Effect of fibrolytic enzymes on lactational performance, feeding behavior, and digestibility in high-producing dairy cows fed a barley silage-based diet.

The objectives of this study were to evaluate the effects of pretreating dairy cow rations with a fibrolytic enzyme derived from Trichoderma reesei (FETR; mixture of xylanase and cellulase; AB Vista, Wiltshire, UK) on lactation performance, digestibility, and feeding behavior in response to feeding a barley silage-based diet. Before starting the dairy trial, in vitro incubations were conducted to determine whether the addition of FETR would have an effect on these animal performance characteristics when applied to a barley silage-based diet for dairy cows. The dairy trial was performed using 8 Holstein dairy cows. The cows were blocked by parity and assigned randomly to 1 of 4 treatments: 0, 0.5, 0.75, and 1 mL of FETR/kg of dry matter (DM) diet in a replicated Latin square design. The pretreatment was applied to the complete diet during the mixing process. The experimental period continued for 22 d, with each experimental period consisting of a 16-d adaptation period and a 6-d sampling period. The daily feed intake of each individual cow was monitored using Insentec feed bins (RIC system, Insentec, Marknesse, the Netherlands). Feeding behavior characteristics were measured during the entire sampling period using the feed bin attendance data. Milk samples were collected in the last 3 d of each experimental period. The addition of FETR linearly increased the in vitro DM digestibility and tended to improve the in vitro digestibility of barley silage. There was a cubic effect of the enzyme levels on the total-tract DM and neutral detergent fiber digestibility. Maximal digestibility was reached at 0.75 mL of FETR/kg of TMR. The milk fat yield, fat-corrected milk, and energy-corrected milk quadratically responded to the incremental levels of FETR. The milk protein percentage linearly improved in response to FETR. Increasing FETR levels resulted in a quadratic effect on feed efficiency. There was no effect of FETR level on feeding behavior. In conclusion, pretreating dairy cow barley silage-based diet with 0.75 mL of FETR/kg of TMR increased the milk production efficiency of dairy cows fed diet containing 34% barley silage (DM basis). The positive effect of adding FETR could benefit the dairy industry in western Canada, where barley silage-based diets are common.

Effect of continuous or intermittent feeding of ergot contaminated grain in a mash or pelleted form on the performance and health of feedlot beef steers.

This study evaluated the effect of feeding ergot contaminated grain continuously or intermittently through backgrounding (BG) and finishing (FN) in a mash or pelleted supplement on the growth performance, health and welfare parameters, and carcass characteristics of feedlot beef steers. Sixty black Angus steers (300 ±â€…29.4 kg BW) were used in a complete randomized 238-d study. Steers were stratified by weight and randomly assigned to four different diets (15 steers/treatment) and individually housed. Treatments included: (1) control [CON; no added ergot alkaloids (EA)], (2) continuous ergot mash (CEM; fed continuously at 2 mg total EA/kg of DM), (3) intermittent ergot mash (IEM; fed at 2 mg total EA/kg of DM, during the first week of each 21-d period and CON for the remaining 2 wk, this feeding pattern was repeated in each period), and (4) intermittent ergot pellet (IEP; fed at 2 mg of total EA/kg of DM as a pellet during the first week of each 21-d period and CON for the remaining 2 wk as described for IEM). Steers were fed barley based BG diets containing 40% concentrate:60% silage (DM basis) for 84 d (four 21-d periods), transitioned over 28 d (no ergot fed) to an FN diet (90% concentrate:10% silage DM basis) and fed for 126 d (six 21-d periods) before slaughter. In the BG phase, steer DMI (P < 0.01, 7.45 vs. 8.05 kg/d) and ADG (P < 0.01) were reduced for all EA diets compared to CON. The CEM fed steers had lower ADG (P < 0.01, 0.735 vs. 0.980 kg) and shrunk final BW (P < 0.01, 350 vs. 366 kg) than CON. CEM had lower gain:feed (P < 0.07, 0.130 vs. 0.142) than CON. In the FN phase, steer DMI (P < 0.01, 9.95 vs. 11.05 kg/d) and ADG (P = 0.04) were also decreased for all EA fed steers compared to CON. Total shrunk BW gain (P = 0.03, 202.5 vs. 225.2 kg), final BW (P = 0.03, 617.9 vs. 662.2 kg), and carcass weight (P = 0.06) decreased for all EA fed steers compared to CON. The percentage of AAA carcasses decreased for all EA fed steers (P < 0.01, 46.7 vs. 93.3%) compared to CON. EA fed steers had increased rectal temperatures (P < 0.01, 39.8 vs. 39.4 °C) compared to CON. Pelleting ergot contaminated grain did not reduce the impact of ergot alkaloids on any of the measured parameters during BG or FN. Continuously or intermittently feeding ergot contaminated diets (2 mg total EA/kg of DM) significantly reduced intake, growth performance, and carcass weight, with minimal impact on blood parameters in feedlot steers. Pelleting was not an effective method of reducing ergot toxicity.

Produced by the fungus Claviceps purpurea, ergot alkaloids (EA) are toxic to beef cattle when consumed and can lead to reduction in feed intake and growth performance, vasoconstriction of the blood vessels, hyperthermia, damage to extremities (ears, tails, and hooves) and in severe cases, death. Grain is often cleaned to meet quality standards, and the resulting screenings are often utilized for feeding livestock and can have high concentrations of EA. The application of heat during pelleting of EA contaminated grain has been suggested to reduce its toxicity. Backgrounding and finishing beef cattle feeding experiments were conducted to assess the effect of continuously or intermittently feeding EA contaminated grain (2 mg/kg of diet DM) either as a pellet or as mash on growth performance, health, and animal welfare. Feeding EA grain continuously or intermittently either as a mash or pellet drastically reduced growth performance of steers, with no difference between treatments.

Fermentation, degradation and microbial nitrogen partitioning for three forage colour phenotypes within anthocyanidin-accumulating Lc-alfalfa progeny.

BACKGROUND: Alfalfa has the disadvantage of having a rapid initial rate of protein degradation, which results in pasture bloat, low efficiency of protein utilisation and excessive nitrogen (N) pollution into the environment for cattle. Introducing a gene that stimulates the accumulation of monomeric/polymeric anthocyanidins might reduce the ruminal protein degradation rate (by fixing protein and/or direct interaction with microbes) and additionally reduce methane emission. The objectives of this study were to evaluate in vitro fermentation, degradation and microbial N partitioning of three forage colour phenotypes (green, light purple-green (LPG) and purple-green (PG)) within newly developed Lc-progeny and to compare them with those of parental green non-transgenic (NT) alfalfa. RESULTS: PG-Lc accumulated more anthocyanidin compared with Green-Lc (P < 0.05), with LPG-Lc intermediate. Volatile fatty acids and potentially degradable dry matter (DM) and N were similar among the four phenotypes. Gas, methane and ammonia accumulation rates were slower for the two purple-Lc phenotypes compared with NT-alfalfa (P < 0.05), while Green-Lc was intermediate. Effective degradable DM and N were lower in the three Lc-phenotypes (P < 0.05) compared with NT-alfalfa. Anthocyanidin concentration was negatively correlated (P < 0.05) with gas and methane production rates and effective degradability of DM and N. CONCLUSION: The Lc-alfalfa phenotypes accumulated anthocyanidin. Fermentation and degradation parameters indicated a reduced rate of fermentation and effective degradability for both purple anthocyanidin-accumulating Lc-alfalfa phenotypes compared with NT-alfalfa.

Effect of feeding barley or corn silage with dry-rolled barley, corn, or a blend of barley and corn grain on rumen fermentation, total tract digestibility, and nitrogen balance for finishing beef heifers.

Five ruminally cannulated heifers were used in an incomplete 6 × 6 Latin square design to determine the effects of cereal silage (barley vs. corn), cereal grain (barley vs. corn vs. a 50:50 blend of barley and corn), and their interaction (S × G) on dry matter intake, ruminal fermentation, total tract digestibility, nitrogen balance, and in situ degradation. Corn silage (CS) or barley silage (BS) was included at 8% of dietary dry matter (DM). Within each silage source, diets contained (DM basis) either dry-rolled barley (BG; 86%), dry-rolled corn (CG; 85%), or an equal blend of barley and corn (BLEND; 85%). Periods were 25 d, with 5 d of dietary transition, 13 d of dietary adaptation, and 7 d of data and sample collection. Samples collected included feed and refusals, total urine and feces, and ruminal fluid. All data were analyzed using the Mixed model of SAS with the fixed effects of silage, grain, and the S × G. Dry matter intake (P ≥ 0.19) and mean ruminal pH (P ≥ 0.096) were not affected by the silage, grain, or S × G. Total short-chain fatty acid concentrations were greater for BLEND than BG or CG (grain, P = 0.003) and for CS (silage, P = 0.009) relative to BS. The molar proportion of acetate was greater for BS-BG and BS-CG (S × G, P < 0.001), while molar proportion of propionate was greater for CS-BG (S × G, P < 0.001) relative to other silage and grain source combinations. Rumen ammonia-N concentration was greater for CG than BG, or BLEND (grain, P < 0.001), and greater for CS compared to BS (silage, P = 0.023). Apparent total tract digestibility of DM, organic matter, neutral detergent fiber, starch, and gross energy were greatest for BG (grain, P ≤ 0.035). Digestible energy content (Mcal/kg) was greater for BG (grain, P = 0.029) than CG and BLEND. Total nitrogen retention (g/d and % of intake) was greatest for CS-BG (S × G, P ≤ 0.033) relative to all other treatments. In situ degradation rates of DM, crude protein, and starch were greater for BG than CG (P ≤ 0.004). The potentially degradable fraction of DM, crude protein, and starch was greater for CG (P ≤ 0.031), while the undegradable fraction was greater for BG (P ≤ 0.046). For silage sources, CS had greater 24 h in situ DM digestibility (P = 0.009) and starch digestibility (24, 48, and 72 h incubations, P ≤ 0.034) relative to BS. Results suggest that while feeding a combination of CS and BG promotes propionate production and greater N retention; few other additive effects were observed.

Use of barley or corn silage when fed with barley, corn, or a blend of barley and corn on growth performance, nutrient utilization, and carcass characteristics of finishing beef cattle.

The objective of this study was to evaluate the effects of the source of silage, cereal grain, and their interaction on growth performance, digestibility, and carcass characteristics of finishing beef cattle. Using a completely randomized design within an 89-d finishing study, 288 steers were randomly assigned to 1 of 24 pens (12 steers/pen) with average steer body weight (BW) within a pen of 464 kg ± 1.7 kg (mean ± SD). Diets were arranged in a 2 × 3 factorial with corn silage (CS) or barley silage (BS) included at 8% (dry matter [DM] basis). Within each silage source, diets contained dry-rolled barley grain (BG; 86% of DM), dry-rolled corn grain (CG; 85% of DM), or an equal blend of BG and CG (BCG; 85% of DM). Total tract digestibility of nutrients was estimated from fecal samples using near-infrared spectroscopy. Data were analyzed with pen as the experimental unit using the Mixed Model of SAS with the fixed effects of silage, grain, and the two-way interaction. Carcass and fecal kernel data were analyzed using GLIMMIX utilizing the same model. There were no interactions detected between silage and grain source. Feeding CG increased (P < 0.01) DM intake by 0.8 and 0.6 kg/d relative to BG and BCG, respectively. Gain-to-feed ratio was greater (P = 0.04) for BG (0.172 kg/kg) than CG (0.162 kg/kg) but did not differ from BCG (0.165 kg/kg). Furthermore, average daily gain (2.07 kg/d) and final body weight did not differ among treatments (P ≥ 0.25). Hot carcass weight (HCW) was 6.2 kg greater (372.2 vs. 366.0 kg; P < 0.01) and dressing percentage was 0.57 percentage units greater (59.53 vs. 58.96 %; P = 0.04) for steers fed CS than BS, respectively. There was no effect of dietary treatment on the severity of liver abscesses (P ≥ 0.20) with 72.0% of carcasses having clear livers, 24.4% with minor liver abscesses, and 3.6% with severe liver abscesses. Digestibility of DM, organic matter, crude protein, neutral detergent fiber, and starch were greater for BG (P < 0.01) than CG or BCG. As expected, grain source affected the appearance of grain kernels in the feces (P ≤ 0.04). Feeding CS silage increased the appearance of fractured corn kernels (P = 0.04), while feeding BS increased fiber appearance in the feces (P = 0.02). Current results indicate that when dry rolled, feeding BG resulted in improved performance and digestibility compared with CG and BCG. Even at low inclusion levels (8% of DM), CS resulted in improved carcass characteristics relative to BS.

Level and source of fat in the diet of gestating beef cows: I. Effects on the prepartum performance of the dam and birth weight of the progeny1.

A 2-yr study was conducted to evaluate the effects of level and source of fat in the diet of gestating beef cows on their prepartum performance and birth weight of progeny. Each year, 75 multiparous (≥3 calving) pregnant Angus cows were stratified by BW (663 ± 21.5 kg) and BCS (2.6 ± 0.12; 1 to 5 scale) and randomly assigned to 1 of 15 outdoor pens. Subsequently, each pen was randomly assigned to 1 of 3 (n = 5) treatments: a low-fat diet (LF; 1.4 ± 0.12% EE) consisting of grass-legume hay, barley straw, and barley grain, or 1 of 2 high-fat diets (HF; 3.3 ± 0.20% EE) that included either a canola seed (CAN) or a flaxseed (FLX) based pelleted feed. Diets were formulated to meet the requirements of pregnant beef cows during the last 2 trimesters of gestation (0.183 ± 4.8 d), adjusted for changes in environmental conditions, and offered such that each pen on average received similar daily amounts of DE (31.2 ± 2.8 Mcal/cow), CP (1.36 ± 0.13 kg/cow), and DM (12.9 ± 1.0 kg/cow). Data were analyzed as a randomized complete block design with contrasts to separate the effects of level (LF vs. HF) and source (CAN vs. FLX) of fat. After 160 d on trial, conceptus corrected-BW (CC-BW) of LF cows (708 kg) and the proportion of overconditioned cows (13.2%) were greater (P ≤ 0.04) than those of HF, with no difference (P ≥ 0.84) between CAN and FLX for CC-BW (697 kg) and proportion of overconditioned cows (3.6% vs. 2.9%). Feeding FLX diet during gestation resulted in cows with a greater (P ≤ 0.01) concentration of conjugated linolenic acid (0.12% vs. 0.05%) and n-3 (0.58% vs. 0.37%) fatty acids, and a tendency (P = 0.09) for conjugated linoleic acid concentration (1.05% vs. 0.88%) to be greater in subcutaneous adipose tissue (SCAT) when compared with cows fed the CAN diet. By the end of gestation, serum NEFA concentration of LF cows (592 µEq/L) was lower (P < 0.01) than that of HF cows, and FLX cows had greater (P < 0.01) serum NEFA concentration than CAN cows (636 vs. 961 µEq/L). Cows receiving the LF diet during gestation gave birth to lighter (P < 0.01) calves compared with those receiving the HF diets (40.2 vs. 42.9 kg), with no difference (P = 0.24) between calves born to CAN (42.4 kg) and FLX (43.3 kg) cows. In conclusion, these results suggest a partitioning of the ME in pregnant beef cows that is dependent on the type of dietary energy, resulting in heavier calves at birth for cows fed high-fat diets. Also, the type of fatty acid in the diet of gestating beef cows affected the fatty acid profile in SCAT and serum NEFA concentration.

Level and source of fat in the diet of gestating beef cows: II. Effects on the postpartum performance of the dam and the progeny.

A study was conducted to evaluate the effects of level and source of fat in the diet of gestating beef cows on the postpartum performance of the dam and the progeny. Each year, 75 mature pregnant (183±4.8 d until calving) Angus cows with similar BW (663±21.5 kg) and BCS (2.6±0.12; 1 to 5 scale) were randomly assigned to one of 15 outdoor pens. Each pen was assigned to one of three iso-caloric and iso-nitrogenous treatments: a low-fat diet (LF; 1.4±0.12% EE), and two high-fat diets (HF; 3.3±0.20% EE) including a canola seed (CAN) or a flaxseed (FLX) based pelleted feed. Diets were formulated to meet the requirements of pregnant beef cows and fed until calving. Data were analyzed as a randomized complete block design with contrasts for the effects of level (LF vs. HF) and source (CAN vs. FLX) of fat. No differences (P≥0.21) were found for BW or calving to weaning ADG of cows. The average BCS during the first 42 d of lactation was greater (P<0.01) for LF compared to HF (2.63 vs. 2.51) with no difference (P=0.35) for CAN vs. FLX cows. Subcutaneous fat thickness over the ribs was greater (P≤0.01) for LF compared to that of HF cows at calving (5.7 vs. 4.3 mm) and at weaning (4.3 vs. 3.7 mm) with no difference (P≥0.11) for CAN vs. FLX cows. Over the first 42 d of lactation, no difference (P≥0.23) was observed for 12-h milk yield. Milk protein concentration was greater (P=0.03) for CAN compared to FLX (3.11 vs. 3.01%) cows while no difference (P≥0.28) was observed for any other milk component. Milk fat from FLX cows had greater (P < 0.01) CLA and CLnA concentrations than that of CAN cows during the first 42 d of lactation. Pregnancy rate of HF cows tended (P=0.07) to be greater than that of LF cows with no difference (P=0.77) for CAN vs. FLX cows. Calves from HF cows were heavier (P≤0.01) at birth (42.9 vs. 40.2 kg) than those from LF cows. From calving to weaning, ADG of calves born to CAN cows was greater (P=0.03) that that of calves born to FLX cows (1.19 vs. 1.13 kg/d) with no difference (P=0.18) for calves born to LF vs. HF cows. At slaughter, progeny of HF cows had greater (P≤0.03) shrunk BW (605 vs. 579 kg) and HCW (355 vs. 339 kg) compared to those from LF cows with no difference (P≥0.16) for progeny of CAN vs. FLX cows. These results show that feeding a HF diet over gestation results in heavier calves at birth and at slaughter, and superior calf gains from birth to slaughter as well as heavier carcasses, possibly due to a developmental programming effect.

Level and source of fat in the diet of gestating beef cows. II. Effects on the postpartum performance of the dam and the progeny1.

A study was conducted to evaluate the effects of level and source of fat in the diet of gestating beef cows on the postpartum performance of the dam and the progeny. Each year, 75 mature pregnant (183 ± 4.8 d until calving) Angus cows with similar BW (663 ± 21.5 kg) and BCS (2.6 ± 0.12; 1 to 5 scale) were randomly assigned to 1 of 15 outdoor pens. Each pen was assigned to 1 of 3 iso-caloric and iso-nitrogenous treatments: a low-fat diet (LF; 1.4 ± 0.12% EE) and two high-fat diets (HF; 3.3 ± 0.20% EE) including a canola seed- (CAN) or a flaxseed (FLX)-based pelleted feed. Diets were formulated to meet the requirements of pregnant beef cows and fed until calving. Data were analyzed as a randomized complete block design with contrasts for the effects of level (LF vs. HF) and source (CAN vs. FLX) of fat. No differences (P ≥ 0.21) were found for BW or calving to weaning ADG of cows. The average BCS during the first 42 d of lactation was greater (P<0.01) for LF compared with HF (2.63 vs. 2.51) with no difference (P = 0.35) for CAN vs. FLX cows. Subcutaneous fat thickness over the ribs was greater (P ≤ 0.01) for LF compared with that of HF cows at calving (5.7 vs. 4.3 mm) and at weaning (4.3 vs. 3.7 mm) with no difference (P ≥ 0.11) for CAN vs. FLX cows. Over the first 42 d of lactation, no difference (P ≥ 0.23) was observed for 12-h milk yield. Milk protein concentration was greater (P = 0.03) for CAN compared with FLX (3.11 vs. 3.01%) cows, whereas no difference (P ≥ 0.28) was observed for any other milk component. Milk fat from FLX cows had greater (P < 0.01) CLA and CLnA concentrations than that of CAN cows during the first 42 d of lactation. Pregnancy rate of HF cows tended (P = 0.07) to be greater than that of LF cows with no difference (P = 0.77) for CAN vs. FLX cows. Calves from HF cows were heavier (P ≤ 0.01) at birth (42.9 vs. 40.2 kg) than those from LF cows. From calving to weaning, ADG of calves born to CAN cows was greater (P = 0.03) that that of calves born to FLX cows (1.19 vs. 1.13 kg/d) with no difference (P = 0.18) for calves born to LF vs. HF cows. At slaughter, progeny of HF cows had greater (P ≤ 0.03) shrunk BW (605 vs. 579 kg) and HCW (355 vs. 339 kg) compared with those from LF cows with no difference (P ≥ 0.16) for progeny of CAN vs. FLX cows. These results show that feeding a HF diet over gestation results in heavier calves at birth and at slaughter, and superior calf gains from birth to slaughter as well as heavier carcasses, possibly due to a developmental programming effect.

Antimicrobial resistance in generic fecal Escherichia coil 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.

Lactobacilli Are Prominent Members of the Microbiota Involved in the Ruminal Digestion of Barley and Corn.

The chemical composition of barley grain can vary among barley varieties (Fibar, Xena, McGwire, and Hilose) and result in different digestion efficiencies in the rumen. It is not known if compositional differences in barley can affect the microbiota involved in the ruminal digestion of barley. The objective of this study was to characterize the in situ rumen degradability and microbiota of four barley grain varieties and to compare these to corn. Three ruminally cannulated heifers were fed a low (60% barley silage, 37% barley grain, and 3% supplement) or high grain (37% barley silage, 60% barley grain, and 3% supplement) diet. One set of bags was used to estimate dry matter (DM), starch and crude protein (CP) degradability. A second set was used to extract DNA from the adherent microbiota and visualize grain after incubation using scanning electron microscopy (SEM). DNA was subjected to amplicon 16S rRNA gene sequencing followed by analysis using QIIME. In the low grain diet, McGwire had the highest effective degradability (ED) of DM (P < 0.01). The ED of starch was highest (P < 0.01) for Fibar, McGwire, and Xena, but the ED of CP was not affected by variety. For the high grain diet, Xena and McGwire had the highest ED of DM (P < 0.01). The ED of starch was highest (P < 0.01) for Xena and Fibar. The ED of protein was highest (P < 0.01) for Xena and McGwire. Although the microbiota did not differ among barley varieties, they did differ from corn and with incubation time. Lactobacilli were dominant members of the mature biofilms associated with corn and barley and were accompanied by a notable increase in the lactic acid utilizing genera, Megasphaera. As none of the cattle exhibited subclinical or clinical acidosis during the study, our results suggest that lactobacilli play a more prominent role in routine starch digestion than presently surmised.

Physiochemical Characteristics and Molecular Structures for Digestible Carbohydrates of Silages.

The main objectives of this study were (1) to assess the magnitude of differences among new barley silage varieties (BS) selected for varying rates of in vitro neutral detergent fiber (NDF) digestibility (ivNDFD; Cowboy BS with higher ivNDFD, Copeland BS with intermediate ivNDFD, and Xena BS with lower ivNDFD) with regard to their carbohydrate (CHO) molecular makeup, CHO chemical fractions, and rumen degradability in dairy cows in comparison with a new corn silage hybrid (Pioneer 7213R) and (2) to quantify the strength and pattern of association between the molecular structures and digestibility of carbohydrates. The carbohydrate-related molecular structure spectral data was measured using advanced vibrational molecular spectroscopy (FT/IR). In comparison to BS, corn silage showed a significantly (P < 0.05) higher level of starch and energy content and higher degradation of dry matter (DM). Cowboy BS had lower feeding value (higher indigestible fiber content and lower starch content) and lower DM degradation in the rumen compared to other BS varieties (P < 0.05). The spectral intensities of carbohydrates were significantly (P < 0.05) correlated with digestible carbohydrate content of the silages. In conclusion, the univariate approach with only one-factor consideration (ivNDFD) might not be a satisfactory method for evaluating and ranking BS quality. FT/IR molecular spectroscopy can be used to evaluate silage quality rapidly, particularly the digestible fiber content.

Efficacy of vaccination against Fusobacterium necrophorum infection for control of liver abscesses and footrot in feedlot cattle in western Canada.

A randomized and blinded field trial was carried out to evaluate the efficacy of a Fusobacterium necrophorum bacterin for control of liver abscesses and footrot under commercial feedlot conditions in western Canada. Half of the vaccinated and half of the unvaccinated control animals had ad libitum access to a forage-based (ALF) growing diet. The other half of each group was limit-fed a grain-based (LFG) growing diet. The overall prevalence of A and A+ liver abscesses in this trial was 16.7%. A strong association was found between diet group and presence of A or A+ liver abscessation at slaughter. Diet group modified the effect of vaccination on the prevalence of liver abscesses at slaughter, and on the incidence of footrot during the feeding period. The odds that a vaccinated animal in the ALF group would have an A or A+ liver abscess at slaughter were less than 1/3 the odds that an unvaccinated animal in the same diet group would have an A or A+ liver abscess at slaughter (OR = 0.27, [95% CI: 0.07 to 1.02], P = 0.05). The overall incidence of footrot in this trial was 6.5%. The odds that a vaccinated animal in the ALF group would be treated for footrot were less than 1/5 the odds that an unvaccinated animal in the same group would be treated for foot-rot (OR = 0.18, [95% CI: 0.04 to 0.82], P = 0.03). Within the LFG group there were no differences between vaccinated and unvaccinated animals in the odds of an animal being treated for footrot, or in the odds of having an A or A+ liver abscess score at slaughter. This trial suggests that vaccination against F. necrophorum infection may have applications to decrease the prevalence of severe liver abscesses at slaughter and decrease footrot treatments in certain diet situations.

Imaging molecular chemistry of Pioneer corn.

Synchrotron Fourier transform infrared (FTIR) microspectroscopy as a rapid, direct, and nondestructive analytical technique can explore molecular chemical features of the microstructure of biological samples. The objective of this study was to use synchrotron FTIR microspectroscopy to image the molecular chemistry of corn (cv. Pioneer 39P78) to reveal spatial intensity and distribution of chemical functional groups in corn tissue. This experiment was performed at the U2B station of the National Synchrotron Light Source in Brookhaven National Laboratory (NSLS-BNL, Upton, NY). The Pioneer corn tissue was imaged from the pericarp, seed coat, aleurone, and endosperm under peaks at 1736 (carbonyl C=O ester), 1510 (aromatic compound), 1650 (amide I), 1550 (amide II), 1246 (cellulosic material), 1160 (CHO), 1150 (CHO), 1080 (CHO), 929 (CHO), 860 (CHO), 3350 (OH and NH stretching), 2929 (CH(2) stretching band), and 2885 cm(-1) (CH(3) stretching band). The results showed that with synchrotron FTIR microspectroscopy, the images of the molecular chemistry of Pioneer corn could be generated. Such information on the microstructural-chemical features of grain corn can also be used for corn breeding programs for selecting superior varieties of corn for targeted food and feed purposes and for prediction of corn quality and nutritive value for humans and animals.

Using synchrotron-based FTIR microspectroscopy to reveal chemical features of feather protein secondary structure: comparison with other feed protein sources.

Studying the secondary structure of proteins leads to an understanding of the components that make up a whole protein. An understanding of the structure of the whole protein is often vital to understanding its digestive behavior in animals and nutritive quality. Usually protein secondary structures include alpha-helix and beta-sheet. The percentages of these two structures in protein secondary structures may influence feed protein quality and digestive behavior. Feathers are widely available as a potential protein supplement. They are very high in protein (84%), but the digestibility of the protein is very low (5%). The objective of this study was to use synchrotron-based Fourier transform infrared (FTIR) microspectroscopy to reveal chemical features of feather protein secondary structure within amide I at ultraspatial resolution (pixel size = 10 x 10 microm), in comparison with other protein sources from easily digested feeds such as barley, oat, and wheat tissue at endosperm regions (without destruction of their inherent structure). This experiment was performed at beamline U2B of the Albert Einstein Center for Synchrotron Biosciences at the National Synchrotron Light Source (NSLS) in Brookhaven National Laboratory (BNL), U.S. Dept of Energy (NSLS-BNL, Upton, NY). The results showed that ultraspatially resolved chemical imaging of feed protein secondary structure in terms of beta-sheet to alpha-helix peak height ratio by stepping in pixel-sized increments was obtained. Using synchrotron FTIR microspectroscopy can distinguish structures of protein amide I among the different feed protein sources. The results show that the secondary structure of feather protein differed from those of other feed protein sources in terms of the line-shape and position of amide I. The feather protein amide I peaked at approximately 1630 cm(-1). However, other feed protein sources showed a peak at approximately 1650 cm(-1). By using multicomponent peak modeling, the relatively quantitative amounts of alpha-helix and beta-sheet in protein secondary structure were obtained, which showed that feather contains 88% beta-sheet and 4% alpha-helix, barley contains 17% beta-sheet and 71% alpha-helix, oat contains 2% beta-sheet and 92% alpha-helix, and wheat contains 42% beta-sheet and 50% alpha-helix. The difference in percentage of protein secondary structure may be part of the reason for different feed protein digestive behaviors. These results demonstrate the potential of highly spatially resolved infrared microspectroscopy to reveal feed protein secondary structure. Information from this study by the infrared probing of feed protein secondary structure may be valuable as a guide for feed breeders to improve and maintain protein quality for animal use.

Using synchrotron transmission FTIR microspectroscopy as a rapid, direct, and nondestructive analytical technique to reveal molecular microstructural-chemical features within tissue in grain barley.

The objective of this study was to use synchrotron transmission FTIR microspectroscopy as a rapid, direct, and nondestructive analytical technique to reveal molecular microstructural-chemical features within tissue in grain barley. The results showed that synchrotron transmission FTIR microspectroscopy could provide spectral, chemical, and functional group characteristics of grain barley tissue at ultrahigh spatial resolutions. The spatially localized structural-chemical distributions of biological components (lignin, cellulose, protein, lipid, and carbohydrates) and biological component ratios could be imaged. Such information on molecular microstructural-chemical features within the tissue can be used for plant breeding programs for selecting superior varieties of barley for special purposes and for prediction of grain barley quality and nutritive value for humans and animals.

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.

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.

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.

Investigating the molecular structural features of hulless barley (Hordeum vulgare L.) in relation to metabolic characteristics using synchrotron-based fourier transform infrared microspectroscopy.

The synchrotron-based Fourier transform infrared microspectroscopy (SR-FTIRM) technique was used to quantify molecular structural features of the four hulless barley lines with altered carbohydrate traits [amylose, 1-40% of dry matter (DM); ß-glucan, 5-10% of DM] in relation to rumen degradation kinetics, intestinal nutrient digestion, and predicted protein supply. Spectral features of ß-glucan (both area and heights) in hulless barley lines showed a negative correlation with protein availability in the small intestine, including truly digested protein in the small intestine (DVE) (r = -0.76, P < 0.01; r = -0.84, P < 0.01) and total metabolizable protein (MP) (r = -0.71, P < 0.05; r = -0.84, P < 0.01). Variation in absorption intensities of total carbohydrate (CHO) was observed with negative effects on protein degradation, digestion, and potential protein supply (P < 0.05). Molecular structural features of CHO in hulless barley have negative effects on the supply of true protein to ruminants. The results clearly indicated the impact of the carbohydrate-protein structure and matrix.