Beyond ruminants: discussing opportunities for alternative pasture uses in New Zealand

peer-reviewedThe New Zealand government has set ambitious goals for primary sector growth and of zero net carbon emissions by 2050. This presents an opportunity and obligation to develop new ideas for grassland production systems to increase export value and generate new job opportunities, while reducing environmental impacts. The aim of this paper is to draw on recent research in Europe to investigate some of the alternative and complementary uses for pasture as a feedstock for a green biorefinery. A biorefinery is a facility, or a series of processes, that convert biomass into a spectrum of value-added products. For example, protein can be extracted mechanically from green biomass once harvested. The residual fibre fraction could be used as a low-nitrogen feed for ruminants to reduce urinary nitrogen, while the liquid protein fraction could be processed to make it suitable for mono-gastric or human consumption. Enzymes can promote protein extraction and controlled conversion of insoluble plant fibres and oligosaccharides to foster gut-health promoting prebiotic food ingredients. Anaerobic digestion of residues can then be used to create energy and soilimproving products. Research and demonstration of these approaches in practice, along with the results of feasibility studies, will be required to see which of these opportunities is a good fit for New Zealand pasture systems

Whole-genome sequencing reveals host factors underlying critical COVID-19

Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2–4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

Whole-genome sequencing reveals host factors underlying critical COVID-19

Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2,3,4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

Effect of amending cattle urine with dicyandiamide on soil nitrogen dynamics and leaching of urinary-nitrogen

Oral administration of dicyandiamide (DCD) to grazing ruminants for excretion in urine represents an alternative delivery technique to conventional broadcast application of DCD to reduce urinary nitrogen (N) losses from grazed pastures. A field lysimeter trial and an allied plot mowing trial were conducted to examine the effects of intermixing DCD in cattle urine on soil and pasture N dynamics and leaching losses in a free-draining pumice soil. DCD was either intermixed with urine to achieve equivalent application rates of 10, 30 or 60 kg DCD haˉ¹, or surface broadcasted as a spray solution (10 or 30 kg DCD haˉ¹) onto the soil surface following urine application and compared to controls (urine and nil-controls without DCD). A single application of ¹⁵N-labelled artificial cattle urine (equivalent to 600 kg N haˉ¹) and corresponding DCD treatments were applied in late autumn and monitored over the following 300 days. DCD altered the partitioning of the applied urine-¹⁵N by increasing plant uptake of urinary-N by 32–60% and decreasing urine-¹⁵N in leachate, which was primarily influenced by the amount of DCD applied. The method of DCD application had no significant effect on leaching of any N constituent, except for ammonium-N, which was higher in the intermixed relative to the spray DCD treatments (26 vs. 18 kg N haˉ¹, respectively; P < 0.05). The total amount of nitrate-N leached was reduced from 217 kg N haˉ¹in the urine-control to 143, 80 and 61 kg N haˉ¹ (P < 0.05) with increasing rates of DCD application of 10, 30 and 60 kg haˉ¹, respectively. Application of DCD also significantly (P < 0.05) decreased the total amounts of ammonium-N and dissolved organic-N (DON) leached, but led to leaching losses of DCD-N. Rapid and large leaching losses of DCD down the soil profile led to spatial separation from the ammonium-N retained in the surface layer. Leaching of DCD (below 600 mm) at 55–69% of that applied represented an important leachable organic-N source (equivalent to 4–27 kg N haˉ¹), and reduced the overall efficacy of DCD in decreasing total N leaching losses. The total N leaching losses from all measured N fractions were 332 kg N haˉ¹ in the urine-control compared to 236, 157 and 154 kg N haˉ¹ at DCD application rates of 10, 30 and 60 kg haˉ¹, respectively. This study highlights the potential benefit from delivering DCD in cattle urine to reduce urinary-N leaching losses, with the most effective targeted single application rate being 30 kg haˉ¹ under the experimental conditions of this study

Reducing greenhouse gas emissions of New Zealand beef through better integration of dairy and beef production

Integrating dairy and beef production offers opportunities to reduce greenhouse gas (GHG) emissions of beef production, which is dominated by emissions related to maintenance of the breeding cow. This study aims to quantify the GHG reduction potential of the New Zealand (NZ) beef sector when replacing beef breeding cows and their calves with dairy beef animals. To this end, we combined a cattle herd model of NZ beef and dairy production with GHG emission calculations of beef production. We computed GHG emissions (to farm-gate stage) of the current amount of beef produced, while increasing the number of dairy beef calves at the expense of the number of suckler-beef calves. GHG emissions were 29% lower per kg carcass weight for dairy beef animals compared to suckler-beef animals. The average emission intensity decreased from 21.3 to 16.7 kg CO2e per kg carcass weight (−22%) as the number of suckler-beef animals declined to zero and dairy beef animals increased. Integrating dairy and beef production would enable the NZ beef sector to reduce annual GHG emissions by nearly 2000 kt CO2e (i.e. 22% of the total sector's emissions), while the dairy sector would improve their social licence to operate by reducing the number of surplus dairy calves slaughtered from 4-days old

Verifying the nitrification to immobilisation ratio (N/I) as a key determinant of potential nitrate loss in grassland and arable soils

The relative dominance of the competing pathways for ammonium, namely, the microbial processes of nitrification ($N$) and immobilisation ($I$), has been suggested as a major factor in controlling nitrogen losses from soils. In this paper we bring together data from four studies in arable and grassland soils to establish whether the ratio $N/I$ is correlated with measured or modelled nitrate loss in drainage water. Individually, measurements of gross nitrogen transformations did not explain the variation in nitrate leaching across all sites. However, amounts of nitrate lost by leaching were well correlated with $N/I$ for all sites. The relative importance of the pathways competing for mineralised nitrogen (expressed as $N/I$) was changed by management and this appears to be an important factor in controlling N loss in arable and grassland soils.Vérification que le rapport entre nitrification et immobilisation (N/I) est un facteur clé déterminant la perte potentielle de nitrate dans les sols cultivés et de prairies. La dominance relative des différents chemins concurrents pour l'ion ammonium, à savoir les processus microbiens de nitrification ($N$) et d'immobilisation ($I$), a été suggérée comme le facteur principal contrôlant les pertes d'azote à partir des sols. Dans ce papier, nous donnons en même temps des données de 4 études dans des sols labourés et de prairies pour établir si le rapport $N/I$ est corrélé avec la perte de nitrates mesurée ou modélisée (dans l'eau de drainage). Des mesures individuelles des transformations globales de $N$ n'expliquent pas la variation du lessivage de nitrates dans l'ensemble des sites. Cependant, les quantités de nitrates perdues par lessivage étaient bien corrélées avec $N/I$ pour tous les sites. L'importance relative des chemins concurrents pour la minéralisation de l'azote (exprimé en $N/I$) a été changée par l'aménagement et cela apparaît être un important facteur dans le contrôle de la perte de N dans les sols labourés et de prairies

Effects of prolonged oral administration of dicyandiamide to dairy heifers on excretion in urine and efficacy in soil

Oral administration of the nitrification inhibitor dicyandiamide (DCD) to grazing ruminants for excretion in urine represents a targeted mitigation strategy to reduce nitrogen (N) losses from grazed pastures. A field trial and allied laboratory incubation study were conducted to examine the effects of oral administration of DCD to non-lactating Friesian dairy heifers on excretion of DCD in urine and efficacy in soil. Dairy heifers were orally administered DCD daily at three treatment levels (low, medium and high; 12, 24 and 36 g DCD heiferˉ¹ day ˉ¹, respectively) and compared to a nil-DCD control group over a 90-day continuous dosing period. There were no adverse effects of DCD administration on heifer health or growth, as inferred by live-weight gain and measured blood metabolite levels. Prolonged administration of DCD to dairy heifers resulted in the sustained excretion of DCD in the urine over 90 days and inhibition of nitrification of urinary-N in the silty peat soil for up to 56 days (incubated at 20 °C; P < 0.001). Field soil sampling (0–75 mm depth) of individual urine patches for DCD analysis revealed that a 3-fold increase in the rate of DCD administered resulted in a similar increase in the concentration of DCD voided in the urine and subsequently deposited in urine patches (median equivalent DCD application rates of 22, 36 and 59 kg ha ˉ¹ for the low, medium and high DCD treatment levels, respectively; P < 0.001). However, large differences (up to 40-fold) existed between individual urine patches in the rate of DCD deposited at each treatment level, which showed a positively skewed distribution. This study highlights the viability of prolonged daily administration of DCD to ruminants for sustained excretion in urine and effective inhibition of nitrification in soil as a practical targeted mitigation technology to reduce urinary-N losses from grazed pastures

Concepts in quality software design /

"From seminars at the National Bureau of Standards in 1972, conducted by S. Rao Kosaraju and Henry F. Ledgard." -t.p.Includes bibliographical references (p. 80-82).Mode of access: Internet