester. Nine wavelengths were used in both equations but only three were common in C1 and C2 equations. These wavelengths were 2139 nm, 2100 nm, and 1445 nm, respectively. The predictions of IVDM utilizing both C1 and C2 were good. Coefficients of determination (r2) and standard error of the estimate (SEE) for calibration and prediction sets were 0.91, 1.7; 0.85, 1.7 for C1 and 0.88, 1.6; 0.77, 1.6 for C2 respectively. Regression analysis within location, however, showed low r2 values for the prediction of IVDM for Pakenham and Winchester in both calibrations. The more mature stage of harvest at these locations might be the cause of the poorer predictions. Key words: In vitro digestibility, whole-plant corn, near infrared reflectance


Sign in / Sign up

Export Citation Format

Share Document