Antimicrobial resistance in generic fecal Escherichia coli obtained from beef cattle on arrival at the feedlot and prior to slaughter, and associations with volume of total individual cattle antimicrobial treatments in one western Canadian feedlot

A prospective observational study was carried out to examine antimicrobial resistance patterns of fecal Escherichia coli isolates of calves on arrival at the feedlot, and then evaluate the associations between the total volume of antimicrobial used for disease treatment and changes in antimicrobial resistance, during the feeding period. No macrolides or tetracyclines were administered in the feed during this study. On arrival, at the animal level, all 3 isolates obtained from 36.6% [95% confidence interval (CI): 29.0 to 44.8] of all cattle sampled (n = 153), were susceptible to all antimicrobials, while 5.9% (95% CI: 2.7 to 10.9) of cattle had at least 1 isolate that was resistant to ≥ 3 antimicrobials out of the 7 antimicrobials tested. The most frequent antimicrobials for which resistance was observed were sulphamethoxazole, ampicillin, and tetracycline where, of all cattle, 44.4% (95% CI: 36.4 to 52.7), 20.3% (95% CI: 14.2 to 27.5), and 17.7% (95% CI: 12.0 to 24.6), respectively had at least 1 resistant isolate. All cattle received antimicrobial metaphylaxis on arrival at the feedlot. Antimicrobial use was described for a cohort of 95 cattle. Antimicrobials were given to 42 of the 95 cattle during the feeding period, to treat disease. Amongst the 42 treated cattle, there were a total of 133 animal daily doses (ADD_Feedlot), where 1 ADD_Feedlot represented 1 day of antimicrobial treatment received by a feedlot animal at the approved dose. Only 1 ADD_Feedlot was given in the 100 days immediately prior to slaughter. There were no associations found between antimicrobial use and antimicrobial resistance in this study.     

Cryopreservation of semen from a stallion with seminal vesiculitis

A 6‐year‐old Warmblood stallion was admitted for semen collection and cryopreservation. On the seventh and subsequent collection days semen samples were contaminated with purulent debris. A diagnosis of seminal vesiculitis was made following ultrasonography and endoscopy of the seminal vesicles. The stallion was treated with systemic and topical antimicrobial therapy and, although this did not cure the condition, subsequent ejaculates were suitable for cryopreservation.     

Chemical imaging of microstructures of plant tissues within cellular dimension using synchrotron infrared microspectroscopy

Synchrotron radiation-based Fourier transform infrared microspectroscopy (SR-FTIR) is an advanced bioanalytical technique capable of exploring the chemistry within microstructures of plant and animal tissues with a high signal to noise ratio at high ultraspatial resolutions (3-10 microm) without destruction of the intrinsic structures of a tissue. This technique is able to provide information relating to the quantity, composition, structure, and distribution of chemical constituents and functional groups in a tissue. The objective of this study was to illustrate how the SR-FTIR technique can be used to image inherent structures of plant tissues on a cellular level (pixel size, approximately 10 microm x 10 microm). The results showed that with the extremely bright synchrotron light, spectra with high signal to noise ratios were obtained from areas as small as 10 microm x 10 microm in the plant tissue, which allowed us to "see" plant tissue in a chemical sense on a cellular level. The ultraspatial resolved imaging of plant tissues by stepping in pixel-sized increments was obtained. Chemical distributions of plant tissues such as lignin, cellulose, protein, lipid, and total carbohydrate could be mapped. These images revealed the chemical information of plant intrinsic structure. In conclusion, SR-FTIR can provide chemical and functional characteristics of plant tissue at high ultraspatial resolutions. The SR-FTIR microspectroscopic images can generate spatially localized functional group and chemical information within cellular dimensions.     

Comparison of wheat or corn dried distillers grains with solubles on rumen fermentation and nutrient digestibility by feedlot heifers

A 5 × 5 Latin square design trial was conducted to evaluate rumen fermentation and apparent nutrient digestibility in 5 rumen-cannulated heifers (420 ± 6 kg) fed a barley-based finishing diet supplemented with 20 or 40% wheat or corn dried distillers grains with solubles (DDGS). The composition of the control diet was 88.7% rolled barley grain, 5.5% supplement, and 5.8% barley silage (DM basis). Increasing the quantity of corn DDGS in the ration resulted in a quadratic decrease in DMI (P = 0.04) and OM intake (P = 0.05). Rumen pH, pH duration, and area under rumen pH thresholds of 5.8 or 5.5 were not affected (P > 0.05) by treatment. Inclusion of wheat DDGS resulted in a quadratic increase (P = 0.05) in pH area below the cutoff value of 5.2, with the most pronounced effect at 20% inclusion. Wheat DDGS linearly increased (P = 0.01) rumen NH(3)-N concentrations. Increasing the inclusion rate of wheat and corn DDGS resulted in quadratic (P = 0.05) and linear (P = 0.04) decreases in rumen propionate, whereas butyrate increased quadratically (P < 0.01) and linearly (P < 0.01), respectively. Feeding wheat DDGS linearly decreased (P < 0.01) DM and OM digestibility values. Inclusion of corn DDGS increased the digestibility values of ether extract (P = 0.05; quadratic response) and CP (P < 0.01; linear response). Neutral detergent fiber digestibility increased in a linear fashion (P = 0.01) as both wheat and corn DDGS inclusion increased, whereas ADF digestibility increased linearly (P = 0.03) for wheat and quadratically (P = 0.02) for corn DDGS. Increased inclusion of wheat DDGS resulted in a linear decrease in GE digestibility (P = 0.01), whereas increasing corn DDGS inclusion linearly increased (P < 0.01) the DE content of the diet. Feeding both wheat and corn DDGS linearly increased (P = 0.01) the excretion of N and P. In summary, replacement of barley grain with up to 40% wheat or corn DDGS did not mitigate rumen pH conditions associated with mild to moderate acidosis in heifers fed a barley-based finishing diet. Supplementing corn DDGS increased nutrient digestibility of all nutrients and, as a result, led to greater DE content. Supplementation of wheat DDGS reduced DM and OM digestibility values, with no effect on DE content. Increased N and P excretion by heifers fed DDGS at 20 or 40% of dietary DM presents a challenge for cattle feeders with respect to nutrient management.     

Feeding flaxseed in grass hay and barley silage diets to beef cows increases alpha-linolenic acid and its biohydrogenation intermediates in subcutaneous fat

The objective of the study was to determine temporal fat deposition and fatty acid profiles in beef cows fed hay- or barley silage-based diets, with or without flaxseed. Crossbred cull beef cows (n = 64, >30 mo of age, 620 ± 5 kg) were removed from grassland pastures, randomly assigned to 16 pens, and given ad libitum access to 50:50 (wt/wt, DM basis) forage:concentrate diets containing 0 or 15% ground flaxseed (DM basis, 5.2% added fat). Diets consisted of hay control (HC), hay+flaxseed (HF), barley silage control (SC), and silage+flaxseed (SF). Backfat biopsies were obtained from each cow at 0, 6, and 12 wk, and at slaughter (~20 wk) to assess fatty acid composition. With the exception of feed efficiency, flaxseed × forage interactions were not significant for backfat accumulation or performance parameters. Flaxseed improved (P < 0.01) feed conversion when supplemented to hay-based diet and increased ADG (P = 0.03), resulting in a heavier (P = 0.02) BW. Compared with hay, barley silage increased (P < 0.01) DMI, ADG, and feed efficiency. Subcutaneous fat contained 0.68% n-3 fatty acids at wk 0, and reached 0.68, 0.81, and 0.94% in HF cows after 6, 12, and 20 wk, respectively (Y(n-3) = 0.0133X + 0.6491, r = 0.87). It was 0.67% at wk 0, and reached 0.65, 0.77, and 0.90% in SF cows after 6, 12, and 20 wk, respectively (Y(n-3) = 0.0121X + 0.6349, r = 0.75). In contrast, weight percentage of n-3 fatty acids decreased in HC cows from 0.63, 0.50, and 0.47, to 0.43%, and in SC cows from 0.63, 0.40, and 0.36, to 0.33% over the 20 wk. A forage × flaxseed interaction (P < 0.05) occurred for many of the α-linolenic acid (ALA) biohydrogenation intermediates, including vaccenic acid (C18:1 trans-11) and CLA (combined C18:2 trans-7,cis-9 and cis-9,trans-11) in plasma, and in subcutaneous fat this also included non-CLA dienes. Concentrations of most α-linolenic acid biohydrogenation intermediates were greater when feeding flaxseed with hay. In conclusion, forage source altered plasma concentrations and rate of accumulation of ALA biohydrogenation products in subcutaneous fat from beef cows fed flaxseed. Factors responsible for this response are yet to be defined, but may include forage-mediated changes in ruminal biohydrogenation of ALA, as well as alterations in fatty acid metabolism and deposition.     

Release of ferulic acid from oat hulls by Aspergillus ferulic acid esterase and trichoderma xylanase

Oat hulls, an agricultural byproduct, contain a relatively high amount of ferulic acid (FA; 4-hydroxy-3-methoxycinnamic acid), which is believed to be inhibitory to oat hull biodegradability by rumen microorganisms. In this paper, Aspergillus ferulic acid esterase (FAE) was investigated for its ability to release FA from oat hulls. The objectives were to determine the effects of particle size of oat hulls (ground to pass through 1 mm and 250 microm screens and a 100 microm sieve) on release of FA by FAE both in the presence and in the absence of Trichoderma xylanase. The results show that the release of FA by FAE was dependent upon the particle size of oat hulls (< or = 250 microm). In the absence of Trichoderma xylanase, little FA was released by FAE. In the presence of Trichoderma xylanase, there was a significant release of FA by FAE, indicating a synergistic interaction between FAE and Trichoderma xylanase on release of FA from oat hulls. These results indicate that FAE is able to break the ester linkage between FA and the attached sugar, releasing FA from oat hulls. This may leave the remainder of the polysaccharides open for further hydrolytic attack by rumen microorganisms. It is likely that removing FA from oat hulls could improve rumen biodegradability, thus improving the nutritional value of oat hulls.     

Surgical correction of rectovaginal fistula in mares and subsequent fertility

Objective To evaluate the fertility of mares bred at various intervals relative to surgical management of rectovaginal fistula (RVF). Materials and Methods Surgical repair of RVF was performed in 28 mares at variable times relative to foaling (30 days to 24 months) and also relative to rebreeding (same cycle or delayed). Postoperative fertility was then evaluated. Results Two mares were already pregnant at the time of surgery and 20 of 23 mares (87%) that were bred immediately prior to or following surgery conceived from their first service. When mares were bred in the same cycle as surgery, the next cycle following surgery or in the following breeding season after surgery the pregnancy rate was 5/5, 5/6 and 10/12, respectively, and the foaling rates were 4/5, 4/6 and 7/12. The two mares already pregnant at the time of surgery foaled successfully. Conclusions Excellent fertility can be achieved following surgical repair of RVF and our results suggest that delaying breeding until the following breeding season is not necessary. In addition, breeding in the same cycle as the surgical repair is a previously unreported technique that should be considered to maintain normal fertility and a yearly foaling interval.     

Enzymic release of reducing sugars from oat hulls by cellulase,as influenced by Aspergillus ferulic acid esterase and trichoderma xylanase

Hydroxycinnamic acids, mainly ferulic and p-coumaric acids, are believed to be inhibitory to ruminal biodegradability of complex cell wall materials such as oat hulls. Previous studies have shown that a novel enzyme, Aspergillus ferulic acid esterase, and Trichoderma xylanase act synergistically to break the ester linkage between ferulic acid and the attached sugar of feruloyl polysaccharides, releasing ferulic acid from oat hulls. In this paper, we examined the enzymic release of reducing sugars from oat hulls by the actions of individual enzymes (Aspergillus ferulic acid esterase at 13 mU, 6.4 U, and 4678.4 U/assay; cellulase at 20 levels, ranging from 7.8 mU to 2772.7 U/assay; Trichoderma xylanase at 20 levels, ranging from 7.8 mU to 4096 U/assay) and by the combined action of cellulase at six levels (62.5 mU, 2 U, 16 U, 128 U, 1024 U, and 2772.7 U/assay), Aspergillus ferulic acid esterase at 13 mU/assay, and Trichoderma xylanase at two levels (1 U and 256 U/assay). The amount of total acid-extractable reducing sugars in the oat hulls used in this study was 793.8 +/- 8.0 microg/mg. The results show that after a 24-h incubation with Aspergillus ferulic acid esterase alone, no reducing sugars were observed to be released from oat hulls. With cellulase as the sole enzyme, as the concentration increased from 7.8 mU to 2772.7 U/assay, the release of reducing sugars increased (P < 0.01) from 0 to 39% of the total present, with the highest release at 512 U/assay. With Trichoderma xylanase alone, as the concentration increased from 7.8 mU to 4096 U/assay, the release of reducing sugars increased (P < 0.01) from 4.9 to 33%, with the highest release at 2048 U/assay. When incubated together with Trichoderma xylanase (1 U or 256 U/assay) and Aspergillus ferulic acid esterase (13 mU/assay), cellulase at all six levels (62.5 mU, 2 U, 16 U, 128 U, 1024 U and 2772.7 U/assay) significantly increased the release of reducing sugars (P < 0.01) from 8 to 69%. These results indicate that the synergistic interaction between Aspergillus ferulic acid esterase and Trichoderma xylanase on the release of ferulic acid from feruloyl polysaccharides of oat hulls makes the remainder of the polysaccharides open for further hydrolytic attack and facilitates the accessibility of the main chain of polysaccharides to cellulase. This action extends the cell wall hydrolysis, thus releasing a higher yield of reducing sugars. Such enzymic pretreatment of oat hulls may provide a unique advantage to rumen microorganisms for the biodegradation of the complex cell walls of byproduct feeds such as oat hulls.     

Sorption and mobility of 14C-labeled imazaquin and metolachlor in four soils as influenced by soil properties

Aqueous batch-type sorption-desorption studies and soil column leaching studies were conducted to determine the influence of soil properties, soil and suspension pH, and ionic concentration on the retention, release, and mobility of [14C]imazaquin in Cape Fear sandy clay loam, Norfolk loamy sand, Rion sandy loam, and Webster clay loam. Sorption of [14C]metolachlor was also included as a reference standard. L-type sorption isotherms, which were well described by the Freundlich equation, were observed for both compounds on all soils. Metolachlor was sorbed to soils in amounts 2-8 times that of imazaquin, and retention of both herbicides was related to soil organic matter (OM) and humic matter (HM) contents and to herbicide concentration. Metolachlor retention was also related to soil clay content. Imazaquin sorption to one soil (Cape Fear) increased as concentration increased and as suspension pH decreased, with maximum sorption occurring in the vicinity of pK(a1) = (1.8). At pH levels below pK(a1) imazaquin sorption decreased as hydronium ions (H3O+) increased and competed for sites. NaCl was more effective than water in desorption of imazaquin at pH levels near the pK(a1). Mechanisms of bonding are postulated and discussed. The mobility of imazaquin through soil columns was in the order Rion > or = Norfolk > Cape Fear > or = Webster, whereas for metolachlor it was Rion > or = Norfolk > Webster > or = Cape Fear. Imazaquin was from 2 to 10 times as mobile as metolachlor.     

Creating community‐based indicators of gender equity: A methodology

It appears that an almost unquestioned development pathway for achieving gender equity and women's empowerment has taken centre stage in mainstream development. This pathway focuses on economic outcomes that are assumed to be achieved by increasing women's access to material things, including cash income, loans, physical assets, and to markets. Gender equity indicators, which measure progress towards these outcomes, cannot escape reinforcing them. We argue that far from being neutral, indicators are embedded in political and ideological agendas that serve as guides to the appropriate conduct of those whose performance or behaviour is being measured. Drawing on participatory feminist, diverse economies and strengths based approaches, we outline a research methodology for developing community‐based indicators that recognises women's and men's participation and relationships in all spheres of life, including the ‘non‐economic’. If indicators are grounded in local meanings and realities, we propose that community members can use them to identify aspirational goals for gender equity, and measure progress towards these goals.