Fecal Near-Infrared Reflectance Spectroscopy to Predict Leymus chinensis of Diets From Penned Sheep in North China

Selective foraging among free-ranging herbivores can make measuring botanical composition of diets challenging. Using near-infrared reflectance spectroscopy (NIRS) on feces for predicting botanical components of individual animal diets is a novel method for studying diet selection. This study was conducted to determine the ability of fecal NIRS to predict the percentage of consumption of Leymus chinensis (Trin.) Tzvel., a dominant species in north China, by sheep (Ovis aries L.). The calibration data set consisted of 47 diets of known L. chinensis composition, paired with corresponding fecal spectra. These pairs were generated in a trial using restricted feeding. Validation pairs (n = 9) were collected in a similar trial that used ad libitum feeding. Derived coefficients of determination (R²) and standard error of calibration were 0.99% and 2.2% for partial least squares (PLS) regression and 0.89% and 7.3% for stepwise regression, respectively. Derived coefficients of determination (r²) and standard error of prediction were 0.78% and 4.8% for PLS regression and 0.90% and 3.2% for stepwise regression, respectively. PLS regression resulted in better calibration than stepwise regression, but when the calibration data set was small, stepwise regression improved the precision and accuracy of predictions compared with the PLS regression. Results of the present study show that a fecal NIRS equation developed from a restricted feeding trial could be used to predict the percentage of L. chinensis in fecal materials collected from voluntary feeding trials.     

Comparison of fecal crude protein and fecal near-infrared reflectance spectroscopy to predict digestibility of fresh grass consumed by sheep

Organic matter digestibility (OMD), an essential criterion for the evaluation of the nutrition of ruminants, cannot be measured easily at pasture. Therefore, the objective of this study was to test and compare 2 methods of OMD prediction based on the fecal CP content (CPf) or near infrared reflectance spectroscopy (NIRS) applied to feces. First, published equations derived from fecal N (Eq. 1(CP), n = 40) and from fecal NIRS (Eq. 1(NIRS), n = 84) were used to predict OMD of an independent validation data set from which in vivo OMD, ranging from 58 to 74%, was measured for 4 regrowth stages of Digitaria decumbens. Second, to establish equations usable in grazing situations and to improve the efficiency of the predictions, new equations were calculated from a large data set (n = 174) using CPf (Eq. 2(CP)) or fecal NIRS (Eq. 2(NIRS)). By applying the CPf method, Eq. 2(CPf) (OMD, % = 88.4 - 263.9/CPf, % of OM; residual SD = 2.92, r(2) = 0.63) showed similar statistical parameters (P < 0.01) when compared with Eq. 1(CP) (OMD, % = 86.6 - 266.2/CPf, % of OM; residual SD = 2.95, r(2) = 0.79). When using fecal NIRS, Eq. 2(NIRS) showed decreased SE of calibration (SEC = 1.48) and of cross-validation (SECV = 1.75) and greater coefficient of determination of cross-validation (R(2)(CV) = 0.85) than the previously published Eq. 1(NIRS) (SEC = 1.78, SECV = 2.02, R(2)(CV) = 0.77). The validation of the 4 equations on the validation data set was satisfactory overall with an average difference between the predicted and the observed OMD ranging from 0.98 to 2.79 percentage units. The Eq. 2(NIRS) was nevertheless the most precise with a decreased residual SD of 2.53 and also the most accurate, because the SD of the average difference between predicted and observed OMD was the lowest. Therefore, fecal NIRS provided the most reliable estimates of OMD and is thus a useful tool to predict OMD at pasture. However, an adequate number of reference data are required to establish good calibration. Indeed, better calibration statistics were obtained by increasing the data set from 84 (Eq. 1(NIRS)) to 174 (Eq. 2(NIRS)). In contrast, using fecal N on a set of 84 or 174 points did not improve the prediction. Both methods are useful for predicting OMD at pasture in certain circumstances, using fecal NIRS when a large data set (n = 84 and n = 174) is available and fecal CP with smaller data sets (n = 40).     

近红外光谱分析技术在黑麦草粉粗蛋白测定中的应用

选取河北省吴桥试区不同品种、不同熟期、不同地块的黑麦草样品65份 ,用凯氏定N法进行了常规粗蛋白含量的测定。从中选出30个粗蛋白含量不同的样品作为近红外漫反射技术(NIR技术)测定的定标样品集。结果指出 :用NIR法得到的预测值与用凯氏定N法得到的测定值间的复相关系数达到R2=0.99 ,定标标样的标准误均方RMSEC=0.34 % ;用21个样品作检测样品集 ,凯氏定N法得到的测定值与NIR预测值间的复相关系数为R2=0.98 ,检测集样品预测标准误均方RMSEP=0.42 %。这一结果表明NIR作为一种黑麦草粉粗蛋白快速分析的技术是可行的     

The application of moxidectin formulations for control of the cattle tick (Boophilus microplus) under Queensland field conditions

Objective To assess the control of the cattle tick (Boophilus microplus) and the performance of commercial cattle treated with the macrocylic lactone endectocide, moxidectin, formulated either as an injection or as a pour-on. Design Groups of 10–12 tick infested cattle were treated with moxidectin injection, moxidectin pour-on or remained untreated (28-day trials) or were treated with deltamethrinethion as a dip (140-day trials). The cattle were exposed to natural tick challenge under field conditions. Procedure Tick numbers on trial cattle were recorded in each trial before the initial treatment and in the 28-day trials at 7, 14, 21 and 28 days or in the 140-day trials, at 28-day intervals before each of the treatments and at the final inspection. Body weights of the cattle were also recorded prior to the initial treatment and at the termination of each trial. Cattle were observed on the day of each treatment and at each inspection for evidence of any reactions to treatment. Results 28-day trials: Significant reductions in tick counts were recorded in both treatment groups when compared with cattle in the untreated group. Weight advantage was recorded in the moxidectin treated groups. 140-day trials: All three treatments resulted in zero or low tick counts at each inspection with the exception of the pour-on treatment at week 8 in one trial and week 9 in the other trial. Additional weight gain was recorded for both the moxidectin treated groups, relative to the deltamethrin-ethion dip groups, but was significant only for the pour-on groups. There was no evidence of any local or systemic adverse reaction in any treated cattle in any trial. Conclusion Good to excellent control of the cattle tick (Boophilus microplus) was demonstrated with the moxidectin formulations in all trials, the injection being particularly effective. An improved performance was recorded in all trials in cattle treated with both moxidectin formulations when compared with the untreated cattle and with cattle treated with the deltamethrin-ethion dip. There was no evidence of any local or systemic adverse reaction to treatment with either moxidectin formulation.     

Risk factors for tick attachment to smallholder dairy cattle in Tanzania

A cross-sectional study was conducted in Tanga and Iringa regions of Tanzania, and a longitudinal study in Tanga, to investigate tick-control methods and other factors influencing tick attachment to the cattle of smallholder dairy farms. Most farmers reported applying acaricides at intervals of 1-2 weeks, most used acaricides that require on-farm dilution and most farmers incorrectly diluted the acaricides. Rhipicephalus appendiculatus and Boophilus spp. ticks were those most-frequently encountered on the cattle, but few cattle carried ticks of any species (only 13 and 4.6% of tick counts of the cattle yielded adult R. appendiculatus and Boophilus spp., respectively). Animals were more likely to carry one or more adult Boophilus spp. ticks if they also carried one or more R. appendiculatus adults (OR=14.4, CI=9.2, 22.5). The use of pour-on acaricides was associated with lower odds that animals carried a R. appendiculatus tick (OR=0.29, CI=0.18, 0.49) but higher odds that they carried a Boophilus spp. tick (OR=2.48, CI=1.55, 3.97). Animals >4 months old and those with a recent history of grazing had higher odds of carrying either a R. appendiculatus (ORs=3.41 and 2.58, CIs=2.34, 4.98 and 1.80, 3.71), or a Boophilus spp. tick (ORs=5.70 and 2.18, CIs=2.34, 4.98 and 1.49. 3.25), but zero-grazing management did not prevent ticks attaching to cattle even when combined with high-frequency acaricide treatments. The odds that animals carried ticks varied amongst the agro-ecological zones (AEZs) and administrative districts where the farms were situated-but there was still considerable residual variation in tick infestation at the farm level.     

Internal parasites of Washington cattle.

The occurrence of internal parasites in Washinton cattle was estimated. During the survey period in 1972 and 1973, more than 3,700 fecal samples from 29 herds and 4 feedlots, and viscera from 55 cattle were examined. The percentage of fecal samples with parasite eggs or oocysts from herds was as follows: oocysts, 77%; "strongyline" eggs, 44%; Nematodirus eggs, 3%; Moniezia eggs, 3%; Fasciola eggs, 2%; Trichuris eggs, 2%; and Dictyocaulus larvae, 1%. The fecal samples from feedlots contained principally strongyline eggs which varied markedly in numbers among groups of cattle in the lots. The predominant parasite in viscera was Ostertagia spp, which was recovered from all of the cattle examined. Other parasites identified in the survey were found less frequently in these examinations. Cattle in dairy and beef operations utilizing irrigated pastures were particularly prone to Fasciola infections, and more strongyline eggs were observed there than in fecal samples from other management systems. Seasonal fluctuations in numbers of strongyline and Fasciola eggs were pronounced.     

Analysis of bovine udder, plate and viscera using near infrared reflectance spectroscopy

The objective of this study was to evaluate near infrared reflectance spectroscopy (NIRS) as an accurate and inexpensive alternative to conventional chemical analyses of nonconsumer bovine tissue. Udder, plate and visceral samples were collected from mature, Charolais-Angus and Hereford-Angus crossbred beef cows at slaughter, ground and analyzed for concentrations of lipid, protein and dry matter using standard AOAC chemical procedures. Samples were analyzed using NIRS. The collection of samples was randomly split into separate calibration and validation sets. Nine calibration equations representing each constituent and tissue combination were developed, using first- or second-order derivative mathematical transformations, and those calibration equations were validated. Correlation coefficients of calibration (R) and validation (r) ranged from .95 to .98 and from .87 to .97, respectively, for all analyses except plate dry matter (r = .77). Standard errors of calibration and prediction ranged from 1.89 to 5.81%. Results from this study are interpreted to indicate that bovine udder, plate and visceral tissue composition can be accurately, quickly and efficiently predicted using NIRS technology.     

A fecal near-infrared reflectance spectroscopy-aided methodology to determine goat dietary composition in a Mediterranean shrubland

An ecologically sound approach to the problem of brush encroachment onto Israeli rangeland might be their utilization by goats, but better knowledge of the feeding selectivity and ability of goats to thrive in encroached areas is required to devise viable production systems. Direct observation of bites could provide precise and accurate estimates of diet selection, but construction of a sufficiently large database would require too much time. The present study describes the first attempt to construct fecal near-infrared reflectance spectroscopy (NIRS) calibrations of the botanical and nutritional composition of the diet, and of the total intake of free-ranging goats, based on reference values determined with bite-count procedures. Calibration of fecal NIRS was based on 43 observations encompassing 3 goat breeds and 4 periods (spring, summer, and fall of 2004, and spring of 2005). Each observation comprised 242 min of continuous recording of the species and bite-type category selected by a single animal, on each of 2 consecutive days. The mass and chemical quality of each species and bite-type category-a total of more than 200,000 bites-were determined by using the simulated bite technique. Associated feces were scanned in the 1,100- to 2,500-nm range with a reflectance monochromator. Fecal NIRS calibrations had reasonable precision for dietary percentages of the 3 main botanical components: herbaceous vegetation (as one category; R(2) = 0.85), Phillyrea latifolia (R(2) = 0.89), and tannin-rich Pistacia lentiscus (R(2) = 0.77), with SE of cross-validation (SECV) of 7.8, 6.3, and 5.6% of DM, respectively. The R(2) values for dietary percentages of CP, NDF, IVDMD, and polyethylene glycol-binding tannins were 0.93, 0.88, 0.91, and 0.74, respectively, with SECV values of 0.9, 2.1, 4.3, and 0.9% of DM, respectively. The R(2) values for intakes of herbaceous vegetation, P. latifolia, and P. lentiscus were 0.80, 0.75, and 0.65, with SECV values of 71, 64, and 46 g of DM/d, respectively. The R(2) values for the daily nutrient intakes were below 0.60. Fecal NIRS data can be used to expand the databases of botanical and nutritional dietary composition when observed and resident animals graze simultaneously, but intakes should be calculated from fecal NIRS-predicted dietary DM composition and an independent evaluation of DMI.     

Observations on the efficacy of ivermectin in the control of cattle ticks in Zambia

The efficacy of multiple subcutaneous injections (200 micrograms/kg) of ivermectin in the control of naturally occurring tick infestations on traditionally managed Tonga-IIa (Sanga type) calves and yearlings was assessed in two field trials. In the first trial Boophilus decoloratus infestations were decreased following treatments at monthly intervals. In the second trial, with weekly and two weekly treatment intervals, infestations of Rhipicephalus appendiculatus were controlled less effectively than infestations of Amblyomma variegatum or Hyalomma truncatum. However, no engorging females of any of the tick species were found on treated animals. In treated cattle, significantly greater liveweight gain occurred than can be attributed to the control of tick infestations alone.     

The effect of East Coast fever immunisation and different acaricidal treatments on the productivity of beef cattle

A trial was performed on a farm in the Coast Province of Kenya to study the effects of East Coast fever immunisation and different acaricidal treatments on the productivity of immunised and unimmunised beef cattle. Eighty cattle were immunised against Theileria parva parva (Marikebuni) by the infection and treatment method and a similar group was left as an unimmunised control. Immunisation had no deleterious effect on the cattle. After immunisation, the immunised and control groups were each subdivided into four groups of 20 and each subgroup was managed under a different tick control regimen. The tick control regimen were, acaricidal spraying twice a week or once every three weeks, the application of acaricide-impregnated ear-tags, and no tick control. During a nine-month exposure period there were 18 cases of East Coast fever among the 80 immunised cattle, three which were severe and the others mild. Among the 80 unimmunised cattle there were 57 cases of East Coast fever, 50 of which were severe. The highest morbidity and mortality occurred in the groups under limited tick control or without tick control. Overall weight gain in the immunised cattle, irrespective of the tick control regimen, was better than the weight gain in the unimmunised groups. Within the immunised groups, the weight gain of the cattle sprayed twice weekly was comparable to the weight gain of the animals with acaricidal ear-tags and was significantly higher than the weight gains in the groups sprayed once every three weeks or with tick control. Preliminary cost/benefit analysis showed that it was uneconomical to maintain unimmunised cattle under limited or no tick control.(ABSTRACT TRUNCATED AT 250 WORDS)     

利用近红外光谱技术快速分析全株玉米青贮营养成分

研究旨在利用近红外光谱技术(near infrared reflectance spectroscopy,NIRS)建立全株玉米青贮6种营养成分的近红外预测模型,为生产实践中合理利用全株玉米青贮饲料资源提供理论依据.选取玉米青贮样品64份作为定标集,16份作为验证集.利用NIRS结合改良偏最小二乘法(modified ...     

Evaluation of concurrent shedding of bovine coronavirus via the respiratory tract and enteric route in feedlot cattle

OBJECTIVE: To assess the relationship between shedding of bovine coronavirus (BCV) via the respiratory tract and enteric routes and the association with weight gain in feedlot cattle. ANIMALS: 56 crossbred steers. PROCEDURES: Paired fecal samples and nasal swab specimens were obtained and were tested for BCV, using antigen-capture ELISA. Paired serum samples obtained were tested for antibodies to BCV, using antibody-detection ELISA. Information was collected on weight gain, clinical signs, and treatments for enteric and respiratory tract disease during the study period. RESULTS: Number of samples positive for bovine respiratory coronavirus (BRCV) or bovine enteric coro navirus (BECV) was 37/224 (17%) and 48/223 (22%), respectively. Some cattle (25/46, 45%) shed BECV and BRCV. There were 25/29 (86%) cattle positive for BECV that shed BRCV, but only 1/27 (4%) cattle negative to BECV shed BRCV. Twenty-seven of 48 (56%) paired nasal swab specimens and fecal samples positive for BECV were positive for BRCV. In contrast, only 10/175 (6%) paired nasal swab specimens and fecal samples negative for BECV were positive for BRCV. Only shedding of BECV was associated with significantly reduced weight gain. Seroconversion to BCV during the 21 days after arrival was detected in 95% of the cattle tested. CONCLUSIONS AND CLINICAL IMPLICATIONS: Feedlot cattle infected with BCV after transport shed BCV from the respiratory tract and in the feces. Fecal shedding of BCV was associated with significantly reduced weight gain. Developing appropriate control measures for BCV infections could help reduce the decreased weight gain observed among infected feedlot cattle.     

近红外反射光谱法(NIRS)分析奶牛精料补充料营养成分的研究

采用滤光片型8620近红外光谱技术(NIRS),结合主成分回归法,以105个不同的奶牛精料补充料样品建立了常规化学成分以及可消化总养分(TDN)含量的近红外定量分析校正模型。常规化学成分中,粗蛋白、粗脂肪、粗灰分、中性洗涤纤维、酸性洗涤纤维、酸性洗涤木质素和可消化总养分含量的校正模型决定系数R2分别为0.9132、0.9016、0.9220、0.9171、0.8928、0.7083和0.8346;研究发现除酸性洗涤木质素之外,其他成分含量的相对分析误差RPD(SD/SEP)均大于2.5,因此除酸性洗涤木质素之外,所建近红外预测模型对奶牛精料补充料常规营养成分以及TDN含量的快速测定具有重要的实际意义。     

Evaluation of bacteriologic culture of individual and pooled fecal samples for detection of Mycobacterium paratuberculosis in dairy cattle herds

OBJECTIVES: To determine the sensitivity of bacteriologic culture of pooled fecal samples in detecting Mycobacterium paratuberculosis, compared with bacteriologic culture of individual fecal samples in dairy cattle herds. STUDY DESIGN: Cross-sectional study. ANIMALS: 24 dairy cattle herds. PROCEDURE: Individual and pooled fecal samples were submitted for bacteriologic culture, and results were compared between these groups. RESULTS: Ninety-four and 88% of pooled fecal samples that contained feces from at least 1 animal with high (mean, > or = 50 colonies/tube) and moderate (mean, 10 to 49 colonies/tube) concentrations of M paratuberculosis, respectively, were identified by use of bacteriologic culture of pooled fecal samples. Prevalences of paratuberculosis determined by bacteriologic culture of pooled and individual fecal samples were highly correlated. CONCLUSIONS AND CLINICAL RELEVANCE: Bacteriologic culture of pooled fecal samples provided a valid and cost-effective method for the detection of M paratuberculosis infection in dairy cattle herds and can be used to estimate prevalence of infection within a herd.     

Comparison of sampling techniques for measuring the antimicrobial susceptibility of enteric Escherichia coli recovered from feedlot cattle

OBJECTIVE: To evaluate the effectiveness of various sampling techniques for determining antimicrobial resistance patterns in Escherichia coli isolated from feces of feedlot cattle. SAMPLE POPULATION: Fecal samples obtained from 328 beef steers and 6 feedlot pens in which the cattle resided. PROCEDURE: Single fecal samples were collected from the rectum of each steer and from floors of pens in which the cattle resided. Fecal material from each single sample was combined into pools containing 5 and 10 samples. Five isolates of Escherichia coli from each single sample and each pooled sample were tested for susceptibility to 17 antimicrobials. RESULTS: Patterns of antimicrobial resistance for fecal samples obtained from the rectum of cattle did not differ from fecal samples obtained from pen floors. Resistance patterns from pooled samples differed from patterns observed for single fecal samples. Little pen-to-pen variation in resistance prevalence was observed. Clustering of resistance phenotypes within samples was detected. CONCLUSIONS AND CLINICAL RELEVANCE: Studies of antimicrobial resistance in feedlot cattle can rely on fecal samples obtained from pen floors, thus avoiding the cost and effort of obtaining fecal samples from the rectum of cattle. Pooled fecal samples yielded resistance patterns that were consistent with those of single fecal samples when the prevalence of resistance to an antimicrobial was > 2%. Pooling may be a practical altemative when investigating patterns of resistance that are not rare. Apparent clustering of resistance phenotypes within samples argues for examining fewer isolates per fecal sample and more fecal samples per pen.     

Isolation of shiga-toxigenic Escherichia coli O157 from hide surfaces and the oral cavity of finished beef feedlot cattle

OBJECTIVE: To determine whether viable shiga-toxigenic Escherichia coli (STEC) O157 could be isolated from hide surface locations and the oral cavity of finished beef feedlot cattle. DESIGN: Within-animal prevalence distribution survey. ANIMALS: 139 finished cattle in 4 pens in a feedlot in Nebraska; prevalence of fecal STEC O157 shedding ranged from 20 to > 90%. PROCEDURE: Samples were collected from 7 sites from each animal: feces, oral cavity, and 5 hide surface locations (lumbar region, ventral aspect of the neck, ventral abdominal midline [ventrum], dorsal thoracic midline [back], and distal aspect of the left hind limb [hock]). RESULTS: Viable STEC O157 were isolated from the oral cavity or 1 or more hide surfaces of 130 cattle, including 50 fecal isolation-negative cattle. Site-specific prevalence of STEC O157 was 74.8% for oral cavity samples, 73.4% for back samples, 62.6% for neck samples, 60.4% for fecal samples, 54.0% for flank samples, 51.1% for ventrum samples, and 41.0% for hock samples. Only 5 cattle tested negative for STEC O157 at all 7 sites. Multiple correspondence and cluster analyses demonstrated that bacterial culture of feces, oral cavity samples, and back samples detected most cattle with STEC O157. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that viable STEC O157 may be isolated from the oral cavity, multiple hide surfaces, and feces of a high percentage of fed beef cattle and that bacterial culture of feces alone generally underestimates the percentage of fed beef cattle from which STEC O157 can be isolated.     

Results of a longitudinal study of the prevalence of Escherichia coli O157:H7 on cow-calf farms

OBJECTIVE: To describe the frequency and distribution of Escherichia coli O157:H7 in the feces and environment of cow-calf herds housed on pasture. SAMPLE POPULATION: Fecal and water samples for 10 cow-calf farms in Kansas. PROCEDURE: Fecal and water samples were obtained monthly throughout a 1-year period (3,152 fecal samples from 2,058 cattle; 199 water samples). Escherichia coli O157:H7 in fecal and water samples was determined, using microbial culture. RESULTS: Escherichia coli O157:H7 was detected in 40 of 3,152 (1.3%) fecal samples, and 40 of 2,058 (1.9%) cattle had > or = 1 sample with E coli. Fecal shedding by specific cattle was transient; none of the cattle had E coli in more than 1 sample. Significant differences were not detected in overall prevalence among farms. However, significant differences were detected in prevalence among sample collection dates. Escherichia coli O157:H7 was detected in 3 of 199 (1.5%) water samples. CONCLUSIONS AND CLINICAL RELEVANCE: Implementing control strategies for E coli O157:H7 at all levels of the cattle industry will decrease the risk of this organism entering the human food chain. Devising effective on-farm strategies to control E coli O157:H7 in cow-calf herds will require an understanding of the epidemiologic characteristics of this pathogen.     

Comparison of fecal samples collected per rectum and off the ground for estimation of environmental contamination attributable to beef cattle

OBJECTIVES: To determine whether sampling feces off the ground replicates prevalence estimates for specific pathogens obtained from fecal samples collected per rectum of adult cows, and to determine characteristics of feces on the ground (fecal pats) that are associated with subsequent identification of Campylobacter spp, Cryptosporidium parvum, and Giardia duodenalis. ANIMALS: A random sample of adult beef cattle from 25 herds located throughout California. PROCEDURE: 1,115 rectal and ground fecal samples were obtained. Samples were submitted for culture of Campylobacter spp and examined, using a direct fluorescent antibody assay, to detect C parvum oocysts and G duodenalis cysts. Characteristics of fecal pats, such as volume and consistency, were recorded. RESULTS: Prevalence of Campylobacter spp was 5.0% (20/401) for rectal fecal samples, which was significantly greater than prevalence determined for ground fecal samples (2/402; 0.5%). Most isolates were C jejuni subsp jejuni. Prevalence of C parvum was higher in rectal fecal samples (6/557; 1.1%) than in ground fecal samples (1/558; 0.2%), but this difference was not significant. Prevalence of G duodenalis did not differ for rectal (36/557; 6.5%) versus ground (26/558; 4.7%) fecal samples. CONCLUSIONS AND CLINICAL RELEVANCE: Evaluation of ground fecal samples may not accurately indicate the prevalence of Campylobacter spp or C parvum in cattle but may reflect prevalence of G duodenalis. Differences in prevalence estimates between the 2 methods suggest inactivation of pathogens in feces after cattle have defecated. Prevalence estimates generated by evaluation of ground fecal samples, however, may more accurately estimate environmental pathogen burden.