Hay Samples Research Articles

Changes in Total and Individual Proteins During Drying, Ensiling, and Ruminal Fermentation of Forages

Effects of wilting, drying, and ensiling on concentrations of proteins in alfalfa, crown vetch, perennial ryegrass, orchardgrass, and tall fescue were studied using SDS-PAGE. Seven to nine proteins were identified in the samples. Wilting forages for 24h on a laboratory bench had little effect on the relative amounts of proteins. Drying forage (on a laboratory bench) for 5 d resulted in a 25 to 30% loss in electrophoretically identified proteins. A 45-kDa protein was more susceptible to hydrolysis during drying than were most other proteins. After ensiling, <10% of the proteins in fresh alfalfa and fescue remained, but crown vetch silage contained 46% of its original proteins. A 54-kDa protein was extremely susceptible to hydrolysis during ensiling, but a 30-kDa protein was relatively resistant. Fresh forage and hay samples were incubated in vitro for 5h to determine degradation of proteins. In general, the 54-kDa protein was most susceptible, and the 30-kDa protein was least susceptible, to ruminal hydrolysis. Certain proteins in hay were more degradable than those in fresh forage. Among fresh forages, alfalfa and fescue contained the lowest concentrations of undegradable proteins. Differences among forage species were considerably less for hay samples.

The contamination of feed, fruits and vegetables with benzo(a)pyrene in Land Brandenburg

Benzo(a)pyren (BaP) was analysed in 218 samples of grass, hay, straw, grains, lettuce, curly kale and apples by means of thin-layer chromatography und analysing other polycyclic aromatic hydrocarbons (PAH) by capillary gas chromatography and mass-spectrometry. Despite the fact that normally BaP concentrations were relatively low, up to 13.5 micrograms BaP per kg hay (dry matter) and 19.3 micrograms BaP per kg lettuce (dry matter) could be detected at some places.

Near Infrared Reflectance Analysis with Single and Multiproduct Calibrations

Single‐product calibrations for near infrared (NIR) spectrophotometers are normally developed for each type of material to achieve a high level of prediction accuracy. Developing multiproduct calibrations with thousands of samples was not practical with personal computers until recently. Advancements in software now make it possible to include thousands of samples into multiproduct calibrations. This study was conducted to evaluate the accuracy of a multiproduct calibration consisting of forage samples. Large single‐product files of hay and fresh forage, haylage, and small grain silage spectra were available for this study. Every sixth sample from each file was reserved to test calibration accuracy. Single‐product calibrations were developed for each product and a multiproduct calibration was developed for all four products. There was very little difference between the accuracy of the multiproduct calibration containing all samples and the single‐product calibrations. In a second study, a multiproduct calibration developed from 756 haylage and small grain silage samples was used to predict the quality of 100 hay samples. The prediction error was found to be unsatisfactory, so 50, 100, 166, and 500 hay samples were added to the multiproduct calibration file to see if the hay prediction errors could be improved. The expanded multiproduct calibration was more accurate than a custom single‐product hay calibration when &lt;150 hay samples were available to develop a custom calibration or expand the multiproduct calibration. This suggests that if only a few samples are available, it may be more cost‐effective to expand a similar product library and recalibrate than to gather a large number of samples for a new calibration.

Using Near Infrared Reflectance Product Library Files to Improve Prediction Accuracy and Reduce Calibration Costs

Deriving a near infrared reflectance spectroscopy (MRS) calibration for new samples is an expensive and time‐consuming process. Often a laboratory analyzing samples with NIRS will receive new samples that are spectrally different from the library samples for that product. This study was performed to develop a method to: (i) identify previously analyzed samples in a product library that best match the spectra of the new samples for a local calibration, (ii) compare the prediction accuracy of the broad product library calibration to the local calibration, and (iii) if necessary, expand the local calibrations with a few of the new samples when greater prediction accuracy is required. Three groups of new samples were obtained for the study. They were 68 hay samples, 106 grass samples, and 110 whole‐plant corn (Zea mays L.) samples. Every third sample was reserved for validation. A product library file of 2176 hay, haylage, and fresh forage spectra supplied the product calibration and similar spectra for the hay and grass samples, and a corn silage product library file of 309 spectra supplied the product calibration and similar spectra for the whole‐plant corn samples. The spectra in the library most similar to the new samples were identified and selected with a new program, MATCH. Local calibrations were developed from these selected samples. Calibration accuracy was tested with the new samples reserved for validation using equations developed from the product library. In 7 of the 12 comparisons, the local calibrations were more accurate than the broad‐product library calibrations, but only two of these calibrations were acceptable. By expanding the local calibrations with 10 samples of each new group and recalibrating, accuracy of the expanded calibrations was similar to the accuracy of custom calibrations derived from the new samples not reserved for validation. Only 30 samples out of 284 needed new reference values to obtain acceptable prediction accuracy. This would have resulted in a cost reduction of 89% in reference value analysis. Guidelines for using this procedure are presented.

Bacterial adhesion to fibre during in vitro incubations under varying osmotic pressure

The effect of increased osmolarity on bacterial adhesion was studied in samples of natural meadow hay and cellulose previously submitted to in vitro digestion. The samples were collected for transmission electron microscopy after undergoing an in vitro digestion process in which the inoculum osmolarity was increased from 240 mmol (control) to 422 ± 30 mmol by adding sodium acetate, bicarbonate and chloride. Transmission electron microscopy showed generalized microbial adhesion of the bacteria to the cell wall and cellulose for all the situations studied. The presence of glycocalyx fibers and wide zones of erosion were evident. No synergistic or depressive effects of the sodium salts were observed. Since some evidence of the difficulty of bacterial attack on well packed structures was provided, this ultrastructural study seems to favour the hypothesis of low cellulose digestibility as a result of the structural arrangement of this polymer.

Comparison of A Qualitative Field Test Versus Laboratory Analysis for Nitrate Concentration in Hybrid Sudangrass Hays

A qualitative field test using .5% diphenylamine in concentrated sulfuric acid was compared to routine laboratory quantification of the nitrate (NO3) concentration in 1,064 hybrid sudangrass hay samples. A visual scoring system was used to define the color changes of a single drop of the diphenylamine solution on the inner tissues of stems of the forage. Scores were 1=clear, 2=yellow, 3=brown, 4=light-blue streaks, 5=solid blue, and 6=black. Diphenylamine has been reported to turn blue when it contacts nitrate in plant tissues. Color scores were assigned at 10 and 20s after the solution contacted the plant tissue. Two stems from each sample were tested with diphenylamine. After laboratory analysis, forage samples were grouped by assayed nitrate content into five classes: 0 to 2,500ppm, 2,500 to 6,000ppm, 6,000 to 10,000ppm, 10,000 to 15,000ppm, and greater than 15,000ppm. The percentages turning blue of either stem sampled were 46, 67, 86, 95, and 100% for each of the classes, respectively. Correlation between the 2Q-s reading and the laboratory quantification was similar to the correlation of the 10-s reading and the laboratory quantification. The diphenylamine test is only a crude field test for the presence of dangerous concentrations of nitrate. A higher percentage of false positives (60.6%) and a low percentage of false negatives (10.7%) indicates that the test is quite conservative.

Determination of diaminopimelic acid in biological materials using high-performance liquid chromatography

A method for the determination of diaminopimelic acid (DAPA) concentrations in feeds and rumen digesta by reversed-phase high-performance liquid chromatography using precolumn derivatization with o-phthaldialdehyde and fluorimetric detection was developed. Samples were oxidized and hydrolysed prior to analyses by HPLC. Hydrogen peroxide and formic acid were used for oxidation; hydrolyses were performed using 3 M hydrochloric acid under vacuum at 120°C for 17 h. Oxidation allowed more space for DAPA-OPA peak elution and hydrochloric acid hydrolysis reduced sample clean-up and extended the column life. Hydrolysates were diluted, adjusted to pH 7 and filtered. A Beckman Model 507 autosampler with a precolumn derivatization cassette was used for the derivatization process and fluorimetric detection was used to measure the OPA derivatives. Samples were prepared in order to have on-column DAPA concentrations in the range 10–100 pmol. The relative recovery of the standard solutions added to the feed samples ranged from 98.4 to 102.8%. The reproducibility of the method was evaluated by the analysis of eight alfalfa hay samples and eight alfalfa hay samples incubated in the rumen for 48 h and they yielded relative standard deviations of 2.04% and 2.02%, respectively.

Ruminal In Vitro Degradability of Protein in Alfalfa Harvested as Standing Forage or Baled Hay

Eighty-nine samples, 45 of standing forage and 44 of baled hay, were collected from alfalfa harvested at various maturities over three cuttings each during 2 yr. Alfalfa was cut and conditioned mechanically; samples of standing forage were collected by removing bunches of forage from windrows and freeze-drying them. Forage was allowed to field cure and was harvested at an average 80% DM as small rectangular bales; samples of baled hay were collected by coring bales after storing for 3 to 6 mo. Samples were analyzed for DM, ADF, total N, fractions of total N present as ADIN, N degraded at 0h, and potentially degradable protein N. Ruminal protein degradation rates and escapes were estimated using an inhibitor in vitro system, assuming that ADIN was unavailable and that ruminal passage rate was .06/h. Standing forage contained smaller fractions of ADIN and N degraded at 0h, contained a larger fraction of potentially degradable N, and had more rapid degradation rates and lower estimated protein escapes than baled hay. Mean degradation rates and estimated escapes were .171/h and 24% for standing forage and .075/h and 40% for baled hay. There were no differences in degradation rate or estimated escape because of harvest year, and neither was significantly related to maturity or to ADF concentration. Results indicate a significant advantage in ruminal protein escape, compared with grazed alfalfa, for alfalfa harvested and stored as hay.

Cantharidin Contamination of Alfalfa Hay

Under laboratory conditions cantharidin was transferred from crushed blister beetles to filter paper. Twenty-one and 27% of the total available cantharidin was recovered from filter paper on which male and female Epicauta occidentalis Werner, respectively, had been crushed. Cantharidin was detected in samples of alfalfa hay infested with blister beetles when the hay was harvested from a field site. Thus, blister beetle–contaminated hay can be partitioned into cantharidin contributed directly by beetle parts and indirectly from cantharidin on the forage itself. Ingestion of crushed, dried beetles in the hay is a greater threat to livestock health than is contaminated hay free of blister beetles.

Management of land and livestock contaminated with polychlorinated biphenyls.

Investigations were conducted on several small neighbouring beef cattle and sheep farms that were found to be contaminated with polychlorinated biphenyls (PCBs). The residues detected contained about 62% w/w chlorine and soil concentrations ranged from 0.35 to 1.9 mg/kg. Beef cattle and sheep grazing the contaminated land had PCB concentrations in their fat of 0.3 to 1.7 mg/kg and 0.19 to 0.45 mg/kg, respectively. The concentration of PCBs in the caudal fat of cattle was 0.3 to 2 times the concentration of PCBs in the land they were grazing and was positively related to stocking rates. PCBs were present in milk fat from cattle at about the same concentration as in caudal fat, and lactation appeared to contribute to decontamination. Wool grease from sheep contained about 1 to 2 times the concentration of PCBs in subcutaneous fat. Calves of contaminated cows also became contaminated. The half-life for decontamination of PCBs in a group of 8 young female beef cattle was calculated at 13 months. PCBs were detected in pasture samples at concentrations ranging from less than 0.01 mg/kg to 0.12 mg/kg. However, PCBs were not detected in any sample of hay cut from these paddocks. In 4 sheep fed a sole ration of this hay, traces of PCBs were detected in their fat following 89 days of feeding. Grazing livestock for meat production on land contaminated with PCBs is not recommended because livestock readily acquire residues, and PCBs persist in soil and livestock for long periods. Grazing sheep for wool production on land contaminated with PCBs may be an option.

Protein, energy and dry matter consumption by racing thoroughbreds: A field survey

A field survey involving 109 horses in 9 stables at a Detroit racetrack was conducted to determine feeding practices and to estimate crude protein (CP), digestible energy (DE), and dry matter (DM) consumption by racing Thoroughbreds, and to compare those intakes with 1989 recommendations of the National Research Council (NRC), "Nutrient Requirements of Horses." Trainers were interviewed regarding: 1) the age and sex of the homes; 2) their feeding practices; and 3) the horse's training and racing schedule. Only adult homes who were actively racing and continuously stabled at the track were included. Body weights (BW) were estimated using a chest girth measurement. The horses had an overall mean body condition score of 5 which indicated average body condition for a racing. Thoroughbred at this track. Feed samples of hay and concentrate from each stable were weighed and analyzed at a commercial laboratory to determine CP, DM, acid detergent fiber (ADF), and estimated energy density. A computer program calculated CP, DE, and DM values for each horse's ration based onamounts fed. The software program included with the 1989 NRC publication was used to compare estimated nutrient intakes with current NRC recommendations for a horse of a given BW. Trainers fed a variety of hays. Eight trainers fed oats and only one fed corn. All trainers fed commercial sweet feeds. The mean total amount of feed for all homes on an "as fed" basis was 13.7 kg. The mean estimated DM intake for all horses was 12.3 kg vs. NRC recommended 11.6 kg. The mean for percentage of roughage in the ration for all stables was 53% vs. a NRC recommendation of 35%. The mean CP% ona DM basis for all stables' rations was 13.8% vs. a NRC recommendation of 11.4%. The means for actual CP and DE intakes for all horses were 1678 g and 33.3 Meal compared with current NRC recommendations of 1324 g CP and 33.1 Meal DE. Protein amounts were above those recommended due to the common practice of feeding relatively higher CP% in the rations than necessary for racehorse performance. These data appear to be more consistent with the recommendations of NRC in 1989 than previous recommendations in 1978.

Fungi in aerosols of hay associated with respiratory distress in dairy cattle

Abstract Three samples of hay associated with an outbreak of bovine respiratory disease were examined for possible etiological agents. The total numbers of viable microorganisms in the samples ranged from 104 to 106 colony-forming units/mg dust. Mycological studies on these samples revealed that the predominant fungi were members of the genus Aspergillus with fever numbers of Penicillium, Phoma, and Aureobasidium. The predominant Aspergilli observed were members of the xerophilic A. glaucus group. Counterimmunoelectrophoretic analysis demonstrated that one of the day samples (sample 3) contained material which reacted with all except two of the bovine sera tested and with serum from both exposed and unexposed human subjects.

The effect of Acremonum coenophalum on intake and digestibility of tall fescue hay horses

Four mature Quarter Horse geldings were used in a crossover experiment to determine whetherAcremonium co- enophialum affects the intake and digestibility of tall fescue hay for horses. The geldings were paired by weight and the pairs were randomly assigned to treatments; one pair received infected (E) hay and the other received uninfected (NE) hay. The geldings were placed in tie stalls for a 14d intake study before being moved to metabolism stalls for a 5d adjustment period and a 7d digestibility trial. During the intake study the geldings were given ad libitum access to the hay, water and a trace mineralized (TM) salt brick. Weights were recorded for each gelding at the beginning of the intake study and at the end of the subsequent collection period. During the adjustment and collection periods, the geldings continued to receive ad libitum access to water and TM salt bricks, but were fed at a constant intake level of 8.64 kg hay/day. Urine was collected daily. Grab samples of hay were taken during both studies. After the first collection period, the horses were allowed three days of rest in a pasture before being returned to tie stalls for the second part of the experiment. Treatments were switched between the pairs for the second half of the experiment in a crossover design. Serum samples were taken weekly and analyzed for prolactin and dopamine levels. Aliquots of hay, feces and urine were analyzed for Kjeldahl-N, long chain fatty acids and gross energy content. Hay and feces were analyzed for DM and neutral detergent fiber (NDF). There was no difference (P>.05) between treatments for average daily intake or weight loss; however, average daily intake trended lower and weight loss trended higher in E geldings than n NE geldings. Crude protein, DM, NDF and long chain fatty acid digestibilities were similar (P>.05) between treatments; how- ever, serum dopamine trended higher and serum prolactin trended lower for E geldings than NE geldings. These data suggest that the endophyte infected tall fescue hay may be less digestible than uninfected hay in horses.

Etiological Investigation of Farmer's Lung Disease: A Serological Study

To confirm the main etiological antigen of farmer's lung in Dafeng County, Jiangsu Province, People's Republic of China, precipitins in serum from 30 patients with farmer's lung were tested with several strains of antigens. Reactions against two strains of T.vulgaris were shown in 46.7% and 66.7% of the patients group, which were significantly higher than in the controls, while the percentage of reactions against Faenia rectivirgula and A. fumigates were low in the patients group and had no significant difference with the controls. The results indicate that the main etiological agents were some strains of T. vulgaris. This finding was consistent with the microbiological study of sputum of the patients and moldy hay samples from the working area.

Physical characteristics of feeds and their relation to nutrient components and dry matter disappearance in sacco

Samples of alfalfa hay (AA), orchardgrass hay (OG), maize silage (CS), alfalfa silage (AS), 70 : 30 (w/w) cracked maize to OG (70G) and 70 : 30 (w/w) barley straw to AA (70S) were collected weekly during each period (six samples per period) of a 6 × 6 Latin square design experiment. The weekly feed samples were pooled within each period and chemically analyzed for protein, neutral detergent fibre (NDF), acid detergent fibre (ADF), lignin and acid detergent insoluble nitrogen (ADIN) content. Grinding resistance, defined as the weight of the dried, preground (to pass through a 5-mm screen) feed that could be ground to pass through a 1-mm screen within the first 10 s, was measured in five replicates. Density of the feeds ground to pass through either a 5-mm or 1-mm screen was also determined dry and after a 24 h soak at 37°C in McDougall's buffer. Significant correlation coefficients were noted among these parameters, with the highest being 0.90 between grinding resistance and ADF content of the feeds. The density and hydration capacity values of the feeds were significantly correlated with various chemical components. Therefore multiple regression equations were developed to estimate feed composition.

Spore exposure arising from stored hay, grain and straw

The quantitative and qualitative differences in microbe exposure arising from hay, grain and straw during the end of the indoor feeding period were investigated by using a six-stage fractionating impactor (model 10—800, Andersen Inc.). Straw samples (n = 5) liberated significantly higher amounts of spores (3.7 x 106 cfu/m3 air) in comparison to hay samples (n = 33) and grain samples (n = 2), which liberated 0.6 x 106 cfu/m3 and 0.2 x 106 cfu/m3 , respectively. Thermotolerant and thermophilic microflora were typical of the exposure originating from straw. Hay liberated about 10 % and grain only 0.7 %, the level of spores of thermotolerant fungi liberated from straw. The corresponding percentages of spores of thermophilic actinomycetes were 5 % and 0.4 %. Thermoactinomyces vulgaris was the dominating microbe in the exposure caused by straw; Aspergillus umbrosus was the major species in the microflora liberated from hay and grain. Other Aspergillus (A.) species (A. fumigatus, A. ochraceus, A. flavus, A. repens, A. versicolor) and Penicillium (P.) species (P. expansum, P. piceum, P. citrinum, P. brevicompactum, P. echinulatum, P. verrucosum var. cyclopium) occurred frequently, and in great amounts, in all the analysed materials. Spores of Cladosporium (C.) species (mainly C. herbarum, C. cladosporioides, and C. macrocarpum) were found frequently, and abundantly, during the handling of hay. The present results suggest that not only the traditional causative agents of farmer’s lung disease but also other fungal and actinomycete species may be found in high concentrations during the handling of bedding and feeding stuffs, and that these fungal and actinomycete exposures may cause respiratory symptoms and other health problems in both man and animals. Special attention should be paid to decreasing the moisture content of hay and straw before storing in order to lower the risk of moulding during the indoor feeding period.

Near Infrared Reflectance Spectroscopy. I. Calibration Techniques for Forage Quality Assessment

Abstract It is very time consuming and resource costly to rank forages by wet laboratory methods; therefore, near infrared reflectance spectroscopy (NIRS) was used to evaluate hybrid bermudagrass (Cynodon dactylon (L.) Pers.) cultivars for improvements In quality. Quality was assessed by the determination of acid detergent fiber (AOF), crude protein (CP), dry matter (DM), and in vitro dry matter digestibility (iVDMD). The samples were taken from plant breeding trials from 1983,1984,1985, and 1986. They included 32 cultivars, 4 cuttings, and 5 replications each for a total of 640 possible observations per year. This paper describes the process by which the NIR spectrometer was calibrated for each constituent and the effect of various methods of calibration on the performance of the NIRS system to determine quality in bermudagrass hybrids. Excellent one-year equations were obtained from calibrations using the bermudagrass parents in the 1983 samples (R2 = 0.83, 0.97, 0.70; SEC = 0.94, 0.76, 3.64, for ADF, CP, and IVDMD, respectively). Attempts to use outside populations did not produce equivalent results for the first year. The 1983 equations did not fit the 1984 and 1985 samples because of changes that were made to the spectrometer and the yearly differences in the samples. The instrument was then recalibrated with a diverse set of legumes and grass hay samples that contained some bermudagrass. These open population calibrations adequately ranked the bermudagrass entries. We documented that bermudagrass genotypes can be quickly and precisely ranked for forage quality traits via use of open population NIRS calibration equation.

High-performance liquid chromatographic determination of 4-methylimidazole in sheep plasma and in ammoniated tall fescue hay

A method for 4-methylimidazole (4MI) extraction and quantitation in body fluids and forage samples was developed. The procedures involve ion-pair extraction of the compound with the quantitation done by ion-pair liquid chromatography. The results indicate that this high-performance liquid chromatographic method is sensitive, reproducible and more rapid than others that have been previously used. The mean recovery of 4MI from plasma and tall fescue ( Festuca arundinacea) hay samples were above 95 and 85%, respectively. The versatility of the procedure makes it suitable for the determination of 4MI in body fluids and in forage samples.

Effects of mastication and microbial contamination on ruminal in situ forage disappearance.

In an experiment to determine the effects of mastication and microbial contamination on in situ forage disappearance, samples of masticated (M) or nonmasticated alfalfa hay (AH), orchardgrass hay (OGH) and bermudagrass hay (BGH) were incubated in the rumen of two steers for 6, 12, 24, 48 and 96 h. Using diaminopimelic acid as a marker, microbial DM and CP contamination ranged from 10.3 to 22.3% and 46.3 to 95.3% of residual DM and CP, respectively. Percentage contamination was influenced by both time of incubation and forage treatment (P less than .001). Corrected DM and CP disappearances (DMD and CPD) were higher than apparent disappearances (P less than .001). Maximal NDF and ADF disappearances (NDFD and ADFD) obtained at 96 h were 58.2, 52.4; 62.7, 62.3 and 56.7, 52.6% for AH, OGH and BGH, respectively. Lag times (h) for corrected DMD and CPD were shorter (at least P less than .05) than for apparent disappearances, except for corrected CPD of AH. There were no differences (P greater than .10) in lag time of NDFD or ADFD among forages. Rates of disappearance (%/h) of corrected DMD and CPD were faster (at least P less than .01) than for apparent disappearances. The total quantity of microbial CP (mg CP/g DM) associated with residues varied with time depending on forage type (P less than .001). There was a significant relationship between the quantity of microbial CP contamination and the extent of disappearance. Masticated forages followed trends similar to those of nonmasticated forages, but the effect of mastication was not consistent. Results support the need for microbial correction of in situ forage residues.

Quantity and characteristics of microorganisms associated with ruminal fluid or particles.

An experiment was conducted to 1) determine quantity of microbial CP and DM associated with undigested feed particles, 2) quantify the amount of microorganisms removed from ruminally incubated forages and 3) compare forage disappearances (D) corrected for microbial contamination, using diaminopimelic acid (DAPA) ratios obtained from particle-associated or fluid-associated microorganisms. Samples of alfalfa hay, bermudagrass hay and orchardgrass hay placed in dacron bags were incubated via ruminal cannula for 6 and 12 h. Whole ruminal contents (WRC) were sampled at the time of bag removal and partitioned into fluid- and particle-associated microorganisms. Particle-associated microorganisms were further divided into loosely-associated (LA) and firmly associated (FA) microorganisms. Percentage microbial CP and DAPA, quantities of OM, CP (mg) and DAPA (micrograms), microbial contamination and microbial contribution to ruminal contents were not affected by time (P greater than .05). The highest concentrations of CP and DAPA were found in fluid and LA, respectively (P less than .01). The total amount (content) of OM, CP and DAPA were highest in FA and lowest in microbes in the fluid fraction. Firmly-associated microorganisms constituted 54.1% of the particle-associated population. Corrected DMD were higher (P less than .01) based on FA than on fluid and LA microbe compositions. Corrected CPD were similar (P greater than .10) between populations except at 6 h, when LA corrected CPD were lower. Theoretically, using FA microorganisms should give the most accurate correction for microbial contamination. However, results indicate that, although the three populations differed in composition, fluid and FA corrected CPD were similar. Corrections based on composition of any of these three populations will yield higher estimates of disappearance compared with uncorrected values.