Timothy mineral concentration and derived indices related to cattle metabolic disorders: A review

2008 ◽  
Vol 88 (6) ◽  
pp. 1043-1055 ◽  
Author(s):  
Sophie Pelletier ◽  
Gilles Bélanger ◽  
Gaëtan F Tremblay ◽  
Perttu Virkajärvi ◽  
Guy Allard

Timothy (Phleum pratense L.) is grown in several countries, mainly for livestock forage. The nutritive value and dry matter (DM) yield of timothy is well established but less information is available on mineral concentration and related indices, like the dietary cation-anion difference (DCAD) and the grass tetany (GT) index. These indices predict the risk of a forage diet to cause metabolic disorders, i.e., milk fever for DCAD and grass tetany for the GT index. Improving our knowledge of factors affecting timothy mineral concentration is important for livestock production. This review paper compares timothy with other common cool-season grasses for mineral concentrations, DCAD, and GT index. Also assessed are variations in timothy mineral concentration affected by harvest and fertilization management, soil mineral availability, and environmental conditions. These results demonstrate the high potential for improvement and use of timothy forage to decrease the incidence of metabolic disorders within the dairy industry. Key words: Milk fever, grass tetany, dietary cation-anion difference, grass tetany index, forage, cool-season grasses

2008 ◽  
Vol 88 (2) ◽  
pp. 325-329 ◽  
Author(s):  
S. Pelletier ◽  
G. F. Tremblay ◽  
G. Bélanger ◽  
P. Seguin ◽  
R. Drapeau ◽  
...  

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


1993 ◽  
Vol 73 (4) ◽  
pp. 1017-1026 ◽  
Author(s):  
N. Ames ◽  
A. R. McElroy ◽  
J. Erfle

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.


1999 ◽  
Vol 79 (2) ◽  
pp. 223-229 ◽  
Author(s):  
G. Bélanger ◽  
R. E. McQueen

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


2004 ◽  
Vol 84 (4) ◽  
pp. 1101-1104 ◽  
Author(s):  
G. Bélanger ◽  
A. Brégard ◽  
R. Michaud ◽  
G. F. Tremblay

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


2005 ◽  
Vol 85 (2) ◽  
pp. 377-383 ◽  
Author(s):  
Paul G. Jefferson

Leaf and stem structural components contribute to variation in nutritive value among timothy (Phleum pratense L.) cultivars. Modelling timothy growth and nutritive value requires a better understanding of this variation. A trial of 11 timothy cultivars was conducted on irrigation at Swift Current, Saskatchewan from 1995 to 1997. Leaf:stem ratio, forage yield, days to maturity, N, P, acid detergent fiber (ADF) and neutral detergent fiber (NDF) concentrations, N/P ratio and P uptake of leaf and stem components were determined for spring growth forage. Two N fertilizer rates (100 and 150 kg N ha-1) did not consistently affect leaf and stem nutritive value. Cultivars differed in maturity, stem P, stem N, stem NDF, leaf NDF and leaf ADF in all 3 yr. Days to maturity was correlated to stem P concentration (r = 0.59, P < 0.05, to 0.77, P < 0.01) and leaf ADF concentration (r = 0.59, P < 0.05, to 0.82, P < 0.01) in all 3 yr but not to stem NDF concentration. Days to maturity was correlated to stem N concentration and leaf NDF concentration in 1995 and 1997 but not in 1996. However, days to maturity did not explain the observed variation among cultivars for stem NDF concentration and several other variables. While maturity differences among timothy cultivars must be taken into account when selecting for improved nutritive value or modelling growth and quality, additional variation for these traits was evident. Key words: Forage quality, Phleum pratense L., maturity, forage yield


Euphytica ◽  
2011 ◽  
Vol 182 (3) ◽  
pp. 325-334 ◽  
Author(s):  
Kazunori Ashikaga ◽  
Tsuneki Tanaka ◽  
Hiroki Fujii ◽  
Hiroyuki Tamaki ◽  
Koichi Sato ◽  
...  

1979 ◽  
Vol 59 (3) ◽  
pp. 839-846 ◽  
Author(s):  
S. P. GUERTIN ◽  
J. C. ST-PIERRE ◽  
P. GERVAIS

A 3-yr study on rates of nitgoren fertilization of timothy (Phleum pratense L.) showed that dry matter yield increased significantly with each increment of N fertilizer up to 448 kg/ha. Bounty outyielded Climax and Clair cultivars. Forage nutritive value index (NVI) was reduced by N fertilization but no significant difference was found among cultivars over the three growth cycles. Third cut forage had the highest and first cut forage the lowest NVI. Total, protein and non-protein nitrogen contents reached their highest values in first and second growth at highest rates of N fertilizer. Potentially toxic levels of nitrate-nitrogen were attained at each harvest only at rates of 448 and 896 kg/ha of N. On average over the season, Climax had the highest and Clair the lowest percentages of total and protein nitrogen while there was no significant difference among cultivars in the non-protein and nitrate nitrogen contents.


2012 ◽  
Vol 92 (5) ◽  
pp. 883-887 ◽  
Author(s):  
Chantale Morin ◽  
Gilles Bélanger ◽  
Gaëtan F. Tremblay ◽  
Annick Bertrand ◽  
Yves Castonguay ◽  
...  

Morin, C., Bélanger, G., Tremblay, G. F., Bertrand, A., Castonguay, Y., Drapeau, R., Michaud, R., Berthiaume, R. and Allard, G. 2012. Short Communication: Diurnal variations of nonstructural carbohydrates and nutritive value in timothy. Can. J. Plant Sci. 92: 883–887. Nonstructural carbohydrate (NSC) concentration in timothy (Phleum pratense L.) increased during the day by 16 to 41 g kg−1 DM (+23 to 137%) in spring and summer growth cycles and reached a maximum value between 12.8 and 13.2 h after sunrise in an area with 15 to 16 h of day length. This increase in NSC concentration was generally accompanied by a decrease in concentrations of neutral detergent fiber (−2 to 6%), acid detergent fiber (−1 to 7%), and N (−6 to 11%).


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