Digestibility and cell wall concentration of early- and late-maturing timothy (Phleum pratense L.) cultivars

1996 ◽  
Vol 76 (1) ◽  
pp. 107-112 ◽  
Author(s):  
G. Bélanger ◽  
R. E. McQueen
Keyword(s):  
Cell Wall ◽  
Nutritive Value ◽  
Field Experiments ◽  
Weight Ratio ◽  
Phleum Pratense ◽  
Early Maturing ◽  
Mathematical Relationships ◽  
The Relationship ◽  
Phleum Pratense L

Ear emergence or heading of early- and late-maturing cultivars of timothy (Phleum pratense L.) in the spring varies by as much as 3 wk. Two field experiments were conducted to describe the evolution of digestibility and cell-wall concentration of early- and late-maturing timothy cultivars during primary growth and to analyze the relationship between parameters of nutritive value and the leaf blade to biomass weight ratio (LWR). Compared with late-maturing cultivars of timothy on a given date, early-maturing cultivars had lower in vitro true digestibilities of DM and cell wall and a greater NDF concentration. Differences in in vitro true DM digestibility and NDF concentration between early- and late-maturing cultivars were not only related to the proportion of leaf blades in the biomass. Different parameters are, therefore, required to describe the mathematical relationships between digestibility and NDF concentration and LWR of early- and late-maturing cultivars. Key words:Phleum pratense, timothy, cultivars, digestibility, cell wall

Leaf and stem nutritive value of timothy cultivars differing in maturity

1997 ◽  
Vol 77 (2) ◽  
pp. 237-249 ◽  
Author(s):  
G. Bélanger ◽  
R. E. McQueen
Keyword(s):  
Cell Wall ◽  
Dry Matter ◽  
Nutritive Value ◽  
Weight Ratio ◽  
Phleum Pratense ◽  
Cultivar Differences ◽  
Early Maturing ◽  
True Digestibility ◽  
Phleum Pratense L

The nutritive value of herbage is a function of the nutritive value of its component leaves and stems and their proportion in the herbage. A previous study indicated that the proportion of leaves in the herbage did not explain entirely the differences in in vitro true digestibility and NDF concentrations between early and late-maturing timothy (Phleum pratense L.) cultivars. It was therefore hypothesized that the leaves and stems of early and late-maturing cultivars differ in nutritive value. The evolution of leaf and stem nutritive value of field-grown timothy cultivars differing in maturity, and the relationships between parameters of leaf and stem nutritive value, and the leaf to weight ratio (LWR) were studied during primary growth in two experiments. On a given date, stems of early-maturing cultivars had in vitro true digestibilities of dry matter and cell wall up to 61 g kg−1 DM and 71 g kg−1 DM lower that those of late-maturing cultivars, respectively. The NDF concentration of stems of early-maturing cultivars was up to 32 g kg−1 DM greater than that of late-maturing cultivars. There were no cultivar differences in leaf in vitro true digestibilities of dry matter and cell wall, and NDF concentration on a given date. At a given LWR, however, the leaves and stems of early-maturing cultivars had greater in vitro true digestibilities of dry matter and cell wall, and a lower NDF concentration than those of late-maturing cultivars. Our results indicate that differences in herbage nutritive value at a given stage of maturity between early- and late-maturing timothy cultivars is explained by a greater nutritive value of leaves and stems of the early-maturing cultivars. Key words: Phleum pratense L., timothy, cultivar, digestibility, cell wall, leaf, stem

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

Leaf and stem nutritive value of timothy genotypes under varying N fertilization

2004 ◽  
Vol 84 (4) ◽  
pp. 1101-1104 ◽  
Author(s):  
G. Bélanger ◽  
A. Brégard ◽  
R. Michaud ◽  
G. F. Tremblay
Keyword(s):  
Cell Wall ◽  
Nutritive Value ◽  
N Fertilization ◽  
Phleum Pratense ◽  
Neutral Detergent Fiber ◽  
Acid Detergent Fiber ◽  
True Digestibility ◽  
Sib Families ◽  
Phleum Pratense L

Populations and half-sib families of timothy (Phleum pratense L.), contrasting in forage N concentration, were studied in two experiments conducted in growth rooms with varying N applications. They differed in leaf and stem in vitro true digestibility (IVTD) of DM and in vitro cell wall digestibility (IVCWD), and in stem neutral detergent fiber (NDF) concentration; this confirms the presence of genetic variability for leaf and stem nutritive value in timothy under both limiting and non-limiting N conditions. Key words: Digestibility, grasses, Phleum pratense, neutral detergent fiber, acid detergent fiber

Delayed harvest affects mineral and NDF concentrations, and digestibility of timothy

2008 ◽  
Vol 88 (2) ◽  
pp. 325-329 ◽  
Author(s):  
S. Pelletier ◽  
G. F. Tremblay ◽  
G. Bélanger ◽  
P. Seguin ◽  
R. Drapeau ◽  
...  
Keyword(s):  
Key Words ◽  
Dry Matter ◽  
Metabolic Disorders ◽  
Nutritive Value ◽  
Phleum Pratense ◽  
Neutral Detergent Fiber ◽  
Fiber Concentration ◽  
Harvest Delay ◽  
Phleum Pratense L

A 1-wk delay after late heading in the harvest of timothy spring growth reduced dietary cation-anion difference (-17%), in vitro digestibilities of dry matter (-7%) and neutral detergent fiber (-10%), and increased neutral detergent fiber concentration (+5%). In summer regrowth, the harvest delay tended to have similar effects, but variations (1-6%) were smaller. Key words: Nutritive value, stages of development, Phleum pratense L., metabolic disorders

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

Lack of relationship between wheat in vitro viscosity and digestibility parameters for pigs

1998 ◽  
Vol 1998 ◽  
pp. 32-32
Author(s):  
F.J. Lewis ◽  
J. McEvoy ◽  
K.J. McCracken
Keyword(s):  
Physical Properties ◽  
Nutritive Value ◽  
Wheat Variety ◽  
Growing Pigs ◽  
Variable Composition ◽  
Wheat Quality ◽  
Inexpensive Method ◽  
Metabolisable Energy ◽  
The Relationship

Whilst wheat is a major component in many pig diets it has the most variable composition of any of the cereals (Bolton & Blair, 1974) with wheat variety and the environment in which it was grown influencing its chemical and physical properties and thus nutritive value. A rapid and inexpensive method for prediction of nutritive value is thus needed to account for these variations in wheat composition. Viscosity is closely related to the soluble arabinoxylan content of wheat (Dusel et al., 1997) with a high in vitro wheat viscosity associated with a reduction in apparent metabolisable energy (AME) for poultry (Classen et al, 1995). The relationship between viscosity and nutritive value for pigs is therefore of interest. The present study investigated the effect of wheat quality measured by extract viscosity, on ileal and overall digestibility using the post-valve ‘T’ caecal (PVTC) canulation method in growing pigs.

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

The effect of temperature on quality characteristics in timothy (Phleum pratense L.) genotypes

1993 ◽  
Vol 73 (4) ◽  
pp. 1017-1026 ◽  
Author(s):  
N. Ames ◽  
A. R. McElroy ◽  
J. Erfle
Keyword(s):  
Dry Matter ◽  
Nutritive Value ◽  
Genetic Factors ◽  
Lignin Content ◽  
Rumen Fluid ◽  
Phleum Pratense ◽  
Effect Of Temperature ◽  
Genotypic Differences ◽  
Genetic Traits ◽  
Phleum Pratense L

Improving the nutritive value of timothy (Phleum pratense L.) through breeding is dependent on selecting for genetic traits which directly contribute to ruminant digestibility. The identification of these traits is the goal of many forage researchers. The objectives of this research were to evaluate the leaf and stem digestibility of six timothy genotypes under different temperature conditions using two methods of estimating digestibility. Correlations between leaf and stem digestibility were not significant, suggesting that separation of these components is nessessary to clearly evaluate genotypic differences. Temperature had an important effect on digestibility, particularly for the stem fraction. Isolating leaf from stem and evaluating genotypes individually across temperatures may permit the identification of more simple genetic factors which control digestibility in timothy. Genotypic differences were observed at all temperatures. The rumen fluid digestion resulted in a much greater range within and among genotypes for both stem and leaf fractions. Genotypes tended to follow the same trends with respect to temperature using both techniques suggesting that only a portion of the dry matter digested by rumen fluid is available to the cellulases used in these experiments. Lignin content was measured for two of the most variable genotypes and the results showed that while levels increased with higher growth temperature, differences between genotypes are more pronounced at 10 °C for both leaf and stem. Key words: Digestibility, forage quality, lignin, temperature, timothy, Phleum pratense L.

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