scholarly journals THE IN VITRO DIGESTIBILITY OF WHOLE GRASSES AND THEIR PARTS AT PROGRESSIVE STAGES OF MATURITY

1963 ◽  
Vol 43 (1) ◽  
pp. 79-87 ◽  
Author(s):  
G. I. Pritchard ◽  
L. P. Folkins ◽  
W. J. Pigden

The in vitro dry matter digestibility (IVD) of timothy, orchard, brome, reed canary, tall fescue and mountain rye grasses decreased at the rate of approximately 0.5 per cent per day throughout the growing season. The most rapid decline in IVD began with head emergence. The earliest maturing grasses tended to be higher in IVD than the other grasses at the flowering stage. The decline in IVD as the season progressed was observed in all portions of the plant, the rate of decline for the heads and stems being greater than for the leaves. The upper segments of the stems tended to have a lower IVD than the basal segments.

2021 ◽  
Vol 9 (11) ◽  
pp. 2403
Author(s):  
Ping Li ◽  
Xiaolong Tang ◽  
Chaosheng Liao ◽  
Maoya Li ◽  
Liangyin Chen ◽  
...  

To effectively use local grass resources to cover the winter feed shortage on the Qinghai-Tibetan Plateau, the silage fermentation and in vitro digestibility of perennial oat (Helictotrichonvirescens Henr.) were investigated. Perennial oat was harvested at the heading/flowering stage, wilted under sunny conditions, chopped, vacuumed in small bag silos, and stored at ambient temperatures (5–15 °C) for 60 days. The silages were treated without (CK) or with local lactic acid bacteria (LAB) inoculant (IN1), commercial LAB inoculant (IN2), and sodium benzoate (BL). Control silages of perennial oat at early heading stage showed higher (p < 0.05) lactate and acetate contents and lower (p < 0.05) final pH, butyrate, and ammonia-N contents than those at the flowering stage. High levels of dry matter recovery (DMR) and crude protein (CP) were observed in IN1- and BL-treated silages, with high in vitro gas production and dry matter digestibility. Compared to CK, additives increased (p < 0.05) aerobic stability by inhibiting yeasts, aerobic bacteria, and coliform bacteria during ensiling. In particular, the local LAB inoculant increased (p < 0.05) concentrations of lactate, acetate and propionate, and decreased concentrations of butyrate and ammonia-N in silages. This study confirmed that local LAB inoculant could improve the silage quality of perennial oat, and this could be a potential winter feed for animals such as yaks on the Qinghai Tibetan Plateau.


1975 ◽  
Vol 15 (76) ◽  
pp. 655 ◽  
Author(s):  
LA Edye ◽  
JB Field ◽  
DF Cameron

Fifteen accessions, comprising Stylosanthes guyanensis (1 ), ., hamata (5), S. humilis (2), S. subsericea (5) and interspecific hybrids (2), were compared when grown in swards with the grass Urochloa mosambicensis at three sites in the dry tropics of Queensland with an average growing season ranging from 11.5 to 22.0 weeks per annum. The swards were harvested at 6-weekly intervals during the growing season at a height of 7.6 cm. Over the three years of the trial, S. hamata CPI 38842 (cv. Verano) was superior in dry matter yield over all sites to the other accessions, including the two S. humilis cultivars cv. Paterson and cv. Lawson. Nodulation problems prevented an adequate comparison of four other S, hamata accessions except at 'Fanning River', where CPI 40264A and 40268 nodulated effectively and were as productive as cv. Verano. All S. hamata accessions perennated but gave lower pod yields and seedling regeneration than S. humilis cultivars. In vitro digestibility of the S. hamata accessions was lower than S. humilis in May but higher in September. Although S. subsericea accessions nodulated readily at all sites, their performance was site-sensitive and all but one accession failed to perennate.


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


1965 ◽  
Vol 45 (5) ◽  
pp. 503-507 ◽  
Author(s):  
D. N. Mowat ◽  
B. R. Christie ◽  
J. E. Winch

The in vitro dry matter digestibility (I.V.D.) of the stem and total leaf fractions of four orchardgrass clones was similar at the preheading stage. Even at 100% head emergence, differences in I.V.D. between stems and living leaves were not great with the early-maturing clones. However, wide differences existed between the values for stems and living leaves in mature plants. Heads were only slightly higher than stems in digestibility.Leaf digestibility was lower for those leaves dead or even partially dead. Nevertheless, in mature plants, dead leaves were higher in I.V.D. than heads or stems. Large differences occurred among clones in stem digestibility. However, the variability among clones in leaf digestibility was small.


2009 ◽  
Vol 49 (7) ◽  
pp. 563 ◽  
Author(s):  
David B. Coates ◽  
Robert J. Mayer

In a study that included C4 tropical grasses, C3 temperate grasses and C3 pasture legumes, in vitro dry matter digestibility of extrusa, measured as in vitro dry matter loss (IVDML) during incubation, compared with that of the forage consumed, was greater for grass extrusa but not for legume extrusa. The increase in digestibility was not caused by mastication or by the freezing of extrusa samples during storage but by the action of saliva. Comparable increases in IVDML were achieved merely by mixing bovine saliva with ground forage samples. Differences were greater than could be explained by increases due to completely digestible salivary DM. There was no significant difference between animals in relation to the saliva effect on IVDML and, except for some minor differences, similar saliva effects on IVDML were measured using either the pepsin–cellulase or rumen fluid–pepsin in vitro techniques. For both C4 and C3 grasses the magnitude of the differences were inversely related to IVDML of the feed and there was little or no difference between extrusa and feed at high digestibilities (>70%) whereas differences of more than 10 percentage units were measured on low quality grass forages. The data did not suggest that the extrusa or saliva effect on digestibility was different for C3 grasses than for C4 grasses but data on C3 grasses were limited to few species and to high digestibility samples. For legume forages there was no saliva effect when the pepsin–cellulase method was used but there was a small but significant positive effect using the rumen fluid–pepsin method. It was concluded that when samples of extrusa are analysed using in vitro techniques, predicted in vivo digestibility of the feed consumed will often be overestimated, especially for low quality grass diets. The implications of overestimating in vivo digestibility and suggestions for overcoming such errors are discussed.


2019 ◽  
Vol 40 (5) ◽  
pp. 2045 ◽  
Author(s):  
Flávio Pinto Monção ◽  
Marco Aurélio Moraes Soares Costa ◽  
João Paulo Sampaio Rigueria ◽  
Marielly Maria Almeida Moura ◽  
Vicente Ribeiro Rocha Júnior ◽  
...  

The objective was to evaluate the productivity, chemical composition, ruminal degradability of dry matter and digestibility of BRS capiaçu grass (Pennisetum purpureum Schum.) managed at five regrowth ages. A completely randomized design with ten replications was used in the BRS capiaçu elephant grass subjected to five cutting intervals (30, 60, 90, 120 and 150 days) in the summer, making a total of 50 plots with a useful area of 4 x 2 m. There were daily increases in the dry matter production in the order of 382 kg ha-1, with 49,859 kg ha-1 being produced at 150 regrowth days. The dry matter content and organic matter linearly increased (P < 0.01) at different regrowth ages. The crude protein content, in vitro dry matter digestibility and in vitro digestibility of neutral detergent fiber linearly reduced (P < 0.01) 0.037%, 0.196% and 0.256% per day, respectively. Potential degradability of dry matter decreased from 68.9% at 30 days to 44.7% at 150 regrowth days (0.194 percentage units per day). The rate of degradation of fraction B 'c' was not modified (P = 0.94), averaging 1.46% hour-1. In the cultivation of BRS capiaçu elephant grass in the summer season, in the northern region of Minas Gerais, the age for harvesting between 90 and 120 days of regrowth is recommended.


2005 ◽  
Vol 48 (spe) ◽  
pp. 161-168 ◽  
Author(s):  
Lúcia de Fátima Araújo ◽  
Ariosvaldo Nunes Medeiros ◽  
Américo Perazzo Neto ◽  
Líbia de Sousa Conrado Oliveira ◽  
Flávio Luiz Honorato da Silva

The microbial protein bioconversion of cactus pear by yeast in solid medium was studied. Three cultivation variables used were: inoculum's concentrations (5, 10 and 15 %), substrate layer thickness (2, 4 and 6 cm) and temperature (30, 34 and 38 ºC). The rate of dry matter production and total protein were determined. Results obtained were variance analysis, gross energy and in vitro dry matter digestibility. The maximum protein amount achieved for the conditions studied in the present work was higher than 26 %, which was compatible or greater than those of conventional concentrates of protein supplements used for animal feed. The protein concentrate of cactus pear had a higher in vitro digestibility index (95.8 %) and did not show any changes in the gross energy value when compared to that of the cactus pear in natura.


1989 ◽  
Vol 40 (3) ◽  
pp. 573 ◽  
Author(s):  
RL McCown ◽  
BH Wall

In the semi-arid tropics, accumulated shed leaf of certain pasture legumes can provide highly nutritious feed for cattle in the dry season. Previous papers in this series have dealt with the fungal spoilage of leaf of Caribbean stylo in response to dew and unseasonal rainfall and the threat to acceptability by cattle. This paper focuses on the effects of varying degrees of moulding and leaching on dry matter digestibility of leaf of this legume. Uniform leaf material of high digestibility was exposed at six locations during the dry season and samples retrieved at 4-weekly intervals. From initial values of 75%. in vitro digestibility dropped to as low as 50%. Degree of moulding, as indicated by a quantitative index of discoloration, accounted for about 80�/o of loss. Moulding was much more important than leaching. This latter finding in the winter-dry tropics contrasts with previous findings in the summer-dry Mediterranean climate.


1978 ◽  
Vol 58 (4) ◽  
pp. 775-781 ◽  
Author(s):  
R. R. MARQUARDT ◽  
J. A. McKIRDY ◽  
A. T. WARD

A series of experiments has been carried out with tannin-free and tannin-containing cultivars of fababeans. The in vitro dry matter digestibility of the cotyledon portion of the two groups of fababeans was the same (88.2%) whereas the in vitro digestibility of the testa portion of the tannin-free cultivars was much higher (27.6%) than that of the tannin-containing cultivars (9.2%). The concentrations of certain cell wall constituents in the testae of tannin-free and tannin-containing cultivars were also different (P < 0.01); the respective average values for the two groups were: condensed tannins, 0.2 and 4.9%; lignin, 4.2 and 6.2%; acid detergent fiber, 72 and 66%; and cellulose, 67 and 60%. There was a negative correlation between the in vitro dry matter digestibility and the amount per unit weight of whole beans of either condensed tannin (r = −0.86, P < 0.01) or lignin (r = −0.89, P < 0.01). When expressed on a similar basis there was no correlation between levels of cellulose or acid detergent fiber and in vitro dry matter digestibility.


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