Water-soluble carbohydrates in perennial ryegrass breeding. III. Relationships with herbage production, digestibility and crude protein content

1989 ◽  
Vol 44 (4) ◽  
pp. 423-430 ◽  
Author(s):  
M. O. HUMPHREYS
Agriculture ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 459
Author(s):  
John W. Piltz ◽  
Craig A. Rodham ◽  
John F. Wilkins ◽  
Belinda F. Hackney

Experiments were conducted at three sites across southern New South Wales, Australia, over three years (2008 to 2010), to evaluate the agronomic and quality parameters of two wheat (Triticum aestivum L.), two barley (Hordeum vulgare L.), two oat (Avena sativa L.) and one triticale (× Triticosecale) variety, grown as monocultures or in combination with purple vetch (Vicia benghalensis L.). Harvests occurred when individual cereal varieties were at the boot, anthesis, milk and soft/mid dough stage of maturity; though drought conditions or lodging forced some soft/mid dough stage harvests to be abandoned. Yield and species composition of mixed crops were measured and digestibility, crude protein, water soluble carbohydrates and fibre content were determined. Yield differed between years reflective of growing season rainfall, which varied from 185 to 479 mm. Drought conditions in 2008 were associated with low yield, vetch inclusion and fibre content and high digestibility, water soluble carbohydrates and cereal crude protein content. Conversely, very favourable conditions in 2010 were associated with high yield and fibre content, and lower digestibility, water soluble carbohydrates and cereal crude protein content. Addition of vetch increased crude protein content all crops in 2009 and 2010, and 50% of the crops in 2008. Lodging was observed in later harvests of cereal/vetch crops in 2009 and 2010.


2002 ◽  
Vol 42 (5) ◽  
pp. 541 ◽  
Author(s):  
J. L. Jacobs ◽  
F. R. McKenzie ◽  
G. A. Kearney

A study determined the effects of differing rates of nitrogen fertiliser [0 (N0), 25 (N1), 50 (N2) and 75�kg N/ha (N3)] during late autumn (T1) and mid- (T2) and late (T3) winter on the nutritive characteristics of perennial ryegrass over a 28-day period after each application. All nitrogen applications were made to pastures with a post-grazed residual mass (dry matter) of 1400 kg/ha. Changes in metabolisable energy followed similar patterns for all treatments within a given period. Metabolisable energy was highest in T1, ranging from 11.8 to 13.1 MJ/kg dry matter, followed by T2 (11.5-12.3 MJ/kg dry matter) and T3 (10.6-11.5 MJ/kg dry matter). Changes in crude protein for all treatments at each application time were similar, irrespective of rate of nitrogen application. At the commencement of treatment application times, the existing crude protein content (%DM) was highest in N3 (T1�19, T2 23, T3 22), followed by N2 (T1 18, T2 21, T3 21), N1 (T1 17, T2 20, T3 20) and N0 (T1 16, T2 17, T3 18). During both T1 and T2, neutral detergent fibre content decreased by 4 percentage units and increased by a similar amount during T3. Generally, neutral detergent fibre content (%DM) was highest during T3 (53-58%), followed by T2 (45-54%) and T1 (43-49%). Water-soluble carbohydrate content (%DM) increased during all treatment periods with the highest level observed during T1 (18-31%) followed by T2 (3-14%) and T3 (1-6%). Nitrate content (measured as nitrate-nitrogen) decreased throughout T1, primarily due to dry conditions, while during T2, levels for N3 and N2 were significantly (P<0.05) higher than for N1 and N0 following nitrogen fertiliser application. During T3, nitrate content increased for all treatments throughout the 28-day period, with highest nitrate levels being observed during T3. The effect of applied nitrogen on mineral content was variable within and across treatment periods. The study indicates that nitrogen fertiliser did not affect metabolisable (apart from N3 elevating metabolisable energy during T3), neutral detergent fibre or water-soluble carbohydrate contents of perennial ryegrass during the 28 days after nitrogen application, but increased crude protein content. Also, nitrogen fertiliser elevated nitrate content in perennial ryegrass. While the elevated nitrate content observed may result in subclinical effects, these levels are not considered fatal for dairy cows. Crude protein content was generally above 20% of dry matter throughout the study and close to 30% of dry matter for short periods during T2. Minimising the effect of excess nitrogen ingested by the grazing animal may require appropriate supplementation of low crude protein containing feeds such as cereal grains. It is argued that the effects of rain and temperature, which impact on soil nitrogen mineralisation, may have a greater influence on perennial ryegrass nitrate content than nitrogen fertiliser.


Agronomy ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 383 ◽  
Author(s):  
Cristian J. Moscoso ◽  
Sarah A. Morgan ◽  
M. Jordana Rivero

The objective of this study was to assess the joint effect of perennial ryegrass cultivars and drying methods on concentrations of water-soluble carbohydrates (WSC) and crude protein (CP) and WSC/CP ratio. AberMagic AR1 and Expo AR1 forage were collected in December 2016, March, June, September and November 2017 and either oven-dried at 60 °C for 48 h (OD_60), at 80 °C for 16 h (OD_80), frozen at −80 °C for 48 h then freeze-dried (−80_FD), or flash-frozen with liquid N then freeze-dried (LN_FD). Data were analyzed by ANOVA in a factorial design with cultivar and drying method as factors. AberMagic AR1 had between 9.0 to 31.5% higher WSC concentration than Expo AR1 in the four samplings. Freeze-drying preserved more WSC than oven-drying treatments (+22.7%), particularly in June. The CP concentration of Expo AR1 was higher only in December (+6.8%), and was 22.9 and 10.9% higher in OD_60 samples compared to LN_FD samples in December and November, respectively. The WSC/CP ratio varied in June, being greater in AberMagic AR1 (+36.1%). Drying method affected WSC/CP ratio in December, June and November where freeze-drying produced greater ratios. Drying techniques generated differences in WSC, CP and WSC/CP ratio, which may affect the accuracy of the estimated impacts of forages on productivity and N use efficiency.


2004 ◽  
Vol 44 (8) ◽  
pp. 763 ◽  
Author(s):  
K. F. Smith ◽  
R. J. Simpson ◽  
R. N. Oram

The effects of site and season on the nutritive value of 16 perennial ryegrass cultivars and 60 half-sib families were assessed at 2 locations in South West Victoria. Crude protein, water-soluble carbohydrates, neutral detergent fibre and in vitro digestibility were measured on vegetative herbage, harvested in either autumn or spring. While no heritable genetic variation for nutritive value parameters was detected in this set of families, consistent differences in the nutritive value of cultivars were measured across sites and seasons. The cultivars Yatsyn1 and Ellett were consistently high in both water-soluble carbohydrates and in vitro digestibility. The differences in mean nutritive value between high and low ranking cultivars were ~40 g/kg water-soluble carbohydrates and 3–5% in vitro digestibility. These consistent differences in forage quality demonstrate the value of measuring forage quality during cultivar evaluation. The identification of cultivars with improved nutritive value will also facilitate the crossing of the alleles that confer this improvement into other genetic backgrounds.


Animals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 253 ◽  
Author(s):  
M. Jordana Rivero ◽  
Oscar L. Balocchi ◽  
Fabián L. Neumann ◽  
Juan A. Siebald

The objective of this study was to evaluate the pasture performance of different cultivars of perennial ryegrass, two “high sugar” and two standard cultivars, under two contrasting agronomic managements (aimed at either decreasing or increasing water soluble carbohydrates concentration), and their effects on the grazing preference of dairy cows. Eight treatments arising from the factorial combination of four cultivars and two managements were randomly applied to 31-m2 plots in three blocks. Pasture dry matter production and growth rate were measured for one year. Three grazing assessments were performed to establish the grazing preferences of six dairy cows in spring, summer and autumn. High sugar cultivars produced less dry matter per hectare than the standard cultivars. Cows consumed more grass and harvested a greater proportion of the pasture under the agronomic management aimed at decreasing sugar concentration, i.e., with a greater nitrogen fertilization rate and under a more frequent defoliation regime, which could be explained by the greater crude protein concentration achieved under this management. The results suggest that the genetic selection for greater levels of sugars was at the expense of herbage yield, and that cows preferred to graze herbage with a greater crude protein level instead of a greater sugar concentration.


1982 ◽  
Vol 6 ◽  
pp. 187-188 ◽  
Author(s):  
A. R. Austin ◽  
M. Gill

The object of the experiment to be reported was to determine the extent to which intake and eating behaviour are influenced by differences in the ratio of nitrogen (N) to water soluble carbohydrates (WSC) in the feed and the liquid phase of boli obtained from oesophageal fistulae. Four feeds were chosen as being likely to cover a range of N to WSC ratios in the liquid phase; these were frozen lucerne, lucerne silage, grass silage and grass silage treated with formaldehyde (46 g/100 g crude protein).


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