scholarly journals Effects of elevated CO<sub>2</sub> and extreme climatic events on forage quality and in vitro rumen fermentation in permanent grassland

2021 ◽  
Vol 18 (16) ◽  
pp. 4841-4853
Author(s):  
Vincent Niderkorn ◽  
Annette Morvan-Bertrand ◽  
Aline Le Morvan ◽  
Angela Augusti ◽  
Marie-Laure Decau ◽  
...  

Abstract. The aim of this study was to analyze changes in botanical and chemical composition, as well as in vitro rumen fermentation characteristics of an upland grassland exposed to climate changes in controlled CO2 concentration, air temperature and precipitation conditions. Grassland was exposed to a future climate scenario coupled with CO2 treatments (390 and 520 ppm) from the beginning of spring. During summer, an extreme climatic event (ECE; 2 weeks of a +6 ∘C increase in temperature, together with severe drought) was applied and then followed by a recovery period. Three cutting dates were considered, i.e. in April, June and November. The results indicate that increases in greenness, nitrogen (N) content and changes in water-soluble carbohydrate profile in association with botanical composition changes for the November cut lead to higher in vitro dry matter degradability (IVDMD) in the rumen. The neutral detergent fiber : nitrogen (NDF:N) ratio appeared to be a key driver of forage quality, which was affected in opposite ways by elevated CO2 and ECE, with a strong impact on rumen fermentation. Atmospheric CO2 concentration in interaction with ECE tended to affect IVDMD, indicating that the effects of elevated CO2 and ECE may partly offset each other. Our findings indicate that the various factors of climate change need to be considered together in order to properly characterize their effects on forage quality and use by ruminants.

2021 ◽  
Author(s):  
Vincent Niderkorn ◽  
Annette Morvan-Bertrand ◽  
Aline Le Morvan ◽  
Marie-Lise Benot ◽  
Angela Augusti ◽  
...  

Abstract. This study was aimed at analyzing changes in botanical and chemical composition, and in vitro rumen fermentation characteristics of an upland grassland exposed to climate changes in controlled conditions except for light intensity, which was the natural one. Grassland was exposed to future climate scenario coupled with CO2 treatments (390 and 520 ppm) from the beginning of spring. During summer, an extreme event (two weeks of increased temperature, +6 °C, associated with severe drought, ECE) was associated. After the ECE, a recovery treatment was performed. Three cutting dates in April, June and November were considered. Our results indicate that increases in greenness, nitrogen (N) content and changes in water-soluble carbohydrate profile for the cut of November result in higher in vitro dry matter degradability (IVDMD) in the rumen. The neutral detergent fiber : nitrogen (NDF : N) ratio appeared to be a main driver of forage quality affected in opposite ways by elevated CO2 and ECE, with a strong impact on rumen fermentation. A trend towards an interaction between atmospheric CO2 concentration and ECE was observed in IVDMD, indicating that their effects could partly offset each other. These findings indicate that the different factors of climate change have to be considered together to characterize their effects on forage quality and use by ruminants.


Agriculture ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1205
Author(s):  
Musen Wang ◽  
Fujin Zhang ◽  
Xinxin Zhang ◽  
Ying Yun ◽  
Lei Wang ◽  
...  

The objective of this work was to evaluate the pH, chemical composition, minerals, vitamins, and in vitro rumen fermentation characteristics of silage prepared with lucerne, sweet maize stalk (MS), and their mixtures. Freshly chopped lucerne and MS were combined in ratios of 100:0 (M0, control), 80:20 (M20), 60:40 (M40), 40:60 (M60), 20:80 (M80), and 0:100 (M100) on a fresh matter basis. Each treatment was prepared in triplicate, and a total of eighteen silos were fermented for 65 days. After 65 days of fermentation, the pH values in M0, M20, M40, M60, M80, and M100 silages were 5.47, 4.84, 4.23, 4.13, 3.79, and 3.61, respectively. As the MS proportion in the mixtures increased, silage K, Ca, P, Na, Fe, and Cu concentrations linearly decreased (p < 0.001) and so did vitamins B5 and K1 and α-tocopherol. In vitro rumen dry matter and organic matter degradability, pH, ammonia, total volatile fatty acid, and gas production linearly decreased (p < 0.01), while neutral detergent fiber concentration linearly increased (p < 0.001), with increasing proportion of MS. The in vitro dry matter and organic matter degradability rapidly decreased when the MS percentage was ≥60%. In conclusion, the M40 silage is the most suitable for livestock utilization in local forage production considering the balance of silage pH, nutritional quality, and in vitro ruminal fermentation characteristics.


Animals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1076 ◽  
Author(s):  
M. Jordana Rivero ◽  
Juan P. Keim ◽  
Oscar A. Balocchi ◽  
Michael R.F. Lee

The objective of this study was to determine the effect of perennial ryegrass (PRG) forages differing in their concentration of water-soluble carbohydrates (WSC) and crude protein (CP), and collected in spring and autumn, on in vitro rumen fermentation variables, nitrogen (N) metabolism indicators and methane (CH4) output, using a batch culture system. Two contrasting PRG pastures, sampled both in autumn and spring, were used: high (HS) and low (LS) sugar pastures with WSC concentrations of 322 and 343 g/kg for HS (autumn and spring), and 224 and 293 g/kg for LS in autumn and spring, respectively. Duplicates were incubated for 24 h with rumen inocula in three different days (blocks). Headspace gas pressure was measured at 2, 3, 4, 5, 6, 8, 10, 12, 18, and 24 h, and CH4 concentration was determined. The supernatants were analysed for individual volatile fatty acids (VFA) concentrations, and NH3-N. The solid residue was analysed for total N and neutral detergent insoluble N. Another set of duplicates was incubated for 4 h for VFA and NH3-N determination. The HS produced more gas (218 vs. 204 mL/g OM), tended to increase total VFA production (52.0 mM vs. 49.5 mM at 24 h), reduced the acetate:propionate ratio (2.52 vs. 3.20 at 4 h and 2.85 vs. 3.19 at 24 h) and CH4 production relative to total gas production (15.6 vs. 16.8 mL/100 mL) and, improved N use efficiency (22.1 vs. 20.9). The contrasting chemical composition modified in vitro rumen fermentation tending to increase total VFA production, reduce the acetate:propionate ratio and CH4 concentration, and improve N use efficiency through lower rumen NH3-N.


2003 ◽  
Vol 104 (1-4) ◽  
pp. 59-70 ◽  
Author(s):  
M.R.F Lee ◽  
R.J Merry ◽  
D.R Davies ◽  
J.M Moorby ◽  
M.O Humphreys ◽  
...  

Animals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 108
Author(s):  
Yichong Wang ◽  
Sijiong Yu ◽  
Yang Li ◽  
Shuang Zhang ◽  
Xiaolong Qi ◽  
...  

Nutritional strategies can be employed to mitigate greenhouse emissions from ruminants. This article investigates the effects of polyphenols extracted from the involucres of Castanea mollissima Blume (PICB) on in vitro rumen fermentation. Three healthy Angus bulls (350 ± 50 kg), with permanent rumen fistula, were used as the donors of rumen fluids. A basic diet was supplemented with five doses of PICB (0%–0.5% dry matter (DM)), replicated thrice for each dose. Volatile fatty acids (VFAs), ammonia nitrogen concentration (NH3-N), and methane (CH4) yield were measured after 24 h of in vitro fermentation, and gas production was monitored for 96 h. The trial was carried out over three runs. The results showed that the addition of PICB significantly reduced NH3-N (p < 0.05) compared to control. The 0.1%–0.4% PICB significantly decreased acetic acid content (p < 0.05). Addition of 0.2% and 0.3% PICB significantly increased the propionic acid content (p < 0.05) and reduced the acetic acid/propionic acid ratio, CH4 content, and yield (p < 0.05). A highly significant quadratic response was shown, with increasing PICB levels for all the parameters abovementioned (p < 0.01). The increases in PICB concentration resulted in a highly significant linear and quadratic response by 96-h dynamic fermentation parameters (p < 0.01). Our results indicate that 0.2% PICB had the best effect on in-vitro rumen fermentation efficiency and reduced greenhouse gas production.


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