Comparing plastic syringes and disposable columns to extract n-alkanes in forage and concentrate feeds

Oliveira, D.A; Tedeschi, L. O.

doi:10.1590/s0103-84782010005000128

Cited by 2 publications

(2 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The n-alkane content was quantified on the basis of the protocol described by Dove and Mayes (2006), which was adapted for the use of the columns, as proposed by Oliveira and Tedeschi (2010). The n-alkane content was analyzed via gas chromatography by a Clarus 580 instrument (PerkinElmer, Inc., Waltham, MA) equipped with a flame ionization detector and capillary column (PerkinElmer Elite-1, 100% dimethyl polysiloxane; 30 m × 0.25 mm and a 0.25-µm film thickness).…”

Section: Chemical Analysesmentioning

confidence: 99%

Progressive inclusion of pearl millet herbage as a supplement for dairy cows fed mixed rations: Effects on methane emissions, dry matter intake, and milk production

Civiero

Delagarde

Berndt

et al. 2021

Journal of Dairy Science

View full text Add to dashboard Cite

The inclusion of grazing in dairy feeding systems can improve animal welfare and reduce feed costs and labor for animal care and manure management. This work aimed to evaluate the effects of including pearl millet herbage (Pennisetum glaucum 'Campeiro') as a supplement for dairy cows fed total mixed rations (TMR). The treatments included 100% TMR offered ad libitum (control, TMR 100 ), 75% TMR ad libitum intake + access to grazing of a pearl millet pasture between the morning and afternoon milkings (7 h/d; pTMR 75 ), and 50% TMR ad libitum intake + access to grazing of a pearl millet pasture between the morning and afternoon milkings (7 h/d; pTMR 50 ). Nine multiparous Holstein and F 1 Jersey × Holstein cows were distributed in a replicated 3 × 3 Latin square design with 3 periods of 21 d (a 16-d adaptation period and a 5-d measurement period). Cows in the TMR 75 and TMR 50 groups stripgrazed a pearl millet pasture with pre-and postgrazing sward height targets of 60 and 30 cm, respectively. The herbage dry matter intake (DMI) increased with decreasing mixed ration supplies, and the total DMI decreased linearly from 19.0 kg/d in the TMR 100 group to 18.0 kg/d in the pTMR 50 group. Milk production decreased linearly from 24.0 kg/d in the TMR 100 group to 22.4 kg/d in the pTMR 50 group, and energy-corrected milk (ECM) production decreased linearly from 26.0 kg/d to 23.6 kg/d. Enteric methane (CH 4 ) emissions decreased linearly from 540 g/d in the TMR 100 group to 436 g/d in the pTMR 50 group, and CH 4 yields (g/kg of DMI) tended to decrease linearly. The CH 4 intensity was similar between treatments, averaging 20 g of CH 4 / kg of ECM. The inclusion of pearl millet herbage in the dairy cow diets decreased the total DMI and milk production to a small extent without affecting CH 4 intensity (g/kg of ECM).

show abstract

Section: Chemical Analysesmentioning

confidence: 99%

Progressive inclusion of pearl millet herbage as a supplement for dairy cows fed mixed rations: Effects on methane emissions, dry matter intake, and milk production

Civiero

Delagarde

Berndt

et al. 2021

Journal of Dairy Science

View full text Add to dashboard Cite

show abstract

“…The n-alkane concentrations in herbage and fecal samples, tablets of controlled-release capsules, and concentrate feeds used were determined in duplicates using the method described by Dillon and Stakelum (1990) and modified by Oliveira (2004). Basically, modifications corresponded to: 1) n-heptane was used as solvent; 2) during the saponification procedure a bath-water was used instead of a dry-block heater and; 3) plastic 5 mL syringes were used to replace the disposable columns (Oliveira and Tedeschi, 2010). The n-alkane determinations and quantifications were made as described by Oliveira et al (2008).…”

Section: Herbage Intake and N-alkane Analysismentioning

confidence: 99%

FECAL N-ALKANES VARIATION IN LACTATING DAIRY COWS GRAZING A TROPICAL PASTURE (Cynodon nlemfÃ¼ensis VANDERYST VAR. NLEMFÃœENSIS)

De Oliveira,

De Medeiros,

Tedeschi

et al. 2015

Trop Subtrop Agroecosyst

View full text Add to dashboard Cite

<p>The objective of this study was to measure fecal n-alkane concentration variation and herbage intake in grazing lactating dairy cows fed with two sources of fat: conjugated linoleic acid (CLA) or Megalac (Control). Cows were dosed with n-alkanes using a controlled-release capsule. There was no difference in herbage dry matter intake between CLA and Control. In the first period, there were no differences in fecal concentration of both natural and synthetic n-alkanes from the capsules. For the second period, there was a difference in fecal concentration for time of collection for all natural, dosed, and alkanes ratios. In the third period, there was a difference for time of collection for natural n-alkanes and their respective ratios, with higher excretion valuesrecorded in the afternoon. In addition, there was an effect of day of collection for all n-alkanes and ratios, with higher excretion values recorded on days 2 and 4. Overall, our results highlight the importance of strict control of grazing management and sward structure in studies where external markers are used. Monitoring herbage, sward and animal managements might have an influence on n-alkanes excretion, causing a change in the ratio of their fecal concentration. These modifications may result in erroneous estimates of intake.</p>

show abstract

Comparing plastic syringes and disposable columns to extract n-alkanes in forage and concentrate feeds

Abstract: Saturated aliphatic hydrocarbons (n-alkanes) were extracted from feed, orts, and bovine fecal samples using disposable, plastic 5mL-syringes as an alternative material to disposable columns, which are normally used in the liquid

Cited by 2 publications

References 7 publications

Progressive inclusion of pearl millet herbage as a supplement for dairy cows fed mixed rations: Effects on methane emissions, dry matter intake, and milk production

Progressive inclusion of pearl millet herbage as a supplement for dairy cows fed mixed rations: Effects on methane emissions, dry matter intake, and milk production

FECAL N-ALKANES VARIATION IN LACTATING DAIRY COWS GRAZING A TROPICAL PASTURE (Cynodon nlemfÃ¼ensis VANDERYST VAR. NLEMFÃœENSIS)

Contact Info

Product

Resources

About