Nutrient selection by dairy cows grazing chicory or perennial ryegrass during spring

2014 ◽  
Vol 54 (10) ◽  
pp. 1646
Author(s):  
S. K. Muir ◽  
G. N. Ward ◽  
J. L. Jacobs

Traditional measures of the nutrient concentration of herbage before grazing may not accurately depict the nutrient intake of grazing animals. An experiment was conducted to investigate differences in DM and nutrient intake, and milk production of lactating cows offered chicory- or perennial ryegrass-based diets during spring on a commercial dairy farm in south-west Victoria. This experiment was conducted in mid-lactation (spring), with chicory (Cichorium intybus L.), perennial ryegrass (Lolium perenne L.) and a mixed sward of chicory and perennial ryegrass offered at two daily allowances (nominally 20 and 30 kg DM/cow to ground level). Selection differentials for estimated metabolisable energy (MJ/kg DM), neutral detergent fibre (NDF; g/kg DM) and acid detergent fibre (g/kg DM) varied (P < 0.05) with forage type, while allowance affected selection for estimated metabolisable energy, crude protein, acid detergent fibre and NDF (P < 0.01). However, the differences in selection differentials observed between the chicory, mixed sward and perennial ryegrass under the same conditions indicated that preferential grazing for leaf rather than stem in chicory may affect nutrient selection in a way that differs from perennial grass species, resulting in much lower intakes of NDF than indicated by traditional measurements of feed characteristics.

2017 ◽  
Vol 57 (7) ◽  
pp. 1392 ◽  
Author(s):  
B. R. Cullen ◽  
D. Bullen ◽  
C. Hutcheson ◽  
J. L. Jacobs ◽  
M. H. Deighton

Previous research has documented nutritive characteristics of perennial ryegrass-based pastures and subsequent nutrient-selection differentials when dairy cows graze such pastures, but there has been little comparable research on alternative pasture grasses. The aim of the present study was to compare the pre-grazing nutritive characteristics of four perennial grasses, how nutrients vary with plant height, and selection differentials achieved by dairy cows grazing these grasses in late winter and late spring. The study utilised an established field experiment, with four replicates of monoculture swards of perennial ryegrass (Lolium perenne L.), tall fescue (Festuca arundinacea Schreb.), cocksfoot (Dactylis glomerata L.) and prairie grass (Bromus willdenowii Kunth.), in western Gippsland, Victoria. Eighty individual tillers per replicate were sampled to ground level immediately pre- and post-grazing in late winter (July–August, vegetative tillers only) and late spring (November–December, vegetative and reproductive tillers sampled separately), dissected into three height categories (0–5 cm, 5–10 cm and 10+ cm) and analysed for nutritive characteristics. For vegetative tillers in both seasons, perennial ryegrass had the highest estimated metabolisable energy concentration and lowest neutral detergent fibre concentration of all species. In spring, reproductive tillers had consistently lower nutritive characteristics than did vegetative tillers. Selection differentials, calculated as the ratio of nutritive characteristics selected by the herd to that available pre-grazing, showed that cows selected herbage with higher crude protein concentration but there was little evidence for selection of higher metabolisable energy concentration. The selection differentials reflected the vertical distribution of nutrients in the tillers. The present results have provided new information to assist in developing grazing guidelines for alternative perennial grasses.


2014 ◽  
Vol 65 (5) ◽  
pp. 479 ◽  
Author(s):  
Belete Shenkute Gemeda ◽  
Abubeker Hassen

This study characterised 16 tropical perennial grass species in terms of in vitro methane output and related their digestibility and rumen fermentation with methane output. The grass samples were collected, dried in a forced oven, and ground and analysed for nutrient composition. In vitro gas production and organic matter digestibility (IVOMD) were determined using rumen fluid collected, strained and anaerobically prepared. A semi-automated system was used to measure gas production through in vitro incubation at 39°C. Anthephora argentea and Stipagrostis ciliate produced the highest concentration of methane in terms of g kg–1 digestible dry matter (DDM) and g kg–1 digestible organic matter (IVOMD). Cenchrus ciliaris, Setaria verticillata and Panicum coloratum produced the lowest (P < 0.05) methane when expressed in terms of g kg–1 DDM and g kg–1 IVOMD. Ash, ether extract, non-fibrous carbohydrate, neutral and acid detergent insoluble nitrogen, and crude protein were negatively correlated with methane production. Methane production positively correlated with neutral and acid detergent fibre, cellulose and hemicellulose. It is important to focus on screening and selecting perennial grass with higher nitrogen content and low methane production to mitigate methane production under tropical conditions.


2006 ◽  
Vol 46 (5) ◽  
pp. 637 ◽  
Author(s):  
B. S. Dear ◽  
G. A. Sandral ◽  
B. C. D. Wilson

The tolerance of 5 perennial grasses during the seedling stage to pre- and post-emergent grass herbicides was examined in 3 glasshouse experiments. The perennial grass species screened were phalaris, (Phalaris aquatica L.), cocksfoot (Dactylis glomerata L.), wallaby grass [Austrodanthonia richardsonii (Cashm.) H.P. Linder], perennial ryegrass (Lolium perenne L.) and tall fescue (Festuca arundinacea Schreb.). Wheat (Triticum aestivum L.) and subterranean clover (Trifolium subterraneum L.) were included as non-target species and annual ryegrass (Lolium rigidum Gaudin) and oats (Avena spp.) as representatives of typical weed species. Herbicides evaluated were fluazifop-p, tralkoxydim, diclofop-methyl, fenoxaprop-p-ethyl, fenoxaprop-p-ethyl + pyrazoline, sethoxydim, flamprop-m-methyl, quizalofop-p-ethyl, clethodim, simazine, imazethapyr, propyzamide, carbetamide, clodinafop-propargyl + cloquintocet-mexyl, propaquizafop, atrazine, trifluralin, triallate, pendimethalin, metribuzin, trifluralin + oryzalin, cyanazine, chlorsulfuron and triasulfuron. Herbicide phytotoxicity was assessed 15 and 30 days after post-emergent herbicide application using the European Weed Research Committee (EWRC) visual score of leaf damage (1 indicating no effect, 9 indicating all plants dead) and plant herbage yield depression relative to the unsprayed control. Plant responses to pre-emergent herbicides were assessed 45 days after sowing. Most herbicides were highly phytotoxic (EWRC score 4–9) to the perennial grass seedlings. However, atrazine, flamprop-m-methyl, imazethapyr, fenoxaprop-ethyl, and triallate caused less severe phytotoxicity (EWRC score 1–4) in phalaris, fescue, cocksfoot and perennial ryegrass from which they could be expected to recover, with yield reductions of between 0 and 45%, 30 days after spraying. Simazine caused yield losses of 20–50% in fescue, phalaris and perennial ryegrass which may be acceptable in swards with high weed burdens. Wallaby grass showed tolerance to flamprop-m-methyl, carbetamide, propyzamide and imazethapyr. Subterranean clover was tolerant of most herbicides with yield losses less than 20% except for the post-emergent herbicides simazine and atrazine, and the pre-emergent herbicides triasulfuron, metribuzin, cyanazine and chlorsulfuron where yield suppression was between 50 and 99%.


1985 ◽  
Vol 104 (1) ◽  
pp. 1-9 ◽  
Author(s):  
S. J. Kennedy ◽  
S. J. Gardiner ◽  
T. J. Gilliland ◽  
M. S. Camlin

SummaryIn research into competition between individual cultivars of one perennial grass species sown in mixtures, fixed matrix designs have been widely used because of difficulties in identifying the components inanatural sward.Extrapolation of results from such fixed designs to the sward situation is often difficult in any but the short-term context.This paper describes the principles, requirements and use of an electrophoretic technique together with a mathematical concept which can be used to distinguish certain perennial ryegrass cultivars when sown in mixtures. Such methods have useful implications for the study of sward composition and competitive ability of ryegrass cultivars sown in mixtures. The number of samples required to study selected 2-way cultivar mixtures using this method is indicated.


2012 ◽  
Vol 67 (2) ◽  
pp. 280-298 ◽  
Author(s):  
P. J. Purcell ◽  
M. O’Brien ◽  
A. Navarro-Villa ◽  
T. M. Boland ◽  
M. McEvoy ◽  
...  

2018 ◽  
Vol 58 (8) ◽  
pp. 1552 ◽  
Author(s):  
C. M. Leddin ◽  
J. L. Jacobs ◽  
K. F. Smith ◽  
K. Giri ◽  
B. Malcolm ◽  
...  

Dairy production systems in south-eastern Australia are based primarily on grazed pasture. Perennial ryegrass (Lolium perenne L.) is the major grass species used in this region and farmers are faced with the challenge of choosing from more than 60 commercially available cultivars. This paper describes the development of a system termed as a forage value index that ranks the overall performance of perennial ryegrass cultivars relative to cultivar Victorian according to the summation of the estimated difference in the value of seasonal dry-matter (DM) yield of the cultivars. Average predicted seasonal DM yields were calculated by analysing the results of eight available perennial ryegrass plot trials across south-eastern Australia, using a multi-environment, multi-harvest linear mixed model. The differences in the model-predicted DM yield of each cultivar was compared with cultivar Victorian in each of five seasonal periods (autumn, winter, early spring, late spring, summer) to generate a series of performance values (1 per period) for each cultivar. Each performance value was then multiplied by an economic value (AU$/kg extra pasture grown) relating to each of four regions (Gippsland, northern Victoria, south-western Victoria, Tasmania) and seasonal period and aggregated to generate an overall forage value index rating for each cultivar. Economic values ranged from AU$0.11 to AU$0.39 per extra kilogram of DM grown, depending on the season and region, which translated into estimated benefits on dairy farms of up to AU$183 per ha per year for farmers that use high-yielding cultivars in place of cultivar Victorian perennial ryegrass.


Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2232
Author(s):  
Bulelani Nangamso Pepeta ◽  
Mehluli Moyo ◽  
Abubeker Hassen ◽  
Ignatius Verla Nsahlai

This study investigated if there is any confounding effect of stocking rate on the use of internal markers to determine and predict the dietary ingredient composition, dry matter intake (DMI) and digestibility of diets consumed by sheep. Fifteen sheep were randomly allocated to stocking rate treatments of one (SR1), two (SR2), four (SR4) and eight (SR8) sheep per pen (space allowance: 31.04 m2, 15.52 m2, 7.76 m2 and 3.88 m2 per sheep, respectively) and fed ad libitum maize stover, sorghum stover and veld hay by supplying 110% of previous day’s intake. Sheep were rotated across the treatments in four periods of 10 days. The proportion of feeds selected and total DMI were similar across all stocking rate treatments. However, diets selected by sheep in SR2 had the highest digestibility compared to other treatments. The prediction of the effective degradability of dry matter using acid detergent fibre content achieved an accuracy of 84.6%. A combination of crude protein and neutral detergent fibre contents achieved 63% accuracy in the prediction of the rate of degradation of feeds. The use of acid insoluble ash (AIA) as an internal marker to predict nutrient intake, digestibility, DMI and dietary ingredient intake accounted for 84.3%, 81.2%, 53.0% and 64.1% of the variation, respectively. The predictions of dietary feed proportions and nutrient quality selected obtained with least squares procedure using a combination of modified acid detergent fibre (MADF), acid detergent lignin (ADL) and AIA accounted for 81.0% and 72.4% of the variation, respectively. In conclusion, regardless of the different stocking rate tested in this study, a combination of MADF, ADL and AIA as internal markers can be used to estimate diet and nutrient selection by sheep using the least squares procedure. Hence, these markers can be used to predict ingredient composition of diet, diet and nutrient selection, nutrient intake and digestibility in free ranging animals.


2016 ◽  
Vol 5 (04) ◽  
pp. 4958
Author(s):  
Dulal De

Hymenachne acutigluma (Steud.) Gilliland, a robust rhizomatous perennial grass spreads on moist and swampy land and also floating in water. Being a grass species, they do not have any cambium for secondary growth. A peculiarity in stem anatomy especially the spongy pith of secondary tissues found in absence of the cambium. The origin and development of the parenchymatous pith tissues has been investigated in the present study. Economically this spongy pith is of very much potent for its high absorbing and filtering capacity and also used as a good fodder.


Genome ◽  
2017 ◽  
Vol 60 (12) ◽  
pp. 1086-1088 ◽  
Author(s):  
Hiroshi Shinozuka ◽  
Noel O.I. Cogan ◽  
German C. Spangenberg ◽  
John W. Forster

RNA-Seq methodology has been used to generate a comprehensive transcriptome sequence resource for perennial ryegrass, an important temperate pasture grass species. A total of 931 547 255 reads were obtained from libraries corresponding to 19 distinct tissue samples, including both vegetative and reproductive stages of development. Assembly of data generated a final filtered reference set of 48 713 contigs and scaffolds. The transcriptome resource will support whole genome sequence assembly, comparative genomics, implementation of genotyping-by-sequencing (GBS) methods based on transcript sampling, and identification of candidate genes for multiple biological functions.


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