The Effects of Season and Diet Composition on the Radiocaesium Intake by Sheep Grazing on Heather Moorland

Salt, C. A.; Mayes, R. W.; Colgrove, P. M.; Lamb, C.S.

doi:10.2307/2404605

Cited by 76 publications

(38 citation statements)

References 19 publications

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“…Estimates of diet composition were obtained for each animal using an optimization procedure that minimizes the sum of squared discrepancies between the actual LCOH proportions in faeces and the estimated proportions, according to Salt et al (1994), using the Solver routine in Microsoft Excel. Additionally, LCOH (C 20 -OH to C 30 -OH) data were combined with alkanes (C 25 -C 31 and C 33 , Ferreira et al, 2007) and LCFA (C 22 -FA to C 28 -FA, C 30 -FA, C 32 -FA and C 34 -FA, Ferreira et al, 2010) data to assess if their combination resulted in an improvement of the accuracy of diet composition estimates.…”

Section: Calculationsmentioning

confidence: 99%

Application of long-chain alcohols as faecal markers to estimate diet composition of horses and cattle fed with herbaceous and woody species

López

Celaya

Santos

et al. 2015

Animal

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Utilization of long-chain alcohols (LCOH) as diet composition markers in horses and cattle was assessed in a study conducted with 12 mature crossbreed mares (385 ± 47 kg BW) and six adult non-lactating cows (499 ± 36 kg BW) of Asturiana de los Valles breed. The LCOH data were combined with alkane and long-chain fatty acid (LCFA) data to test the applicability of combining these markers to estimate diet composition. Animals were randomly divided into groups of three animals and received a daily total amount of 1.0 kg dry matter/100 kg BW of diets composed of different proportions of ryegrass ( Lolium perenne) and woody species ( Ulex gallii and heather). Diet composition was estimated from even-chain LCOH (C 20 -OH to C 30 -OH) combined or not with alkane (C 25 -C 31 and C 33 ) and/or LCFA (C 22 -FA to C 28 -FA, C 30 -FA, C 32 -FA and C 34 -FA) concentrations in diet components and faeces by least-squares procedures, using marker faecal concentrations uncorrected for incomplete faecal recovery (FR0) or corrected using mean recoveries across diets within animal species (FR1). Results showed large differences between plant species in their LCOH profiles, and that these markers offered additional discriminatory information to that provided by alkanes and LCFA. The LCOH markers were incompletely recovered in the faeces of both animal species. In cattle, LCOH FR tended to increase with carbon-chain length in a linear manner in both diets ( P < 0.001), whereas in horses overall data showed a curvilinear relationship between these variables. Combination of LCOH, LCFA and alkanes resulted in more accurate diet estimates. Correction of faecal LCOH concentrations to incomplete FR led to more accurate diet composition estimates in both animal species. Results obtained in this study suggest the usefulness of LCOH markers combined with alkanes and LCFA to estimate diet composition of horses and cattle grazing mixed grassy-woody plant communities.

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Section: Calculationsmentioning

confidence: 99%

Application of long-chain alcohols as faecal markers to estimate diet composition of horses and cattle fed with herbaceous and woody species

López

Celaya

Santos

et al. 2015

Animal

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“…Therefore, there is potential for them to be used as markers in the estimation of diet composition from the pattern of n-alkane concentrations in the faeces, assuming that they are fully recovered or, if faecal recoveries are incomplete, that relative recoveries are known (Dove & Mayes, 1991). The usual method for estimating diet composition from the pattern of n-alkanes in faeces and in plant species is based on a least-squares procedure using the available n-alkanes (Salt, Mayes, Colgrove et al, 1994;Dove & Moore, 1995;Mayes, Dove et al, 1995).…”

Section: Composition Of the Dietmentioning

confidence: 99%

Seasonal and spatial variation in the diet of the wild rabbit (Oryctolagus cuniculus L.) in Portugal

Martins¹,

Milne²,

Rego³

2002

Journal of Zoology

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The seasonal and spatial pattern of diet composition of a population of wild rabbits Oryctolagus cuniculus L. occupying a southern Portuguese montado was estimated using the n-alkane technique. The diet was analysed in terms of components that are relevant to habitat management. The dietary categories considered were gum cistus leaves and¯owers, cork oak and holm oak seedlings and acorns, cereals, olive tree regrowth and grass-forb species. The objectives were to assess the changes in diet across seasons in relation to the reproductive cycle of the rabbits, and to relate these changes to herbaceous biomass availability and to habitat structure, in terms of density of scrub cover and accessibility to arable crops. The results demonstrated that the diet was dominated by grass-forbs, and cereals when they were available. Browse was an important component of the diet and became more important in a year of low herbaceous biomass availability and in areas dominated by dense scrub. A similar phenomenon was observed in relation to consumption of acorns in winter. Seasonal and spatial variation in diet composition suggested a strategy aimed at maintaining a high quality diet. This was supported by the observed high dry matter digestibility of the diet during most of the year. The relevance of growing arable crops and providing fodder, as a means of increasing the carrying capacity of montados for rabbits and protecting the natural regeneration of trees, is discussed.

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“…Estimating diet selection Oesophageal-fistulated (OF) animals have been used to estimate the botanical composition of the consumed diet (Coates et al, 1987;Salt et al, 1994), but this approach rests on a number of assumptions (most significantly that OF animals select a diet similar to non-OF animals) that were questioned by Mayes and Dove (2000). Microhistological procedures are used to identify the plants that an animal has selected and grazed.…”

Section: A Framework For Nutritional Ecologymentioning

confidence: 99%

“…NIRS analyses of polyethylene glycol in the faeces of dosed goats have been used to estimate faecal output (Landau et al, 2002), and provided an estimate of digestibility can be obtained intake can be estimated. One of the major problems with using NIRS to estimate nutritional factors is the need to have a reliable calibration curve based on known intake measurements across the full range of diets the animal might encounter.Estimating diet selection Oesophageal-fistulated (OF) animals have been used to estimate the botanical composition of the consumed diet (Coates et al, 1987;Salt et al, 1994), but this approach rests on a number of assumptions (most significantly that OF animals select a diet similar to non-OF animals) that were questioned by Mayes and Dove (2000). Microhistological procedures are used to identify the plants that an animal has selected and grazed.…”

mentioning

confidence: 99%

Opportunities for telemetry techniques in studies on the nutritional ecology of free-ranging domesticated ruminants

Swain

Friend

2013

Animal

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The principles of domestic herbivore nutrition are well understood and have been developed through detailed physiological studies, although methods to accurately measure field-based intake still challenge herbivore nutrition research. Nutritional ecology considers an animal's interaction with the environment based on its nutritional demands. Although there are a number of theoretical frameworks that can be used to explore nutritional ecology, optimal foraging provides a suitable starting point. Optimal foraging models have progressed from deterministic techniques to spatially explicit agent-based simulation methods. The development of optimal foraging modelling points towards opportunities for field-based research to explore behavioural preferences within studies that have an array of nutritional choices that vary both spatially and temporally. A number of techniques including weighing animals, weighing herbage, using markers (both natural and artificial) and sampling forage, using oesophageal-fistulated animals, have been used to determine intake in the field. These intake measurement techniques are generally most suited to studies that occur over a few days and with relatively small (often less than 10) groups of animals. Over the last 10 years, there have been a number of advances in automated behavioural monitoring technology (e.g. global positioning systems) to track animal movement. A number of recent studies have integrated detailed spatial assessments of vegetation using on-ground sampling and satellite remote sensing; these data have been linked to behavioural preferences of herbivores. Although the recent studies still do not address nutritional interactions over months or years, they do point to methods that could be used to address landscape scale nutritional interactions. Emerging telemetry techniques used to monitor herbivore behavioural preferences and also to determine detailed landscape vegetation mapping provide the opportunity for future herbivore nutritional ecology studies.

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The Effects of Season and Diet Composition on the Radiocaesium Intake by Sheep Grazing on Heather Moorland

Cited by 76 publications

References 19 publications

Application of long-chain alcohols as faecal markers to estimate diet composition of horses and cattle fed with herbaceous and woody species

Application of long-chain alcohols as faecal markers to estimate diet composition of horses and cattle fed with herbaceous and woody species

Seasonal and spatial variation in the diet of the wild rabbit (Oryctolagus cuniculus L.) in Portugal

Opportunities for telemetry techniques in studies on the nutritional ecology of free-ranging domesticated ruminants

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