scholarly journals Machine Learning Algorithms to Predict Forage Nutritive Value of In Situ Perennial Ryegrass Plants Using Hyperspectral Canopy Reflectance Data

2020 ◽  
Vol 12 (6) ◽  
pp. 928 ◽  
Author(s):  
Chaya Smith ◽  
Senani Karunaratne ◽  
Pieter Badenhorst ◽  
Noel Cogan ◽  
German Spangenberg ◽  
...  

Nutritive value (NV) of forage is too time consuming and expensive to measure routinely in targeted breeding programs. Non-destructive spectroscopy has the potential to quickly and cheaply measure NV but requires an intermediate modelling step to interpret the spectral data. A novel machine learning technique for forage analysis, Cubist, was used to analyse canopy spectra to predict seven NV parameters, including dry matter (DM), acid detergent fibre (ADF), ash, neutral detergent fibre (NDF), in vivo dry matter digestibility (IVDMD), water soluble carbohydrates (WSC), and crude protein (CP). Perennial ryegrass (Lolium perenne) was used as the test crop. Independent validation of the developed models revealed prediction capabilities with R2 values and Lin’s concordance values reported between 0.49 and 0.82, and 0.68 and 0.89, respectively. Informative wavelengths for the creation of predictive models were identified for the seven NV parameters. These wavelengths included regions of the electromagnetic spectrum that are usually excluded due to high background variation, however, they contain important information and utilising them to obtain meaningful signals within the background variation is an advantage for accurate models. Non-destructive field spectroscopy along with the predictive models was deployed infield to measure NV of individual ryegrass plants. A significant reduction in labour was observed. The associated increase in speed and reduction of cost makes targeting NV in commercial breeding programs now feasible.

1982 ◽  
Vol 99 (3) ◽  
pp. 547-553 ◽  
Author(s):  
I. B. Norris ◽  
H. Thomas

SUMMARYThe effect of drought on the growth and subsequent recovery growth of containergrown perennial ryegrass plants was assessed in a glasshouse. Dry-matter production and percentage of water-soluble carbohydrates were measured, and non-destructive measurements of growth components (leaf extension, leaf appearance and tillering) were made.Drought had an effect upon all the variables recorded. Selecting for improved recovery growth was considered to be of more economic importance than selecting for improved growth during drought and the implications of defoliation are discussed in relation to drought recovery.It was concluded that subjecting pot-grown plants to drought was a useful technique when screening selections for response to drought.


1998 ◽  
Vol 38 (8) ◽  
pp. 821 ◽  
Author(s):  
K. F. Smith ◽  
R. J. Simpson ◽  
R. N. Oram ◽  
K. F. Lowe ◽  
K. B. Kelly ◽  
...  

Summary. Two lines of perennial ryegrass (Lolium perenne L.), cv. Aurora and breeding line Ba 11351, from the United Kingdom with elevated concentrations of water-soluble carbohydrates in the shoot were compared with the standard cultivars, Ellett, Vedette and Kangaroo Valley, in pure grass swards under irrigation at Kyabram, Victoria, and Gatton, Queensland, and under natural rainfall at Condah, Victoria, during 1995–97. Near infrared reflectance spectroscopy was used to predict the water-soluble carbohydrate, crude protein, in vitro dry matter digestibility, neutral and acid detergent fibre, and Klason lignin concentrations of the perennial ryegrass herbage. Herbage yield and water-soluble carbohydrate differed between cultivars at each site at most harvests, with the high water-soluble carbohydrate lines usually yielding less and having higher water-soluble carbohydrate concentrations than the 3 standard cultivars. However, the high water-soluble carbohydrate lines also had higher water-soluble carbohydrate concentrations at harvests where their yield was equal to the standard cultivars. The other nutritive value traits differed significantly at more than half of the 32 harvests: the high water-soluble carbohydrate lines had higher crude protein and dry matter digestibility, and lower neutral detergent fibre, the neutral detergent fibre containing less acid detergent fibre and lignin than did the standard cultivars. The high water-soluble carbohydrate lines were more susceptible to crown rust during spring and summer than the standard cultivars at Kyabram and Gatton: heavy infections reduced yield, water-soluble carbohydrate, dry matter digestibility and crude protein. Higher water-soluble carbohydrate may depend on only a few genes, as does rust resistance and it seems likely that high yielding, high water-soluble carbohydrate cultivars can be developed by recombination and selection.


1998 ◽  
Vol 38 (2) ◽  
pp. 145 ◽  
Author(s):  
K. F. Smith ◽  
G. A. Kearney ◽  
R. A. Culvenor

Summary. Seasonal variation in herbage yield, and in the concentrations of water-soluble carbohydrates, crude protein, in vitro dry matter digestibility, neutral detergent fibre, acid detergent fibre and lignin in the herbage was measured for 5 perennial ryegrass (Lolium perenne L.) cultivars grown in 3 contrasting environments. Two separate trials were sown in one of the environments. The yield and nutritive value data were subjected to antedependence analyses to detect the presence of serial correlations between data from different harvest dates. Significant (P<0.05) antedependence was found in 2, 3, 3 and 6 of the 7 variables in the 4 experiments respectively. It was shown that serial correlations between harvest dates had the potential to cause the overestimation of the significance of cultivar effects in ANOVA of data from individual harvest dates, and in harvest and cultivar × harvest effects in combined ANOVA across all harvest dates unless statistical procedures appropriate for use with repeated measurements data were adopted.


2015 ◽  
Vol 54 (1) ◽  
pp. 31-40 ◽  
Author(s):  
G. A. Burns ◽  
P. O’Kiely ◽  
D. Grogan ◽  
S. Watson ◽  
T. J. Gilliland

Abstract This study examined 169 of the newest varieties of three ryegrass species, perennial (Lolium perenne L.), Italian (Lolium multiflorum Lam.) and hybrid (Lolium boucheanum Kunth), from Recommended List trials in Ireland. The traits examined were yield, dry matter concentration, three nutritive value traits (in vitro dry matter digestibility, water-soluble carbohydrate on a dry matter basis and crude protein concentration) and two ensilability traits (buffering capacity and water soluble carbohydrate concentration on an aqueous phase basis). Varietal monocultures of each species underwent a six cut combined simulated grazing and silage management in each of two years following sowing. Perennial ryegrass yielded less than both other species in one-year-old swards, but less than only Italian ryegrass in two-year-old swards, but generally had the higher in vitro dry matter digestibility and crude protein values. Italian ryegrass displayed the most favourable ensilability characteristics of the three species with perennial ryegrass less favourable and hybrid ryegrass intermediate. Overall, despite the high yields and favourable nutritive value and ensilability traits recorded, the general differences between the three ryegrass species studied were in line with industry expectations. These findings justify assessing the nutritive value and ensilability of ryegrass species, in addition to yield, to allow farmers select species that match farming enterprise requirements.


Agronomy ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 293 ◽  
Author(s):  
Chaya Smith ◽  
Noel Cogan ◽  
Pieter Badenhorst ◽  
German Spangenberg ◽  
Kevin Smith

The nutritive value (NV) of perennial ryegrass is an important driver of productivity for grazing stock; therefore, improving NV parameters would be beneficial to meat and dairy producers. NV is not actively targeted by most breeding programs due to NV measurement being prohibitively slow and expensive. Nondestructive spectroscopy has the potential to reduce the time and cost required to screen for NV parameters to make targeted breeding of NV practical. The application of a field spectrometer was trialed to gather canopy spectra of individual ryegrass plants to develop predictive models for eight NV parameters for breeding programs. The targeted NV parameters included acid detergent fibre, ash, crude protein, dry matter, in vivo dry matter digestibility, in vivo organic matter digestibility, neutral detergent fibre, and water-soluble carbohydrates. The models were developed with partial least square regression. Model predicted ranking of plants had R2 between (0.87 and 0.39) and lab rankings of highest preforming plants. The highest ranked plants, which are generally the selection target for breeding programs, were accurately identified with the canopy-based model at a speed, cost and accuracy that is promising for NV breeding programs.


2018 ◽  
Vol 58 (6) ◽  
pp. 1043 ◽  
Author(s):  
A. Jonker ◽  
G. Molano ◽  
E. Sandoval ◽  
P. S. Taylor ◽  
C. Antwi ◽  
...  

Elevated water-soluble carbohydrate (WSC) concentration in the diet may affect rumen fermentation and consequently reduce methane (CH4) emissions. The objective of the present study was to determine CH4 emissions from male sheep (8 per treatment) in respiration chambers for 48 h and fed either a conventional diploid (CRG), a high-sugar diploid (HSG) or a tetraploid (TRG) perennial ryegrass cultivar, each offered at 0.7 or 1.0 kg dry matter (DM)/day during periods in early spring 2013 (P1), early autumn 2014 (P2) and late spring 2014 (P3). There was a significant (P < 0.001) interaction between cultivar and period for CH4 yield (g/kg DM intake). In P1 yield was 9% lower (P = 0.007) for sheep fed HSG than for sheep fed CRG or TRG, in P2 yield was 16% lower (P < 0.001) for sheep fed TRG than that for sheep fed CRG or HSG, and in P3 yield was 15% lower (P < 0.001) for sheep fed TRG than that for sheep fed CRG, with HSG-fed sheep being intermediate and not significantly different from either CRG or TRG. Despite there being a cultivar × period interaction, overall, CH4 yield was lower for sheep fed HSG or TRG than for sheep fed CRG (P < 0.001). There were no cultivar × level of feed offer interactions and, overall, yield of CH4 was 9% higher (P = 0.003) for sheep offered 0.7 than for sheep offered 1.0 kg DM/day. In each period, one or other of the high-WSC diploid (HSG) or tetraploid cultivars (TRG) gave lower CH4 yields than did the control diploid (CRG), suggesting that CH4 yield is reduced by characteristics of these cultivars. However, the effect was not consistently associated with either cultivar and could not be attributed to higher forage water-soluble carbohydrate concentrations.


Author(s):  
A P Williams ◽  
J E Cockbum ◽  
J K S Tweed

The conservation of herbage as silages results in a reduction in the nutritive value of the crop as a result of extensive proteolysis. Measurement of the major end products of proteolysis such as ammonia and amino acids has been studied extensively e.g. Oshima el al. (1979). Considerably less attention has been given to the fate of plant proteins during ensilage (Fairbairn et al., 1988). Since this may lead to a better understanding of the mechanisms involved in proteolysis and thus to improvement in its control the present study was designed to follow changes in the major nitrogenous constituents, particularly proteins and peptides, through time course sampling of silages made from perennial ryegrass with and without additives.Perennial ryegrass (23% dry matter) was ensiled in laboratory silos (1 kg fresh matter), either untreated (UT) or treated with formic acid (FA) (ADD-F, BP Chemicals, UK: 3.3 l/tonne) or a cellulase enzyme preparation (E) (FSO-1), Forum Feeds, Finland; 0.22 1/tonne).


1982 ◽  
Vol 99 (1) ◽  
pp. 153-161 ◽  
Author(s):  
D. A. Davies ◽  
T. E. H. Morgan

SUMMARYHerbage characteristics of perennial ryegrass (Lolium perenne L.), cocksfoot (Dactylis glomerata L.), tall fescue (Festuca arundinacea Schreb.) and timothy (Phleum pratense L.) pastures were obtained whilst rotationally grazed by ewes and their single lambs at a fixed stocking rate of 25/ha on an upland site (305 m O.D.) in mid-Wales. Drymatter production of cocksfoot averaged 32·1 kg/ha/day over the 3-year duration of the trial (1975·7) and was 13·3 kg/ha/day lower than that of the other three grass species. This resulted in a 8 kg/ha/day reduction in dry-matter intake on cocksfoot; this was significantly lower (P < 0·05) than that achieved on the other grasses, which were similar to one another around 36 kg/ha/day.In vitro digestibility of the herbage ranked in the order perennial ryegrass > timothy = cocksfoot > tall fescue. Intake of digestible organic matter (DOMI) was lower on cocksfoot than on perennial ryegrass and timothy. Differences were also detected in crude protein, water-soluble carbohydrates and sodium composition between species.Dry-matter intake was positively correlated with herbage growth rates (r = 0·95, P < 0·001) but not to digestibility of herbage on offer (r = 0·18). Both ewe and lamb live-weight gains were positively related to intake of dry matter and DOMI.Reference is made to comparative yield data between the grasses obtained under cutting trials. In the 2nd and 3rd harvest years (1967–1967) growth rates in the grazing experiment were 76, 61, 81 and 80% of the 66·2, 66·7, 67·8 and 65·0 kg D.M./ha/day obtained under a cutting regime on perennial ryegrass, cocksfoot, tall fescue and timothy swards respectively. This illustrates the danger involved in assessing the potential of grasses based on such information.The results are discussed in relation to the value of the species for use under grazing in the uplands.


Sign in / Sign up

Export Citation Format

Share Document