Author
Karen A. Beauchemin
Other affiliations: University of Guelph
Bio: Karen A. Beauchemin is an academic researcher from Agriculture and Agri-Food Canada. The author has contributed to research in topics: Silage & Rumen. The author has an hindex of 83, co-authored 423 publications receiving 22351 citations. Previous affiliations of Karen A. Beauchemin include University of Guelph.
Topics: Silage, Rumen, Beef cattle, Dry matter, Neutral Detergent Fiber
Papers published on a yearly basis
Papers
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TL;DR: In this paper, a variety of nutritional management strategies that reduce enteric methane (CH4) production are discussed, such as increasing the level of grain in the diet, inclusion of lipids and supplementation with ionophores (>24ppm) are most likely to be implemented by farmers.
Abstract: A variety of nutritional management strategies that reduce enteric methane (CH4) production are discussed. Strategies such as increasing the level of grain in the diet, inclusion of lipids and supplementation with ionophores (>24 ppm) are most likely to be implemented by farmers because there is a high probability that they reduce CH4 emissions in addition to improving production efficiency. Improved pasture management, replacing grass silage with maize silage and using legumes hold some promise for CH4 mitigation but as yet their impact is not sufficiently documented. Several new strategies including dietary supplementation with saponins and tannins, selection of yeast cultures and use of fibre-digesting enzymes may mitigate CH4, but these still require extensive research. Most of the studies on reductions in CH4 from ruminants due to diet management are short-term and focussed only on changes in enteric emissions. Future research must examine long-term sustainability of reductions in CH4 production and impacts on the entire farm greenhouse gas budget.
984 citations
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TL;DR: Results from in vitro batch culture studies provide evidence that EO and their components have the potential to improve N and/or energy utilization in ruminants and identification of EO that favorably alter fermentation without resulting in broad overall inhibition of rumen fermentation, continues to be a major challenge for researchers.
472 citations
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TL;DR: It is demonstrated that sunflower oil, ionophores, and possibly some yeast products can be used to decrease the GE lost as methane from cattle, but fiber digestibility is impaired with oil supplementation.
Abstract: Methane emitted from the livestock sector contributes to greenhouse gas (GHG) emissions. Understanding the effects of diet on enteric methane production can help refine GHG emission inventories and identify viable GHG reduction strategies. Our study focused on measuring methane and carbon dioxide emissions, total-tract digestibility, and ruminal fermentation in growing beef cattle fed a diet supplemented with various additives or ingredients. Two experiments, each designed as a 4 x 4 Latin square with 21-d periods, were conducted using 16 Holstein steers (initial BW 311.6 +/- 12.3 kg). In Exp. 1, treatments were control (no additive), monensin (Rumensin, Elanco Animal Health, Indianapolis, IN; 33 mg/kg DM), sunflower oil (400 g/d, approximately 5% of DMI), and proteolytic enzyme (Protex 6-L, Genencor Int., Inc., CA; 1 mL/kg DM). In Exp. 2, treatments were control (no additive), Procreatin-7 yeast (Prince Agri Products, Inc., Quincy, IL; 4 g/d), Levucell SC yeast (Lallemand, Inc., Rexdale, Ontario, Canada; 1 g/d), and fumaric acid (Bartek Ingredients Inc., Stoney Creek, Ontario, Canada; 80 g/d). The basal diet consisted of 75% barley silage, 19% steam-rolled barley grain, and 6% supplement (DM basis). Four large chambers (two animals per chamber) were equipped with lasers and infrared gas analyzers to measure methane and carbon dioxide, respectively, for 3 d each period. Total-tract digestibility was determined using chromic oxide. Approximately 6.5% of the GE consumed was lost in the form of methane emissions from animals fed the control diet. In Exp. 1, sunflower oil decreased methane emissions by 22% (P = 0.001) compared with the control, whereas monensin (P = 0.44) and enzyme had no effect (P = 0.82). However, oil decreased (P = 0.03) the total-tract digestibility of NDF by 20%. When CH(4) emissions were corrected for differences in energy intake, the loss of GE to methane was decreased by 21% (P = 0.002) using oil and by 9% (P = 0.09) using monensin. In Exp. 2, Procreatin-7 yeast (P = 0.72), Levucell SC yeast (P = 0.28), and fumaric acid (P = 0.21) had no effect on methane emissions, although emissions as a percentage of GE intake were 3% (non-significant, P = 0.39) less for steers fed Procreatin-7 yeast compared with the control. This study demonstrates that sunflower oil, ionophores, and possibly some yeast products can be used to decrease the GE lost as methane from cattle, but fiber digestibility is impaired with oil supplementation.
460 citations
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TL;DR: In this article, the authors have demonstrated that supplementing dairy cow and feedlot cattle diets with fiberdegrading enzymes has significant potential to improve feed utilization and animal performance, mainly due to improvements in ruminal fiber digestion resulting in increased digestible energy intake.
Abstract: Research has demonstrated that supplementing dairy cow and feedlot cattle diets with fiberdegrading enzymes has significant potential to improve feed utilization and animal performance. Ruminant feed enzyme additives, primarily xylanases and cellulases, are concentrated extracts resulting from bacterial or fungal fermentations that have specific enzymatic activities. Improvements in animal performance due to the use of enzyme additives can be attributed mainly to improvements in ruminal fiber digestion resulting in increased digestible energy intake. Animal responses are greatest when fiber digestion is compromised and when energy is the first-limiting nutrient in the diet. When viewed across a variety of enzyme products and experimental conditions, the response to feed enzymes by ruminants has been variable. This variation can be attributed to experimental conditions in which energy is not the limiting nutrient, as well as to the activities and characteristics of the enzymes supplied, underor over-supplementation of enzyme activity, and inappro
404 citations
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TL;DR: A life cycle assessment (LCA) was conducted to estimate whole-farm greenhouse gas (GHG) emissions from beef production in western Canada as discussed by the authors, where the authors determined the relative contributions of the cow-calf and feedlot components to these emissions, and examined the proportion of whole farm emissions attributable to enteric methane (CH 4 ).
378 citations
Cited by
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TL;DR: In this article, the authors present a document, redatto, voted and pubblicato by the Ipcc -Comitato intergovernativo sui cambiamenti climatici - illustra la sintesi delle ricerche svolte su questo tema rilevante.
Abstract: Cause, conseguenze e strategie di mitigazione Proponiamo il primo di una serie di articoli in cui affronteremo l’attuale problema dei mutamenti climatici. Presentiamo il documento redatto, votato e pubblicato dall’Ipcc - Comitato intergovernativo sui cambiamenti climatici - che illustra la sintesi delle ricerche svolte su questo tema rilevante.
4,187 citations
30 Apr 1984
TL;DR: A review of the literature on optimal foraging can be found in this article, with a focus on the theoretical developments and the data that permit tests of the predictions, and the authors conclude that the simple models so far formulated are supported by available data and that they are optimistic about the value both now and in the future.
Abstract: Beginning with Emlen (1966) and MacArthur and Pianka (1966) and extending through the last ten years, several authors have sought to predict the foraging behavior of animals by means of mathematical models. These models are very similar,in that they all assume that the fitness of a foraging animal is a function of the efficiency of foraging measured in terms of some "currency" (Schoener, 1971) -usually energy- and that natural selection has resulted in animals that forage so as to maximize this fitness. As a result of these similarities, the models have become known as "optimal foraging models"; and the theory that embodies them, "optimal foraging theory." The situations to which optimal foraging theory has been applied, with the exception of a few recent studies, can be divided into the following four categories: (1) choice by an animal of which food types to eat (i.e., optimal diet); (2) choice of which patch type to feed in (i.e., optimal patch choice); (3) optimal allocation of time to different patches; and (4) optimal patterns and speed of movements. In this review we discuss each of these categories separately, dealing with both the theoretical developments and the data that permit tests of the predictions. The review is selective in the sense that we emphasize studies that either develop testable predictions or that attempt to test predictions in a precise quantitative manner. We also discuss what we see to be some of the future developments in the area of optimal foraging theory and how this theory can be related to other areas of biology. Our general conclusion is that the simple models so far formulated are supported are supported reasonably well by available data and that we are optimistic about the value both now and in the future of optimal foraging theory. We argue, however, that these simple models will requre much modification, espicially to deal with situations that either cannot easily be put into one or another of the above four categories or entail currencies more complicated that just energy.
2,709 citations
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TL;DR: The current state and perspectives of biogas production, including the biochemical parameters and feedstocks which influence the efficiency and reliability of the microbial conversion and gas yield are reviewed.
Abstract: Anaerobic digestion of energy crops, residues, and wastes is of increasing interest in order to reduce the greenhouse gas emissions and to facilitate a sustainable development of energy supply. Production of biogas provides a versatile carrier of renewable energy, as methane can be used for replacement of fossil fuels in both heat and power generation and as a vehicle fuel. For biogas production, various process types are applied which can be classified in wet and dry fermentation systems. Most often applied are wet digester systems using vertical stirred tank digester with different stirrer types dependent on the origin of the feedstock. Biogas is mainly utilized in engine-based combined heat and power plants, whereas microgas turbines and fuel cells are expensive alternatives which need further development work for reducing the costs and increasing their reliability. Gas upgrading and utilization as renewable vehicle fuel or injection into the natural gas grid is of increasing interest because the gas can be used in a more efficient way. The digestate from anaerobic fermentation is a valuable fertilizer due to the increased availability of nitrogen and the better short-term fertilization effect. Anaerobic treatment minimizes the survival of pathogens which is important for using the digested residue as fertilizer. This paper reviews the current state and perspectives of biogas production, including the biochemical parameters and feedstocks which influence the efficiency and reliability of the microbial conversion and gas yield.
2,440 citations