Ruminal pH regulation and nutritional consequences of low pH

Dijkstra, J.; Ellis, J.L.; Kebreab, E.; Strathe, A. B.; López, Secundino; Bannink, A.

doi:10.1016/j.anifeedsci.2011.12.005

Cited by 287 publications

(235 citation statements)

References 97 publications

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“…Elevated microbial N capture in the rumen when more energy substrates are available for microbes may reduce net NH 3 production and consequently urea excretion, but will increase urine losses of nucleic acid N synthesized as part of microbial biomass production (Tamminga, 1992). Detrimental effects of large amounts of fermentable carbohydrates on ruminal pH and fibre degradation may occur (Firkins and Reynolds, 2005;Dijkstra et al, 2012), reducing efficiency of conversion of feed into milk or meat. Therefore, diets should be balanced carefully.…”

Section: Diet Effects On Level Of N In Urinementioning

confidence: 99%

Diet effects on urine composition of cattle and N2O emissions

Dijkstra

Oenema

Groenigen

et al. 2013

Animal

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311

215

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Ruminant production contributes to emissions of nitrogen (N) to the environment, principally ammonia (NH 3 ), nitrous oxide (N 2 O) and di-nitrogen (N 2 ) to air, nitrate (NO 3 2 ) to groundwater and particulate N to surface waters. Variation in dietary N intake will particularly affect excretion of urinary N, which is much more vulnerable to losses than is faecal N. Our objective is to review dietary effects on the level and form of N excreted in cattle urine, as well as its consequences for emissions of N 2 O. The quantity of N excreted in urine varies widely. Urinary N excretion, in particular that of urea N, is decreased upon reduction of dietary N intake or an increase in the supply of energy to the rumen microorganisms and to the host animal itself. Most of the N in urine (from 50% to well over 90%) is present in the form of urea. Other nitrogenous components include purine derivatives (PD), hippuric acid, creatine and creatinine. Excretion of PD is related to rumen microbial protein synthesis, and that of hippuric acid to dietary concentration of degradable phenolic acids. The N concentration of cattle urine ranges from 3 to 20 g/l. High-dietary mineral levels increase urine volume and lead to reduced urinary N concentration as well as reduced urea concentration in plasma and milk. In lactating dairy cattle, variation in urine volume affects the relationship between milk urea and urinary N excretion, which hampers the use of milk urea as an accurate indicator of urinary N excretion. Following its deposition in pastures or in animal houses, ubiquitous microorganisms in soil and waters transform urinary N components into ammonium (NH 4 1 ), and thereafter into NO 3 2 and ultimately in N 2 accompanied with the release of N 2 O. Urinary hippuric acid, creatine and creatinine decompose more slowly than urea. Hippuric acid may act as a natural inhibitor of N 2 O emissions, but inhibition conditions have not been defined properly yet. Environmental and soil conditions at the site of urine deposition or manure application strongly influence N 2 O release. Major dietary strategies to mitigating N 2 O emission from cattle operations include reducing dietary N content or increasing energy content, and increasing dietary mineral content to increase urine volume. For further reduction of N 2 O emission, an integrated animal nutrition and excreta management approach is required.Keywords: nitrogen, urine, cattle, nitrous oxide, mitigation ImplicationsCattle contribute to global warming through emission of nitrous oxide (N 2 O) from urine and faeces. Urinary nitrogen (N) is much more susceptible to gaseous losses than faecal N. To reduce urinary N excretion and N 2 O emission and improve N efficiency of cattle, dietary levels of N should be decreased and an optimal balance between N and energy substrates in the diet should be aimed at. Increasing urine volume by increased dietary mineral contents appears a promising N 2 O mitigation strategy, particularly in pasture. Further reduction of effective mitigation strategies...

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Section: Diet Effects On Level Of N In Urinementioning

confidence: 99%

Diet effects on urine composition of cattle and N2O emissions

Dijkstra

Oenema

Groenigen

et al. 2013

Animal

Self Cite

311

215

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“…Endogenous C flow was estimated from endogenous CP and fat flow using the C content of bacterial fat and protein according to Reichl and Baldwin (1975). Possible bicarbonate flow at the duodenum was not considered as it was assumed that all bicarbonate is converted into CO 2 in the abomasum (Aschenbach et al, 2011;Dijkstra et al, 2012). According to glucose fermentation stoichiometry, 3 mol C are used for 1 mol Ac (2 mol C for Ac, 1 mol C for CO 2 ) and for 1 mol Pr, and 6 mol C for 1 mol Bu (4 mol C for Bu, 2 mol C for CO 2 ) and for 1 mol Va.…”

Section: Calculationsmentioning

confidence: 99%

Methane production and diurnal variation measured in dairy cows and predicted from fermentation pattern and nutrient or carbon flow

Brask

Weisbjerg

Hellwing

et al. 2015

Animal

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Many feeding trials have been conducted to quantify enteric methane (CH 4 ) production in ruminants. Although a relationship between diet composition, rumen fermentation and CH 4 production is generally accepted, the efforts to quantify this relationship within the same experiment remain scarce. In the present study, a data set was compiled from the results of three intensive respiration chamber trials with lactating rumen and intestinal fistulated Holstein cows, including measurements of rumen and intestinal digestion, rumen fermentation parameters and CH 4 production. Two approaches were used to calculate CH 4 from observations: (1) a rumen organic matter (OM) balance was derived from OM intake and duodenal organic matter flow (DOM) distinguishing various nutrients and (2) a rumen carbon balance was derived from carbon intake and duodenal carbon flow (DCARB). Duodenal flow was corrected for endogenous matter, and contribution of fermentation in the large intestine was accounted for. Hydrogen (H 2 ) arising from fermentation was calculated using the fermentation pattern measured in rumen fluid. CH 4 was calculated from H 2 production corrected for H 2 use with biohydrogenation of fatty acids. The DOM model overestimated CH 4 /kg dry matter intake (DMI) by 6.1% ( R 2 = 0.36) and the DCARB model underestimated CH 4 /kg DMI by 0.4% ( R 2 = 0.43). A stepwise regression of the difference between measured and calculated daily CH 4 production was conducted to examine explanations for the deviance. Dietary carbohydrate composition and rumen carbohydrate digestion were the main sources of inaccuracies for both models. Furthermore, differences were related to rumen ammonia concentration with the DOM model and to rumen pH and dietary fat with the DCARB model. Adding these parameters to the models and performing a multiple regression against observed daily CH 4 production resulted in R 2 of 0.66 and 0.72 for DOM and DCARB models, respectively. The diurnal pattern of CH 4 production followed that of rumen volatile fatty acid (VFA) concentration and the CH 4 to CO 2 production ratio, but was inverse to rumen pH and the rumen hydrogen balance calculated from 4 × (acetate + butyrate)/2 × (propionate + valerate). In conclusion, the amount of feed fermented was the most important factor determining variations in CH 4 production between animals, diets and during the day. Interactions between feed components, VFA absorption rates and variation between animals seemed to be factors that were complicating the accurate prediction of CH 4 . Using a ruminal carbon balance appeared to predict CH 4 production just as well as calculations based on rumen digestion of individual nutrients.Keywords: modelling methane, VFA, enteric fermentation, carbon, dairy cow Implications Methane (CH 4 ) is a potent greenhouse gas that arises from feed fermentation in the rumen and large intestine of ruminant animals. The quantity of CH 4 depends on daily feed intake, feed chemical composition and feed rumen digestibility. Therefore, the present paper was ...

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“…This effect may be due to the absence of corn in the diet containing glycerin and 70% roughage, as the pH of the ruminal environment is probably higher and thus favours the performance of cellulolytic microorganisms responsible for cellulose degradation (DIJKSTRA et al, 2012).…”

Section: Resultsmentioning

confidence: 99%

Effects of the inclusion of glycerin in diets containing 30 or 70% roughage on feed disappearance and digestibility

Homem¹,

Cremasco²,

Almeida³

et al. 2018

SCA

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The objective of this study was to evaluate in vitro nutrient disappearance and in vivo nutrient digestibility of cattle diets containing 70 or 30% roughage, with and without glycerin supplementation. Four Nellore cattle were used in the study based on a 4 × 4 Latin Square design in a 2 × 2 factorial arrangement. Inclusion of glycerin and roughage proportion did not affect the nutrient disappearance of each ingredient (P > 0.05). Regardless of the inclusion of glycerin, a reduction in the proportion of roughage led to an increase (P < 0.05) in DMDis (64 vs. 72%), NDFDis (41 vs. 54%), and ADFDis (31 vs. 44%) of the total rations. Inclusion of glycerin resulted in an increase (P < 0.05) in DMD (70 vs. 62%) and a reduction (P < 0.05) in CPD (32 vs. 38%) and STD (82 vs. 74%). The diet containing 30% roughage led to higher (P < 0.05) DMD (67 vs. 65%) and CPD (35 vs. 33%) in comparison with the 70% roughage diet, but did not differ (P > 0.05) in STD (78%). Inclusion of glycerin at 20% of the total DM increased the utilisation of dietary DM without affecting the fibrous fraction of the diet. Glycerin supplementation in diets containing 70% roughage improves neutral detergent fibre digestibility. Key words: INDF. Glycerol. Ingredients. In vitro. In vivo. Total ration. ResumoO objetivo deste estudo foi avaliar o desaparecimento in vitro de nutrientes e a digestibilidade in vivo de alimentos para bovinos contendo 70 ou 30% de forragem, com e sem suplementação de glicerina. Foram utilizados quatro bovinos Nelore num delineamento quadrado latino 4 × 4 em um esquema fatorial 2 × 2. A inclusão de glicerina e forragem não afetou o desaparecimento de nutrientes dos ingredientes (P > 0,05). Independentemente da inclusão de glicerina, uma redução na proporção de forragem provocou um aumento (P < 0,05) na DesMS (64 vs. 72%), DesFDN (41 versus 54%) e DesFDA (31 vs. 44%) das rações totais. A inclusão de glicerina resultou em um aumento (P < 0,05) na DMS (70 contra 62%) e uma redução (P < 0,05) na DPB (32 vs. 38%) e DAM (82 versus 74%). A dieta contendo 30% de forragem proporcionou maior (P < 0,05) DMS (67 vs. 65%) e DPB (35 versus 33%) em comparação à 1 Drs. em Zootecnia, Universidade Estadual Paulista, FCAV, Jaboticabal, SP, Brasil.

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Ruminal pH regulation and nutritional consequences of low pH

Cited by 287 publications

References 97 publications

Diet effects on urine composition of cattle and N2O emissions

Diet effects on urine composition of cattle and N2O emissions

Methane production and diurnal variation measured in dairy cows and predicted from fermentation pattern and nutrient or carbon flow

Effects of the inclusion of glycerin in diets containing 30 or 70% roughage on feed disappearance and digestibility

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