Leaf morphogenesis influences nutritive-value dynamics of tall fescue (Lolium arundinaceum) cultivars of different leaf softness

2017 ◽  
Vol 68 (1) ◽  
pp. 51 ◽  
Author(s):  
J. R. Insua ◽  
M. G. Agnusdei ◽  
O. N. Di Marco

The objective of this study was to compare the dynamics of neutral detergent fibre (NDF), and the 24-h in-vitro digestibility of NDF (NDFD) and dry matter (DMD) in leaf blades of two tall fescue (Lolium arundinaceum (Schreb.) Darbysh.) cultivars of different leaf softness: a soft- and a tough-leaved cultivar. The experiment was conducted during the summer regrowth of three replicated, dense mini-swards per cultivar arranged in a completely randomised design, all grown under non-limiting water, nitrogen and phosphorus. Cultivars were harvested eight times over 14 weeks to measure morphogenetic traits and nutritive value in six predefined leaf-age categories (from growing to complete senescence). The leaf lifespan and leaf length of the first three successive leaves were measured on 30 marked tillers throughout the experiment. Following analysis of variance, linear regression models were fitted to describe variations of NDF, NDFD and DMD with increasing leaf age and leaf length. Similar leaf NDF contents were found for the two cultivars, which remained stable throughout the leaf lifespan and increased markedly during leaf senescence. Leaf NDFD and leaf DMD both declined with increasing leaf age and length for the two cultivars. However, owing to shorter leaf lifespan of the soft-leaved cultivar, this decline in leaf NDFD and leaf DMD was faster for the soft- than for the tough-leaved cultivar. These results suggest that the soft-leaved cultivar will require more frequent defoliations than the tough-leafed cultivar to prevent decreases in nutritive value.

2018 ◽  
Vol 69 (11) ◽  
pp. 1165 ◽  
Author(s):  
J. R. Insua ◽  
M. G. Agnusdei ◽  
S. A. Utsumi ◽  
G. D. Berone

The aim of this study was to quantify the relative importance of leaf age and leaf length on the dynamics of neutral detergent fibre (NDF), and 24-h in vitro digestibility of NDF (NDFD) and dry matter (DMD) of tall fescue (Lolium arundinaceum (Schreb) Darbysh.). Mini-swards were conditioned and used to conduct two experiments, the first with 4-cm plant stubble height in spring–summer 2009 and autumn–winter 2011, and the second with 4-cm or 10-cm plant stubble height in spring–summer 2011. Plants were harvested at consecutive leaf-appearance intervals to measure nutritive value up to the four-leaf stage. In parallel, leaf morphogenetic traits (appearance, elongation and lifespan) and sheath length of the successive leaves produced on marked tillers were measured. Leaf NDF contents remained stable with increasing leaf age and length but showed a marked variation across seasons. Leaf NDFD and DMD showed a consistent decrease with increasing leaf age and length, and irrespective of growing season or residual pasture height. The negative effect of leaf age and length on digestibility was related to variations in sheath tube length and associated differences in leaf appearance and elongation rates. These findings highlight the relevance of monitoring the sheath tube length as a complementary measure to leaf stage for further management of the NDFD and DMD of grass forages. Although the focus of this study was tall fescue swards, the same morphogenetic implications on forage nutritive value could apply to other temperate and tropical grass species; however, the testing of this hypothesis warrants carefully controlled investigations.


2019 ◽  
Vol 111 (2) ◽  
pp. 714-724 ◽  
Author(s):  
Juan R. Insua ◽  
Mónica G. Agnusdei ◽  
Germán D. Berone ◽  
Bruno Basso ◽  
Claudio F. Machado

2011 ◽  
Vol 62 (12) ◽  
pp. 1098 ◽  
Author(s):  
M. G. Agnusdei ◽  
O. N. Di Marco ◽  
F. R. Nenning ◽  
M. S. Aello

A greenhouse experiment was performed to determine the effect of leaf age and length on neutral detergent fibre (NDF) and in vitro NDF digestibility (NDFD) during a vegetative regrowth of Chloris gayana. Dense micro swards were grown in two plots under non-limiting conditions of water, phosphorus and nitrogen. Plants were harvested at seven consecutive leaf appearance intervals. Leaf blades were dissected from individual tillers and separated into five age categories (from early growing to pre-senescence). Leaf blade and sheath length were measured and leaves of the same category were bulked for NDF and NDFD analysis. The leaf lifespan (LLS) was determined in 15 marked tillers per plot. Linear and curvilinear functions were used to describe the relationships between NDF and NDFD with leaf age and length. The NDF concentration increased until half of LLS, concomitantly with leaf expansion, and remained stable thereafter. However, NDFD declined curvilinearly through the complete LLS. The final length of consecutively formed leaves increased through regrowth, this change being associated with an increase in NDF and a decline in NDFD. Results were consistent with previous findings for temperate species and highlight the importance of leaf length, in addition to leaf age, to determine leaf blade digestibility.


Author(s):  
Ondrej Pastierik ◽  
Milan &#;imko ◽  
Ondrej Hanu&#;ovský ◽  
Miroslav Jurá&#;ek ◽  
Branislav Gálik ◽  
...  

The aim of this study was to determined nutritive value of five hybrids varying in maturity sown to plots of experimental site located in southern Slovakia. Nutrient contents and digestibility parameters were obtained from samples of herbage or silages to estimate net energy of lactation (NEL) contents and milk yield (MY) potential based on in vivo digestibility of organic matter (DOM), pepsin-cellulase in vitro digestibility of OM (IVOMD) using Ankom DaisyII Incubator (Ankom Technology Corp., NY, USA), cellulase digestibility of OM (CDOMD), neutral detergent fiber (CDNDF) or in vitro digestible non starch carbohydrates (IVDNSC). Genotype effect accounted for differences in carbohydrates content and crude protein (CP). Linear regression models increased coefficient of determination (R2) when CDOMD and IVOMD were included to predict in vivo apparent digestibility NDF (NDFD) but RMSE were higher compared to DOM. Structural carbohydrate contents had mostly precise estimates but limited R2 as the predictors of DOM, NDFD and NEL in combination with in vitro digestibility determinants. There was negative relationship of IVOMD and DOM (r = - 0.72; p < 0.01) but positive as it comes to CDOMD (r = 0.81; p < 0.01). Equations based on CDOMD (E7), IVDNSC and CP (E8) and CDNDF and Starch (E9) were selected to predict NEL. Residuals of NEL (observed – predicted) ranged from – 0.57 to 0.41 MJ/kg. Mid-late hybrids had higher MY kg/ha and MY kg/Mg than early (FAO 340). E7 and E9 were sensitive to ADL content while E8 favored hybrids rich in Starch.


2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 31-31
Author(s):  
Kevin R Meng ◽  
Eric Bailey ◽  
Josh Zeltwanger ◽  
Hannah Allen ◽  
Mikaela Adams ◽  
...  

Abstract Chemical seed-head suppression of endophyte infected tall fescue (Lolium arundinaceum) improves stocker cattle performance but may decrease forage yield. Spring nitrogen application increases tall fescue growth with a concomitant increase in ergot alkaloids, produced by the symbiotic endophyte Epichloë coenophiala. We hypothesized that greater amounts of nitrogen applied to tall fescue would increase forage yield and offset losses in forage production from chemical suppression of seed-heads with metsulfuron without effect on alkaloid concentration. Ninety-six steers (270 ± 20 kg) were randomly assigned to one of sixteen paddocks (1.8 ha) on April 18 and continuously grazed for 57 d. Paddocks were blocked by previous use (n = 4) and randomly assigned to one of four treatments; no metsulfuron, no nitrogen (NEGCON), metsulfuron with 0 (MET0), 67 (MET67), or 134 (MET134) kg/ha of ammonium nitrate, applied March 11. Steers grazing MET0 paddocks were removed 17 d early due to insufficient forage availability. Steer weight, forage yield, forage nutritive value and ergot alkaloids in forage samples were measured monthly. Seed-head frequency and species composition were determined in June. Metsulfuron application reduced (P &lt; 0.01) tall fescue seed-heads by 80%. Metsulfuron decreased (P = 0.03) ergovaline but ergovaline increased (P &lt; 0.01) at each monthly sampling across treatments. Nitrogen had no impact on ergovaline concentration (P = 0.50). Forage yield tended to be least (P = 0.07) for MET0, intermediate for NEGCON and MET67, and tended to be greatest for MET134 (P = 0.08). Steer ADG was not affected by treatment (P &lt; 0.80). Metsulfuron decreased NDF (P=0.02) regardless of fertilization rate. Forage CP increased with fertilization (P &lt; 0.01) and no differences were detected between NEGCON and MET0 (P = 0.45). Species composition was not impacted (P &gt;0.07) by treatment. Metsulfuron decreased seed-head growth and ergovaline concentration in tall fescue. Additional nitrogen fertilizer ameliorated forage yield lost to metsulfuron application but did not impact steer gain.


2021 ◽  
Vol 99 (Supplement_2) ◽  
pp. 22-22
Author(s):  
Charles A Zumbaugh ◽  
Susannah A Gonia ◽  
Kathryn M Payne ◽  
Thomas B Wilson

Abstract The objectives of this experiment were to determine changes in the nutritive value and ergot alkaloid concentrations of endophyte-infected tall fescue hay and haylage during a 180-d storage period. Forage from a single field of Kentucky-31 tall fescue was cut for hay in late June and allowed to dry in the field. The dry matter (DM) of the windrow of cut forage was measured every 2 h after clipping. Forage was sampled from the windrow in 6 location blocks once forage DM reached target levels for haylage and hay treatments. Haylage and hay samples were taken when the DM of the windrow reached 50% and 80%, respectively. Seven subsamples of each treatment within block were chopped to 1.91 cm in length with a lettuce chopper and vacuum sealed in oxygen-excluding bags. Sample bags were stored indoors and opened at 30 d intervals over the 180-d storage period. Samples were analyzed for pH, nutritive value, and individual ergot alkaloid concentrations using high-performance liquid chromatography. Within each storage day, treatment within block was considered the experimental unit. Data were analyzed in SAS using the MIXED procedure with fixed effects of treatment, day, and the treatment by day interaction. Location block was considered a random effect. As expected, pH was decreased for haylage compared to hay at all time points (P &lt; 0.01) and DM was greater (P &lt; 0.01) for hay compared to haylage. Neutral detergent fiber values were greater (P &lt; 0.01) for hay compared to haylage and declined during storage (P &lt; 0.01). Total ergot alkaloid concentrations did not differ by treatment (P = 0.61), but ergovaline concentrations declined (P &lt; 0.01) during storage. Collectively, these results indicate minimal differences in nutritive value and ergot alkaloid concentrations between hay and haylage during storage, and that ergovaline concentrations decline during storage.


Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1441
Author(s):  
Youssef Chebli ◽  
Samira El Otmani ◽  
Mouad Chentouf ◽  
Jean-Luc Hornick ◽  
Jean-François Cabaraux

Forest rangelands contribute largely to goat diets in the Mediterranean area. Information about browsed plant quality is essential for adequate feeding management. The purpose of this study was to evaluate the temporal changes in chemical composition and in vitro digestibility of the main plant species selected by goats in the Southern Mediterranean forest rangeland during two consecutive years; these were very contrasted (dry and wet). The browsed species were composed of herbaceous, eleven shrubs, and four tree species. Overall, large variability in chemical composition, in vitro organic matter digestibility (IVOMD), and metabolizable energy (ME) was observed among species, grazing season (spring, summer, and autumn), and years within each species. Crude protein (CP) content varied from 60 to 240 g/kg dry matter (DM). The fiber fractions, except for Quercus suber, increased significantly by advancing maturity. Due to the water stress, the lignin level presented a higher value during the spring of the dry year. Condensed tannin (CT) content varied from 2 to 184 g/kg DM. CP, IVOMD, and ME showed a negative correlation with lignin and CT. Based on the results presented herein, it is concluded that the nutritive value of the browsed plant species was highest in the spring and lowest during the summer and autumn of both studied years. With a good grazing management strategy, the selected plant species by goats could guarantee high-quality feeding resources throughout the year.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chatchai Kaewpila ◽  
Pongsatorn Gunun ◽  
Piyawit Kesorn ◽  
Sayan Subepang ◽  
Suwit Thip-uten ◽  
...  

AbstractImproving the nutrition of livestock is an important aspect of global food production sustainability. This study verified whether lactic acid bacteria (LAB) inoculant could promote ensiling characteristics, nutritive value, and in vitro enteric methane (CH4) mitigation of forage sorghum (FS) mixture silage in attacking malnutrition in Zebu beef cattle. The FS at the soft dough stage, Cavalcade hay (CH), and cassava chip (CC) were obtained. The treatments were designed as a 4 × 2 factorial arrangement in a completely randomized design. Factor A was FS prepared without or with CH, CC, and CH + CC. Factor B was untreated or treated with Lactobacillus casei TH14. The results showed that all FS mixture silages preserved well with lower pH values below 4.0 and higher lactic acid contents above 56.4 g/kg dry matter (DM). Adding LAB boosted the lactic acid content of silages. After 24 h and 48 h of in vitro rumen incubation, the CC-treated silage increased in vitro DM digestibility (IVDMD) with increased total gas production and CH4 production. The LAB-treated silage increased IVDMD but decreased CH4 production. Thus, the addition of L. casei TH14 inoculant could improve lactic acid fermentation, in vitro digestibility, and CH4 mitigation in the FS mixture silages.


2014 ◽  
Vol 71 (1) ◽  
pp. 102-111 ◽  
Author(s):  
J. O. Scheneiter ◽  
J. Camarasa ◽  
J. R. Carrete ◽  
C. Amendola
Keyword(s):  

1987 ◽  
Vol 65 (5) ◽  
pp. 949-953 ◽  
Author(s):  
James S. Coleman ◽  
Clive G. Jones ◽  
William H. Smith

The interaction of an acute ozone dose, plant genotype, and leaf ontogeny on the development of cottonwood leaf rust on eastern cottonwood (Populus deltoides Bartr.) was investigated. A rust-resistant (ST 66) and a rust-susceptible (ST 109) clone were exposed to charcoal-filtered air or were fumigated with 393 μg m−3 (0.20 ppm) ozone for 5 h. Forty hours after fumigation, leaf material of different developmental ages was inoculated with urediospores of Melampsora medusae Thum., and uredia production was measured after 10 days. Ozone fumigation of cottonwoods significantly reduced uredia production by M. medusae on both clones and all leaf ages without causing visible leaf injury or measurable changes in cottonwood height growth, leaf production, leaf length, or root/shoot biomass. Uredia production was strongly affected by ozone treatment, cottonwood genotype, and leaf age, but interactions among these three factors did not occur.


Sign in / Sign up

Export Citation Format

Share Document