Showing papers by "Karen A. Beauchemin published in 2008"
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
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
TL;DR: Both HR and LR cows altered their sorting behavior in response to acidosis challenges, and severe acidosis was associated with increased sorting for the longer particles in the diet and against the shorter particles, likely to lessen the effects of the very.
197 citations
TL;DR: This study indicates that cows become more prone to acidosis over time even though they decrease intake of the challenge grain to avoid acidosis, especially for cows fed diets low in physically effective fiber and at high acidosis risk.
126 citations
TL;DR: Slower eating rate and greater time spent eating may help prevent ruminal acidosis by increasing the total daily salivary secretion in dairy cows.
102 citations
TL;DR: Monensin controlled-release capsules improved the efficiency of milk production of grazing dairy cows by increasing the yield of milk solids, however, a higher dose rate of monensin may be needed to reduce methane emissions from cows grazing pasture.
63 citations
TL;DR: WCS appears to be a promising supplement for reducing methane emissions and increasing milk production from dairy cattle when pasture is limited in quantity and has a low nutritive value.
Abstract: The experimental objective was to determine if whole cottonseed (WCS) could be used as a dietary supplement to reduce enteric methane emissions and profitably increase milk production from dairy cattle over the summer period when pasture is limited in quantity and has a low nutritive value. Fifty lactating cows, ~200 days in milk, were randomly allocated to one of two groups (control or WCS). Cows were offered lucerne hay (in the morning) and pasture silage (in the afternoon) made from a predominantly ryegrass sward in one group for 5 weeks. The hay and silage were placed on the ground in a bare paddock. Cows in each group were also individually offered cracked grain in a feed trough at 3 kg DM/cow.day at milking times. In addition, at milking times, cows in the WCS group were individually offered 2.7 kg DM/cow.day of untreated WCS with their grain supplement. Measurements of methane emissions (n = 12), using the SF6 tracer technique, were made in weeks 3 and 5 after the commencement of feeding treatments. Supplementation with WCS significantly reduced methane emissions by 12% (g/cow.day) and by 21% (g/cow.kg milk solids) and significantly increased yield of milk (n = 25) by 15%, milk fat by 19% and milk protein by 16%. WCS had no effect on concentration of milk fat or lactose, but resulted in a significant 3% decrease in protein concentration. WCS appears to be a promising supplement for reducing methane emissions and increasing milk production from dairy cattle when pasture is limited in quantity and has a low nutritive value.
56 citations
TL;DR: In this article, the authors compare CH4 emissions from a typical feedlot in Australia (Queensland) and in Canada (Alberta) and also compare these against modelled emissions.
Abstract: Raising beef cattle in open feedlots is a well established practice in Canada and is gaining acceptance in Australia because it results in more consistent meat quality. These facilities are regional 'hot spots' of methane (CH4) emissions, resulting from the high stocking density and the large amount of fermentation occurring in the rumen (enteric CH4). Our objective was to compare CH4 emissions from a typical feedlot in Australia (Queensland) and in Canada (Alberta) and also to compare these against modelled emissions. Methane concentration and wind data were monitored over a portion of each feedlot and a dispersion model was used to calculate CH4 emissions during a summer period. The average CH4 emission was 166 ± 90 and 214 ± 61 g/animal.day for the feedlot in Queensland and in Alberta, respectively. The lower CH4 emission at the Queensland feedlot was attributed to the lighter weight of the cattle, and consequently their lower intake, and supplementation of the diet with lipids. The lipid effect on CH4 emissions is also speculated to cause some models to overestimate the measured CH4 emissions. A lower CH4 emission also occurred during daylight hours at the Queensland feedlot and was attributed in part to heat stress as defined by the temperature-humidity index.
51 citations
TL;DR: The transient nature of the inhibition of methane production by the antibodies may have arisen from instability of the antibodies in ruminal fluid, or to the presence of non-culturable methanogens unaffected by the antibody activity that was administered.
Abstract: In vitro dry matter disappearance (IVDMD) and production of methane, volatile fatty acids (VFA) and ammonia from an early lactation diet or from freeze-dried alfalfa were assessed in the presence of anti-methanogen antibody treatments in two in vitro ruminal incubations (experiments 1 and 2). In experiment 1, hens were immunised with crude cell preparations of Methanobrevibacter smithii, Methanobrevibacter ruminantium or Methanosphaera stadtmanae and complete Freund’s adjuvant (CFA). Semipurified egg antibodies (IgY) prepared from the hens’ eggs (α-SMICFA, α-RUMCFA, or α-STADCFA, respectively) were dispensed into 24 replicate vials (400 μL per vial) containing 500 mg of an early lactation total mixed ration (18% crude protein; 33% neutral detergent fibre; DM basis). Vials containing an equal volume of semipurified antibodies from eggs of non-immunised hens were included as a control. In experiment 2, hens were immunised with one of the three antigenic preparations combined with Montanide ISA 70 adjuvant. Triplicate vials per time point included 0.6 g of freeze-dried egg powder (α-SMIMon, α-RUMMon, α-STADMon; 19.0 ± 2.6 mg IgY/g) or a mixture of all three (ComboMon) and 500 mg of freeze-dried alfalfa. Total gas, methane production and pH were measured at intervals over 24 h. After 24 h, samples were analysed for VFA, ammonia and IVDMD. In experiment 1, cumulative CH4 production was similar (P > 0.05) among treatments at each sampling time. At 24 h, average CH4 production across treatments was 27.03 ± 0.205 mg/g DM. In experiment 2, α-SMIMon, α-STADMon and ComboMon reduced methane production at 12 h (P ≤ 0.05) compared with the control, but by 24 h, CH4 levels in all treatments were similar (P > 0.05) to the control. At 24 h, total VFA concentrations were lower (P < 0.05) in α-RUMMon and α-SMIMon than in the control. The transient nature of the inhibition of methane production by the antibodies may have arisen from instability of the antibodies in ruminal fluid, or to the presence of non-culturable methanogens unaffected by the antibody activity that was administered.
37 citations
TL;DR: A meta-analysis of data from in vitro studies was performed to identify the key enzymic activities in feed enzyme additives, and their dose rates, that improve degradation of alfalfa hay and corn silage as mentioned in this paper.
37 citations
TL;DR: It is hypothesized that the fermentation of corn silage by a mixed culture of rumen microorganisms in an in vitro system could be increased using exogenous fibrolytic enzyme additives, and that the improvement would depend on the dose of cellulase or xylanase activity provided.
Abstract: We hypothesized that the fermentation of corn silage by a mixed culture of rumen microorganisms in an in vitro system could be increased using exogenous fibrolytic enzyme additives (FE), and that the improvement would depend on the dose of cellulase or xylanase activity provided. An in vitro assay was used to determine the effects of FE on gas production (GP) and degradability of fibre after 24 h of incubation in buffered ruminal fluid. Eight FE with endoglucanase and xylanase activities were evaluated at one dose (0.5 mg g-1 of forage dry matter), providing variable units of enzymic activity. Only one product improved fibre degradability (9.1 and 29.9% increases for neutral and acid detergent fibre, respectively; P < 0.05). The FE were reassessed when added to supply the same dose of enzymic activity: 807 units of endoglucanase or 477 units of xylanase activity g-1 of forage dry matter (a unit was defined as nmol of reducing sugar released min-1). The FE had greater impact on GP (21% increase; P < 0.05) ...