Fecal Chemistry Research Articles

Detection of winter tick, Dermacentor albipictus, infestations using near infrared reflectance spectroscopy of bovine feces

The objective of this study was to determine whether artificial infestations of D. albipictus could be detected in cattle using near infrared reflectance spectroscopy of bovine feces (fNIRS) and if detection capability was sensitive to size of tick infestation and phase of on-host stage-specific tick development. Fecal samples were collected daily from six non-infested then later tick-infested Bos taurus yearling heifers who each served as their own control. Cattle with D. albipictus infestations arising from as few as 1000 larvae were identified by fecal chemistry changes using fNIRS technology. In two separate trials, three animal pairs were infested with one of three treatment levels (low: ∼ 1000, medium: ∼ 4000, and high: ∼ 8000) of D. albipictus larvae in a repeated measures experimental design. Trial 1 consisted of tick naïve cattle while Trial 2 consisted of prior tick exposed cattle. Date of drop and daily sum of engorged female ticks were tabulated to characterize each infestation. Cluster, common factor, principal component and MANOVA analyses were used to define and assess fecal spectra changes associated with experimental stages of infestation. Cluster analyses found significant differences in fecal samples for heifer pairs in each treatment level group (low, medium, and high) in Trial 1 and then in Trial 2 from two pre-infestation control periods (outside and inside), three stages of tick development (larval feeding, nymphal feeding, adult feeding), and post-tick recovery periods. Five shifts in fecal chemistry of non-infested and tick-infested periods were identified by six clusters of NIRS fecal spectra measured between 576 and 1126 nm. The PCA’s resulted in 97.56% and 97.77% for Trials 1 and 2 respectively of the total variation in the 1050 frequencies being explained by the first three principal components (P1, P2, P3). Results from the MANOVA and the Wilk’s Lambda test for both trials showed highly significant evidence (p-values < 0.0001) of a difference in the means of the three principal components across the six Stages. There was significant evidence in Trial 1 (p-values = 0.0067) and Trial 2 (p-values < 0.0001) of a difference between the means of the three principal components across the three levels of tick infestation. These significant pair-wise comparisons reflect developmental phases of tick attachment and blood-feeding that define periods of increasing, peak and declining stress identified in five fecal chemistry shifts defined by six fecal spectral clusters.

Bovine fecal chemistry changes with progression of Southern Cattle Tick, Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) infestation

Surveillance for cattle fever ticks is an essential activity in the U.S. Cattle Fever Tick Eradication Program which prevents reestablishment of these tick vectors of the pathogens causing bovine babesiosis. Other methods of detecting tick infested cattle could augment current physical inspection of restrained cattle by program inspectors. The objective of this study was to determine whether a single infestation of ∼5000 Rhipicephalus (Boophilus) microplus larvae induced changes in fecal chemistry that were detectable using near-infrared reflectance spectroscopy (NIRS). Fecal samples were collected daily from 6 tick-infested and 6 non-infested Bos taurus yearling heifers. Each infested animal received ticks from one of 6 different strains of laboratory colonies of R. microplus. Date of drop and daily sum of engorged female ticks were tabulated to characterize each infestation. Cluster, common factor, principal component and MANOVA analyses were used to define and assess fecal spectra changes associated with experimental stages of infestation. Cluster analyses found no significant differences in fecal samples from each of the 6 infested heifers. Two shifts in fecal chemistry of infested animals were identified by three clusters of NIRS fecal spectra. The first cluster was comprised of samples from pre-infestation to 9 days after infestation, a period inclusive of larval tick attachment and feeding. The second cluster was comprised of samples from day 10–22 corresponding to the period of nymphal feeding, adult feeding, and early drop of engorged females. A third cluster was comprised of samples from days 23−46 corresponding to the period of engorged female drop and declining tick numbers. A Tukey-Kramer multiple comparison procedure identified significant differences in fecal spectra between five experimental stages of R. microplus infestation for principal component 1 including pre-infestation to nymphal feeding, pre-infestation to adult feeding, larval feeding to adult feeding, nymphal feeding to adult feeding and nymphal feeding to engorged female drop; for principal component 2 including pre-infestation to nymphal feeding, pre-infestation to adult feeding, and pre-infestation to engorged female drop; and for principal component 3 including pre-infestation to drop, and adult feeding to drop. These significant pair-wise comparisons reflect developmental phases of tick attachment and blood-feeding that define periods of increasing, peak and declining stress identified in two fecal chemistry shifts defined by three fecal spectra clusters. Among non-infested animals, two shifts in fecal chemistry were also detected by three fecal-spectra clusters that occurred in synchrony with those of their tick-infested counterparts. There were no significant differences in principal components or MANOVA analyses between infested and non-infested animals and the pattern of significant pair-wise Tukey-Kramer multiple comparisons for non-infested animals were similar to those of infested animals. This unintended confounding effect is attributed to the manner in which all 12 animals were preconditioned as a group, then isolated in randomly assigned blind stalls in a common barn facility for the study, creating the basis for physiological stress resonance among non-infested animals.

Estimating the Suitability for the Reintroduced Arabian Oryx (Oryx leucoryx, Pallas 1777) of Two Desert Environments by NIRS-Aided Fecal Chemistry

The re-introduction paradigm is that Arabian Oryx (Oryx leucoryx) herds adjust the size of their home ranges depending on the availability of vegetation, which is directly related to rainfall. In Israel, Arabian oryx were released in two hyper-arid sites: the Arava Valley and in the Paran wilderness, belonging to the Sudanese and the Saharo–Arabian biogeographic zones, respectively. While post-release survival was similar in both, reproductive success in the Paran wilderness reintroduction site was extremely low, resulting in an acute decline of the reintroduced population over time. The hypothesis that impaired nutrition might be associated with this finding was assessed with near-infrared spectroscopy (NIRS)-aided chemistry of monthly sampled fecal pellets, used as remote sensing evidence of ingested diets, throughout a year. Fecal nitrogen (FN), used as an estimate of nutritional status, was consistently higher in the Arava. Grass was never the sole or even a major dietary component. The dietary contribution of tannin-rich browse was high and steady all year-round in the Arava and increased steadily in Paran from winter to summer, corresponding to the period of availability of Acacia raddiana pods in both regions. The oryx in Paran had a home-range that was ten-fold, compared to the Arava, suggesting less feed availability. Acacia browsing may mitigate the effects of temporal variance in primary production. Under such conditions, oryx should be preferably released in areas that support significant acacia stands.

126 Detection of fecal chemistry changes in cattle infested with the Southern Cattle Tick, Rhipicephalus (Boophilus) microplus

Abstract Bovine babesiosis, a highly fatal tick-borne disease of cattle, was eliminated from the United States in the last century through tick eradication programs against 2 species of cattle fever ticks. The threat to the U.S. cattle industry continues through tick introductions from Mexico. The standard method of detecting Cattle Fever Ticks [Rhipicephalus (B.) annulatus and R. (B.) microplus] in the state-federal tick eradication program is physical examination of restrained cattle to find attached ticks. New methods of detecting tick-infested cattle could improve reliability and reduce animal stress. The objective of this study was to determine whether changes in fecal chemistry induced by tick infestation was detectable using near-infrared reflectance spectroscopy (NIRS). Fecal samples were collected daily from 6 stanchioned Bos taurus yearling heifers (initial mean weight 163.3 kg +/- 4.7 kg) at the USDA Cattle Fever Tick Research Laboratory, Edinburg, TX, before, during, and after an infestation of 5000 R. (B.) microplus larvae. Cluster analyses were conducted using GRAMS IQ for NIR spectra in the 576–1126 nm range to test for fecal chemistry changes different from pre-infestation condition, and coincident with the biological phases of the tick infestation. The first three factors of spectral variation accounted for 87.87% of spectral variation among all samples. Factors 1, 2, and 3 had F-Ratios for the Reduced Eigenvalues of 941.59, 387.44, and 221.79, respectively. Three-dimensional analysis for these 3 factors shows shifts in sample clusters away from pre-infestation and coincident with progressive tick blood-feeding and post-infestation recovery. We conclude that fecal NIRS may provide a tool for detection of tick-infested cattle; however, further testing is needed to determine the sensitivity of detection on cattle with varying levels of tick burden, and a protocol developed and evaluated for fecal sampling under field conditions

Near Infrared Spectroscopy and Fecal Chemistry as Predictors of the Diet Composition of White-Tailed Deer

Overbrowsing by white-tailed deer (Odocoileus virginianus Zimmermann) on Anticosti Island (Canada) created a need to develop efficient methods for estimating their foraging patterns. We tested the ability of near infrared (NIR) spectra of feces and of fecal chemical properties to predict diet composition of different individuals. We first used a principal component-based discriminant analysis to sort the NIR spectra of fecal samples (n = 102) obtained from two groups of captive deer that had been fed two different diets. The diets differed only in their relative abundance of balsam fir (Abies balsamea [L.] P.Mill.) and white spruce (Picea glauca [Moench] Voss.) foliage. The calibrated model allowed us to assign 28 of 30 validation fecal samples (93.3 %) to the correct diet. In a second study, we attempted to estimate the proportion of coniferous, deciduous, herbaceous, and lichenous forages in diets of free-ranging white-tailed deer, as determined by fecal microhistology. Both NIR spectra and chemical properties of feces were used as predictors of diet composition. NIR spectra were analyzed using partial least-squares regression (PLSR), whereas fecal chemical properties were analyzed using mixed-linear regressions (MLRs). The PLSR models were robust (R2 = 0.89; ratio of prediction to deviation = 3.2) for predicting the amount of coniferous fragments, but not for predicting the relative amounts of balsam fir, white spruce, and deciduous and lichenous fragments within feces. MLR models revealed a positive relationship (47% variance explained) between acid detergent lignin (ADL) and coniferous fragments within feces. ADL and cellulose explained 24% of variance in deciduous fecal fragments, whereas ADL alone explained 22% of variance in balsam fir fecal fragments. These results suggest that NIR spectroscopy and fecal chemical properties have several applications on Anticosti Island, such as measuring the degree of variation in diets within a given home range or determining dietary conifer intake during winter.

Climate change and cattle nutritional stress

AbstractOwing to the complex interactions among climate, plants, cattle grazing, and land management practices, the impacts of climate change on cattle have been hard to predict. Predicting future grassland ecosystem functioning relies on understanding how changes in climate alter the quantity of forage produced, but also forage quality. Plant protein, which is a function of plant nitrogen concentrations, and digestible energy limit the performance of herbivores when in short supply; moreover, deficiencies can be expensive to mitigate. To better understand how changes in temperature and precipitation would affect forage protein and energy availability, we analyzed over 21 000 measurements of cattle fecal chemistry acquired over 14 years in the continental US. Our analysis of patterns in forage quality among ecologically defined regions revealed that increasing temperature and declining precipitation decreased dietary crude protein and digestible organic matter for regions with continental climates. Within regions, quality also declined with increased temperature; however, the effects of precipitation were mixed. Any future increases in precipitation would be unlikely to compensate for the declines in forage quality that accompany projected temperature increases. As a result, cattle are likely to experience greater nutritional stress in the future. If these geographic patterns hold as a proxy for future climates, agriculture will require increased supplemental feeds or the consequence will be a decrease in livestock growth.

Evaluation of the Effect of Four Fibers on Laxation, Gastrointestinal Tolerance and Serum Markers in Healthy Humans

Background: Average dietary fiber intake in the United States is roughly half of the recommended amount. As new dietary fiber products are introduced to increase fiber intake, it is critical to evaluate the physiological effects of such fibers. Aims: This study examined the effect of 4 fibers derived from maize or tapioca on fecal chemistry, gastrointestinal (GI) symptoms and serum markers of chronic disease. Methods: Twenty healthy subjects completed the single-blind crossover study in which 12 g/day of fiber (pullulan, Promitor™ Resistant Starch, soluble fiber dextrin or Promitor Soluble Corn Fiber) or placebo (maltodextrin) were consumed for 14 days followed by a 21-day washout. GI symptom surveys were completed (days 3 and 14), stools were collected (days 11–14), diet was recorded (days 12–14) and fasting blood samples were obtained (day 15). Results: The 4 test fibers were well tolerated, with mild to moderate GI symptoms. Total short-chain fatty acid (SCFA) concentrations did not differ among the treatments. Fecal pH and individual SCFAs were affected by some treatments. Stool weight and serum markers of chronic disease did not change with these treatments. Conclusion: Increasing fiber intake by 12 g/day was well tolerated and may have a positive impact on colon health due to fermentation.

A human, double-blind, placebo-controlled, crossover trial of prebiotic, probiotic, and synbiotic supplementation: effects on luminal, inflammatory, epigenetic, and epithelial biomarkers of colorectal cancer

BackgroundDiet is an important factor in colorectal carcinogenesis; thus, dietary supplements may have a role in colorectal cancer prevention. ObjectiveThe objective was to establish the relative luminal, epithelial, and epigenetic consequences of prebiotic, probiotic, and synbiotic dietary supplementation in humans. DesignThis was a randomized, double-blind, placebo-controlled, 4-wk crossover trial of resistant starch and Bifidobacterium lactis, either alone or as a combined synbiotic preparation, in 20 human volunteers. Rectal biopsy, feces, and serum samples were collected. The rectal mucosal endpoints were DNA methylation at 16 CpG island loci and LINE-1, epithelial proliferation (Ki67 immunohistochemistry), and crypt cellularity. The fecal endpoints were short-chain fatty acid concentrations, pH, ammonia, and microbiological profiles (by denaturing gradient gel electrophoresis and sequencing). Serum endpoints were a panel of cytokines and high-sensitivity C-reactive protein. ResultsSeventeen subjects completed the entire study. The synbiotic intervention fostered a significantly different fecal stream bacterial community than did either the prebiotic (P = 0.032) or the probiotic (P = 0.001) intervention alone, in part because of a greater proportion of patients harboring fecal Lachnospiraceae spp. These changes developed in the absence of any significant differences in fecal chemistry. There were no differences in epithelial kinetics. ConclusionsThis synbiotic supplementation with B. lactis and resistant starch, in the doses used, induced unique changes in fecal microflora but did not significantly alter any other fecal, serum, or epithelial variables. This trial was registered in the Australian New Zealand Clinical Trials Registry at www.anzctr.org.au as ACTRN012606000115538.

Characterization of fecal bacterial populations in canines: effects of age, breed and dietary fiber.

The effects of age, breed, and diet on fecal chemistry, enzyme activity, and bacterial populations of dogs were studied. Eighteen dogs from two age groups (young: 2.5 +/- 0.5 years, old: 10.9 +/-0.7 years) and three different breeds (German shepherds, miniature schnauzers, and English setters) were rotated through a Latin Square design such that every dog was fed each of the diets. The test diets included a low-fiber (control) diet and a 10% fiber diet which contained 5% soybean hulls and 5% beet pulp. Inclusion of 10% fiber in the diet decreased the fecal concentration of ammonia, sulfide, and indole. Fiber inclusion significantly increased acetic, propionic, and butyric acid concentrations, while fecal pH decreased by 0.4 units. Fresh fecal samples were plated on selected aerobic and anaerobic culture media and DNA extracted for denaturing gradient gel electrophoresis (DGGE) analysis of PCR-amplified 16S ribosomal DNA fragments. Plate counts showed significant effects of breed (p < or = 0.05) and age (p < or = 0.01) on selected aerobic and anaerobic bacterial counts, while no significant effect of diet was found. Analysis of PCR-DGGE banding patterns showed there was a tendency for individual dogs to cluster together according to age (young or old dogs) and also for size (large or small dogs). However, the outstanding conclusion obtained from the DGGE analysis of fecal bacterial profiles was that individual dogs had their own characteristic banding pattern which was unique and stable. The relative stability and individuality of the patterns indicates that each individual harbored a characteristic fecal bacterial community which was independent of diet.

Effects of Dietary Arabinogalactan on Gastrointestinal and Blood Parameters in Healthy Human Subjects

Objectives: Arabinogalactan (AG) is a non-digestible soluble dietary fiber that resists hydrolytic enzyme action and enters the large bowel intact where it is fermented by resident microflora. To determine whether AG has similar physiological properties to other soluble dietary fibers, we examined the effect of 15 and 30 g per day of a commercially available AG from Western Larch on several gastrointestinal and blood parameters.Methods: Gastrointestinal parameters included fecal microflora, fecal enzyme activity, fecal short-chain fatty acids, fecal pH, fecal weight, transit time and bowel frequency. Blood parameters included total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, Apo-A1, Apo-B, glucose and insulin. The study consisted of two three-week diet treatments with no washout period. Participants (n=20, 11 males, 9 females) consumed their usual diet in addition to 15 or 30 g AG in a beverage sweetened with aspartame as compared to their usual diet with the control beverage.Results: Significant increases in total fecal anaerobes were observed with 15 g (p=0.01) and 30 g AG (p=0.001). A significant increase (p=0.02) in Lactobacillus spp. was observed when subjects consumed AG for a total of six weeks regardless of dose. There were no significant changes in other microflora, fecal enzyme activity, transit time, frequency, fecal weight, fecal pH and short-chain fatty acids. Fecal ammonia levels decreased with 15 g (p=0.001) and 30 g (p=0.002) AG. No significant changes in blood lipids or blood insulin were observed.Conclusions: These data suggest that dietary AG is easily incorporated into the diet, well tolerated in subjects and has some positive effects on fecal chemistry.

The Importance of Routine Sigmoidoscopic Examination in Asymptomatic Patients

The Importance of Routine Sigmoidoscopic Examination in Asymptomatic Patients