THE EFFECT OF NURSERY CONDITIONS ON THE IN VITRO DIGESTIBILITY OF TIMOTHY (Phleum pratense L.)

1986 ◽  
Vol 66 (2) ◽  
pp. 307-313 ◽  
Author(s):  
A. R. McELROY ◽  
B. R. CHRISTIE
Keyword(s):  
Predictive Value ◽  
Phleum Pratense ◽  
Relative Performance ◽  
In Vitro Digestibility ◽  
Whole Plant ◽  
Growth Room ◽  
Growing Conditions ◽  
Phleum Pratense L

Fifteen timothy (Phleum pratense L.) genotypes of similar maturity were grown in simulated sward (100 plants m−2), spaced-plant (1 plants m−2) and growth room nurseries for 2 yr or harvests. The whole plant in vitro digestibility (IVD) was determined at early heading. IVD values were strongly influenced by growing conditions and highly significant [Formula: see text] year × genotype and harvest × genotype interactions were found. The precision of IVD determination was similar in all nurseries. Correlation between genotype means of simulated sward and other nurseries, although significant [Formula: see text] is some cases, was too low to be of predictive value. Some genotypes tended to rank relatively high in all nurseries, but the relative performance of most genotypes was inconsistent. It is concluded that the choice of nursery techniques used to predict the sward performance of timothy genotypes is more critical than is generally assumed.Key words: Timothy, Phleum pratense L., in vitro digestibility, IVD, nursery competition

scholarly journals VARIATION IN DIGESTIBILITY DECLINE WITH ADVANCE IN MATURITY AMONG TIMOTHY (Phleum pratense L.) GENOTYPES

1986 ◽  
Vol 66 (2) ◽  
pp. 323-328 ◽  
Author(s):  
A. R. McELROY ◽  
B. R. CHRISTIE
Keyword(s):  
Forage Quality ◽  
Phleum Pratense ◽  
In Vitro Digestibility ◽  
Single Population ◽  
Population Mean ◽  
Unit Increase ◽  
Selection For ◽  
Phleum Pratense L

The in vitro digestibility (IVD) of timothy (Phleum pratense L.) declines with advance in maturity. Forage quality reductions resulting from late harvesting could be minimized by developing cultivars with reduced IVD decline during maturation. This study examines variation for IVD decline among timothy genotypes. Clones originating from a single population were grown in simulated swards (100 plants m−2) at two Ontario locations in 1980 and 1981. Harvests were made every 5–6 d from early heading to late anthesis. Relative IVD declines were determined by regressing genotype performance on the population mean over several harvests. Considerable variation was found for relative IVD decline, but this parameter was not associated with IVD at early heading. Genotypes were identified which showed high IVD at heading and a 20% reduction in digestibility decline from heading to late anthesis. Changes in IVD were not associated with changes in the leaf content of forage. It is concluded that selection for reduced IVD decline, in addition to high digestibility at heading, might result in a 2–3% unit increase at anthesis.Key words: Timothy, Phleum pratense L., in vitro digestibility, IVD, IVD decline

INFLUENCE OF HARVEST SYSTEMS AND NITROGEN RATES ON YIELDS, QUALITY AND PERSISTENCE OF CHAMP TIMOTHY IN THE SEEDING AND POSTSEEDING YEARS

1976 ◽  
Vol 56 (3) ◽  
pp. 715-723 ◽  
Author(s):  
H. T. KUNELIUS ◽  
M. SUZUKI ◽  
K. A. WINTER
Keyword(s):  
Full Range ◽  
Phleum Pratense ◽  
In Vitro Digestibility ◽  
N Application ◽  
System A ◽  
Yield Quality ◽  
N Rates ◽  
Nitrogen Rates ◽  
Phleum Pratense L

The interaction effects of harvest systems and rates of N on yield, quality and persistence of Champ timothy (Phleum pratense L.) were studied in a 4-yr field experiment. In the seeding year, total dry matter (DM) yields were highest (4.41 tons/ha) for the harvest taken 12 wk after seeding. Total DM yields increased with increasing N application up to 148 kg N/ha/yr. During the 3 postseeding yr, timothy was harvested four (system A), three (B) or two (C) times per season. Nitrogen was applied at five rates from 33 to 165 kg/ha; three times for systems A and B and twice per season for system C. Total DM yields showed increases for the full range of N application for systems A and B, but up to 132 kg/ha/application for system C. The tissue N concentrations were increased by increasing rates of fertilizer N while the in vitro digestibility of DM (IVDDM) was not generally changed. Forage with high IVDDM of 68.0 to 72.0% was produced under systems A and B whereas under C, IVDDM ranged from 55.9 to 65.1% during the season. The NO3-N concentrations of tissue frequently exceeded 0.15% levels at N rates above 132 kg/ha/application. High rates of N tended to thin the stand, but weeds were most prevalent where the lowest N rate was used.

EFFECTS OF 25 YEARS OF N, P AND K FERTILIZATION ON YIELD, PERSISTENCE AND NUTRITIVE VALUE OF A TIMOTHY SWARD

1989 ◽  
Vol 69 (2) ◽  
pp. 501-512 ◽  
Author(s):  
G. BÉLANGER ◽  
J. E. RICHARDS ◽  
R. B. WALTON
Keyword(s):  
Crude Protein ◽  
Nutritive Value ◽  
Maximum Yield ◽  
Phleum Pratense ◽  
In Vitro Digestibility ◽  
Botanical Composition ◽  
Phleum Pratense L ◽  
K Fertilization

The effects of over 25 yr of levels of applied N, P and K on forage DM yield, crude protein content, in vitro digestibility (IVD), botanical composition and persistence of a timothy (Phleum pratense L.) sward were assessed in a long-term field experiment on an acidic Riverbank L. Ammonium nitrate (0, 90, 180, 270 kg N ha−1), superphosphate (0, 15, 29, 44 kg P ha−1) and muriate of potash (0, 47, 94, 141 kg K ha−1) were applied annually in all possible combinations to a timothy sward since 1960. In the first 3 yr of the experiment, only N and K were required for maximum yield and persistence of timothy. The requirement for applied P, however, increased with time; in the last 3 yr (1985–1987) of the trial, the highest level of applied P resulted in profitable forage DM yield increases. After 25 yr, the productivity of the timothy sward was dependent upon a balanced application of all three macronutrients; absence of any one nutrient resulted in little or no response to applications of the other nutrients. The long-term persistence of timothy was solely dependent on K fertilization. The proportion of bentgrass and bluegrass species declined with increasing levels of applied K while that of timothy increased. The change in botanical composition due to applied N and K significantly affected IVD and crude protein content.Key words: N, P, K, fertilization, yield, persistence, timothy

GENOTYPE × ENVIRONMENT INTERACTIONS FOR IN VITRO DIGESTIBILITY OF TIMOTHY (Phleum pratense L.) GENOTYPES

1986 ◽  
Vol 66 (2) ◽  
pp. 315-321 ◽  
Author(s):  
A. R. McELROY ◽  
B. R. CHRISTIE
Keyword(s):  
Zea Mays L ◽  
Genetic Material ◽  
Phleum Pratense ◽  
In Vitro Digestibility ◽  
Environment Interaction ◽  
Important Goal ◽  
Genotype Environment Interaction ◽  
Selection For ◽  
Phleum Pratense L

Improved in vitro digestibility (IVD) is an important goal in timothy (Phleum pratense L.) breeding. This study examines the effect of genotype × environment (GE) interactions on individual genotypes and examines two methods for identifying superior parental genotypes. Fifteen genotypes of similar maturity were grown in simulated swards (100 plants m−2) at five locations. IVD was determined at early heading. Highly significant effects were found for genotype, year, location and all their interactions. A regression stability analysis indicated that most genotypes responded in a predictable manner to environment. Genotypes which performed relatively well in all environments were identified. However, some useful genetic material, being "unstable", would be discarded using this approach. Genotypes with consistently high IVD were identified using a technique developed for grouping corn (Zea mays L.) hybrids. This approach is considered the more efficient for identifying superior parental genotypes. Although genotype (IVD should be based on performance in several environments, it is suggested that selection for IVD stability is important in developing narrow-based but not wide-based synthetics.Key words: Timothy, Phleum pratense L., genotype × environment interaction, in vitro digestibility, IVD

scholarly journals COMPARISON OF NEAR INFRARED CALIBRATIONS FOR ESTIMATING IN VITRO DIGESTIBILITY IN WHOLE-PLANT CORN HYBRIDS

1987 ◽  
Vol 67 (2) ◽  
pp. 557-562 ◽  
Author(s):  
E. V. VALDES ◽  
R. B. HUNTER ◽  
G. E. JONES
Keyword(s):  
Dry Matter ◽  
Near Infrared ◽  
Mature Stage ◽  
In Vitro Digestibility ◽  
Infrared Reflectance ◽  
Near Infrared Reflectance ◽  
Corn Hybrids ◽  
Dry Matter Digestibility ◽  
Whole Plant

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

RELATIONSHIPS AMONG WHOLE-PLANT MOISTURE, GRAIN MOISTURE, DRY MATTER YIELD, AND QUALITY OF WHOLE-PLANT CORN SILAGE

1975 ◽  
Vol 55 (1) ◽  
pp. 77-84 ◽  
Author(s):  
T. B. DAYNARD ◽  
R. B. HUNTER
Keyword(s):  
Moisture Content ◽  
Dry Matter ◽  
Yield Potential ◽  
In Vitro Digestibility ◽  
Research Station ◽  
Whole Plant ◽  
Grain Moisture ◽  
Plant Moisture ◽  
Plant Moisture Content

Identical experiments were conducted at the Elora Research Station, near Guelph, Ontario in 1970 and 1971 with the objective of determining the relationships among whole-plant dry matter (DM) yield, whole-plant moisture content, and grain moisture content of corn (Zea mays L.) during the later part of the growing season. Each experiment involved eight commercial hybrids representative of the range in maturity, endosperm type, lodging resistance, and grain yield potential of corn hybrids grown commercially in central Ontario. The hybrids were sampled at weekly intervals over an 8-wk period beginning approximately 1 September; the sampled plants were divided into their leaf, stalk, husk, ear and grain components and oven-dried. Fresh and dry weights were used to calculate dry matter (DM) yields and "at harvest" moisture contents of the various components, and of the entire plant. Averaged across the eight hybrids, maximum DM yield was attained at whole-plant moisture content of 66–70%, and a grain moisture content of 45–50%. Among hybrids, 66% whole-plant moisture corresponded to a range in grain moisture content from 41 to 47%. Two additional experiments were grown also at Elora in 1970 and 1971 to evaluate the effects of harvest date on the DM yield and in vitro digestibility of corn plants and their component plant parts. Each experiment involved four representative commercial hybrids which were sampled at four equal time intervals during the month of September, and divided into grain, cob, husks (including shank) and stover (including leaves, leaf sheaths, stalks and tassels) for dry weight and in vitro digestibility measurement. Whole-plant DM digestibility was essentially constant over a range of whole-plant moisture from 76 to 56% in 1970, and from 76 to 64% in 1971. The consistency of whole-plant digestibility was the result of compensating changes in component yield and digestibility. A decrease in the digestibility of the stover, husks and cob with delayed harvest was compensated for by an increase in the proportion of grain in the whole-plant yield.

VARIABILITY OF IN VITRO DIGESTIBILITY AMONG CLONES OF BROMEGRASS AND ORCHARDGRASS

1968 ◽  
Vol 48 (1) ◽  
pp. 67-73 ◽  
Author(s):  
B. R. Christie ◽  
D. N. Mowat
Keyword(s):  
Dactylis Glomerata ◽  
Bromus Inermis ◽  
In Vitro Digestibility ◽  
Phenotypic Characteristics ◽  
Whole Plant ◽  
Stems And Leaves ◽  
Dactylis Glomerata L ◽  
Whole Plants ◽  
Genotypic Effects

Individual clones of bromegrass (Bromus inermis Leyss) and orchardgrass (Dactylis glomerata L.) were harvested at corresponding stages of maturity within each species. The orchardgrass clones were harvested in 1962, and the in vitro digestibility (IVD) was based on the whole plant. Bromegrass clones, harvested in 1965 and 1966, were separated into leaves and stems. The IVD of each component was determined, and from these, the IVD for the whole plant was estimated.Among 444 orchardgrass clones, IVD values ranged from 49 to 68%. Most of the variation was attributed to genotypic effects. For approximately 250 clones of bromegrass, IVD values ranged from 66 to 75%, 58 to 73%, and 62 to 74%, for leaves, stems, and whole plants respectively. Over the 2-year period, differences among stems and whole plants were significant. Correlations between leaf and stem digestibilities were significant but of low magnitude. Ten clones of bromegrass had stems and leaves of equal digestibility.In bromegrass, IVD values showed no relationship to several phenotypic characteristics.

BARREN RING, A DESCRIPTION AND STUDY OF CAUSAL RELATIONSHIPS

1965 ◽  
Vol 43 (9) ◽  
pp. 1043-1054 ◽  
Author(s):  
J. I. Toohey ◽  
C. D. Nelson ◽  
G. Krotkov
Keyword(s):  
Bacterial Culture ◽  
Test Organism ◽  
Phleum Pratense ◽  
Pseudomonas Aureofaciens ◽  
Phytotoxic Activity ◽  
Number Of Microorganisms ◽  
Barren Soil ◽  
Bacteria And Fungi ◽  
Phleum Pratense L

A description is given of a rare soil disease, called "barren ring", which occurs in some old, deserted pastures. It is an expanding ring-shaped area of diameter up to 17 meters in which the vegetation is killed. Regeneration of normal vegetation occurs in the center of the ring. A number of microorganisms were isolated from the barren soil and tested for phytotoxicity in vitro. Of 24 pure strains of bacteria and fungi isolated, only one bacterium showed phytotoxicity to the test organism, Phleum pratense L. It was identified as a strain of Pseudomonas aureofaciens Kluyver. Bioautography of extracts of the bacterial culture showed that there are two compounds extractable in benzene which have both antibiotic and phytotoxic activity. However, it has not been established that this bacterium is the sole causal agent of the disease and it is suggested that it is caused by an association of microorganisms.

Leaf and stem nutritive value of timothy grown with varying N nutrition in spring and summer

1999 ◽  
Vol 79 (2) ◽  
pp. 223-229 ◽  
Author(s):  
G. Bélanger ◽  
R. E. McQueen
Keyword(s):  
Cell Wall ◽  
Nutritive Value ◽  
Nitrogen Deficiency ◽  
Phleum Pratense ◽  
Shoot Biomass ◽  
Negative Effect ◽  
N Deficiency ◽  
Rate Of Decline ◽  
Phleum Pratense L

Nitrogen fertilization is known to have a limited effect on the digestibility of grasses. In a previous paper, however, we reported that N deficiency increased the proportion of leaves in the shoot biomass, and hence, indirectly increased the digestibility of timothy (Phleum pratense L). This was mitigated by the direct negative effect of N deficiency on the digestibility of leaves or stems or both early in the regrowth. The objective of this study was to determine the direct effect of N deficiency on three parameters of nutritive value of leaves and stems of timothy cv. Champ. The evolution of leaf and stem in vitro true digestibility (IVTD), in vitro cell wall digestibility (IVCWD), and neutral detergent fiber (NDF) concentration of field-grown timothy fertilized with four rates of N was studied during a spring and summer regrowth cycle by sampling at weekly intervals. The rate of decline in leaf nutritive value in spring was greater than that in summer, and was less than the rate of decline in stem nutritive value during spring. Nitrogen deficiency consistently increased the NDF concentration of leaves but had a lesser effect on the NDF concentration of stems. Nitrogen deficiency decreased leaf IVCWD when the leaf-to-weight ratio (LWR) was high early in the spring and summer regrowth cycles. At the end of regrowth when LWR values were low, leaf IVCWD was greatest when no N was applied. As a result, the negative effect of N deficiency on the leaf IVTD during the early part of the spring and summer regrowth cycles diminished as the regrowth cycles progressed. Nitrogen deficiency had a limited effect on stem IVCWD. We concluded that the direct negative effect of N deficiency on the digestibility of the timothy shoot biomass can be attributed primarily to its effect on the NDF concentration and cell wall digestibility of leaves. Key words: Phleum pratense L., grasses, digestibility, cell wall, nitrogen

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