Showing papers by "Karen A. Beauchemin published in 2007"
TL;DR: Feeding up to 2% of the dietary DM as quebracho tannin extract failed to reduce enteric methane emissions from growing cattle, although the protein-binding effect of the que bracho tANNin extract was evident.
Abstract: Our objective was to determine if condensed tannin extract from quebracho trees (Schinopsis quebracho-colorado; red quebracho) could be used to reduce enteric methane emissions from cattle. The experiment was designed as a repeated 3 x 3 Latin square (4 squares) with 3 treatments (0, 1, and 2% of dietary DM as quebracho tannin extract) and 3 28-d periods. Six spayed Angus heifers (238 +/- 13.3 kg of initial BW) and 6 Angus steers (207 +/- 8.2 kg of initial BW) were each assigned to 2 squares. The measured condensed tannin content of the extract was 91%, and the basal diet contained 70% forage (DM basis). Feeding quebracho tannin extract had no effect on BW, ADG, or nutrient intakes. Furthermore, it had no effect on DM, energy, or fiber (ADF and NDF) digestibility, but apparent digestibility of CP decreased linearly (P < 0.001) by 5 and 15% with 1 and 2% quebracho tannin extract, respectively. There were no effects of quebracho tannin extract on methane emissions (g/d, g/kg of DM, % of GE intake, or % of DE intake). Feeding up to 2% of the dietary DM as quebracho tannin extract failed to reduce enteric methane emissions from growing cattle, although the protein-binding effect of the quebracho tannin extract was evident.
361 citations
TL;DR: The SF6 tracer technique is reasonably accurate for inventory purposes and for evaluating the effects of mitigation strategies on CH4 emissions, and was higher for the SF6 technique than for the chamber technique.
261 citations
TL;DR: It is concluded that, under the conditions imposed, feeding additional concentrate prepartum does not reduce postpartum RA, and the incidence and severity of RA increases immediately post partum, emphasizing the need to develop and implement feeding strategies that reduce this risk.
231 citations
TL;DR: In this paper, a study was conducted to investigate the impact of several lipid sources that supplied mainly long-chain fatty acids (FA) for their potential to reduce methane emissions from growing cattle.
Abstract: A study was conducted to investigate the impact of several lipid sources that supplied mainly long-chain fatty acids (FA), for their potential to reduce methane emissions from growing cattle. Sixte...
167 citations
TL;DR: In this article, the effects of essential oils (EO) and essential oil compounds (EOC) on in vitro rumen microbial fermentation were investigated, and the results showed that EOC compounds improved the performance of microbial fermentation.
Abstract: The objective of this study was to investigate the effects of essential oils (EO) and essential oil compounds (EOC) on in vitro rumen microbial fermentation. Treatments were: control (no additive),...
143 citations
TL;DR: This study shows that the risk of ruminal acidosis is high for cows fed a low F:C diet, particularly when finely chopped silage is used, and intake of dietary peNDF is a good indicator ofRuminal pH status of dairy cows.
129 citations
TL;DR: The results indicate that cows rapidly adjust their sorting behavior when subjected to a dietary change, and they exhibit more sorting for short particles and against long particles, NDF, and peNDF when fed an LF diet.
120 citations
TL;DR: This study showed that CIN exhibited antimicrobial activity in both CC systems, but the effects were more pronounced in the Rusitec than in the DF system, and supplementation of CIN at the concentration evaluated in this study may not be nutritionally beneficial to ruminants.
110 citations
TL;DR: Enzyme products that improve in vitro degradation of forages may have the potential to improve lactational performance of dairy cows.
93 citations
TL;DR: This study documented the quantity of NH3 emitted from a feedlot housing growing beef cattle located in southern Alberta, Canada and found evidence that rain suppressed the NH3 emission.
Abstract: Livestock manure is a significant source of ammonia (NH 3 ) emissions. In the atmosphere, NH 3 is a precursor to the formation of fine aerosols that contribute to poor air quality associated with human health. Other environmental issues result when NH 3 is deposited to land and water. Our study documented the quantity of NH 3 emitted from a feedlot housing growing beef cattle. The study was conducted between June and October 2006 at a feedlot with a one-time capacity of 22,500 cattle located in southern Alberta, Canada. A backward Lagrangian stothastic (bLS) inverse-dispersion technique was used to calculate NH 3 emissions, based on measurements of NH 3 concentration (open-path laser) and wind (sonic anemometer) taken above the interior of the feedlot. There was an average of 3146 kg NH 3 d -1 lost from the entire feedlot, equivalent to 84 μg NH 3 m -2 s -1 or 140 g NH 3 head -1 d -1 . The NH 3 emissions correlated with sensible heat flux (r 2 =0.84) and to a lesser extent the wind speed (r 2 = 0.56). There was also evidence that rain suppressed the NH 3 emission. Quantifying NH 3 emission and dispersion from from farms is essential to show the impact of farm management on reducing NH 3 -related environmental issues.
86 citations
TL;DR: The authors evaluated a series of recombinant, single activity experimental enzyme products including 13 endoglucanases (END) and 10 xylanases (XY) for their potential to improve in vitro ruminal degradation of alfalfa hay in two experiments.
TL;DR: Two in vitro experiments were performed to identify promising exogenous fibrolytic enzyme products (EFE) and optimum dose rates (DR) for improving the degradation of alfalfa hay and corn silage, and there was no relationship between added xylanase activity and NDF degradability.
TL;DR: It is demonstrated that selection of barley grain can affect milk fat production and rumen fermentation to an extent at least as great as changes in dietary starch concentration.
TL;DR: The results indicate that feeding dairy cows a low F:C diet is beneficial in terms of increasing feed intake, microbial N synthesis, and milk production, and that increasing dietary peNDF, through an increased proportion of forage or increased FPL, improves fiber digestion because of improved rumen function.
TL;DR: Oral supplementation of E. faecium alone or in combination with Saccharomyces cerevisiae (yeast) on mediators of the acute phase response in feedlot steers resulted in no effect on the mediators or the mechanism(s) by which E. Faecium and yeast stimulated production of acute phase proteins in feedLot steers.
Abstract: Two experiments were conducted to investigate the effects of oral supplementation of the lactic-acid-producing bacterium Enterococcus faecium EF212 alone or in combination with Saccharomyces cerevisiae (yeast) on mediators of the acute phase response in feedlot steers. Eight fistulated steers were used to study the effects of E. faecium alone or with yeast in a crossover design with 2 Latin squares, 4 steers within each square, and 2 periods. The length of each period was 3 wk, with a 10-d adaptation and an 11-d measurement period. The experimental diet contained 87% steam-rolled barley, 8% whole-crop barley silage, and 5% supplement (DM basis). In Exp. 1, treatments were control vs. the lactic-acid-producing bacterium E. faecium (6 x 10(10) cfu/d). In Exp. 2, treatments were control vs. E. faecium (6 x 10(10) cfu/d) and S. cerevisiae (6 x 10(10) cfu/d). The bacteria and yeast supplements were blended with calcium carbonate to supply 6 x 10(10) cfu/d when top-dressed into the diet once daily at the time of feeding (10 g/d). Steers fed the control diet received only carrier (10 g/d). Blood samples were collected from the jugular vein on d 17 and 21 of each period, and serum amyloid A (SAA), lipopolysaccharide binding protein (LBP), haptoglobin, and alpha1-acid glycoprotein (alpha1-AGP) were measured. Supplementation of feed with E. faecium had no effect on concentrations of SAA, LBP, haptoglobin, or alpha1-AGP in plasma compared with those of controls. However, feeding E. faecium and yeast increased (P = 0.02) plasma concentrations of SAA, LBP, and haptoglobin but had no effect on plasma alpha1-AGP. In conclusion, oral supplementation of E. faecium alone had no effect on the mediators of the acute phase response that were measured, whereas feeding of E. faecium and yeast induced an inflammatory response in feedlot steers fed high-grain diets. Further research is warranted to determine the mechanism(s) by which E. faecium and yeast stimulated production of acute phase proteins in feedlot steers.
TL;DR: Larger improvements in degradability of alfalfa hay occurred for enzyme products containing mainly fibrolytic, rather than proteolytic, activity, suggesting that improvements in fibre degradation would increase availability of glucose precursors to the animal.
TL;DR: Reducing ruminal starch degradation of barley grain may not improve the productivity of lactating dairy cows, and greater milk production for cows fed CM can be attributed to greater DMI.
TL;DR: Results indicate that feeding P15 alone increased SAA and lowered plasma haptoglobin, whereas, feeding PE elevated concentrations of SAA, but had no effect on plasma haPToglobin.
Abstract: Six ruminally cannulated steers were used in a replicated 3 × 3 Latin square with 2 wk for adaptation and 1 wk for measurements to study the effects of Propionibacterium P15 (P15) alone or in combination with Enterococcus faecium EF212 (PE) on acute phase response. Treatments were: (i) carrier (control), (ii) P15, and (iii) PE. The bacterial treatments [109 colony forming units (CFU) d-1] mixed in whey powder (carrier), or whey powder alone for control animals, were top-dressed once daily at the time of feeding (10 g steer-1 d-1). Blood samples were obtained from jugular veins on the last day of each period at 0, 6, and 12 h after feeding of bacteria and serum amyloid A (SAA), haptoglobin, lipopolysaccharide de-binding protein (LBP) were measured by ELISA and alpha1-acid glycoprotein (α1-AGP) by radial immunodiffusion. Results indicate that feeding P15 alone increased SAA and lowered plasma haptoglobin, whereas, feeding PE elevated concentrations of SAA, but had no effect on plasma haptoglobin. No signifi...