Using 77Se-Labelled Foliar Fertilisers to Determine How Se Transfers Within Wheat Over Time

Foliar selenium (Se) fertilisation has been shown to be more efficient than soil-applied fertilisation, but the dynamics of absorption and translocation have not yet been explored. An experiment was undertaken to investigate time-dependent changes in the absorption, transformation, and distribution of Se in wheat when 77Se-enriched sodium selenate (Sefert) was applied to the leaves at a rate of 3.33 μg Se per kg soil (equivalent to 10 g ha−1) and two growth stages, namely stem elongation, Zadoks stage 31/32 (GS1), and heading stage, Zadoks stage 57 (GS2). The effect of urea inclusion in foliar Se fertilisers on the penetration rates of Se was also investigated. Wheat was harvested at 3, 10, and 17 days and 3, 10, and 34 days after Se applications at GS1 and GS2, respectively. Applying foliar Se, irrespective of the formulation, brought grain Se concentration to a level high enough to be considered adequate for biofortification. Inclusion of N in the foliar Se solution applied at an early growth stage increased recoveries in the plants, likely due to improved absorption of applied Se through the young leaves. At a later growth stage, the inclusion of N in foliar Se solutions was also beneficial as it improved the assimilation of applied inorganic Se into bioavailable selenomethionine, which was then rapidly translocated to the grain. The practical knowledge gained about the optimisation of Se fertiliser formulation, method, and timing of application will be of importance in refining biofortification programs across different climatic regimes.

252 Effects of Increasing Urea in Corn Silage Diets and Duration of Ensiling on the Rumen Undegradable Protein Content of Corn Silage

Two experiments were conducted to evaluate the effects of increasing urea in a corn silage cattle diet and ensiling time (ET) impact on rumen undegradable crude protein (RUP) content of corn silage. In Exp. 1, ten ruminally- and duodenally cannulated heifers (body weight 265 ± 16 kg) were utilized in a 4 × 4 Latin square design and treatments were urea included at 0, 0.5, 1, or 1.5% of dietary dry matter (DM). In Exp. 2, corn silage samples were collected during feedout at 32-d intervals from the time of ensiling (d 0) to 160 d post-ensiling followed by separation in water to forage and grain components. Forage and grain samples were ruminally incubated in two steers to calculate RUP content of corn silage. In Exp. 1, DM intake increased linearly from 5.7 to 6.8 kg/d as urea inclusion increased (P < 0.001). Apparent total tract digestibility of DM and organic matter increased linearly from 55.8% to 60.8%, and 60.1% to 64.9%, respectively (P < 0.001). Total tract digestibility of neutral and acid detergent fiber increased linearly with increasing urea inclusion (P ≤ 0.004). In Exp. 2, the RUP content of the corn grain component decreased from 43.7% of CP at day 0 to 15.8% and 10.0% of CP after 32 and 96 d of ensiling, respectively (quadratic, P < 0.01). The RUP content of the forage averaged 19.3% of CP across ET ranging from 21.5 to 17.8% of CP (P ≥ 0.28). Estimated from the individual components, the RUP content of whole corn silage decreased from 32% to 17.1% of CP after 160 d in storage, a portion of which is digestible. Urea supplementation improved digestibility of corn silage diets and RUP content of corn silage decreased with storage time, primarily driven by changes in the corn grain component.

Reply to comment on Couzi et al . (2018): a phenomenological model for structural phase transitions in incommensurate alkane/urea inclusion compounds

In a recent paper (Couzi et al. 2018 R. Soc. open sci. 5 , 180058. ( doi:10.1098/rsos.180058 )), we proposed a new phenomenological model to account for the I↔II↔“III” phase sequence in incommensurate n -alkane/urea inclusion compounds, which represents an alternative interpretation to that proposed in work of Toudic et al. In a Comment (Toudic et al. 2019 R. Soc. open sci. 6 , 182073. ( doi:10.1098/rsos.182073 )), Toudic et al. have questioned our assignment of the superspace group of phase II of n -nonadecane/urea, which they have previously assigned, based on a (3 + 2)-dimensional superspace, as C222 1 (00 γ )(10 δ ). In this Reply, we present new results from a comprehensive synchrotron single-crystal X-ray diffraction study of n -nonadecane/urea, involving measurements as a detailed function of temperature across the I↔II↔“III” phase transition sequence. Our results demonstrate conclusively that “main reflections” ( h, k, l , 0) with h+k odd are observed in phase II of n -nonadecane/urea (including temperatures in phase II that are just below the transition from phase I to phase II), in full support of our assignment of the (3+1)-dimensional superspace group P2 1 2 1 2 1 (00 γ ) to phase II. As our phenomenological model is based on phase II and phase “III” of this incommensurate material having the same (3+1)-dimensional superspace group P2 1 2 1 2 1 (00 γ ), it follows that the new X-ray diffraction results are in full support of our phenomenological model.

337 Effect of adding urea to finishing diets containing two different inclusions of distillers grains on steer performance and carcass characteristics

Crossbred beef steers (n = 384) were utilized to evaluate the effects of adding urea to a dry rolled corn based finishing diet containing low inclusions of wet distillers grains plus solubles (WDGS). Treatments were set up as a 2 × 4 factorial arrangement with factors consisting of WDGS inclusion at either 12 or 20% of diet dry matter (DM) and urea inclusion at either 0, 0.4, 0.8, 1.2% of diet DM. Cattle were blocked and stratified by initial body weight (BW) and assigned randomly to treatment. The heavy block of cattle were harvested after 160 d on feed (DOF) and the middle and light blocks of cattle were harvested after 179 DOF. The model include the fixed effects of weight block, WDGS inclusion, urea inclusion, and their interactions. There were no significant interactions (P > 0.12) observed between WDGS inclusion and urea inclusion in the diet; therefore, only main effects are discussed. Increasing inclusion of WDGS improved (P < 0.04) carcass adjusted ADG and G:F. Dry matter intake was reduced (P = 0.04) with increasing WDGS inclusions. Fat thickness was increased (P = 0.04) with increased WDGS inclusion; however, no other carcass characteristics were significantly affected by WDGS inclusion. Cubic effects of urea inclusion were observed (P < 0.05) for HCW, final BW, ADG, and DMI on a carcass adjusted and live BW basis; however, cubic effects with increasing urea inclusion are of minimal biological relevance. There were no linear or quadratic responses (P > 0.11) for increasing urea inclusion in the diet for performance measurements or carcass characteristics. Increasing WDGS inclusion in the diet improved performance. Added urea in the diet had minimal impact on performance, regardless of wet distillers grains plus solubles inclusion.

PSII-4 Effect of urea and distillers inclusion in dry rolled corn based diets on heifer performance and carcass characteristics

Crossbred heifers (n = 96) were utilized to study the effects of increasing wet distillers grains plus solubles (WDGS) and urea inclusion in a dry rolled corn (DRC) based finishing diet on performance and carcass characteristics. Heifers were individually fed using a calan gate system with a 2 × 2 factorial arrangement of treatments. Orts were collected once a week and analyzed for dry matter (DM) content and used to correct DM intake (DMI). Factors included WDGS inclusion at either 10 or 20% of diet DM and urea inclusion at either 0 or 1.2% of diet DM. Cattle were stratified by body weight (BW) and assigned randomly to treatment. Blood samples were taken at 3 points during the feeding period and analyzed for blood urea nitrogen content. The model included urea and WDGS inclusions and their interactions as fixed effects. There were no interactions (P > 0.08) between WDGS and urea inclusion for any performance or carcass characteristics so only main effects are discussed. There was no difference for initial BW, final BW, ADG, and G:F on a live or carcass adjusted basis (P > 0.26) for either urea or distillers inclusion in the diet. Dry matter intake was reduced (P = 0.03) with increased urea inclusion; however, WDGS inclusion did not influence DMI (P = 0.29). No difference (P > 0.10) was detected for urea or WDGS inclusion for any carcass characteristics. Blood urea nitrogen was greater (P < 0.01) for cattle fed increasing levels of both urea and WDGS. Added distillers and urea in the diet had minimal impact on performance or carcass characteristic suggesting supplemental urea in a DRC-based finishing diets is of minimal benefit when feeding at least 10% WDGS.

Effect of Zeolite Addition on the Properties of Bioplastic Composites of Carboxymethyl Cellulose-Urea

Bioplastic composites based on carboxymethyl cellulose (CMC) and urea have been successfully synthesised at various amount of zeolites. Urea inclusion into the bioplastics was supposed to result in nitrogen slow-release composites. The bioplastic composites were prepared by solvent casting the precursor gel containing 0.5 % (w/w) urea in CMC in the petri dishes. The zeolites content was varied at 0.1, 0.5, 1.0, 2.0, and 3.0 % (w/w to CMC). It showed that the addition of zeolites to the bioplastic composites up to 0.5% increased their tensile strength. More addition of zeolites decreased the strain of the bioplastic composite. It could be due to the formation of hydrogen bonds between CMC and zeolites. The amount of urea absorbed in the bioplastics increased as the amount of zeolites increases. It is possibly to be due to the strong interaction between urea and zeolites. The ammonium ions may interact with interchangeable cations in the zeolite. This interaction will also extend the time for the bioplastics to biodegrade. The presence of zeolites in the CMC polymer chains is useful to give nitrogen slow-release composites.