AgResearch

Ammonia (NH3) is a major environmental pollutant, responsible for approximately 50% of the PM2.5 pollution in Europe, contributing to eutrophication and acidification. Approximately 15% and 30% of NH3 is emitted from poultry production systems in Europe and North America, respectively. Therefore, it is important to understand the factors affecting NH3 emission factor (NH3 EF) from poultry production systems. In this study, we analysed the DATAMAN database to identify and quantify NH3 EF for different poultry housing systems. The data was classified into four production systems, including broiler production and layer production in North America and Europe· NH3 EF were calculated for these systems. Results showed that the NH3 EF from Europe-based layer production system was lower (52.7%) than North America-based layer production system; the difference was statistically significant (p=0.0483). Similarly, the NH3 EF for broiler production systems in Europe was 43% lower than that for North American systems (p=0.0084). The effect of litter management systems on NH3 EF was not significant (p=0.387). However, the NH3 EF for European-based new litter system (where the litter is removed after every flock) was 40% lower than North American-based built-up litter system (where several flocks are reared on the same litter). In this study, the EF from studies published after 2010 was 54% lower than those from studies published before 2010 (p=0.007), probably due to improved poultry production systems. Further emission research on newer, improved production systems is required to accurately calculate NH3 EF which is highly needed to improve the emission inventorying of modern poultry houses.

Improve marine toxin analysis, toxicity assessment to ensure appropriate monitoring and regulation.

Agriculture is important for producing food but can have environmental impacts on water quality. There is a need to develop mitigation strategies for pastoral farming systems to find a better balance between food production and environmental footprint. This study used a paired catchment experimental design to test the effectiveness of three mitigation strategies targeting the critical source areas (CSAs) that were ephemeral streams in deer grazed pastures. The runoff from four small catchments on the same hill slope (2.2–3.6 ha) was monitored for 2 years, under typical farm management. The mitigation options of: full fencing, partial fencing and temporary fencing was then applied to the CSA areas in three of the catchments. The fourth catchment was left unchanged as a control to account for different weather conditions in the pre- and post-treatment phases. Post-treatment monitoring was conducted for a further 2 years. The effectiveness of the mitigation options was calculated for both reducing contaminant concentrations (nitrogen, phosphorus, sediment and E. coli ) under low-flow conditions and contaminant loads during storm events. The effectiveness of the three mitigation options for reducing low-flow concentrations ranged from not effective for filterable reactive phosphorus (FRP), total phosphorus (TP), and total suspended solids (TSS) to 83 % effective for reducing E. coli . The effectiveness of the three mitigation options for reducing storm-flow event loads ranged from not effective for FRP to 93 % effective for reducing E. coli . The CSA managements all mitigate multiple contaminants and hence will have multiple water quality benefits downstream. • Three options for mitigating critical source areas were tested. • Contaminants of nitrogen, phosphorus, sediment and E. coli were measured. • Full fencing was more effective than partial or temporary fencing options. • Low flow concentrations were reduced by up to 83 % for E. coli. • Total loads were reduced by up to 93 % for E. coli.

Sweetness is sensed by sweet taste receptor heterodimer (TAS1R2/TAS1R3) which responds to sucrose, glucose, fructose, and galactose. Limiting added sugar in dairy foods while maintaining sweetness for palatability is important in healthy food design. We investigated the influence of sugar composition in yoghurt on sweet receptor activation and on subsequent sensory sweetness perception. We found that sweet receptor activation was enhanced by the addition of sucrose post-fermentation to Yoflex® yoghurts (CH-1 <i>Streptococcus thermophilus</i>, <i>Lactobacillus delbrueckii </i>subsp. <i>bulgaricus </i>and YF-L811 <i>Lactobacillus rhamnosus</i>, <i>Lactobacillus delbrueckii </i>subsp. <i>bulgaricus</i>). Sensory evaluation by trained panellists supported these findings. Analytical profiling revealed variability in residual sugar composition, particularly galactose. Receptor assays revealed a novel potentiating effect of galactose on sucrose-induced receptor activation. Sugar type and composition are key determinants of yoghurt sweetness and can be predicted by <i>in vitro </i>sweet receptor assays to determine sugar synergies as a strategy for minimising added sugars in dairy products.

This study presents a perspective on how partnerships engaging private-sector actors could support greenhouse gas mitigation in African ruminant livestock value chains. Through using value chain governance theory and illustrative examples, we highlight potential contributions of these partnerships rather than demonstrate realised mitigation effectiveness. Using illustrative examples from beef cattle grazing, intensive dairy, and mohair fibre from several countries (South Africa, Kenya, Tanzania and Rwanda), we described partnership design. Across these illustrative examples, partnerships involving agribusiness companies and livestock producers linked low-emission practices to markets through quality-based milk pricing, village milk-collection hubs, the development of certification standards for mohair, and pilot programs in rangeland restoration and manure recycling. In some examples, public and nonprofit organisations helped finance embedded services (notably, grazing-plan support and milk-quality testing for price premiums) using buyer contributions, public budgets, or donor projects, including where livestock producers could not readily capture mitigation benefits.

Meat metabolites are important for understanding meat quality such as flavour and nutritional value but also for providing insights into on-farm effects on muscle metabolism. This study determined the effects of ewes managed under contrasting dietary management systems (fodder beet (FB) and perennial ryegrass (RG)) during pregnancy on lamb carcass weight and meat metabolites after slaughter. Lambs were slaughtered at ~160 days, carcass weight was recorded, and sub-samples of the M. Longissimus thoracis were collected for evaluation of meat metabolite concentrations using Nuclear Magnetic Resonance spectroscopy. Lambs born to FB ewes had lower carcass weights than those from RG ewes (p&lt;0.05). Glucose-1-phosphate and malate concentrations were higher (p&lt;0.03 and p=0.08, respectively) and anserine concentrations were lower (p&lt;0.04) in meat of lambs from FB vs. RG ewes. In conclusion, the FB compared to RG regime had long-term impacts on offspring carcass weight and meat metabolites.

Abstract The yak ( Bos grunniens ) serves as an exceptional model for studying high-altitude adaptation mechanisms due to its evolutionary success in the hypoxic environment of the Qinghai-Tibet Plateau. While previous research has largely focused on genetic and physiological traits of yaks, the interactions between rumen microbiota and host physiology under hypoxic conditions remain poorly understood. As the largest digestive organ in ruminants, the rumen and its microbiota play a central role in digestion and host nutrition. In this study, a comparative analysis of digestive metabolism and rumen microbiota was carried out in yaks and cattle under varying atmospheric oxygen levels. Our findings reveal that yaks have developed unique microbial strategies to cope with energy deficits in hypoxic stress. These include a shift in rumen microbiota toward amino acid degradation and enhanced long-chain fatty acid biosynthesis, thereby improving energy acquisition despite reduced nutritional intake. However, this metabolic adaptation comes at a physiological cost - reduced microbial crude protein (MCP) synthesis leads to elevated ruminal NH 3 -N levels, and increased fatty acid metabolism and urea cycle activity contribute to hepatic stress. This study presents the first evidence of metabolic trade-offs in high-altitude adaptation, demonstrating that yaks optimize microbial-mediated energy production at the expense of liver health. These insights deepen our understanding of host-microbiome coevolution mechanisms in extreme environments and highlight biological costs associated with adaptation.

Natural levels of Immunoglobulin A (IgA) in bovine milk provide the opportunity to generate added‐value nutrition and immune milk products. This article investigated the concentration of IgA in milk from both individual cows and dairy herds over multiple lactations, with a focus on parameters which may inform the establishment and maintenance of dairy herds with high IgA concentrations. Considerable variation in IgA was observed at both the herd and individual animal level. Heritability of IgA was moderate (0.33–0.37) and both cow age and milk percent protein had a significant positive correlation with IgA concentration. In the second part of the study, the maintenance of IgA concentrations in a High IgA herd, selected from the multiherd cohort, were profiled over two seasons. The IgA:protein ratios in the herd were 55% higher than in unselected animals and stabilised by mid late lactation. Older animals tended to maintain their high, intermediate, or low status both within a season and between years. Together, this article provides information which will assist in the design of High IgA herd selection and maintenance policies, which may lead to the development of future functional foods and ingredients.

Narrow-leaved plantain ( Plantago lanceolata L.) has potential to reduce N 2 O emissions from pastoral livestock systems. This study aimed to 1) compare N 2 O emissions between plantain and ryegrass (R) swards, and 2) determine if N 2 O emissions differed between three plantain cultivars with differing biological nitrification inhibition (BNI) potential (High (H), Medium (M), and Low (L)). Experiments were performed in two locations of New Zealand (Waikato and Southland) with differing soil types, latitude, and climate. Swards were established in a split-plot randomised block design with dairy cow urine (U) and non-urine (NoU) treatments. For the U treatments, cumulative N 2 O emissions in Waikato were similar between all plantain cultivars and ryegrass (1588 ± 108 g N ha −1 ). However, in Southland, cumulative N 2 O emissions from plantain swards were ∼50 % less than from ryegrass (mean 501 cf. 979 g N ha −1 ), with emissions differing by up to 212 g N ha⁻¹ between cultivars P < 0.05). For the NoU treatments, plantain reduced cumulative N 2 O emissions compared with ryegrass by an average of 60 % (Waikato) and 53 % (Southland), with no differences among plantain cultivars. Urine N₂O emission factors (EF₃) were 0.20 % (H, L) and 0.23 % (M, R) in Waikato ( P = 0.893), and 0.05 % (M, L), 0.07 % (H), and 0.11 % (R) in Southland ( P < 0.001). The observed differences between sites and cultivars may relate to variation in management practices, soil type and physicochemical properties, localised climate, and plant traits. While plantain can reduce N₂O emissions compared to ryegrass swards, the magnitude of this reduction varies between cultivars and is environment specific. • Plantain cumulative N 2 O emissions were similar to ryegrass in Waikato. • Cumulative N 2 O emissions were similar between plantain cultivars in Waikato. • Plantain cumulative N 2 O emissions were smaller than from ryegrass in Southland. • Cumulative N 2 O emissions differed between plantain cultivars in Southland. • Plant chemistry and physiology may explain cultivar N 2 O emission differences.