Combination of long-chain alcohols and fatty acids with alkanes as faecal markers to estimate feed intake and digestibility in horses and cattle fed on grass-heathland vegetation communities

2016 ◽  
Vol 96 (2) ◽  
pp. 221-231 ◽  
Author(s):  
Carlos López López ◽  
Rafael Celaya ◽  
Ana Sofia Santos ◽  
Miguel A.M. Rodrigues ◽  
Koldo Osoro ◽  
...  

Application of long-chain alcohols (LCOH) and long-chain fatty acids (LCFA) combined with alkanes as faecal markers to estimate dry matter intake (DMI) and dry matter digestibility (DMD) of equines and cattle was assessed. Six crossbred mares, randomly divided in two groups (H1 and H2), and three nonlactating cows (C) were housed in individual stalls. Groups H1 and C were fed on a diet of ryegrass (Lolium perenne, 0.7) and heather (Erica spp., Calluna vulgaris, 0.3), and H2 received ryegrass (0.4), heather (0.3) and gorse (Ulex gallii, 0.3). Digestibility was estimated using LCOH (C28-OH and C30-OH) and LCFA (C28-FA, C30-FA, and C32-FA) as internal markers. For DMI estimation, animals received daily a paper pellet containing C24, C32, and C36n-alkanes. Intake was estimated from the faecal ratio of naturally occurring LCOH, LCFA, and dosed n-alkanes, and was compared with the known DMI values. In horses, all markers provided accurate estimates of DMD. Similarly, LCOH provided accurate estimates of DMD in cattle, whereas LCFA underestimated it (P < 0.05). Intake estimates were affected (P < 0.05) by the marker pair used in calculations. In general, the C24:C24-FA pair provided the most accurate DMI estimates. Results suggest the usefulness of combining epicuticular compounds as faecal markers to estimate DMI, DMD and diet composition of horses and cattle grazing grass-heathland communities, simultaneously.

1982 ◽  
Vol 99 (1) ◽  
pp. 215-224 ◽  
Author(s):  
J. C. Mathers ◽  
E. L. Miller

SUMMARYTwo experiments were carried out with adult sheep to investigate the effects of chloral hydrate (CH) on rumen metabolism and on the sites and extent of digestion.Experiment 1 confirmed that CH is a very potent methane inhibitor; doses of 1 or 4 g/day reduced methane production to 4% of that observed in the absence of the drug. In both experiments, CH administration altered the proportions of volatile fatty acids in rumen fluid. The main changes were an increase in propionic acid and a decrease in acetic acid with smaller increases in the proportion of isovaleric, valeric and caproic acids. Stoichiometric calculations indicated that only 21% of the hydrogen saved by prevention of methanogenesis was diverted to the synthesis of additional propionic and butyric acids and the fate of the remaining hydrogen was not determined unequivocally.CH had little effect on the extent of biohydrogenation in the rumen of the long-chain fatty acids in dried grass.The apparent digestibility of ether extract was reduced (P< 0·05) by CH but those of other proximate constituents and energy were little affected. There were no s gnificant effects of CH on the extent of digestion of dry matter, organic matter, non-ammonia nitrogen or ash between the mouth and abomasum, abomasum and terminal ileum or ileum and anus.


2004 ◽  
Vol 142 (1) ◽  
pp. 71-78 ◽  
Author(s):  
H. A. M. ALI ◽  
R. W. MAYES ◽  
C. S. LAMB ◽  
B. L. HECTOR ◽  
A. K. VERMA ◽  
...  

Previous investigations have shown that the long-chain fatty alcohols and long-chain fatty acids of plant waxes have potential as diet composition markers. This study was conducted to measure faecal recoveries of long-chain fatty alcohols (C20–C30) and long-chain fatty acids (C20–C32) in sheep fed mixed diets. Methodology for quantitative analysis of these compounds in feed and faeces is also presented. The method was an extension of the original n-alkane method of Mayes et al. (1986) in which separate hydrocarbon (n-alkanes, n-alkenes and branched-chain alkanes), alcohol (free+esterified) and acid (free+esterified) fractions could be obtained from a single sample. A fraction containing alcohols and sterols was eluted from the silica gel column after removal of the hydrocarbons. Sterols were removed from alcohols using aminopropyl solid-phase extraction columns. Alcohols were converted to their trimethylsilyl (TMS) ethers and run on a gas chromatograph (GC). Acids were extracted from the aqueous phase of saponification products after removal of hydrocarbons, alcohols and sterols, purified through silica gel columns and were converted into their methyl esters (FAMES) prior to analysis on a GC. Tests were carried out to evaluate the reproducibility of the results obtained from the analytical method developed for quantifying alcohols and acids. Twelve sheep, in metabolism crates, were offered (0·8 kg DM/animal/day) four different mixtures of hill grass (Agrostis capillaris), birch (Betula pendula) leaves and current season's growth of heather (Calluna vulgaris) and bilberry (Vaccinium myrtillus) for 17 days. Total daily faeces and feed refusals collections were carried out over the last 7 days. Faeces collections were bulked for each animal. Representative samples of feed, refusals and faeces were analysed for alcohols and acids using the described method. Faecal recoveries of alcohols and acids were calculated from the ratio of output and input of each marker. The results showed high, though incomplete, faecal recoveries for both alcohols and acids. Alcohols had consistently higher faecal recoveries compared with acids. Mean (±S.E.) faecal recovery values for alcohols C20, C22, C24, C26, C28 and C30 were 0·58±0·04, 0·67±0·01, 0·72±0·008, 0·80±0·007, 0·94±0·005 and 1·01±0·02, respectively, whereas those of acids C20, C22, C24, C26, C28, C30and C32 were 0·47±0·02, 0·57±0·02, 0·61±0·02, 0·77±0·017, 0·84±0·01, 0·79±0·015 and 0·84±0·013, respectively. Increasing chain-length had a significant effect (P<0·05) on the recoveries of both alcohols and acids (R2=0·808, 0·741, respectively). Different dietary plant mixtures had no effect (P>0·05) on the recoveries of alcohols and acids in faeces.


2005 ◽  
Vol 143 (1) ◽  
pp. 85-95 ◽  
Author(s):  
H. A. M. ALI ◽  
R. W. MAYES ◽  
B. L. HECTOR ◽  
A. K. VERMA ◽  
E. R. ØRSKOV

Few methods exist for estimating quantitatively the diet composition of free-ranging herbivores. The current study examined whether long-chain fatty alcohols (alcohols) or long-chain fatty acids (acids) could be used along with n-alkanes to allow reliable diet composition estimates to be made in herbivores consuming complex diets. Twelve Scottish Blackface wether sheep housed in metabolism crates were fed four different mixtures of three plant species (three animals per mixture) for a seven-period experiment. Concentrations of cuticular wax n-alkanes, alcohols and acids were estimated in samples of individual plant species, and the faeces from animals that consumed mixtures of these species. These concentrations were then used to calculate the dietary proportions of each species by a least-squares optimization procedure. To explore the differences between the estimation methods (individual markers and their combinations), the mean squares of errors (EMS) between the actual and predicted proportions of plant species were calculated.In three out of the four mixtures, alcohols had the lowest discrepancies (lowest EMS values), followed by n-alkanes and then acids. Acids yielded the lowest discrepancy in one mixture and the highest in the others.It is concluded that, for this particular set of mixtures, alcohols had great potential to estimate composition of complex diets. However, the estimation using acids was less good and n-alkanes were of intermediate potential. Estimation from the combination of the three marker classes was always better than using the poorest individual marker.


2016 ◽  
Vol 38 (2) ◽  
pp. 163
Author(s):  
Isabella Ribeiro Ferrari ◽  
Claudete Regina Alcalde ◽  
Ludmila Couto Gomes ◽  
Bruna Susan de Labio Molina ◽  
Orlando Rus Barbosa ◽  
...  

This study aimed to evaluate the effect of the addition of calcium salts of long chain fatty acids (CSFA) on the intake and digestibility of diets. Twenty-five female goat kids housed in digestibility cages and subjected to heat stress of 32°C in a climatic chamber, were used. The female kids were distributed in a randomized block design with five treatments: control (without inclusion of CSFA) and 6.25; 12.50; 18.75 and 25.00 g CSFA kg-1 of DM. The inclusion of CSFA in rations did not influence water intake (3.08 L day-1), dry matter (0.66 kg day-1), organic matter (0.62 kg day-1), crude protein (0.12 kg day-1), neutral detergent fiber (0.27 kg day-1) and total carbohydrate (0.47 kg day-1). The results of the digestibility of dry matter (0.66 kg kg-1), organic matter (0.67 kg kg-1), crude protein (0.78 kg kg-1), neutral detergent fiber (0.47 kg kg-1) and total carbohydrate (0.63 kg kg-1) were not affected by the treatments. However, there was a positive linear effect on the intake and digestibility of ether extract. Therefore, the addition of calcium salts of long chain fatty acids in the diets for female kids under heat stress of 32°C does not influence the intake and digestibility of dry matter and nutrients, except for ether extract, which is intrinsic to the product added to the rations. 


2004 ◽  
Vol 84 (4) ◽  
pp. 705-711 ◽  
Author(s):  
C. Gonthier ◽  
A. F. Mustafa ◽  
R. Berthiaume ◽  
H. V. Petit ◽  
D. R. Ouellet

Four lactating Holstein cows fitted with ruminal and duodenal cannulae were used in a 4 × 4 Latin square study to determine the effects of feeding micronized and extruded flaxseed on ruminal biohydrogenation (BH) and digestibility of fatty acids (FA) in the gastrointestinal tract. Four diets were formulated: a control diet with no flaxseed (C); a raw flaxseed diet (RF); a micronized flaxseed diet (MF); and an extruded flaxseed diet (EF). Flaxseed diets contained 126 g kg-1 flaxseed (dry matter basis). Experimental periods (n = 4) consisted of 21 d of diet adaptation and 7 d of data collection. Flaxseed supplementation increased (P < 0.05) intake of individual long-chain FA, reduced (P < 0.05) ruminal BH of total unsaturated C18, and increased (P < 0.05) duodenal flow of individual long-chain FA except for C18:2. Feeding flaxseed increased (P < 0.05) post-ruminal digestibility of C18:1, C18:2, and C18:3 and total tract digestibility of C16:0, C18:2, C18:3, and of total long-chain FA. Heat treatment had no effect on ruminal BH, duodenal flow and digestibility of unsaturated FA. Ruminal BH of C18:3 was higher (P < 0.05), while the duodenal flow of C18:3 was lower (P < 0.05) for cows fed EF than for those fed MF. Intake and duodenal flow of C16:0 were higher (P < 0.05) for cows fed MF relative to those fed EF. It was concluded that inclusion of flaxseed in dairy cow diets increased duodenal flow of polyunsaturated FA. However, heat treatments were not effective in protecting unsaturated FA from ruminal BH. Key words: Flaxseed, ruminal biohydrogenation, fatty acid, heat treatment


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