Comparison of n-alkanes and chromium oxide methods for estimating herbage intake by grazing dairy cows

Malossini, F.; Bovolenta, S.; Piasentier, Edi; Piras, C.; Martillotti, F.

doi:10.1016/0377-8401(96)00954-6

Cited by 41 publications

(32 citation statements)

References 15 publications

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“…Other comparisons of markers, mainly Cr v. n-alkanes, were performed at grazing, only allowing a relative comparison of different methods. In most of these grazing studies, as in our experiment, pasture intake was greater when estimated using Cr 2 O 3 than using n-alkanes (15% to 19%; Piasentier et al, 1995;Malossini et al, 1996;Morenz et al, 2006). However, the opposite result has also been observed (212% for Cr 2 O 3 v. n-alkanes; Dove et al, 2000).…”

Section: Discussioncontrasting

confidence: 37%

“…This is, however, the only means of determining the accuracy of a method because of the precise measurement of actual intake, a good estimation of the composition of the selected food and the possible total faecal collection enabling the determination of faecal marker recovery. Although marker comparisons have already been conducted on dairy cows at pasture (Malossini et al, 1996;Morenz et al, 2006), no comparative studies on dairy cows have been conducted indoors. The ability of the n-alkanes technique, alone or combined with the 13 C technique, to estimate pasture and maize silage proportions when maize silage intake is unknown has been tested by García et al (2000).…”

Section: Introductionmentioning

confidence: 99%

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N-alkanes v. ytterbium/faecal index as two methods for estimating herbage intake of dairy cows fed on diets differing in the herbage : maize silage ratio and feeding level

Pérez-Ramírez

Peyraud

Delagarde

2012

Animal

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The aim of this study was to compare the n-alkanes and the ytterbium (Yb)/faecal index techniques as two methods for estimating the herbage intake of dairy cows fed indoors on different herbage : supplement ratios and feeding levels. The supplement was a mixture of maize silage and soyabean meal (ratio of 87 : 13 on a dry matter (DM) basis). In all, four treatments were studied. The herbage : supplement ratio in the diet was 25 : 75, 50 : 50, 75 : 25 and 50 : 50 for treatments 1, 2, 3 and 4, respectively. Animals were offered for treatments 1, 2 and 3, 100% of ad libitum intake measured before the experiment and 70% of ad libitum intake for treatment 4. Cows were fed herbage in the morning and supplement in the evening. A total of six lactating Holstein dairy cows were used in a 4 3 4 Latin square with four 14-day periods. Herbage and supplement intakes, faecal output (FO), in vivo organic matter (OM) digestibility and faecal recovery of markers were measured on the last 5 days of each period. Intake was estimated with the two methods and from two faecal sampling techniques, that is, total faecal collection v. grab sampling during milking. Mean herbage intake as fed, or estimated from n-alkanes or from the Yb/faecal index was 7.7, 8.1 and 10.2 kg DM, respectively. The mean prediction error, expressed as a fraction of actual herbage intake, was 0.10 and 0.50 for the n-alkanes and Yb/faecal index methods, respectively. The n-alkanes method clearly showed much better accuracy than the Yb/faecal index method for estimating intake, irrespective of the faecal sampling method, herbage : silage proportion or feeding level. For the nalkanes method, herbage intake was slightly overestimated (7%) when herbage proportion in the diet was high, due to a ratio of faecal C 33 : C 32 recovery .1. The high bias for the Yb/faecal index was due to the cumulative effect of overestimation of FO (mean recovery of Yb 5 0.92) and underestimation of the diet indigestible fraction (28%). Between-treatment variations of FO were on average well estimated by Yb. Between-treatment variations of OM digestibility estimated using the faecal index technique were lower than those observed in vivo. It is concluded that intake of grazing dairy cows receiving high levels of maize silage supplement should be estimated using the n-alkanes method.

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Section: Discussioncontrasting

confidence: 37%

Section: Introductionmentioning

confidence: 99%

N-alkanes v. ytterbium/faecal index as two methods for estimating herbage intake of dairy cows fed on diets differing in the herbage : maize silage ratio and feeding level

Pérez-Ramírez

Peyraud

Delagarde

2012

Animal

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“…Malossini et al, 1996;Oliveira et al, 2007). Likewise it is a routine to use these techniques in conjunction with estimates of in vitro digestibility (Tilley and Terry, 1963) to determine herbage intake.…”

mentioning

confidence: 99%

Forage intake and botanical composition of feed for cattle fed Brachiaria/legume mixtures

Macedo

Tarré²,

Ferreira³

et al. 2010

Sci. agric. (Piracicaba, Braz.)

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A key contribution to study the cycling of nutrients in soil/plant/animal systems is the evaluation of the consumption of forage and their nutrients by cattle. The objective of this study was to test techniques to evaluate faecal production, in vitro digestibility, forage consumption and the proportion of legume in the acquired diet. Five Zebu steer calves were confined and fed five diets of different combinations of Brachiaria dictyoneura and Desmodium ovalifolium. All quantities of faeces were collected per animal and these values were found to compare favourably with those derived from using the chromium oxide technique. In vitro digestibility ranged from 7 to 10% higher than the actual in vivo digestibility. Faecal samples from steers fed with diets with 25% or more of grass in the mixture were found to be depleted in δ 13 C between 1.7 and 2.1‰, but no depletion was observed when the diet was 100% D. ovalifolium. There was a positive linear regression (r 2 = 0.97***) of the δ 13 C of the diet with the δ 13 C of faeces, but if the acquired diet contained a very high proportion of legume, the legume content could be underestimated by as much as 10%. None of the internal indicators, such as lignin or ash content of the diets, were useful to predict feed intake, but the chromium oxide external indicator performed satisfactorily. The 13 C analysis of the faeces was an effective predictor of the proportion of the legume in the consumed diet. Key words: Brachiaria dictyoneura, Desmodium ovalifolium, 13 C abundance, digestibility, forage intake Consumo e composição da forragem ingerida por bovinos alimentados com Brachiaria e uma leguminosa RESUMO: Uma contribuição fundamental para o estudo da ciclagem de nutrientes no sistema solo/planta/ animal é a avaliação do consumo pelo gado de forragem e dos nutrientes nela contidos. Testaram-se, sob condições controladas, técnicas para avaliar a produção fecal, digestibilidade in vitro, consumo de forragem e a proporção de leguminosa ingerida na dieta. Cinco novilhos de Zebu foram confinados e alimentados com quantidades conhecidas de cinco rações com diferentes proporções de Brachiaria dictyoneura e Desmodium ovalifolium. Todas as fezes bovinas foram recolhidas e pesadas e estes valores foram comparáveis com as estimativas da produção fecal derivadas do uso da técnica de óxido de cromo. A digestibilidade in vitro variou de 7 a 10% acima da digestibilidade in vivo atual. Amostras de fezes de novilhos alimentados com dietas com 25% ou mais de capim na mistura apresentaram abundância de 13 C por entre 1,7 e 2,1‰, mas este empobrecimento isotópico não foi observado quando a dieta era com 100% D. ovalifolium. Houve correlação positiva linear (r 2 = 0,97***) entre δ 13 C da dieta com o δ 13 C das fezes, mas o conteúdo de leguminosa foi subestimado em mais de 10% quando a dieta ingerida foi de 100% de leguminosa. Nenhum dos indicadores internos, como o conteúdo de lignina ou cinzas, foram úteis para prever o consumo de forragem, mas os resultados da técnica utilizando ó...

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“…Individual variations of the n-alkanes did not interfere with forage intake estimation, but the variation in the fecal concentration ratio of the pair of nalkanes used in the estimation process is very important (Dove & Mayes, 1991;Mayes & Dove, 2000). Malossini et al (1996) worked with lactating cows and compared the estimates of forage intake obtained with chromium oxide and with the C 31 :C 32 n-alkane ratio. The authors reported that the methods differed from each other, but there was a positive correlation between them (r = 0.62).…”

Section: Resultsmentioning

confidence: 99%

Estimating forage intake of lactating dual-purpose cows using chromium oxide and n-alkanes as external markers

Oliveira

Medeiros

Tedeschi

et al. 2007

Sci. agric. (Piracicaba, Braz.)

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The n-alkanes have been used to estimate forage dry matter intake, digestibility and the diet composition in grazing animals. The objective this study was to compare chromium oxide and nalkanes techniques used to estimate forage intake. Twenty lactating dual-purpose cows receiving two sources of fat (treatments: conjugated linoleic acid (CLA) or Megalac (control)) plus 4 kg of concentrate were dosed with n-alkanes and chromium oxide to estimate the intake of stargrass (Cynodon nlemfüensis Vanderyst var. nlemfüensis). The in vitro dry matter (DM) digestibility of the stargrass and concentrate were used to estimate the nutritive value of the digesta. The n-alkanes between C 23 and C 36 were quantified in the digesta and feces. The regression between metabolizable energy requirement (MEr, ) and supply derived from forage DM intake estimated using chromium oxide was ME Intake Cr = 19.1 + 0.62 MEr (R 2 = 0.27) and the same relationship estimated using C 35 :C 36 n-alkane ratio was ME Intake C35:C36 = 9.3 + 0.77 MEr (R 2 = 0.52). There was a treatment effect on fecal concentration of chromium oxide with daily and period variations. For the n-alkane technique, treatment and period effects and a linear effect of day of collection on the fecal concentrations of C 35 were found. For C 36 fecal concentrations, there was a treatment effect and a quadratic effect of collection day. There was no treatment effect on the fecal concentration of the C 35 :C 36 ratio, but a period effect and a linear effect of day of collection were found. Estimates of daily intake using the two markers were different, but those obtained using the C 35 :C 36 pair of n-alkanes were more precise than those obtained using chromium oxide and in vitro digestibility. Management of experimental animals could have influenced the concentration of markers in the feces, determining variations and inconsistencies that partially explain the inaccuracy of the estimates. Key words: diet composition, digestibility, grazing ESTIMATIVA DO CONSUMO DE FORRAGEM EM VACAS MESTIÇAS LACTANTES USANDO ÓXIDO CRÔMICO E N-ALCANOS COMO MARCADORES EXTERNOSRESUMO: Os n-alcanos têm sido utilizados para estimar o consumo de matéria seca, a digestibilidade e a composição da dieta de animais em pastejo. O objetivo desse estudo foi comparar as técnicas de óxido crômico e n-alcanos usadas para estimar o consumo de forragem. Vinte vacas lactantes cruzas Holandês × Gir recebendo duas fontes de gordura (tratamentos: CLA (ácido linoleico conjugado) ou Megalac (controle)) mais 4 kg de concentrado foram dosadas com n-alcanos e óxido crômico para estimar o consumo de estrela-africana (Cynodon nlemfüensis Vanderyst var. nlemfüensis). A digestibilidade in vitro da matéria seca da estrela africana e do concentrado foi usada para estimar o valor nutritivo da dieta. Foram quantificados n-alcanos entre C 23 e C 36 na dieta e fezes. A regressão entre exigência e o consumo de energia metabolizável (EMr, ) derivada da matéria seca da forragem calculada usando óxido de cromo foi ConsumoCr = 1...

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Comparison of n-alkanes and chromium oxide methods for estimating herbage intake by grazing dairy cows

Cited by 41 publications

References 15 publications

N-alkanes v. ytterbium/faecal index as two methods for estimating herbage intake of dairy cows fed on diets differing in the herbage : maize silage ratio and feeding level

N-alkanes v. ytterbium/faecal index as two methods for estimating herbage intake of dairy cows fed on diets differing in the herbage : maize silage ratio and feeding level

Forage intake and botanical composition of feed for cattle fed Brachiaria/legume mixtures

Estimating forage intake of lactating dual-purpose cows using chromium oxide and n-alkanes as external markers

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