Comparison by direct animal calorimetry of the net energy values of an early and a late season growth of herbage

Corbett, J. L.; Langlands, JP; McDonald, I.; Pullar, J. D.

doi:10.1017/s0003356100037661

Cited by 52 publications

(41 citation statements)

References 26 publications

(18 reference statements)

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“…The utilization of less-mature herbage (strategy 5) has been shown to lower methane yields. Corbett et al (1966) also observed greater methane losses for late-season compared to early-season herbage. The common factor between these strategies is the relative proportions of soluble and structural carbohydrates within the plant tissue.…”

Section: Discussionmentioning

confidence: 72%

Evaluation of dietary strategies to reduce methane production in ruminants: A modelling approach

Benchaar¹,

Pomar²,

Chiquette³

2001

Can. J. Anim. Sci.

220

152

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Benchaar, C., Pomar, C. and Chiquette, J. 2001. Evaluation of dietary strategies to reduce methane production in ruminants: A modelling approach. Can. J. Anim. Sci. 81: 563-574. The objective of this study was to use the modelling approach to assess the effectiveness of different existing nutritional strategies to reduce methane production from ruminants. For this purpose, a modified version of a mechanistic and dynamic model of rumen digestion was used. Simulated strategies included: dry matter intake (DMI), forage to concentrate ratio, nature of concentrate (fibrous vs. starchy concentrate), type of starch (slowly vs. rapidly degraded), forage species (legume vs. grass), forage maturity, forage preservation method (dried vs. ensiled), forage processing, and upgrading and supplementation of poor quality forages (straw). This study showed that mathematical modelling is a valuable tool to evaluate the impact of a given dietary manipulation not only on methanogenesis but also on the metabolism of the whole rumen system. Depending on the nature of the intervention, methane production can be reduced by 10 to 40%. Increasing DMI and the proportion of concentrate in the diet reduced methane production (-7 and -40%). Methane production was also decreased with the replacement of fibrous concentrate with starchy concentrate (-22% ) and with the utilization of less ruminally degradable starch (-17%). The use of more digestible forage (less mature and processed forage) resulted in a reduction of methane production (-15 and -21%). Methane production was lower with legume than with grass forage (-28%), and with silage compared to hay (-20%). Supplementation or ammoniation of straw did not reduce methane losses, but had a positive impact on the efficiency of rumen metabolism. The modelling approach demonstrated that reduction of methane production from ruminants is a complex challenge. Implementation of any strategy must take into account the possible consequences on the efficiency of the entire rumen system. Key words: Ruminants, methane reduction, modelling approach Benchaar, C., Pomar, C. et Chiquette, J. 2001. Evaluation de stratégies alimentaires pour réduire la production de méthane chez les ruminants: approche modélisatrice. Can. J. Anim. Sci. 81: 563-574. L'objectif de cette étude est d'utiliser la modélisation mathématique pour évaluer et expliquer l'impact de différentes stratégies alimentaires appliquées pour réduire la production de méthane chez les ruminants. Pour cela, une version modifiée d'un modèle dynamique et mécaniste de la digestion ruminale a été utilisée. Les différentes stratégies alimentaires évaluées sont: le niveau d'ingestion, la proportion de concentré dans la ration, la nature du concentré (fibreux vs. amylacé), la dégradabilité ruminale de l'amidon (lentement vs. rapidement dégradable), l'espèce (légumineuse vs. graminée), la maturité et la méthode de conservation du fourrage, et le traitement chimique et la supplémentation de la paille. Les résultats des simulations obtenus montrent que la prod...

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Section: Discussionmentioning

confidence: 72%

Evaluation of dietary strategies to reduce methane production in ruminants: A modelling approach

Benchaar¹,

Pomar²,

Chiquette³

2001

Can. J. Anim. Sci.

220

152

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“…Joyce (1974) stated that the poor performance of sheep grazing on kikuyu grass could be a primary result of an inadequate energy intake, uncomplicated by a protein deficiency. A low energy intake of pasture will be reflected in terms of a reduced proportion of propionic acid in relation to acetic acid in the rumen of sheep (Corbett et al 1966), due to higher proportions of structural carbohydrates and lower soluble carbohydrates (Ulyatt 1971). A low energy content will also limit the utilisation of non-protein nitrogen (NPN) in the rumen for providing microbial protein (MP) to the animal (Satter & Roffler 1977), resulting in an accumulation of ammonia in the rumen (Leng 1990).…”

Section: Introductionmentioning

confidence: 99%

Kikuyu (Pennisetum clandestinum) pasture for sheep. 2. Production and nutritional status of ewes with or without lupin (Lupinus albus) supplementation

Brand¹,

Franck²,

Coetzee

1999

New Zealand Journal of Agricultural Research

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Kikuyu pasture was grazed continuously for 12 months by 20 dry and 40 producing South African Mutton Merino (SAMM) and Merino ewes at a stocking density of 23 ewes ha -1 . Supplementary sweet lupin seed was supplied to one group of producing ewes of each breed during pregnancy and lactation at a rate of 0.5% of the liveweights of the ewes. Rumen fluid samples for the determination of pH, volatile fatty acids (VFA), and ammonia-nitrogen (NH 3 -N) were collected from rumen-fistulated wethers corresponding to the periods of late pregnancy and early lactation of ewes. Rumen NH3-N concentrations (8.7 mg 100 ml -1 and 5.4 mg 100 ml -1 ) were low during both periods of sampling. Rumen VFA concentrations (12.3 mmol 100 ml -1 and 9.2 mmol 100 ml -1 )were within normal ranges. Supplementation significantly increased blood urea concentration of ewes. Supplemented ewes lost less weight than the unsupplemented ewes (P 0.02) during the experimental period. Pregnancy (P 0.001) as well as lactation (P 0.0001) reduced greasy wool production. Supplementation increased birthweight of lambs by 21% (P 0.0007). Rumen parameters indicated no severe deficiency in either protein or energy intake. A lack of response in wool and lamb growth due to lupin supplementation was primarily A98055Received 2 1 October 1998; accepted 16 July 1999 ascribed to a high CP degradability of lupin seed. Production of the different breeds was in accordance with their respective genetic potential.

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“…Two models were used following the suggestion of Corbett et al (1966). In model 1 it was assumed that the efficiency of utilization of dry matter and metabolizable energy for maintenance was the same for the two grasses, and there could be differences between the two grasses only in terms of efficiency of utilization of dry matter and metabolizable energy for production (Fig.…”

Section: Discussionmentioning

confidence: 99%

“…In a comparison 396 G. D. TUDOR AND D. J. MINSON between spring-and autumn-grown ryegrass they reported that the quantity of energy in the nutrients absorbed from the spring grass was 15% higher than from an equal quantity of autumn grass, although there was a difference of only 6 percentage units in energy digestibility. This difference in energy absorption could be one factor causing the difference in efficiency of utilization of metabolizable energy (ME) between spring and autumn grasses recorded by Corbett et al (1966) and Blaxter et al (1971).…”

Section: Introductionmentioning

confidence: 99%

The utilization of the dietary energy of pangola and setaria by young growing beef cattle

Tudor

Minson²

1982

J. Agric. Sci.

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The net energy values for growth and fattening of two artificially dried tropical grasses-, pangola {Digitaria decumbens) and setaria (S. sphacelata var. sericea cv. Nandi), of similar estimated metabolizable energy content (8-07 and 7-96 MJ/kg D.M.) were determined with cattle using a slaughter technique. Growing cattle with a mean initial weight of 175 kg were given equal quantities of dry matter of the two grasses at each of three planes of nutrition above maintenance for a period of 152 days.The initial energy, fat and protein content of the total body of the 24 test animals was estimated from regressions relating fasted live weight to thes"e components, derived from 12 similar cattle slaughtered at the beginning of the feeding period. The final energy, fat and protein content of the test animals was determined directly by chemical analysis. The metabolizable energy (ME) content of the grasses was estimated from the level of digestible energy (DE) determined with eight cattle, assuming that ME = 0-815 DE.The cattle fed pangola gained more live weight, empty-body weight, fat, protein and energy than animals fed similar quantities of setaria. The net energy value for growth and fattening (NE f ) was determined using regressions relating energy retention to the quantity of dry matter eaten. NE, in MJ/kg dry matter was 2-27 for pangola and 1-31 for setaria.Efficiency of utilization of ME for growth and fattening (k f ) was .27-7% for pangola and 16-9% for setaria. These values for tropical grasses are lower than any values reported for temperate pasture species. Thus the lower efficiency of utilization of ME may cause the lower production of cattle which graze tropical grasses.It was concluded that as the k, values of different tropical grasses are not constant, k, values should be measured on a wider range of tropical grasses so that this factor can be taken into account when evaluating grasses in animal production systems.

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Comparison by direct animal calorimetry of the net energy values of an early and a late season growth of herbage

Abstract: 1966). Comparison by direct animal calorimetry of the net energy values of an early and a late season growth of herbage.

Cited by 52 publications

References 26 publications

Evaluation of dietary strategies to reduce methane production in ruminants: A modelling approach

Evaluation of dietary strategies to reduce methane production in ruminants: A modelling approach

Kikuyu (Pennisetum clandestinum) pasture for sheep. 2. Production and nutritional status of ewes with or without lupin (Lupinus albus) supplementation

The utilization of the dietary energy of pangola and setaria by young growing beef cattle

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