Research Note: Effect of diet with different proportions of ryegrass on breast meat quality of broiler geese.

This study was conducted to determine the effects of diet with different proportions of ryegrass on breast meat quality of geese. In total, 240 healthy male Yangzhou geese (28-day-old) with similar body weight were divided randomly into 4 diet groups (control group: fed commercial diets; treatment groups I, II, and III: fed ryegrass and commercial diet in the ratios of 1.5:1, 2:1, and 3:1, respectively), the birds being fed from the age of 29 to 70 D. The results shows that the body weights of 70-day-old geese of treatment groups II and III were lower than those in the control group, whereas those of geese of treatment group I were similar to those of the control group. The contents of flavor amino acid and total (essential) amino acids in treatment groups I and II were higher than those in treatment group III (P < 0.05). In addition, grass supplementation reduced saturated fatty acid content and increased that of omega-3 (n-3) polyunsaturated fatty acids, relative to the control group (P < 0.05). Finally, among the 6 minerals analyzed in breast muscle, differences existed in Zn, Se, and Cu contents among the geese fed with different proportions of ryegrass. Zn content of geese from treatment groups II and III was significantly higher than that of those of the control group; Cu content was lower with grass intake and was significantly higher in the control group than in treatment group III; Se content was significantly higher in the control group than in both groups II and III (all at P < 0.05). The results from this study indicated that geese fed with low proportions of ryegrass (1.5:1 or 2:1) showed good growth performance and increased total (essential) amino acid, flavor amino acid, n-3 polyunsaturated fatty acid, and Zn content in meat, which had a certain guiding value for the production of high-quality goose meat under intensive feeding conditions.

Effects of endophyte-infected tall fescue seed and protein supplementation on stocker steers: I. Growth performance and hemodynamic responses.

Fescue toxicosis is a multifaceted syndrome common in cattle grazing endophyte-infected tall fescue and is detrimental to growth and performance. Recent research has shown that supplementing protein has the potential to enhance growth performance in weaned steers. Therefore, the objective of this study was to evaluate the effect of supplemental CP on physiological parameters in stocker steers experiencing fescue toxicosis. Thirty-six weaned Angus steers (6 mo of age) stratified by weight (196.1 ± 3.6 kg) were assigned to a 2 × 2 factorial arrangement for 56 d: endophyte-free (EF) seed and 14% CP (EF-14; n = 9), EF seed and 18% CP (EF-18; n = 9), endophyte-infected (EI) seed and 14% CP (EI-14; n = 9), and EI seed and 18% CP (EI-18; n = 9). Steer growth and hemodynamic responses were collected weekly during ergot alkaloid exposure. On day 14 of the trial, iButton temperature data loggers were subcutaneously inserted in the lateral neck region to record hourly body temperature for 42 d. Data were analyzed using PROC MIXED of SAS with repeated measures. No differences were observed in DMI, BW, ADG, F:G, or BCS during the treatment period (P > 0.05). Hair shedding scores, rectal temperatures, surface temperatures, and respiration rates were greater in EI steers compared to EF steers regardless of supplemental CP (P < 0.05). However, subcutaneous body temperature was greater in EI-14 steers (37.94 °C) compared to other steer groups (37.60, 37.68, 37.72 ± 0.04 °C for EF-14, EF-18, and EI-18, respectively; P < 0.05). Prolactin concentrations tended to be greater in EF steers when compared to EI steers (P = 0.07). Heart rate and hematocrit were reduced for EI-18 steers compared to other steer groups (P < 0.05). Caudal artery diameter was reduced in EI-18 steers compared to EI-14 steers (2.60 vs. 2.75 ± 0.05 mm, respectively; P < 0.05) and caudal vein diameter was reduced in EI-18 steers (3.20 mm) compared to all other steer groups (3.36, 3.39, 3.50 mm for EF-14, EF-18, and EI-14, respectively; P < 0.05). However, there was no difference observed in systolic or diastolic blood pressure during the treatment period (P > 0.05). Based on the data, exposure to low to moderate levels of ergot alkaloids during the stocker phase had a negative impact on hemodynamic responses and supplemental CP had minimal impact to alleviate symptoms. Therefore, feeding additional protein above established requirements is not expected to help alleviate fescue toxicosis.

Effect of substituting fresh-cut perennial ryegrass with fresh-cut white clover on bovine milk fatty acid profile.

BACKGROUND: Including forage legumes in dairy systems can help address increasing environmental/economic concerns about perennial ryegrass monoculture pastures. This work investigated the effect of substituting fresh-cut grass with increasing quantities of fresh-cut white clover (WC) on milk fatty acid (FA) profile and transfer efficiency of dietary linoleic (LA) and α-linolenic (ALNA) acids to milk fat. Three groups of three crossbred dairy cows were used in a 3 × 3 crossover design. Dietary treatments were 0 g kg-1 WC + 600 g kg-1 grass, 200 g kg-1 WC + 400 g kg-1 grass, and 400 g kg-1 WC + 200 g kg-1 grass. All treatments were supplemented with 400 g kg-1 concentrates on a dry matter basis. Cows had a 19-day adaptation period to the experimental diet before a 6-day measurement period in individual tie stalls. RESULTS: Increasing dietary WC did not affect dry matter intake, milk yield or milk concentrations of fat, protein or lactose. Milk polyunsaturated FA concentrations (total n-3, total n-6, LA and ALNA) and transfer efficiency of LA and ALNA were increased with increasing dietary WC supply. CONCLUSION: Inclusion of WC in pastures may increase concentrations of nutritionally beneficial FA, without influencing milk yield and basic composition, but any implications on human health cannot be drawn. © 2018 The Authors. Journal of the Science of Food and Agriculture published by JohnWiley & Sons Ltd on behalf of Society of Chemical Industry.

Cryopreservation Of Nili-Ravi Buffalo Bull Sperm in Cryodiluent Supplemented with Lolium perenne Protein Preparations.

BACKGROUND: Semen from the Nili-Ravi buffalo bull, Bubalus bubalis, shows poor survival after freeze storage compared to bovine (Bos taurus and Bos indicus) semen. Freeze-susceptibility distinctions in these two genera have been attributed to differences in sperm membranes. MATERIALS AND METHODS: We measured the impact of protein preparations derived from a frost-resistant perennial grass, Lolium perenne, with ice recrystallization inhibition activity on the low temperature storage of B. bubalis semen. RESULTS: When the L. perenne preparations (0.1, 1, 10 µg/mL) were added to buffalo semen [2 ejaculates per bull (N=3) per replicate (r=3)] in Tris-citrate extender (50×106sperm mL-1), there was no impact on semen quality, as measured by sperm motility and plasma membrane integrity, after storage at 4 degree C (P>0.05). However, when semen supplemented with the grass proteins (0.1 and 1 µg mL-1) was evaluated after freezing and storage in liquid nitrogen for 24 h, post-thaw sperm progressive motility and plasma membrane integrity was higher (P<0.05) than in control samples. Post-thaw sperm viability and sperm acrosome integrity was similar (P > 0.05) to controls. CONCLUSION: The improvement in cryopreserved buffalo sperm progressive motility and plasma membrane integrity suggests that the use of these easily-made preparations may improve fertility after cryopreservation and offers the prospect of improved conception rates after artificial insemination with cryopreservation.

Antioxidant, anti-inflammatory and anti-septic potential of phenolic acids and flavonoid fractions isolated from Lolium multiflorum.

CONTEXT: Interest has recently renewed in using Lolium multiflorum Lam. (Poaceae) (called Italian ryegrass; IRG) silage as an antioxidant and anti-inflammatory diet. OBJECTIVE: This study investigated the antioxidant, anti-inflammatory and anti-septic potential of IRG silage and identified the primary components in IRG active fractions. MATERIALS AND METHODS: Total 16 fractions were separated from the chloroform-soluble extract of IRG aerial part using Sephadex LH-20 column before HPLC analysis. Antioxidant and anti-inflammatory activities of the fractions at doses of 0-100 µg/mL were investigated using various cell-free and cell-mediated assay systems. To explore anti-septic effect of IRG fractions, female ICR and BALB/c mice orally received 40 mg/kg of phenolic acid and flavonoid-rich active fractions F7 and F8 every other day for 10 days, respectively, followed by LPS challenge. RESULTS: The active fractions showed greater antioxidant and anti-inflammatory potential compared with other fractions. IC50 values of F7 and F8 to reduce LPS-stimulated NO and TNF-α production were around 15 and 30 µg/mL, respectively. Comparison of retention times with authentic compounds through HPLC analysis revealed the presence of caffeic acid, ferulic acid, myricetin and kaempferol in the fractions as primary components. These fractions inhibited LPS-stimulated MAPK and NF-κB activation. Supplementation with F7 or F8 improved the survival rates of mice to 70 and 60%, respectively, in LPS-injected mice and reduced near completely serum TNF-α and IL-6 levels. DISCUSSION AND CONCLUSION: This study highlights antioxidant, anti-inflammatory and anti-septic activities of IRG active fractions, eventually suggesting their usefulness in preventing oxidative damage and inflammatory disorders.

Characterization of Proanthocyanidins from Seeds of Perennial Ryegrass (Lolium perenne L.) and Tall Fescue (Festuca arundinacea) by Liquid Chromatography-Mass Spectrometry.

Perennial ryegrass (Lolium perenne) and tall fescue (Festuca arundinacea) are forage species of the grass family (Poaceae) that are key components of temperate pasture-based agricultural systems. Proanthocyanidins (PAs) are oligomeric flavonoids that, when provided as part of a farm animal's diet, have been reported to improve animal production and health. Up to now, forage grasses have been deemed not to produce PAs. This paper reports for the first time the detection of polymerized PAs in aqueous methanolic extracts of seed tissue of both perennial ryegrass and tall fescue, using LC-MS/MS. We have determined the structure of the PAs to be trans-flavan-3-ol-based, consisting predominately of afzelechin and catechin and linked primarily by B-type bonds. Investigations into the leaf tissue of both species failed to detect any PAs. This discovery opens the possibility of using genetic engineering tools to achieve tannin accumulation in leaf tissue of perennial ryegrass and tall fescue.

Effects of ewes grazing sulla or ryegrass pasture for different daily durations on forage intake, milk production and fatty acid composition of cheese.

Sulla (Sulla coronarium L.) forage is valued for its positive impact on ruminant production, in part due to its moderate content of condensed tannin (CT). The duration of daily grazing is a factor affecting the feed intake and milk production of ewes. In this study, the effects of grazing sulla pasture compared with annual ryegrass, and the extension of grazing from 8 to 22 h/day, were evaluated with regard to ewe forage intake and milk production, as well as the physicochemical properties and fatty acid (FA) composition of cheese. During 42 days in the spring, 28 ewes of the Comisana breed were divided into four groups (S8, S22, R8 and R22) that grazed sulla (S) or ryegrass (R) for 8 (0800 to 1600 h) or 22 h/day, and received no feeding supplement. In six cheese-making sessions, cheeses were manufactured from the 48 h bulk milk of each group. Compared with ewes grazing ryegrass, those grazing sulla had higher dry matter (DM) intake, intake rate and milk yield, and produced milk that was lower in fat and higher in casein. Ewes grazing for 22 h spent more time eating, which reduced the intake rate, increased DM and nutrient intake and milk yield, and reduced milk fat. Due to the ability of CT to inhibit the complete ruminal biohydrogenation of polyunsaturated fatty acids (PUFA), the FA composition of sulla cheese was more beneficial for consumer health compared with ryegrass cheese, having lower levels of saturated fatty acids and higher levels of PUFA and n-3 FA. The FA profile of S8 cheese was better than that of S22 cheese, as it was higher in branched-chain FA, monounsaturated FA, PUFA, rumenic acid (c9,t11-C18:2), and had a greater health-promoting index. The effect of short grazing time on sulla was attributed to major inhibition of PUFA biohydrogenating ruminal bacteria, presumably stimulated by the higher accumulation of sulla CT in the rumen, which is related to a higher intake rate over a shorter eating time. Thus, grazing sulla improved the performance of ewes, thereby increasing, especially with short grazing time, the nutritional properties of cheese fat.

Variation in Alkaloid Production from Genetically Diverse Lolium Accessions Infected with Epichloë Species.

Widespread infection of Epichloë occultans in annual ryegrass in Australia suggests that infection provides its weedy host, Lolium rigidum, some ecological advantage. Initial studies determined the distribution and profiles of known Epichloë alkaloids (epoxy-janthitrems, ergovaline, lolines, lolitrem B, and peramine) in plant extracts using a combination of GC-FID and HPLC techniques utilizing a single accession of Australian L. rigidum. However, the lolines N-acetylnorloline (NANL) and N-formylloline (NFL) were the only alkaloids detected and were highly concentrated in the immature inflorescences of mature plants. Additional glasshouse studies subjected a wide range of Australian L. rigidum haplotypes and international annual Lolium accessions to a suite of analyses to determine alkaloid levels and profiles. Again, NFL and NANL were the key lolines produced, with NFL consistently predominating. Considerable variation in alkaloid production was found both within and between biotypes and accessions evaluated under identical conditions, at the same maturation stage and on the same tissue type. The pyrrolopyrazine alkaloid peramine was also present in 8 out of 17 Australian biotypes of L. rigidum and 7 out of 33 international accessions infected with Epichloë spp.; the highest peramine concentrations were observed in seed extracts from L. rigidum collected from Australia. This study represents the first report of alkaloids from a geographically diverse collection of annual ryegrass germplasm infected with Epichloë spp. when grown under identical controlled conditions.

Stable isotope tracing: a powerful tool for selenium speciation and metabolic studies in non-hyperaccumulator plants (ryegrass Lolium perenne L.).

Selenium is both essential and toxic for mammals; the range between the two roles is narrow and not only dose-dependent but also related to the chemical species present in foodstuff. Unraveling the metabolism of Se in plants as a function of Se source may thus lead to ways to increase efficiency of fertilization procedures in selenium deficient regions. In this study, stable-isotope tracing was applied for the first time in plants to simultaneously monitor the bio-incorporation of two inorganic Se species commonly used as foodstuff enrichment sources. Occurrence and speciation of Se coming from different Se sources were investigated in root and leaf extracts of ryegrass (Lolium perenne L.), which had been co-exposed to two labeled Se species ((77)SeIV and (82)SeVI). Although the plant absorbed similar amounts of Se when supplied in the form of selenite or selenate, the results evidenced marked differences in speciation and tissues allocation. Selenite was converted into organic forms incorporated mostly into high molecular weight compounds with limited translocation to leaves, whereas selenate was highly mobile being little assimilated into organic forms. Double-spike isotopic tracer methodology makes it possible to compare the metabolism of two species-specific Se sources simultaneously in a single experiment and to analyze Se behavior in not-hyperaccumulator plants, the ICP-MS sensitivity being improved by the use of enriched isotopes.

Pollensomes as Natural Vehicles for Pollen Allergens.

Olive (Olea europaea) pollen constitutes one of the most important allergen sources in the Mediterranean countries and some areas of the United States, South Africa, and Australia. Recently, we provided evidence that olive pollen releases nanovesicles of respirable size, named generically pollensomes, during in vitro germination. Olive pollensomes contain allergens, such as Ole e 1, Ole e 11, and Ole e 12, suggesting a possible role in allergy. The aim of this study was to assess the contribution of pollensomes to the allergic reaction. We show that pollensomes exhibit allergenic activity in terms of patients' IgE-binding capacity, human basophil activation, and positive skin reaction in sensitized patients. Furthermore, allergen-containing pollensomes have been isolated from three clinically relevant nonphylogenetically related species: birch (Betula verrucosa), pine (Pinus sylvestris), and ryegrass (Lolium perenne). Most interesting, pollensomes were isolated from aerobiological samples collected with an eight-stage cascade impactor collector, indicating that pollensomes secretion is a naturally occurring phenomenon. Our findings indicate that pollensomes may represent widespread vehicles for pollen allergens, with potential implications in the allergic reaction.

Phosphorus in manure and sewage sludge more recyclable than in soluble inorganic fertilizer.

Phosphorus (P) flow from deposits through agriculture to waterways leads to eutrophication and depletion of P reserves. Therefore, P must be recycled. Low and unpredictable plant availability of P in residues is considered to be a limiting factor for recycling. We identified the determinants for the plant-availability of P in agrifood residues. We quantified P in Italian ryegrass (Lolium multiflorum) and in field soil fractions with different plant availabilities of P as a response to manure and sewage sludge with a range of P capture and hygienization treatments. P was more available in manure and in sludge, when it was captured biologically or with a moderate iron (Fe)/P (1.6), than in NPK. Increasing rate of sludge impaired P recovery and high Fe/P (9.8) prevented it. Anaerobic digestion (AD) reduced plant-availability at relevant rates. The recovery of P was increased in AD manure via composting and in AD sludge via combined acid and oxidizer. P was not available to plants in the sludge hygienized with a high calcium/P. Contrary to assumed knowledge, the recyclability of P in appropriately treated residues can be better than in NPK. The prevention of P sorption in soil by organic substances in fertilizers critically enhances the recyclability of P.

Fragipan horizon fragmentation in slaking experiments with amendment materials and ryegrass root tissue extracts.

Slaking experiments were conducted of fragipan clods immersed in solutions of poultry manure, aerobically digested biosolid waste (ADB), fluidized bed combustion byproduct (FBC), D-H2O, CaCO3, NaF, Na-hexa-metaphosphate, and ryegrass root biomass. The fragipan clods were sampled from the Btx horizon of an Oxyaquic Fragiudalf in Kentucky. Wet sieving aggregate analysis showed significantly better fragmentation in the NaF, Na-hexa-metaphosphate, and ryegrass root solutions with a mean weight diameter range of 15.5-18.8 mm compared to the 44.2-47.9 mm of the poultry manure, ADB, and FBC treatments. Dissolved Si, Al, Fe, and Mn levels released in solution were ambiguous. The poor efficiency of the poultry manure, ADB, and FBC treatments was attributed to their high ionic strength, while the high efficiency of the NaF, Na-hexa-metaphosphate, and rye grass root solutions to their high sodium soluble ratio (SSR). A slaking mechanism is proposed suggesting that aqueous solutions with high SSR penetrate faster into the fragipan capillaries and generate the critical swelling pressure and shearing stress required to rupture the fragipan into several fragments. Additional fragmentation occurs in a followup stage during which potential Si, Al, Fe, and Mn binding agents may be released into solution. Field experiments testing these findings are in progress.

Positive regulations of adipogenesis by Italian ryegrass [Lolium multiflorum] in 3T3-L1 cells.

BACK GROUND: Intramuscular fat deposition in the meat animal is relatively new strategy for developing the meat quality. Fat deposition is largely depending on the adipocyte proliferation and differentiation. Therefore, we investigated the effect of chloroform extract of L. multiflorum [CELM] on cell proliferation, lipid accumulation and adipocyte differentiation in 3T3-L1 cells and body weight of mouse. RESULTS: We identified 6,9-Octadecatrienoic acid, Hexadecanoic acid, 2-hydroxypropanoic acid, butane-2,3-diol and hexane-1,2,3,4,5,6-hexaol in CELM. L. multiflorum extract increased the cell viability, lipid accumulation, cell cycle progression and key transcriptional and secretory factors like PPRAγ2, C/CEBP-α, adiponectin, aP2, GLUT-4, FAS and SREBP-1 mRNA expression as compared with control cells. For in-vivo, mice administered with CELM significantly increased body weight throughout the experiment periods. Further, the identified fatty acids like 3, 6, 9-Octadecatrienoic acid and Hexadecanoic acid was docked with target protein [PPRAγ2] using HEX 6.12. The least binding energy considered as high affinity with target protein. The maximum affinity with the target protein was observed in the Hexadecanoic acid followed by 3, 6, 9-Octadecatrienoic acid. The binding efficacy of Hexadecanoic acid and 3, 6, 9-Octadecatrienoic acid to the active site of PPAR-γ2 may be enhanced the adipocyte differentiations. CONCLUSION: These findings suggest that CELM stimulates adipogenesis via activating the PPARγ-mediated signaling pathway in adipocyte which could be useful for the development of meat quality in animals.

In vitro and in vivo enhancement of adipogenesis by Italian ryegrass (Lolium multiflorum) in 3T3-L1 cells and mice.

Adipogenesis is very much important in improving the quality of meat in animals. The aim of the present study was to investigate the in vitro and in vivo adipogenesis regulation properties of Lolium multiflorum on 3T3-L1 pre-adipocytes and mice. Chemical composition of petroleum ether extract of L. multiflorum (PET-LM) confirmed the presence of fatty acids, such as α-linolenic acid, docosahexaenoic acid, oleic acid, docosatetraenoic acid, and caprylic acid, as the major compounds. PET-LM treatment increased viability, lipid accumulation, lipolysis, cell cycle progression, and DNA synthesis in the cells. PET-LM treatment also augmented peroxysome proliferator activated receptor (PPAR)-γ2, CCAAT/enhancer binding protein-α, adiponectin, adipocyte binding protein, glucose transporter-4, fatty acid synthase, and sterol regulatory element binding protein-1 expression at mRNA and protein levels in differentiated adipocytes. In addition, mice administered with 200 mg/kg body weight PET-LM for 8 weeks showed greater body weight than control mice. These findings suggest that PET-LM facilitates adipogenesis by stimulating PPARγ-mediated signaling cascades in adipocytes which could be useful for quality meat development in animals.

Monitoring the rumen pectinolytic bacteria Treponema saccharophilum using real-time PCR.

Treponema saccharophilum is a pectinolytic bacterium isolated from the bovine rumen. The abundance of this bacterium has not been well determined, reflecting the lack of a reliable and accurate detection method. To develop a rapid method for monitoring T. saccharophilum, we performed pyrosequencing of genomic DNA isolated from rumen microbiota to explore the 16S rRNA gene sequences of T. saccharophilum candidates. Species-specific primers were designed based on fifteen sequences of partial 16S rRNA genes generated through pyrosequencing with 97% or higher similarity with T. saccharophilum DSM2985 along with sequence from type strain. The relative abundance of T. saccharophilum was quantified in both in vitro and in vivo rumen systems with varied pectin-containing forages using real-time PCR. There was a clear association of T. saccharophilum with alfalfa hay, which contains more pectin than Chinese wild rye hay or corn stover. The relative abundance of T. saccharophilum was as high as 0.58% in vivo, comparable with the population density of other common rumen bacteria. It is recognized that T. saccharophilum plays an important role in pectin digestion in the rumen.

Antioxidant effects of ryegrass phenolics in lamb liver and plasma.

Sixteen lambs were divided into two groups and fed two different diets. Eight lambs were stall-fed with a concentrate-based diet (C), and the remaining eight lambs were allowed to graze on Lolium perenne (G). The antioxidant status was measured in the liver and plasma samples before and after solid-phase extraction (SPE) to probe the antioxidant effects that grass phenolic compounds may have conferred onto the animal tissues. The liver and plasma samples from grass-fed lambs displayed a greater antioxidant capacity than the tissues from C lamb group, but only if samples had not been passed through SPE cartridges. Finally, the feed and animal tissues, which had been purified by SPE, were analysed by liquid chromatography combined with mass spectrometry (LC���MS) to identify phenolic compounds present in L. perenne and to evaluate the results from the antioxidant assays. It would appear that the improvement of the antioxidant capacity of lamb liver and plasma from lambs fed ryegrass was not related to the direct transfer of phenolic compounds from grass to the animal tissues.

Milk production and composition of mid-lactation cows consuming perennial ryegrass-and chicory-based diets.

Dry matter intakes (DMI), nutrient selection, and milk production responses of dairy cows grazing 3 herbage-based diets offered at 2 allowances were measured. The 2 allowances were 20 (low) and 30 (high) kg of dry matter (DM)/cow per day and these were applied to 3 herbage types: perennial ryegrass (PRG) and chicory (CHIC+) monocultures and a mixed sward of chicory and perennial ryegrass (MIX). The CHIC+ diet was supplemented with alfalfa hay (approximately 2 kg of DM/cow per day) to maintain dietary neutral detergent fiber (NDF) concentration and all diets were supplemented with energy-based pellets (6 kg of DM/cow per day). Holstein-Friesian dairy cows averaging 136 ± 30 d in milk were allocated to 4 replicates of the 6 treatments using stratified randomization procedures. Cows were adapted to their experimental diets over a 14-d period, with measurements of DMI, milk yield, and composition conducted over the following 10 d. Herbage DMI was lowest (12.8 vs. 14.0 kg of DM/d) for CHIC+ compared with the MIX and PRG, although total forage intake (grazed herbage plus hay) was similar (14.0 to 15.0 kg of DM/d) across the 3 treatments. Milk production, milk protein, and milk fat concentrations were not different between herbage types. Grazed herbage DMI increased with increasing herbage allowance and this was associated with increased milk protein concentration (3.23 to 3.34%) and total casein production (41.7 to 43.6 mg/g). Concentrations of polyunsaturated fatty acids in milk fat, particularly linoleic acid, were increased in milk from cows offered the CHIC+ or the MIX diets, indicating potential benefits of chicory herbage on milk fatty acid concentrations. Although feeding CHIC+ or MIX did not increase milk yield, these herbage types could be used as an alternative to perennial ryegrass pasture in spring.

Supplementing lactating dairy cows fed high-quality pasture with black wattle (Acacia mearnsii) tannin.

A reduction in urinary nitrogen (N) excretion from dairy cows fed pasture containing a high N concentration in the dry matter (DM) will have environmental benefits, because losses to soil water and air by leachate and nitrous oxides (N2O) will be reduced. Condensed tannins (CT) reduce digestion of N, and provision as a dietary additive could have nutritional benefits for production, but the amount required and the responses to different sources of CT on milk production have not been defined. Two experiments were conducted to evaluate effects of supplementation with CT extracted from black wattle (Acacia mearnsii De Wild.) on milk production and faecal N concentration by lactating dairy cows grazing a vegetative Perennial ryegrass (Lolium perenne L.)-based pasture. In one experiment, CT was administered as a drench, twice daily, to 38 multiparous Holstein-Friesian cows assigned to four treatments; control (CONT, 0 g/day), low CT (LCT, 111 g/day), medium CT (MCT, 222 g/day) and high CT (HCT, 444 g/day), grazing as a single group. The CT supplementation affected milk yield (P < 0.001) with a trend of declining milk yield as CT concentration increased from about 0.6 to about 2.9% of dietary DM. Milk urea nitrogen (MUN) decreased at MCT and HCT levels of supplementation (P < 0.01) but milk fat, CP and lactose percentage were not affected by CT supplementation. The CT supplementation increased N concentration in faeces for LCT and MCT treatments (P < 0.05), suggesting partitioning of dietary N away from urine. When CT was pelleted with grain, in a second experiment and fed twice daily as a supplement at milking, it reduced the acceptability relative to pellets without CT, and tended to lower milk production from 25.4 to 24.5 kg/day, although the decline was not significant (P > 0.05). The diet of cows fed pellets with CT contained about 1.2% CT in the DM but neither milk constituents nor MUN were affected by CT-supplemented grain (P > 0.05). These findings demonstrate beneficial effects for production of low concentrations (c. 0.6% DM) of CT from black wattle when given to cows grazing pasture with an N concentration of 3.8%, and suggest a diversion of N from urine, but when CT exceeded about 1.4% of dietary DM, milk production was depressed. The value of supplementing a pasture diet for lactating dairy cows with black wattle tannin extract will depend on costs of supplementation, returns from milk production and liabilities associated with N losses to urine.

Unique and cross-reactive T cell epitope peptides of the major Bahia grass pollen allergen, Pas n 1.

BACKGROUND: Bahia grass pollen (BaGP) is a major cause of allergic rhinitis. Subcutaneous allergen-specific immunotherapy is effective for grass pollen allergy, but is unsuitable for patients with moderate to severe asthma due to the risk of anaphylaxis. T cell-reactive but IgE nonreactive peptides provide a safer treatment option. This study aimed to identify and characterize dominant CD4(+) T cell epitope peptides of the major BaGP allergen, Pas n 1. METHODS: Pas n 1-specific T cell lines generated from the peripheral blood of BaGP-allergic subjects were tested for proliferative and cytokine response to overlapping 20-mer Pas n 1 peptides. Cross-reactivity to homologous peptides from Lol p 1 and Cyn d 1 of Ryegrass and Bermuda grass pollen, respectively, was assessed using Pas n 1 peptide-specific T cell clones. MHC class II restriction of Pas n 1 peptide T cell recognition was determined by HLA blocking assays and peptide IgE reactivity tested by dot blotting. RESULTS: Three Pas n 1 peptides showed dominant T cell reactivity; 15 of 18 (83%) patients responded to one or more of these peptides. T cell clones specific for dominant Pas n 1 peptides showed evidence of species-specific T cell reactivity as well as cross-reactivity with other group 1 grass pollen allergens. The dominant Pas n 1 T cell epitope peptides showed HLA binding diversity and were non-IgE reactive. CONCLUSIONS: The immunodominant T cell-reactive Pas n 1 peptides are candidates for safe immunotherapy for individuals, including those with asthma, who are allergic to Bahia and possibly other grass pollens.

Rapid and accurate analyses of silicon and phosphorus in plants using a portable X-ray fluorescence spectrometer.

The elemental analysis of plant material is a frequently employed tool across biological disciplines, yet accurate, convenient and economical methods for the determination of some important elements are currently lacking. For instance, digestion-based techniques are often hazardous and time-consuming and, particularly in the case of silicon (Si), can suffer from low accuracy due to incomplete solubilization and potential volatilization, whilst other methods may require large, expensive and specialised equipment. Here, we present a rapid, safe and accurate procedure for the simultaneous, nonconsumptive analysis of Si and phosphorus (P) in as little as 0.1 g dried and ground plant material using a portable X-ray fluorescence spectrometer (P-XRF). We used certified reference materials from different plant species to test the analytical performance of P-XRF and show that the analysis suffers from very little bias and that the repeatability precision of the measurements is as good as or better than that of other methods. Using this technique we were able to process and analyse 200 ground samples a day, so P-XRF could provide a particularly valuable tool for plant biologists requiring the simultaneous nonconsumptive analysis of multiple elements, including those known to be difficult to measure such as Si, in large numbers of samples.