Effect of nicotinic acid supplementation on digestion, metabolism, microbiome, and production in late-lactation Holstein cows.

The purpose of this experiment was to determine if nicotinic acid (NA) effects on dairy cows and rumen microbial characteristics are forage type dependent (corn silage, CS; grass silage, GS). Four late lactation (days in milk = 225 +/- 12 d) Holstein cows were used in a 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments. The main effects were a CS (66.10% CS) based diet or a GS (79.59%) based diet with or without 12 g/d NA. Each experimental period lasted for 28 d. Milk production and milk components, blood metabolites, apparent total-tract nutrient digestibilities, minutes rumen pH were below 5.8 as an indicator of ruminal acidosis, and body temperature changes were analyzed as indicators of heat stress. Nicotinic acid supplementation did not improve apparent total-tract nutrient digestibility. Feeding a GS-based diet improved NDF and hemicellulose digestibility. Feeding a CS-based diet increased the apparent total-tract digestibility of fat, and minutes rumen pH below 5.8 for a greater proportion of the time. The CS-based diet also improved milk yield, milk fat and protein yields, and energy-corrected milk yield; however, somatic cell count and BHB were also increased. Supplementing NA tended to decrease nonesterified fatty acids, especially when combined with GS where DMI was low. There was a trend for the total protozoa population to increase when GS and NA were fed but decreased when CS and NA were fed. Nicotinic acid tended to decrease rumen protozoal populations of Dasytricha, but increased populations of Ophryoscolex and Diplodiniinae with GS diets and decreased with CS diets. Entodiniinae were increased with CS but NA had no effect. Body temperature was increased when a CS-based diet was fed when compared with a GS-based diet. More research is needed to determine how NA can affect rumen microbial protein synthesis and what kind of diets will provide the optimum effect.

Ancient DNA, lipid biomarkers and palaeoecological evidence reveals construction and life on early medieval lake settlements.

Direct evidence of ancient human occupation is typically established through archaeological excavation. Excavations are costly and destructive, and practically impossible in some lake and wetland environments. We present here an alternative approach, providing direct evidence from lake sediments using DNA metabarcoding, steroid lipid biomarkers (bile acids) and from traditional environmental analyses. Applied to an early Medieval Celtic settlement in Ireland (a crannog) this approach provides a site chronology and direct evidence of human occupation, crops, animal farming and on-site slaughtering. This is the first independently-dated, continuous molecular archive of human activity from an archeological site, demonstrating a link between animal husbandry, food resources, island use. These sites are under threat but are impossible to preserve in-situ so this approach can be used, with or without excavation, to produce a robust and full site chronology and provide direct evidence of occupation, the use of plants and animals, and activities such as butchery.

Dietary starch level and rumen-protected methionine, lysine, and histidine: Effects on milk yield, nitrogen, and energy utilization in dairy cows fed diets low in metabolizable protein.

Our objective was to investigate the interactions between starch level and rumen-protected Met, Lys, His (RP-MLH) on milk yield, plasma AA concentration, and nutrient utilization in dairy cows fed low metabolizable protein diets (mean = -119 g/d of metabolizable protein balance). Sixteen multiparous Holstein cows (138 ± 46 d in milk, 46 ± 6 kg/d in milk) were used in a replicated 4 × 4 Latin square with a 2 × 2 factorial arrangement of treatments. Each period lasted 21 d with 14 d for diet adaptation and 7 d for data and sample collection. Dietary starch level varied by replacing (dry matter basis) pelleted beet pulp and soyhulls with ground corn resulting in the following treatments: (1) 20% pelleted beet pulp and 10% soyhulls (reduced starch = RS), (2) RS plus RP-MLH (RS+AA), (3) 30% ground corn (high starch = HS), and (4) HS plus RP-MLH (HS+AA). Dietary starch concentrations averaged 12.3 and 34.4% for RS and HS basal diets, respectively. Diets were supplemented with RP-MLH products to supply digestible Met, Lys, and His. Compared with RS and RS+AA diets, HS and HS+AA diets increased yields of milk (37.9 vs. 40.1 kg/d) and milk protein (1.07 vs. 1.16 kg/d) and decreased dry matter intake (25.9 vs. 25.2 kg/d), milk urea N (12.6 vs. 11.0 mg/dL), and plasma urea N (13.3 vs. 11.6 mg/dL). Milk N efficiency was greater in cows fed the HS and HS+AA than RS and RS+AA diets (28.9 vs. 25%), and RP-MLH supplementation improved milk true protein concentration. Starch level × RP-MLH interactions were observed for plasma concentrations of Arg and Lys, with RP-MLH being more effective to increase plasma Arg (+16%) and Lys (+23%) when supplemented to the RS than the HS basal diet. Replacing pelleted beet pulp and soyhulls with ground corn lowered the plasma concentrations of all essential AA except Met and Thr. In addition, the plasma concentrations of His and Met increased with RP-MLH. The apparent total-tract digestibilities of neutral and acid detergent fiber were lower, and those of starch and ether extract greater in cows offered the HS and HS+AA diets than RS and RS+AA diets. Urinary excretion of urea N decreased by replacing pelleted beet pulp and soyhulls with ground corn. Enteric CH4 production, CH4 yield, and CH4 intensity all decreased in the HS and HS+AA versus RS and RS+AA diets. Diets did not affect the intakes of gross energy, metabolizable energy, and net energy of lactation. In contrast, digestible energy intake increased with feeding the RS and RS+AA diets, whereas CH4 energy decreased in cows fed the HS and HS+AA diets. Supplementation with RP-MLH had no effect on energy utilization variables. Overall, the lack of interactions between dietary starch level and RP-MLH supplementation on most variables measured herein showed that the effects of starch intake and RP-MLH were independent or additive.

Production and nitrogen metabolism in lactating dairy cows fed finely ground field pea plus soybean meal or canola meal with or without rumen-protected methionine supplementation.

We showed previously that dairy cows fed [diet dry matter (DM) basis] 25% finely ground field pea (GFP) plus rumen-protected (RP)-Met and RP-Lys had greater milk true protein yield and plasma Met concentration, but lower plasma His, compared with those fed GFP without rumen-protected AA supplementation. The goal of the present study was to investigate the effects of diets containing soybean meal (SBM) or canola meal (CM) with or without a source of RP-Met on production, nutrient digestibility, and N metabolism in cows fed 25% GFP. Sixteen mid-lactation Holstein cows were used in a replicated 4 × 4 Latin square with a 2 × 2 factorial arrangement of treatments (21-d periods). Cows were fed (DM basis) 35% corn silage, 14% grass-legume haylage, 25% GFP, and 11% SBM or 13.5% CM with or without 0.095% RP-Met supplementation as Smartamine M (Adisseo USA Inc., Alpharetta, GA). Protein source effects were observed for most production variables; cows fed diets containing CM plus GFP had greater DM intake, yields of milk and milk fat and true protein, and milk N efficiency than those offered SBM plus GFP. Feeding CM plus GFP also reduced the concentrations of milk urea N and plasma urea N, and the urinary excretion of NH3 N and urea N, suggesting improved N use efficiency. Moreover, replacing SBM with CM increased the concentrations of all essential AA (except Arg) in plasma collected from the coccygeal blood vessels. A protein source × RP-Met interaction was observed for the concentration of His in coccygeal plasma, with circulating His decreasing only when RP-Met was supplemented to the diet containing SBM plus GFP. Based on the arteriovenous difference method, Lys was the first limiting AA overall, with Met being the first limiting AA in diets that did not receive RP-Met. Apparent total-tract digestibilities of DM, organic matter, N, and acid detergent fiber increased with feeding SBM plus GFP versus CM plus GFP. Most variables were not affected by RP-Met supplementation, except plasma Met concentration, which increased by 63%. Collectively, our results indicate that CM appears to be a better companion rumen-degradable protein source to GFP than SBM, due to improved yields of milk and milk protein and N use efficiency.

Multicentre evaluation of Erytra Eflexis®, a benchtop fully automated analyser with a compact design for routine use in blood transfusion laboratory.

OBJECTIVES: Evaluation of the compact benchtop Erytra Eflexis® automated analyser was performed at three health centres representing a range of routine transfusion workload. BACKGROUND: Automation instruments with the simplicity and flexibility adequate for small- to mid-sized blood transfusion services are an unmet need. METHODS: Performance in pre-transfusion testing (2109 ABO/D, 382 Rh/K phenotype, 2001 antibody screening, 113 antibody identification, 151 DAT, 88 extended phenotype; 655 cross matching) in comparison to Erytra® as reference device was assessed. Throughput [time to first result (TTFR), final turn-around time (TAT), processing rate] was calculated; usability and adaptability in laboratory practice under routine and with emergency samples were surveyed. RESULTS: Agreement between systems was 99·8% (11/5499 test discrepancies, all due to weak/doubtful positive reactions). Erytra Eflexis produced six true positives (two Rh/D, two B positives, two screening), four false positives (three screening and one cross matching) and one false negative (screening). Processing of eight routine samples with the Erytra Eflexis for ABO/Rh(D) and screening took 34-38 min and 32-37 min, respectively, independent of the simultaneous processing of a STAT sample, whether or not the incubator for STAT was reserved. In this scenario, a STAT sample requested within 2 min after the routine load was processed in 14-26 min. Processing rate tended to stabilise and optimise in the larger workloads, particularly in ABO/Rh(D)/K cards (16·7, 18 and 19·5 results/h for 10, 15 and 24 specimens, respectively). CONCLUSION: Erytra Eflexis analyser was found to be reliable and suitable for pre-transfusion routine tests performed in a small-/medium-sized blood transfusion laboratory.

Incremental amounts of rumen-protected histidine increase plasma and muscle histidine concentrations and milk protein yield in dairy cows fed a metabolizable protein-deficient diet.

The dairy industry can benefit from low crude protein (CP) diets due to reduced N excretion, but shortages of Met, Lys, and His may limit milk protein synthesis. We studied the effect of incremental amounts of rumen-protected (RP)-His on plasma and muscle AA profile, nutrient utilization, and yields of milk and milk true protein in dairy cows. Eight multiparous Holstein cows (130 ± 30 d in milk) were randomly assigned to treatment sequences in a replicated 4 × 4 Latin square design with 28-d experimental periods. Treatments included a basal diet composed (dry matter basis) of 50% corn silage, 15% haylage, and 35% concentrate supplemented with 0, 82, 164, and 246 g/d of RP-His and 11 g/d of RP-Met. Milk, plasma, and muscle samples were collected weekly or every other week during all 4 periods, whereas spot urine and fecal grab samples were taken only in wk 4 of each period. Data were analyzed individually by week using linear, quadratic, and cubic orthogonal polynomials and repeated measures. Plasma His increased linearly with RP-His during wk 1 (30.3 to 57.2 µM) to wk 4 (33.2 to 63.1 µM). Plasma carnosine increased linearly with supplemental RP-His except in wk 2. No treatment effect was observed for plasma 3-methylhistidine except a quadratic effect in wk 3. Inclusion of RP-His showed linear effects on muscle His in wk 2 (20.1 to 32.5 µM) and 4 (20.3 to 35.5 µM). Whereas muscle anserine and carnosine concentrations were not affected by treatments in wk 4, anserine responded quadratically and carnosine showed a trend for a quadratic response to RP-His in wk 2. During wk 4, treatments did not affect urinary excretion of total purine derivatives, as well as dry matter intake and milk concentrations of fat and true protein. In contrast, milk yield tended to increase linearly (31.2 to 32.7 kg/d) and milk true protein yield responded linearly (0.93 to 0.98 kg/d) and tended to increase quadratically to RP-His supplementation in wk 4. Also, milk urea-N (11.7 to 12.9 mg/dL) and urinary excretion of urea-N (23.7 to 27.0% of N intake) increased linearly with feeding RP-His in wk 4. Overall, RP-His was effective to enhance plasma and muscle concentrations of His and milk protein synthesis. Elevated milk urea-N and urinary excretion of urea-N suggest that plasma His may have exceeded the requirement with excess N converted to urea in the liver. Future research is needed to determine the bioavailability of RP-His supplements to improve the accuracy of diet formulation for AA.

The plasma free amino acid dose-response technique: A proposed methodology for determining lysine relative bioavailability of rumen-protected lysine supplements.

Estimates of Lys bioavailability of rumen-protected Lys (RP-Lys) supplements are often obtained using in vitro or 2-step in situ techniques, with little to no data determining efficacy and bioavailability in vivo. The objective of this study was to further evaluate and refine the use of the plasma free AA dose-response technique as a method for determining Lys relative bioavailability of RP-Lys supplements. Thirteen dose-response Latin square studies using 87 lactating, ruminally cannulated multiparous Holstein cows (days in milk from 55 to 315 and milk yield from 12 to 62 kg/d at the start of the studies) were conducted to measure the relative bioavailability of RP-Lys supplements. Intestinal (1 study) and abomasal (12 studies) infusions of Lys ranged from 0 to 84 g/d, and experimental periods ranged from 4 to 21 d. Basal diets were formulated to be adequate in metabolizable Met, but varied in predicted metabolizable Lys (5.04 to 6.81% of metabolizable protein). One to 4 daily blood samples were taken from the coccygeal vessels for 1 to 3 consecutive days in each period. Plasma Lys concentration in cows assigned to the control treatment (0 g/d Lys) ranged from 1.83 to 5.21% of total plasma AA, whereas that from cows duodenally or abomasally infused with Lys ranged from 2.53 to 7.51% of total plasma AA. Results from studies involving more than 2 amounts of infused Lys confirmed linearity of response. The following variables were regressed against the plasma Lys dose-response slopes generated from the Lys infusion treatments to examine their effects on the magnitude of the slopes: plasma Lys concentration of the control diet, plasma Lys concentration at the greatest amount of infused Lys, net energy of lactation and metabolizable protein balances, metabolizable protein supply, days in milk, milk yield, milk concentrations of fat, true protein, and lactose, milk true protein yield, and dry matter intake. The variable having the greatest effect on the magnitude of the dose-response slope was the plasma Lys concentration at the greatest amount infused. The relative bioavailability of evaluated RP-Lys supplements using the plasma free AA dose-response technique ranged from 5 to 87%. It was concluded that plasma free Lys increases in a linear fashion to increasing amounts of absorbed Lys and that the dose-response technique is an appropriate technique for evaluating RP-Lys supplements.

Short communication: The mammalian lignan enterolactone is absorbed by newborn dairy calves fed enterolactone-enriched milk.

Flaxseed is the richest source of the plant lignan secoisolariciresinol diglucoside, which is converted to the mammalian lignans enterolactone (EL) and enterodiol by the gut microbiota of ruminants and humans. Enterolactone has been associated with improved animal and human health due to its antioxidant and anticarcinogenic properties. The objective of this study was to determine the pharmacokinetics of EL in newborn dairy calves fed milk replacer or EL-enriched milk. We hypothesized that newborn Holstein calves fed EL-enriched milk would have greater area under the curve and plasma concentration of EL compared with those fed milk replacer. On d 5 of life, calves were administered 2 L of milk replacer (n = 10; low-EL treatment: 123 nmol/L of EL) or 2 L of EL-enriched milk (n = 10; high-EL treatment: 481 nmol/L of EL) during the morning feeding (0700 h). Blood samples were taken from the jugular vein before (0 h) and at 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12, 24, and 48 h after oral administration of treatments. The area under the curve for the plasma concentration of EL was analyzed according to the trapezoidal rule between 0 and 12 h after treatment administration, and it was greater in high- (26 nmol/L × h) than low-EL calves (4.30 nmol/L × h). Similarly, the maximum concentration of EL in plasma was greater in high- (5.06 nmol/L) versus low-EL calves (1.95 nmol/L). Furthermore, the time after treatment intake to reach maximum plasma concentration of EL was faster in high- (4.31 h) compared with low-EL (4.44 h) treatment. Calves were able to absorb EL, indicating that EL-enriched milk can potentially be used as source of EL to pre-weaned ruminants.

Production and nitrogen utilization in lactating dairy cows fed ground field peas with or without ruminally protected lysine and methionine.

Previous research has shown that cows fed ≥24% of the diet dry matter (DM) as field peas decreased milk yield as well as concentration and yield of milk protein, possibly due to reduced DM intake and limited supply of Lys and Met. Twelve multiparous and 4 primiparous lactating Holstein cows were randomly assigned to 1 of 4 diets in a replicated 4 × 4 Latin square design. The diets contained (DM basis) 34.8% corn silage, 15.2% grass-legume silage, 5.9% roasted soybean, 2.4% mineral-vitamin premix, 2.0% alfalfa pellets, and either (1) 36% ground corn, 2.4% soybean meal, and 1.3% urea (UR), (2) 29.7% ground corn, 9.8% soybean meal, 0.13% ruminally protected (RP) Lys, and 0.07% RP-Met (CSBAA), (3) 25% ground field peas, 12.3% ground corn, and 2.4% soybean meal (FP), or (4) FP supplemented with 0.15% RP-Lys and 0.05% RP-Met (FPAA). Our objective was to test the effects of FP versus UR, FPAA versus CSBAA, and FPAA versus FP on milk yield and composition, N utilization, nutrient digestibility, ruminal fermentation profile, and plasma concentration of AA. Milk yield did not differ across diets. Compared with cows fed UR, those fed FP had greater DM intake, concentration and yield of milk true protein, apparent total-tract digestibility of fiber, urinary excretion of purine derivatives, and concentrations of total volatile fatty acids in the rumen and Lys in plasma, and less milk urea N and ruminal NH3-N. The concentration of milk urea N, as well as the concentration and yield of milk fat increased in cows fed FPAA versus CSBAA. Moreover, cows fed FPAA had greater ruminal concentration of total volatile fatty acids, increased proportions of acetate and isobutyrate, and decreased proportions of propionate and valerate than those fed CSBAA. The plasma concentrations of His, Leu, and Phe decreased, whereas plasma Met increased and plasma Lys tended to increase in cows fed FPAA versus CSBAA. Concentration of milk true protein, but not yield, was increased in cows fed FPAA versus FP. However, cows fed FPAA showed decreased concentrations of His and Leu in plasma compared with those fed FP. Overall, compared with the CSBAA diet, feeding FPAA did not negatively affect milk yield and milk protein synthesis. Furthermore, RP-Lys and RP-Met supplementation of the FP diet did not improve milk yield or milk protein synthesis, but decreased urinary urea N excretion.

Effects of human visitation on calf growth and performance of calves fed different milk replacer feeding levels.

Twenty-eight newborn Holstein heifer calves from the university herd and 8 newborn Holstein heifer calves from a commercial herd were blocked by birth and herd into 1 of 4 treatments: conventional [20% crude protein (CP), 20% fat] milk replacer (MR; treatment C) with (1) or without (0) human visitation, or a higher plane of MR nutrition (28% CP, 20% fat) regimen (treatment A) with (1) or (0) without human visitation. Calves on C MR treatments received 454g of MR from d 2 to 41. Calves on A MR received 916g of MR from d 2 to 8 and 1134g of MR from d 9 to 41. Visitation with calves occurred at 1030 and 1430h daily from d 1 to 56 and comprised verbal stimulation and stirring of starter grain. An opaque curtain divided the calf nursery, with calves in the front half assigned to visitation treatments and those in the rear half not assigned to visitation treatments. Calves were fed their MR treatment until d 43 (preweaning), after which all calves received half of their allotment of MR until d 49 (weaning). Calves were tracked for the next week until d 56 (postweaning). Starter grain and MR intakes were measured daily along with weekly body weight and skeletal measurements. One half of the calves on each treatment had blood samples taken via jugular venipuncture on d 41 (preweaning), 43, 45, 47, 49, and 51 (postweaning) to evaluate blood glucose, urea, nonesterified fatty acids, and cortisol concentrations. During the preweaning and weaning phases, calves on A0 and A1 treatments consumed more MR, less starter, and weighed more than the C0 and C1 calves. Calves on A0 and A1 had greater average daily gain (ADG), hip and withers gain, were taller at the hip, and had larger girths during the preweaning phase. Overall, body weight, withers and hip heights, and heart girths were greater in A0 andA1 calves during the weaning week. Efficiency of utilization of estimated metabolizable energy (ME) intake (ADG/ME) were similar. Glucose and nonesterified fatty acids concentrations were greater in visited calves preweaning. An interaction for glucose was observed during weaning, with A1 calves having the highest concentration and A0 calves having the lowest concentrations during weaning. Cortisol tended to be higher in visited calves during weaning. Postweaning, calves formerly fed A0 and A1 treatments had lower blood glucose and tended to have higher urea and cortisol concentrations than C0 and C1 treatments. The higher plane of nutrition fed calves tended to have higher cortisol concentrations indicating that they experienced more stress due to the removal of MR more than calves fed conventionally. Calves fed the higher plane of MR nutrition consumed more dry matter, ME, and water weighed more, had a greater ADG, and were taller than calves fed the conventional MR. These calves were more efficient (ADG/dry matter intake) when expressed on a dry matter basis, but had similar efficiency when expressed on an ME basis (ADG/ME). Visiting calves did little to reduce the stress of weaning when calves are fed the higher plane of nutrition MR feeding regimen.

Incremental amounts of Ascophyllum nodosum meal do not improve animal performance but do increase milk iodine output in early lactation dairy cows fed high-forage diets.

The objective of this study was to investigate the effects of incremental amounts of Ascophyllum nodosum meal (ANOD) on milk production, milk composition including fatty acids and I, blood metabolites, and nutrient intake and digestibility in early lactation dairy cows fed high-forage diets. Twelve multiparous Jersey cows averaging (mean±standard deviation) 40±21 d in milk and 464±35 kg of body weight and 4 primiparous Jersey cows averaging 75±37 d in milk and 384±17kg of body weight were randomly assigned to treatment sequences in a replicated 4×4 Latin square design. Each period lasted 21 d with 14 d for diet adaptation and 7 d for data and sample collection. Cows were fed a total mixed ration (64:36 forage-to-concentrate ratio) supplemented (as fed) with 0, 57, 113, or 170 g/d of ANOD. Milk yield as well as concentrations and yields of milk components (fat, protein, lactose, milk urea N) were not affected by increasing dietary amounts of ANOD. Concentration (from 178 to 1,370 µg/L) and yield (from 2.8 to 20.6 mg/d) of milk I increased linearly in cows fed incremental amounts of ANOD as a result of the high concentration of I (820 mg/kg of dry matter) in ANOD. Overall, only minor changes were observed in the proportion of milk fatty acids with ANOD supplementation. Quadratic trends were observed for dry matter intake and total-tract digestibilities of organic matter and neutral detergent fiber, whereas negative linear trends were observed for serum concentration of cortisol and crude protein digestibility with ANOD supplementation. Serum concentrations of triiodothyronine and thyroxine were not affected by ANOD supplementation and averaged 1.1 and 48.4 ng/mL, respectively. However, feeding increasing amounts of ANOD linearly reduced the plasma concentration of nonesterified fatty acids (from 164 to 132 mEq/L). Quadratic effects were found for the total-tract digestibility of ADF and urinary output of purine derivatives, suggesting that ANOD supplementation may stimulate growth of ruminal cellulolytic bacteria in a dose-dependent fashion. In general, feeding incremental amounts of ANOD to early lactation dairy cows dramatically increased milk I concentration and output with no effect on animal performance.

Anionic salts in the prepartum diet and addition of sodium bicarbonate to colostrum replacer, and their effects on immunoglobulin G absorption in the neonate.

The objectives of this experiment were to determine whether feeding anionic salts to prepartum Holstein cows affected their calf's colostral IgG passive transfer and whether adding sodium bicarbonate to a colostrum replacer (CR) would increase the efficiency of IgG absorption. Forty Holstein cows and their resulting calves were assigned to a 2 x 2 factorial arrangement of treatments in a randomized complete block design based on expected date of calving. Three weeks before the projected due date, cows were placed on 1 of 2 treatments: a diet without anionic salts (dietary cation-anion difference of +77 mEq/kg) or a diet with anionic salts (dietary cation-anion difference of -100 mEq/kg). Within 45 min after birth, all calves received 1 dose of a commercially available CR (132g of IgG) without or with supplemental sodium bicarbonate (19.5 g/dose). A half-dose of CR (66g of IgG) and sodium bicarbonate (9.75g) was fed at 6h of age. Calves received milk replacer at 12, 24, 36, and 48h. Blood samples were obtained from calves at 0, 6, 12, 24, and 48h and were analyzed for IgG concentration. Cows fed the diet supplemented with anionic salts had lower DMI on d 8, 5, 4, and 1 and lower urine pH 2 and 1 wk before parturition compared with cows fed the diet without supplemental anionic salts. Calves born from dams receiving anionic salts had similar IgG concentrations (15.1 vs. 14.4g/L) and apparent efficiency of absorption values (29.2 vs. 28.2%) compared with calves born from dams not fed anionic salts. Calves receiving supplemental sodium bicarbonate in the CR had higher serum IgG concentrations at 12 (14.4 vs. 12.0g/L), 24 (16.3 vs. 13.2g/L), and 48h (14.6 vs. 11.2g/L) and higher apparent efficiency of absorption values (31.2 vs. 26.1%) than calves that did not receive sodium bicarbonate in the CR. Calves receiving sodium bicarbonate also had greater area under the curve values for IgG absorption compared with calves not receiving sodium bicarbonate. There was a trend for an interaction with calves born from dams fed anionic salts having a greater area under the curve when fed supplemental sodium bicarbonate. Of the 40 calves in the study, 90% obtained adequate passive transfer (serum IgG > or = 10g/L). This study indicates that feeding anionic salts to the dam has no effect on passive transfer, whereas adding sodium bicarbonate to the CR increased IgG uptake in calves.

New artificial dielectric metamaterial and its application as a terahertz antireflection coating.

We describe a novel artificial dielectric material that has applications at millimeter and submillimeter wavelengths. The material is manufactured from layers of metal mesh patterned onto thin polypropylene sheets, which are then bonded together using a hot pressing process to provide planar rugged discs that can be reliably cycled to cryogenic temperatures. The refractive index of this material can be tuned by adjusting the geometry and spacing of the metal mesh layers. We demonstrate its usage by designing and characterizing a broadband antireflection coating for a Z-cut crystalline quartz plate. The coating was fabricated and applied to the quartz using the hot press technique and characterized using a Fourier transform spectrometer. The performance is shown to be in good agreement with a high frequency structure simulator and transmission line modeling results.

Effects of providing two forms of supplemental methionine to periparturient Holstein dairy cows on feed intake and lactational performance.

Eighteen primiparous and 42 multiparous Holstein cows were blocked according to parity and expected calving date and assigned randomly to 1 of 3 dietary treatments: 1) a basal diet (negative control), 2) the basal diet plus 2-hydroxy-4-methylthio butanoic acid isopropyl ester (MetaSmart, Adisseo Inc., Antony, France), or 3) the basal diet plus rumen-protected Met (Smartamine M, Adisseo Inc., Alpharetta, GA). Treatments were initiated 21 d before expected calving and continued through 140 d postpartum. Diets were similar in ingredient and chemical composition, except for the content of Met in metabolizable protein. MetaSmart [0.35% prepartum and 0.54% postpartum in diet dry matter (DM)] and Smartamine M (0.06% prepartum and 0.10% postpartum in diet DM) were added to the basal diet in amounts needed to achieve a 3.0:1 ratio of Lys to Met in metabolizable protein. Prepartum DM intake (DMI; 13.5 kg/d), body weight (687 kg), body condition score (3.81), postpartum milk yield (42.0 kg/d), milk fat yield (1,549 g/d), milk fat content (3.66%), milk true protein yield (1,192 g/d), and milk urea N content (12.9 mg/dL) were not different among treatments. Postpartum DMI and body condition score were greater and the ratios of milk:DMI and milk N:feed N were less for cows fed the MetaSmart diet than for cows fed the control and Smartamine M diets. Milk protein content was greater for the Smartamine M (2.87%) and MetaSmart (2.81%) treatments than for the control treatment (2.72%). Concentrations of Met and Met + Cys in total plasma AA were different among treatments, with values for the Smartamine M treatment being the highest, followed by the MetaSmart and control treatments. The results indicated that both MetaSmart and Smartamine M are effective in providing metabolizable Met, but clarification of their relative contributions to metabolizable Met is still needed.

Effects of colostrum replacer supplemented with lactoferrin on the blood plasma immunoglobulin G concentration and intestinal absorption of xylose in the neonatal calf.

The objective of this experiment was to determine the effect of lactoferrin (Lf) supplementation of colostrum replacer (CR) fed as 1 or 2 doses on apparent efficiency of IgG absorption, serum IgG concentrations, and xylose absorption/intestinal development in neonatal Holstein bull calves. Eighty bull calves were assigned to a 2 x 4 factorial arrangement of treatments in a randomized complete block design. Calves used were from the University of New Hampshire (n = 48) or a commercial dairy (n = 32). All calves were fed CR according to manufacturer's recommendations +/- Lf treatment within 90 min of birth. Lactoferrin treatments were 0 (control), 0.5, 1, and 2 g/d of supplemental Lf. At 12 h of age, calves were fed a second feeding of CR +/- supplemental Lf or 2 L of milk replacer +/- supplemental Lf. Calves continued to be fed milk replacer +/- supplemental Lf every 12 h for the duration of study. Blood samples were collected for determination of IgG and total serum protein at 0, 6, 12, 18, 24, and 48 h. Calves, except those fed 1 dose of CR plus 1 or 2 g of Lf, had serum IgG concentrations > or = 10 g/L at 24 h. Lactoferrin supplementation had no effect on serum IgG or total serum protein concentrations. Calves fed 2 doses of CR had greater serum IgG concentrations compared with calves fed 1 dose of CR. Apparent efficiency of absorption of IgG was less in calves fed 2 doses of CR compared with calves fed 1 dose of CR. Lactoferrin supplementation (up to 1 g/d) resulted in decreased apparent efficiency of absorption of IgG. At the sixth feeding (60 +/- 2 h of age), D-xylose (0.5 g/kg BW) was mixed with milk replacer +/- supplemental Lf (n = 48) to determine xylose absorption by the small intestine. Blood was collected at 0, 2, 4, 6, 8, and 12 h after feeding xylose for determination of plasma glucose and xylose concentrations. Xylose means and area under the curve resulted in quadratic effects. Feeding calves 0.5 or 1 g/d supplemental Lf resulted in decreased plasma xylose concentrations compared with calves fed 0 or 2 g/d of supplemental Lf. Colostrum replacer or supplemental Lf did not affect plasma glucose concentrations. This study indicates that supplementing Lf at 0.5 or 1 g/d to calves fed CR has a negative effect on apparent efficiency of IgG absorption and xylose absorption.

Extent of methionine limitation in peak-, early-, and mid-lactation dairy cows.

Five multiparous, ruminally and duodenally cannulated Holstein cows were assigned to 5 x 5 Latin squares at wk 2 (experiment 1), wk 11 to 13 (experiment 2), and wk 17 to 19 postpartum (experiment 3) to determine extent of Met limitation. Treatments were duodenally infused and consisted of 10 g/d of l-Lys plus 0, 3.5, 7.0, 10.5, or 16.0 g/d of dl-Met in experiments 1 and 2 and 8 g/d of l-Lys plus 0, 5, 10, 15, or 20 g/d of dl-Met in experiment 3. Calculated Lys contributions to total AA (TAA) in duodenal digesta for control treatments were 8.6, 7.5, and 9.0% for experiments 1, 2, and 3, respectively. Methionine contributions to TAA for the 5 infusion treatments were 1.9, 2.1, 2.2, 2.4, and 2.7% for experiment 1; 2.1, 2.3, 2.4, 2.5, and 2.7% for experiment 2; and 1.8, 2.0, 2.2, 2.4, and 2.5% for experiment 3, respectively. Milk protein yield increased linearly in experiments 1 and 2, indicating that Met contribution to TAA in duodenal digesta for maximal milk protein synthesis exceeded 2.7 for early-lactation cows. In experiment 2, a quadratic relationship was found between level of infused Met and milk protein content, with the response reaching a plateau when 12.2 g of Met was infused, corresponding with a Met contribution to TAA in duodenal digesta of 2.4%. In experiment 3, milk protein content increased quadratically, but milk yield declined linearly with increasing levels of infused Met; hence, milk protein yield was unaffected by treatment. The calculated plateau point of the milk protein content response curve was determined to be 12.4 g of infused Met, which corresponds to a Met contribution to TAA in duodenal digesta of 2.3%. Experiment 3 results indicate that the required level of Met in duodenal digesta for maximizing milk protein yield is lower than that required for maximizing milk protein content.

Effect of incremental urea supplementation of a conventional corn silage-based diet on ruminal ammonia concentration and synthesis of microbial protein.

One primiparous and 3 multiparous lactating Holstein cows fitted with ruminal and duodenal cannulas were used in a 4 x 4 Latin square design to determine the efficacy of adding urea to a corn silage-based diet on ruminal fermentation and microbial protein synthesis. Dietary treatments were 0, 0.3, 0.6, and 0.9% urea in diet dry matter (DM); urea was manually top dressed and incorporated into the ration. The basal diet contained (DM basis) 52% forage (with 61% of forage provided as corn silage) and 48% concentrate ingredients. The basal diet was formulated to meet National Research Council (NRC, 2001) requirements for energy and all nutrients except rumen-degradable protein (RDP) and metabolizable protein. Experimental periods lasted 14 d with the first 9 d for adaptation. The basal diet, without urea addition, contained 9.2% RDP in DM and had a predicted RDP balance of -167 g/d (NRC, 2001). There were no effects of dietary treatment on ruminal true digestibility of organic matter or ruminal apparent digestibility of neutral detergent fiber and acid detergent fiber. Total ruminal volatile fatty acid concentrations increased linearly with increasing urea level. Feeding increasing amounts of urea quadratically increased rumen ammonia N concentrations (9.0, 11.9, 12.8, and 17.4 mg/dL at 0, 0.3, 0.6, and 0.9% urea supplementation, respectively), passage of microbial N, and microbial N in duodenal digesta as a percentage of nonammonia N. The results of this study indicate that there were some positive effects of adding urea to the described lactating dairy cow diet, and that microbial protein synthesis was maximized at an average ruminal ammonia N concentration of 12.8 mg/dL when urea was added at 0.6% in diet DM.

Growth characteristics of calves fed an intensified milk replacer regimen with additional lactoferrin.

The objective of this study was to evaluate the effect of lactoferrin addition to milk replacer varying in crude protein (CP) on dry matter intake, growth, and days medicated. Thirty-four Holstein heifer calves were assigned to 4 treatments in a 2 x 2 factorial arrangement of treatments in a randomized complete block design. Treatments were as follows: 562 g daily of a nonmedicated conventional milk replacer (20% CP:20% fat) feeding regimen with or without 1 g of supplemental bovine lactoferrin (n = 9 for both treatments) or a nonmedicated intensified milk replacer feeding regimen (28% CP:20% fat) fed on a metabolizable energy basis (0.2 Mcal/kg BW(0.75)) from d 2 to 9, and at 0.27 Mcal/kg BW(0.75) from d 10 to 42 with or without 1g supplemental bovine lactoferrin (n = 8 for both treatments). Calves were fed pelleted starter (25% CP) in 227.5-g increments beginning on d 2 and had free access to water. Calves remained on the study for 14 d postweaning. Dry matter intake was determined daily. Growth measurements were taken weekly. Blood samples were taken twice weekly for determination of blood urea N. On d 10 of life, calves were subjected to a xylose challenge. Calves on conventional treatments ate more starter preweaning, during weaning, and postweaning. Preweaning, intensively fed calves had higher dry matter intakes. Weights of intensified-fed calves were greater at weaning. Intensified milk replacer-fed calves had greater average daily gain preweaning and overall and higher gain:feed ratios preweaning, but conventionally fed calves had higher gain:feed ratios during weaning. Intensified milk replacer-fed calves had greater hip heights during weaning and postweaning and greater heart girths preweaning, weaning, and postweaning. Days medicated were greater preweaning and overall for intensified-fed calves. There were no differences among treatments for xylose absorption. Calves on conventional treatments had increased blood urea nitrogen concentrations preweaning. There were no effects of lactoferrin on any experimental variable. Intensified milk replacer-fed calves consumed less starter but had higher average daily gains overall and larger frames and greater BW than conventionally fed calves. An intensified milk replacer feeding regimen promotes faster growth during the preweaning period when compared with calves fed conventional treatments, but supplemental bovine lactoferrin was not beneficial under these experimental conditions.

Dietary forage and nonfiber carbohydrate contents influence B-vitamin intake, duodenal flow, and apparent ruminal synthesis in lactating dairy cows.

The objective of this experiment was to quantify intakes, duodenal flows, and ruminal apparent synthesis (AS) of B-vitamins in lactating dairy cows fed diets varying in forage and nonfiber carbohydrate (NFC) contents. Eight (4 primiparous and 4 multiparous) ruminally and duodenally cannulated Holstein cows were assigned to 4 dietary treatments in a replicated 21-d period, 4 x 4 Latin square design with a 2 x 2 factorial treatment arrangement. Diets, fed as TMR, contained (DM basis) 2 levels of forage (35 and 60%) and 2 levels of NFC (30 and 40%). The forage portion of the diets contained 50% corn silage, 33% alfalfa hay, and 17% grass hay. Soybean hulls and beet pulp (2:1) and corn meal and ground barley (2:1) were included to achieve desired NFC concentrations. No supplemental B-vitamins were fed. B-vitamin AS was calculated as the amount of a specific B-vitamin flowing to the duodenum minus its daily orts-corrected intake. Dry matter and organic matter intakes were higher for cows fed the 35% forage diets and the 40% NFC diets. Increasing dietary forage content decreased ruminal AS of pyridoxine, folic acid, and B12. Increasing dietary NFC content increased ruminal AS of nicotinic acid, nicotinamide, niacin, pyridoxal, B6, and folic acid but decreased AS of B12. Across diets, amounts of B-vitamins synthesized were highest for niacin, followed by riboflavin, B12, thiamin, B6, and folic acid. Biotin AS values were negative for all diets, suggesting either no ruminal synthesis or that destruction by ruminal microflora was greater than synthesis. B-vitamin intake, duodenal flow, and ruminal synthesis are influenced by dietary forage and NFC contents.

Improving intestinal amino acid supply of pre- and postpartum dairy cows with rumen-protected methionine and lysine.

Eighty-four Holstein cows were assigned to a randomized block experiment to determine effects of supplementing pre- and postpartum diets containing highLys protein supplements with rumen-protected Met and Lys. Before parturition, cows received a basal diet with 1) no rumen-protected amino acids (AA), 2) 10.5 g/d of Met from rumen-protected Met, or 3) 10.2 g/d of Met and 16.0 g/d of Lys from rumen-protected Met plus Lys. After parturition, cows continued to receive AA treatments but switched to diets balanced for 16.0 or 18.5% crude protein (CP). Diets were corn-based; supplemental protein was provided by soybean products and blood meal. Cows received treatments through d 105 of lactation. Compared with basal and Met-supplemented diets, Met + Lys supplementation increased yield of energy-corrected milk, fat, and protein, and tended to increase production of 3.5% fat-corrected milk. Significant CP x AA interactions were observed only for milk protein and fat content. Supplementation of the 16% CP diet with Met and Met + Lys had no effect on milk true protein and fat content. However, Met and Met + Lys supplementation of the 18.5% CP diet increased milk protein content by 0.21 and 0.14 percentage units, respectively, and Met supplementation increased fat content by 0.26 percentage units. Results of this study indicate that early-lactation cows fed corn-based diets are responsive to increased intestinal supplies of Lys and Met and that the responses depend on dietary CP concentration, supply of metabolizable protein, and intestinal digestibility of the rumen-undegradable fraction of supplemental proteins.