Department of Agricultural Sciences

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The Department of Agricultural Sciences consists of animal science, plant science and farm management and agribusiness staff members.

The range of research conducted is quite extensive including: conversion of forests into pasture, alternative dryland pasture species, grain legume agronomy, sustainability in farming systems, nitrogen fixation and nitrogen cycling, shelter on dairy farms, economic viability of NZ farming systems, animal nutrition, immunology etc.

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Recent Submissions

  • ItemOpen Access
    A review of grass species yields and growth rates in Northland, New Zealand
    (Informa UK Limited on behalf of the Royal Society Te Aparangi, 2024-05-12) Teixeira, CSP; Olykan, ST; Moot, Derrick
    Pastoral farming is a major land use in New Zealand's Northland region, with 3,171 farm holdings and a total area of 637,500 hectares in 2022. The region's pasture grasses include temperate (C3) and subtropical and tropical (C4) grasses which support dairy, and sheep and beef production from grazing. In lowland areas, C3 and some annual C4 grasses are prevalent where cultivation occurs, while perennial C4 grasses dominate areas with low soil fertility and summer dry conditions. Grass-based pasture growth rates (kg dry matter/ha/day) from published and unpublished sources were assembled into the AgYields database. Among the resident and sown grasses tested in Kaitaia, Kaikohe, Whangarei and Dargaville, perennial ryegrass represented ∼60% of the total data points. Dominant kikuyu pastures represented 23% and the remaining species represented 17%. Rates of growth ranged from 5 to 120 kg DM/ha/day, being lowest in late autumn-winter and highest in early summer. Data were compared and agronomic traits (i.e. drought tolerance, biomass production and tillering) are discussed to assess species suitability for the Northland environment. The medium-term prospect suggests an urgent need to improve research into management of cocksfoot and tall fescue-based pastures to provide viable alternatives to overcome the decreasing persistence of perennial ryegrass.
  • ItemOpen Access
    Yield and persistence of legume monocultures grown in the Lees Valley, South Island High Country
    (New Zealand Grassland Association, 2023) Olykan, ST; Mills, A; Lucas, RJ; Smith, M; Moot, Derrick
    Six legume monocultures were established in the Lees Valley, North Canterbury (400 m a.s.l.), which has long cold winters. The stony soils have low pH, high aluminium concentration, and low water holding capacity, which can lead to severe summer soil moisture deficits. The aim was to identify legumes that would survive and persist in this environment and, therefore, increase the available nitrogen in the pastoral system. Legume populations of 88±12 seedlings/m² were established and ranged from 45 (sub clover) to 197 seedlings/m² (Caucasian clover). The highest yields were from ‘Pawera’ red clover at 2.5 and 2.9 t DM/ ha in Years 2 and 3, ‘Demand’ white clover produced 1.7 and 2.6 t DM/ha, and ‘Endura’ Caucasian 1.8 and 1.7 t DM/ha. ‘Kaituna’ lucerne yields were low at 0.7 and 1.4 t DM/ha. Caucasian clover was the most persistent legume. A visual assessment in Year 5 found Caucasian was the only legume still dominating its plot (69%) with the lowest area of bare ground (11%). ‘Leura’ subterranean and ‘Bolta’ balansa annual clovers survived for four years but accumulated annual yields were low (<1.0 t DM/ha/yr), and the presence of unsown species was high (>50%). While red and white clover provided the highest yields for two years, Caucasian clover was the most persistent species and is therefore a legume recommended for this environment.
  • ItemOpen Access
    Pasture production: A compilation of historical datasets from farms in Bay of Plenty
    (New Zealand Grassland Association, 2023) Teixeira, C; Gee, T; Hawke, M; Moot, Derrick
    Bay of Plenty district, and particularly the Rotorua Lakes area, has a diverse terrain and soil types which influence pasture production. Regular measurement of pasture production enables short term decision making on a farm scale and is invaluable for catchment, district and regional long term management strategies. Thomas (Tom) M. Gee, was a retired farmer with more than 18 years of field trial experience with MAF Field Research Division. He collected data from more than 30 farms after he retired. Data from other sites in the district were collected in the early 1970s by MAF technicians stationed in Whakatane and Tauranga and later by AgResearch staff and a farm consultant based in Rotorua. Tom Gee’s mission was to use these measurements to provide farmers with rates of growth (ROG) data to inform them about their farm. The Gee farm (Fairbank) of 200 ha was originally leased from Ngati Whakaue Tribal Lands in 1916 and then purchased before much of it was sold back to the Incorporation in 1970. Tom retired in 1989 but kept meticulously recording pasture growth rates on different farms up to ~ 2007. Some field notes were lost, but datasets with gaps are still useful to assist monthly growth rates calculations. His valuable and extensive (almost 25 years) on farm field records have been retrieved, compiled, assembled, and digitised, to be saved electronically, and entered into the AgYields National Database hosted at Lincoln University. Part of this legacy dataset has been summarised and dry matter yields and growth rates calculated, consistent with previous methods, to provide a quantified description of mean monthly pasture growth rates across the Bay of Plenty region, in New Zealand.
  • ItemOpen Access
    Legume yield and persistence in grass and herb pasture mixtures in Lees Valley, South Island High Country
    (New Zealand Grassland Association, 2023) Olykan, ST; Mills, A; Lucas, RJ; Smith, M; Moot, Derrick
    Four experiments were established to identify productive and persistent dryland pasture mixtures that included legumes to supply nitrogen and a suitable grass and/or herb companion species. There was a Caucasian clover-herbs (plantain and/or chicory) mixture experiment, and three grass-clover mixture experiments: ryegrass cultivars, dryland grass species (brome, cocksfoot, or tall fescue), or timothy +/-herbs (plantain and/or chicory), all sown with white and sub clovers. The site was in Lees Valley, an intermontane basin in North Canterbury (400 m a.s.l.), which experiences long cold winters, has soils of low pH and high aluminium, with low water holding capacity and severe summer soil moisture deficits. In the first two years of the grass-clover mixtures, the ryegrass and dryland grass-clover pasture mixtures were the most productive with total yields of ~4,400 kg DM/ha. In the dryland grass mixtures, the yield of the brome and cocksfoot grass component increased from Year 1 to 2 (1350 to 2830 kg DM/ha) while tall fescue declined (970 to 800 kg DM/ha). The equivalent timothy grass yields were low averaging ~320 kg DM/ ha/yr. Across the grass-clover mixtures, the average white clover yield was 1800±210 kg DM/ha in Year 1 and represented 43% of total DM, compared with 8% sub clover. In Year 2, the white clover produced 930±90 kg DM/ha, which represented 29% of total annual yield. Sub clover did not re-establish. Grass cultivars/species in the mixture experiments had no effect on white clover yield. White clover yields peaked in October-November of both years with growth rates of ~16 kg DM/ha/d. At the start of the summer dry period, from November onwards, white clover growth rates declined resulting in lower yields. In the Caucasian-herbs experiment, total yield in Years 1 and 2 was ~2750 kg DM/ha/yr. In both years Caucasian clover yields were lower when grown in herb-based mixtures compared with a monoculture (Year 1: ~400 versus 1800±270 kg DM/ha, Year 2: 920 versus 1750±210 kg DM/ha). Plantain contributed ~1740 kg DM/ha/yr to the total yield. The persistence and productivity of grass-legume-herb mixtures for dryland pastures are discussed. Cocksfoot was a productive grass in Lees Valley because of its aggressive growth habit and resilience in dryland conditions. Caucasian clover was a productive when grown as a monoculture.
  • PublicationOpen Access
    Unveiling a microexon switch: novel regulation of the activities of sugar assimilation and plant-cell-wall-degrading xylanases and cellulases by Xlr2 in Trichoderma virens
    (MDPI, 2024-05) Castañeda-Casasola, CC; Nieto-Jacobo, MF; Soares, A; Padilla-Padilla, EA; Anducho-Reyes, MA; Brown, C; Soth, S; Esquivel-Naranjo, EU; Hampton, John; Mendoza-Mendoza, A
    Functional microexons have not previously been described in filamentous fungi. Here, we describe a novel mechanism of transcriptional regulation in Trichoderma requiring the inclusion of a microexon from the Xlr2 gene. In low-glucose environments, a long mRNA including the microexon encodes a protein with a GAL4-like DNA-binding domain (Xlr2-∝), whereas in high-glucose environments, a short mRNA that is produced encodes a protein lacking this DNA-binding domain (Xlr2-β). Interestingly, the protein isoforms differ in their impact on cellulase and xylanase activity. Deleting the Xlr2 gene reduced both xylanase and cellulase activity and growth on different carbon sources, such as carboxymethylcellulose, xylan, glucose, and arabinose. The overexpression of either Xlr2-∝ or Xlr2-β in T. virens showed that the short isoform (Xlr2-β) caused higher xylanase activity than the wild types or the long isoform (Xlr2-∝). Conversely, cellulase activity did not increase when overexpressing Xlr2-β but was increased with the overexpression of Xlr2-∝. This is the first report of a novel transcriptional regulation mechanism of plant-cell-wall-degrading enzyme activity in T. virens. This involves the differential expression of a microexon from a gene encoding a transcriptional regulator.
  • PublicationOpen Access
    Five-year old diversified pasture supports greater lamb liveweight gain than a standard perennial ryegrass-white clover pasture
    (New Zealand Grassland Association, 2023-03-01) Maxwell, Thomas; Cartwright, HS; Meyer, JL; Al-Marashdeh, Omar
    This study investigated liveweight gain of lambs grazing five-year-old pasture of either Italian ryegrass, red clover and plantain (Diversified) or perennial ryegrass and white clover (Standard). Coopworth lambs were born to either diversified or standard pasture and reared there until weaning in December (early summer). Liveweight gain (LWG) from tailing to weaning was 23% higher in lambs on diversified pasture (0.335 kg LWG/lamb/day) compared to those on standard pasture (0.272 kg LWG/lamb/day). From summer to autumn (December to May), liveweight, pasture mass, botanical composition and nutritive quality was measured as weaned lambs progressed through rotationally grazed paddocks of either diversified or standard pasture. Similar lamb liveweight gain between pasture types was observed over summer and autumn, with both groups averaging 0.187 kg LWG/lamb/day. From December to May, dry matter intakes (DMI) and feed conversion efficiencies (FCE) were similar between lambs grazing on either diversified or standard pasture. Average final lamb liveweight off diversified pasture was 4.2 kg higher than off standard pasture. The higher pre-weaning liveweight gain and subsequent greater weaning liveweight off diversified pasture was maintained throughout the summer and autumn.
  • PublicationOpen Access
    Milksolids production of dairy cows grazing lucerne and perennial ryegrass in spring
    (New Zealand Society of Animal Production (Inc), 2013) Smith, G; Bryant, Racheal; Edwards, G
    The potential of New Zealand grazing systems is dependant on the dry matter (DM) yield, nutritive characteristics, and utilisation of pasture. The most common pasture is a mixture of ryegrass and white clover, which is tolerant of a wide range of environments and management (Kemp et al. 1999). However species such as these with shallow root systems and poor growth in high temperatures will have reduced herbage accumulation and quality during dry summer periods (Hoglund & White 1985). As demand for irrigation has increased to alleviate these problems, it has also raised questions about water allocation impacts on dairy farm production and profit (Thorrold et al. 2004). For Canterbury, which experiences hot, dry summers, lucerne is a potential source of high quality feed due to its active warm season growth and greater water use efficiency (Mills & Moot 2010).
  • PublicationOpen Access
    Formulation of pasture seed mixtures with emphasis on the effect of nitrogen fertilisation : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
    (Lincoln University, 2023) Myint, Thinzar Soe
    The aim of this study was to determine the optimal proportions of pasture mixtures and amounts of seed and nitrogen fertiliser (N) to maximize yield and quality. Three monocultures and seven species mixtures, that differed widely in their proportions (0 to 1) of perennial ryegrass, white clover and plantain were sown at 1,000 and 2,000 viable seeds/m2 and with either 0 or 225 kg N/ha/year. Plots were drilled in 2.1 x 6 m plots on 31 March 2017 and measured for four years. The plots were grazed in common by sheep eight times annually (except the first defoliation after sowing when they were cut) and irrigated when required. Herbage accumulation and its proportions of sown species and weeds were determined at each harvest over four years (2017/2018–2020/2021); nutritive value (metabolisable energy (ME), crude protein (CP) and neutral detergent fibre (NDF)) over three years (2018/2019–2020/2021), and light interception and radiation use efficiency (RUE) over two years (2018/2019–2019/2020). To quantify the fractional intercepted radiation of pastures, an accurate method of measuring light interception was investigated. Fractional intercepted radiation was measured or predicted using a SunScan plant canopy analyser, GreenSeeker handheld sensor, rising plate meter (RPM), destructive harvests, and the combinations of SunScan and GreenSeeker, and SunScan and RPM. A hybrid method of SunScan and RPM (fractional light interception values ≤0.3 of SunScan were replaced with the predicted values using RPM) was chosen as an accurate method based on the parameters of extinction coefficient, critical LAI, R2 values, standard errors of regression. Response variables were quantified using diversity-interaction modelling to quantify effects of species ‘identity’ (monoculture performance or average monoculture performance of species in the mixtures) and ‘diversity’ (the excess of mixture performance over that expected from average performance of species in the mixtures). Seed density did not influence species identity and diversity effects on pasture yield and quality in any year. The annual total dry matter yields of ryegrass and plantain averaged over four years were 16.8 and 16.6 t DM/ha/year without N fertiliser, and 19.1 and 18.9 t DM/ha/year with N. White clover had the same production (14.9 t DM/ha/year) ± N. Mixtures produced diversity effects (additional dry matter yield). The highest extra dry matter yield (4.32 t DM/ha/year) among binary mixtures was obtained from the ryegrass-white clover mixture at the average of two N treatments. Three-species mixtures needed N to produce higher extra yield than binary mixtures. The extra benefit produced by the equal-proportional mixture of three species with N was 5.20 t DM/ha/year. The annual weed yield was lowest in perennial ryegrass (1.68 t DM/ha/year) at average N (average of 0 and 225 kg N/ha/year). The weed yield of ryegrass reduced from 2.16 at the –N level to 1.2 t DM/ha/year at the +N level. There was no N effect on weed yields of white clover and plantain. Mixtures reduced weed yield, and the highest amount of weed reduction was found in the even three-species mixtures (3.28 t/ha/year). Nutritive values were likely to be a function of identity effects and there was no effect of N. At average N, ME was higher in perennial ryegrass (11.0 MJ kg/DM) and white clover (11.0 MJ kg/DM) than in plantain (10.7 MJ kg/DM). CP was higher in white clover (25.7%) than plantain (20.5%) and perennial ryegrass (19.2%). Higher neutral detergent fibre (NDF) was found in perennial ryegrass (47.8%) than plantain (36.3%) and white clover (35.0%). After four years, an equi-proportional mixture of perennial ryegrass and white clover, based on seed count and equivalent to 12 kg PR and 7 kg WC (19 kg total coated seed)/ha at the low seed density (1000 seeds/m2), produced an optimal balance of increased total yield (20.6 t DM/ha/year), weed suppression (3% of total yield), ME (11 MJ/kg DM), CP (21.7%) and NDF (44%) at the –N level. The optimal mixture at the +N level was the three-species mixture with the proportion of 0.4 PR: 0.3 WC: 0.3 P equivalent to 9.60 kg PR, 4.20 kg WC, and 6.0 kg P (19.8 kg total coated seeds/ha) at the low seed density. It produced 23.0 t DM/ha/year with no weed, 10.8 MJ ME kg/DM, 19.5% CP, and 46.1% NDF. The equi-proportional seed mixture of perennial ryegrass and white clover changed to a mixture of 71% ryegrass, 26% white clover, and 3% weed as the actual proportions in the sward averaged over four years, yielding 20 t DM/ha/year. At the +N level, all three species mixtures, which changed to ryegrass-dominant mixtures in a four-year period, remained the highest-yielding mixtures, producing 20.8–22.4 t DM/ha/year. Differences in dry matter yield among mixtures were fully explained by the combined effect of light interception and radiation use efficiency (RUE). The optimal mixtures ±N that maximised intercepted light and RUE simultaneously were the same mixtures that produced maximum dry matter yield. They provided 188 and 170 MJ/m2/year more intercepted photosynthetically active radiation (PAR) and 0.23 g DM/MJ PAR more RUE. This study provided the two optimal seed mixtures for ±N level that maximised total dry matter yield with high quality and minimised weed yield under irrigated conditions. The dry matter yield differences among monocultures and mixtures were explained by the accumulated intercepted PAR and RUE. Moreover, there was an observation that accumulated intercepted PAR and RUE values changed depending on the methods used to measure light interception.
  • PublicationOpen Access
    On-animal sensors may predict paddock level pasture mass in rotationally grazed dairy systems
    (Elsevier B.V., 2024-04) Edwards, JP; Qasim, M; Bryant, Racheal; Thomas, C; Wright-Watson, C; Zobel, G; Neal, MB; Eastwood, CR
    Precision livestock farming aims to improve animal welfare and farm management using digital technology. We investigated the potential of individual on-animal sensors to predict paddock-level pasture mass, an important metric for grazing management in pasture-based dairy systems. The study consisted of four groups of 25 cows assigned to different pasture allocations (ranging from an estimated 80% to 120% of their energy requirements) over two 20-day experimental periods (late spring and late summer). Each cow was fitted with five sensors that measured a range of behaviours, including rumination time, eating/grazing time, activity and lying time. These data were used to build predictive models of pasture mass, which was estimated by calibrated rising plate meter. Our results show that rumination time was the most critical behaviour for predicting paddock-level pasture mass; the best predicted was post-grazing pasture mass (kg DM/ha) with a maximum Adjusted-R² value of 0.58 using a linear model. Including pasture and behaviour data at less than 24-hour resolution did not improve model performance, likely due to the importance of rumination, which is a diurnal behaviour. It is unclear whether this level of predictive ability is practically useful for making grazing management decisions; however, given its near real-time nature, low effort, and objectivity, the approach may provide value to farmers. Further evaluation is needed to determine how providing these data affects farmers' decision-making processes and therefore its value. In conclusion, our proof-of-concept experiment demonstrates the potential of individual on-animal sensors to predict post-grazing pasture mass, and this could help farmers make informed decisions for grazing management.
  • PublicationOpen Access
    Can the inclusion of forage chicory in the diet of lactating dairy cattle alter milk production and milk fatty acid composition? Findings of a multilevel meta analysis
    (Multidisciplinary Digital Publishing Institute (MDPI), 2024-04-01) Mangwe, MC; Bryant, Racheal; Olszewski, A; Herath, G; Al-Marashdeh, Omar
    In traditional ryegrass/white clover (Lolium perenne L./Trifolium repens L.) pastoral systems, forage herbs such as chicory (Cichorium intybus L.) present an opportunity to fill feed deficits during late spring and summer. Although multiple research publications have evaluated the efficacy of chicory for enhancing milk production and milk fatty acid (FA) profile, no publication has quantitatively synthesised the body of research. This systematic review and meta-analysis examined the effect of chicory on milk production and composition, as well as on the milk fatty acid composition of dairy cattle. A total of 29 comparisons from 15 unique research publications involving 597 dairy cattle were used to develop a dataset for analysis. Three-level random-effect and robust variance estimator models were used to account for the hierarchical structure of the data and the dependency of effect sizes within publications. Chicory inclusion increased milk yield when compared to grass-based diets {weighted mean difference (WMD) = 1.07 (95% CI 0.54–1.60) kg/cow/d, p < 0.001}, but it provided a similar milk yield when compared to other forages such as legumes and herbs {dicots; WMD = −0.30, (95% CI −89–0.29) kg/cow/day, p = 0.312}. Increases in milk yield were congruent with differences in DM intake (p = 0.09) and ME intakes (p = 0.003), being similar in chicory-fed and dicot-fed cows but higher than grass-fed cows. Chicory feeding’s effect on milk solids was twice as high during mid lactation {154 days in milk; WMD = 0.13, (95% 0.081–0.175) kg/cow/day, p < 0.001} as during late lactation {219 days in milk; WMD = 0.06, (95% 0.003–0.13) kg/cow/day, p = 0.041}. In line with milk yield, greater and more significant effect sizes were found for alpha linolenic acid {ALA; WMD = 0.20 (95% CI 0.06–0.35) g/100 g FA, p = 0.011} when chicory was compared to grass species only. Comparing chicory with dicots suggests that chicory inclusion did not impact ALA concentrations {WMD = 0.001 (95% CI −0.02–0.2) g/100 g FA, p = 0.99}. There were no differences in conjugated linoleic acid concentration in the milk of cows fed chicory or control diets. The study provides empirical evidence of chicory’s efficacy for improved milk production and milk fatty acid composition.
  • PublicationOpen Access
    Ovine KRTAP36-2: A new keratin-associated protein gene related to variation in wool yield
    (MDPI, 2023-11) Zhou, Huitong; Li, W; Bai, L; Wang, J; Luo, Y; Li, S; Hickford, Jonathan
    Keratin-associated proteins (KAPs) are structural components of wool fibres. High-glycine/tyrosine (HGT)-KAPs are a subset of the KAP family, and their abundance in fibres varies. In this study, we report the discovery of an ovine HGT-KAP gene to which we assigned the name KRTAP36-2. Polymerase chain reaction and single-strand conformation polymorphism (PCR-SSCP) analyses revealed four variants of this gene in a screening population of 170 sheep from a variety of breeds. The DNA sequencing of the variants revealed four single-nucleotide polymorphisms (SNPs) and a dinucleotide deletion. Three of these SNPs were in the coding region, and one of these was non-synonymous and potentially led to the amino acid substitution p.Cys27Gly near the middle of the protein. The remaining SNP was located near the putative TATA box, and the di-nucleotide deletion was near the putative transcription initiation site. The effect of this variation in KRTAP36-2 was investigated in 274 Southdown × Merino lambs that were the progeny of five sires. Variation was only found to be associated with wool yield, that is, the proportion of the greasy fleece that remained as clean fleece upon scouring (expressed as a percentage). This may have some value in increasing wool production.
  • PublicationOpen Access
    Spatiotemporal expression and haplotypes identification of KRT84 gene and their association with wool traits in Gansu Alpine Fine-wool sheep
    (MDPI, 2024-02) Yu, X; Li, S; Zhou, Huitong; Zhao, F; Hu, J; Wang, J; Liu, X; Li, M; Zhao, Z; Hao, Z; Shi, B; Hickford, Jonathan
    Keratin (K) is a major protein component of hair and is involved in hair growth and development. In this study, we analysed the expression, localization, and polymorphism of the K84 gene (KRT84) in Gansu Alpine Fine-wool sheep using immunofluorescence, RT-qPCR, and PARMS (penta-primer amplification refractory mutation system). Haplotypes of KRT84 were also constructed and their relationship with wool traits analysed. It was revealed that KRT84 was highly expressed in hair follicles, including the inner root sheath, outer root sheath, and hair medulla and at all six lamb ages investigated from 1 to 270 days of age. Three SNPs were detected in KRT84 exon 1, and they formed three haplotypes (named H1, H2, and H3) and six genotypes. Analyses revealed an association between haplotype combinations (diplotypes) and the mean fibre curvature, mean staple length, mean staple strength, mean fibre diameter, the coefficient of variation of fibre diameter, and comfort factor for these sheep. These results suggest that KRT84 is of importance in determining several key traits in Gansu Alpine Fine-wool sheep and that the gene could possibly be used as a genetic marker for wool trait selection in these sheep.
  • PublicationOpen Access
    Screening and identification of lncRNAs in preadipocyte differentiation in sheep
    (Springer Nature, 2024-03-04) Hao, Z; Jin, X; Hickford, Jonathan; Zhou, Huitong; Wang, L; Wang, J; Luo, Y; Hu, J; Liu, X; Li, S; Li, M; Shi, B; Ren, C
    Studies of preadipocyte differentiation and fat deposition in sheep have mainly focused on functional genes, and with no emphasis placed on the role that long non-coding RNAs (lncRNAs) may have on the activity of those genes. Here, the expression profile of lncRNAs in ovine preadipocyte differentiation was investigated and the differentially expressed lncRNAs were screened on day 0 (D0), day 2(D2) and day 8(D8) of ovine preadipocyte differentiation, with their target genes being predicted. The competing endogenous RNA (ceRNA) regulatory network was constructed by GO and KEGG enrichment analysis for functional annotation, and some differentially expressed lncRNAs were randomly selected to verify the RNA-Seq results by RT-qPCR. In the study, a total of 2517 novel lncRNAs and 3943 known lncRNAs were identified from ovine preadipocytes at the three stages of differentiation, with the highest proportion being intergenic lncRNAs. A total of 3455 lncRNAs were expressed at all three stages of preadipocyte differentiation, while 214, 226 and 228 lncRNAs were uniquely expressed at day 0, day 2 and day 8, respectively. By comparing the expression of the lncRNAs between the three stages of differentiation stages, a total of 405, 272 and 359 differentially expressed lncRNAs were found in D0-vs-D2, D0-vs-D8, and D2-vs-D8, respectively. Functional analysis revealed that the differentially expressed lncRNAs were enriched in signaling pathways related to ovine preadipocyte differentiation, such as mitogen-activated protein kinase (MAPK) pathway, the phosphoinositide 3-kinase protein kinase B (PI3K-Akt) pathway, and the transforming growth factor beta (TGF-β) pathway. In summary, lncRNAs from preadipocytes at different stages of differentiation in sheep were identified and screened using RNA-Seq technology, and the regulatory mechanisms of lncRNAs in preadipocyte differentiation and lipid deposition were explored. This study provides a theoretical reference for revealing the roles of lncRNAs in ovine preadipocyte differentiation and also offers a theoretical basis for further understanding the regulatory mechanisms of ovine preadipocyte differentiation.
  • PublicationOpen Access
    Horticultural management - Financial planning
    (Lincoln College, University College of Agriculture, 1982) Stevens, R.B.
    Financial planning is an essential function of the business manager. While none of the financial planning techniques are mathematically difficult, the role of those techniques in integrating the numerous business functions and describing their inter-relationships often gives the appearance of complexity. The purpose of this manual is to present instructional material and worked examples on financial planning techniques in a clear and structured manner. This manual will be complemented by individual study guides for each of the six sections in the course. These will state the educational objectives for each section and questions and exercises that must be done to show understanding and mastery of those stated objectives. It is not intended that this manual replace the desirability of attending lectures and tutorials or to take additional notes as appropriate. In fact, the manual layout has been designed to permit and encourage supplementary note-taking. Further explanation of topics, together with detailed examples will be given in lectures to elaborate on the content of the manual. The references or readings cited should be read to provide a broadened appreciation of the study topics.
  • PublicationOpen Access
    Horticultural management - Critical Path Method
    (Lincoln College, University College of Agriculture, 1982) Stevens, R.B.
    The CPM family of planning techniques are a potent tool in the organisation and control of work programmes. Techniques such as these are no panacea: problems in t.he collection of data, the setting of subobjectives and in the implementation of the work plan are recurring decisions to be taken by management otherwise the benefits of the formalised expression of the work plan will be negated. The use of CPM in horticulture has, to date, been limited to a few construction, crop scheduling and planting programmes. However, as the maintenance and development operations of local authority parks departments in particular, become constrained by the availability of finance, greater emphasis will be placed on the optimum utilisation of resources and associated financial control. For determining project resource requirements, for constructing the resource use plan and for assessing the project cost with regard to quantifiable contingencies, the critical path methods have, at present, no equal.
  • PublicationOpen Access
    Lactobacillus buchneri and molasses can alter the physicochemical properties of cassava leaf silage
    (Elsevier B.V., 2023-11) Bakare, AG; Zindove, Titus; Bhavna, A; Devi, A; Takayawa, SL; Sharma, AC; Iji, PA
    In developing countries where feed resources are scarce, cassava leaves can be used as feed for animals. However, the use of cassava leaves is limited mainly because of their high fibre content and overall acceptability by animals. The resolution to this problem is to process the cassava leaves by ensiling and using additives. Therefore, the objective of the study was to determine the effects of including different inclusion levels of molasses and bacteria concentration on the physicochemical properties of cassava leaf silage. Molasses was added at inclusion levels of 0, 3, 5 and 7 g/100g of the chopped cassava leaves, and Lactobacillus buchneri was mixed with chopped cassava leaves at different concentrations of 0, 3.1 × 10⁶ cfu/ml, 3.1 × 10⁸ cfu/ml and 3.1 × 10¹⁰ cfu/ml. The effects of inclusion level of molasses on the colour, smell and texture of cassava leaf silage were significant (P < 0.05). Inclusion of bacteria concentration also influenced the smell of silage (P < 0.05). Effects of the inclusion level of molasses and bacteria concentration resulted in decreased pH, crude protein and crude fibre of silage (P < 0.05). There was a quadratic relationship between Ca and K with inclusion level of molasses in cassava leaf silage (P < 0.05). A positive linear relationship was observed between Mg and molasses inclusion levels in cassava leaf silage (P < 0.05). Using principal component analysis (PCA), molasses had a strong positive correlation with PCA 1, whereas crude fibre, pH and crude protein had a positive correlation with PCA 2. The inclusion level of bacterial concentration was negatively correlated to Ca, CP, P and CF. From the study, the use of molasses and L. buchneri can greatly improve the physicochemical qualities of cassava leaf silage.
  • PublicationOpen Access
    ESMAX for spatial agroecology: A conceptual spatial model for the quantification and visualisation of ES performance from different configurations of landscape
    (Wiley & Global Initiative of Sustainable Agriculture and Environment, 2024-03) Morris, R; Davis, Shannon; Grelet, GA; Gregorini, Pablo
    Introduction: Agriculture is confronted by the dual challenges of increasing global demand for food production while reducing negative impacts on the environment. One suggested solution is transitioning modern industrial agriculture to more agroecologically-informed practices, thus realigning increased food production with the carrying capacity of Earth Systems. The transition to multifunctional agroecological systems, that promote the production of multiple ecosystem services (ES) as well as food production, requires an adaptive management process that addresses climate-change, market complexity, practical implementation and knowledge transfer. Materials & Methods: This work proposes a spatially explicit methodology to support this process. Spatial agroecology, in this context, combines a new Geographic Information Systems (GIS)-based model (ESMAX) with development of a ‘solution space’ to assist stakeholders identify configurations of agroecological components (in this case, trees on farm) at the scale of a 1 ha paddock to supply a targeted range of regulating ES (cooling effect, flood mitigation and habitat). ESMAX uses distance-decay characteristics specific to each type of regulating ES to quantify and visualise the influence of spatial configuration of ES-supplying tree clumps on overall ES performance. Results: The results from this application of spatial agroecology suggest regulating ES production at farm and paddock scale is influenced by the arrangement of trees on farm. ESMAX's results show paddocks with large tree clumps return the best cooling effect, while small clumps deliver the best flood mitigation and most suitable habitat. Evenly dispersed arrangements of small tree clumps provide the best multifunctional performance across all three ES modelled in this work. Conclusion: Designed spatial agroecological interventions can affect landscape multifunctionality at paddock scale, where practical decisions are made and implemented. This provides spatially explicit support of an adaptive management process. Utilising agroecological systems as spatial mechanisms for supplying critical regulating ES also highlights a new function for agriculture in the Anthropocene epoch.
  • PublicationOpen Access
    The biological control of the red clover casebearer in New Zealand : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
    (Lincoln University, 2024) Faulkner, Joel
    Biocontrol of insect pests represents an important aspect of sustainable crop management that has potential to reduce the current reliance on chemical control measures. However, often the potential of all forms of biocontrol is undermined in contemporary productive systems and their resulting landscapes. In New Zealand seed three species of clover feeding moths of the Coleophora genus have seriously hindered red and white clover seed production during the last 100 years in New Zealand. From the 1920s until the 1960s two species of white clover casebearer (Coleophora mayrella and C. alcyonipennella) caused varying levels of seed yield reduction in white clover seed crops. During the 1960s efforts were made by government science agencies to establish parasitoid wasps of these species. This programme was highly successful, resulting in the total suppression of clover casebearer seed pests in New Zealand, until the arrival of the red clover casebearer (C. deauratella) during 2016. This pest quickly spread throughout the country’s clover growing regions, leading to yield reductions. This thesis explores the arthropod community of red clover seed crops under a main theme of ‘the biocontrol of the red clover casebearer’. The experiments employed are varied, although typically with a major aim being exploring the function of species within the red clover seed crop ecosystem. Three species of parasitoid wasp were able to successfully use C. deauratella as a host; Bracon variegator, Pteramalus puparum and Eupelmus (Macroneura) messene. The red clover casebearer was clearly undergoing remission as a pest and only two damaging populations of this pest could be located. The predominant parasitoid, B. variegator, had a field parasitism incidence of up to 75% on C. deauratella, but despite this these two populations of the pest persisted. Over the course of these experiments it was noted that a fungal growth was leading to mortality of C. deauratella larvae. From infected C. deauratella cases a potentially entomopathogenic strain of Fusarium pseudograminearum was isolated and identified through PCR sequencing. It is still uncertain how C. deauratella is being regulated in New Zealand red clover seed crops. The role of parasitoid wasps, a potential fungal pathogen and other unknown biocontrol agents is yet to be determined.
  • PublicationOpen Access
    Beef cattle production systems and constraints among subsistence farmers across the Fijian windward–leeward divide
    (SAGE, 2023-06) Singh, S; Bakare, AG; Iji, PA; Zindove, Titus
    The objective of the study was to describe beef production systems and constraints among subsistence farmers across the Fijian windward–leeward divide. Data were collected from a total of 200 beef cattle owners from windward and leeward locations (100 each) using a structured questionnaire. In both geographical regions, the heads of the households were mostly males and married. Cattle were ranked as the most important species of livestock kept in both leeward and windward areas. In both leeward and windward locations, cattle were mainly kept as a source of income and draught power. Challenges to cattle production differed with the production environment. The major challenges faced by cattle farmers in leeward locations were drought and pasture shortage while farmers in windward locations mainly had theft and disease cases. The odds ratio of Hindu farmers practicing tethering as a grazing method was five times higher than Christian farmers (p < 0.05). Farmers with medium pieces of land were 14 times more likely to use paddocks for grazing their cattle than those with small pieces of land (p < 0.05). Farmers in both leeward and windward locations mostly kept non-descript cattle breeds (>60%) and did not control mating. It was concluded that challenges faced by farmers differed with the production environment but feeding and breeding practices were the same across windward and leeward management locations.
  • PublicationOpen Access
    Designing grazing systems that enhance the health of New Zealand high-country grasslands
    (Elsevier B.V., 2023-12) Pereira, FC; Maxwell, Thomas; Smith, Carol; Charters, Stuart; Mazzetto, AM; Gregorini, Pablo
    More sustainable pastoral livestock production systems are required to face the challenge of reconciling agricultural production and environmental impact. Although the need for more holistic approaches, such as systems thinking and design theory, is acknowledged, systemic research applying those theories to create healthier systems remains underexplored. A multiple steps holistic approach involving modelling, geographic information systems, and decision-making analysis was used to design, assess, and contrast alternative scenarios that represent distinct grazing management to the current grazing management of a high-country station in New Zealand used as a case study to enhance grassland health. Three alternative scenarios were created, and five main parameters used to assess grassland health were obtained from the evaluation of the designed scenarios. From all the parameters, soil erosion control and increased production were ranked as the most and least important, respectively, to be considered in the design process. A multi-criteria evaluation defined that the best-compromise scenario to enhance grassland health is the scenario with lower soil erosion, as a result of applying adaptive and flexible management at the paddock level, the lower total emission of greenhouse gases (only sheep herd grazing), and greater profitability (due to production costs reduction, as cattle were removed from the station), compared to the ‘status quo’. Our design methodology produced a variety of alternatives that enhanced the health of grasslands in different parameters while still maintaining or increasing profitability. The use of multi-criteria evaluation facilitated the decision of the most contextualised and best-compromise scenario for New Zealand high country grasslands.