Search

Abstract Background Combinations of grasses and nitrogen-fixing legumes are ubiquitous in most natural and derived pastoral grasslands. This was not formerly the case in New Zealand’s unique indigenous grasslands that are now frequently impacted by exotic pasture grasses and legumes. Understanding the co-existence of native and exotic plants is the broad focus of this research. Aims Spillover of nitrogen (N) from clovers to grasses in diverse pasture is well known. We question whether grasses provide reciprocal nutritional benefits to legumes. Does the mutual exploitation of soil biogeochemistry by legumes and grasses help to explain their coexistence and, if so, does this have implications for biodiversity in NZ’s novel native grassland communities? Methods Combinations of grasses and legumes, including a native tussock grass, were grown in a nutrient-poor (low P, S, Ca, Mg, Mn, and B) high country soil in a pot experiment, quantifying the foliar acquisition of nutrients from soil. Field data were obtained by sampling foliage of clover in single- and mixed-species patches in a more fertile lowland pasture. Results Benefits of legume and grass growing together were reflected in enhanced productivity and higher uptake of a range of key nutrients. This was most evident but not restricted to a combination of two exotic species: cocksfoot and white clover. In the nutrient-poor soil, legumes grew better in combination with different species of introduced grasses. Uptake of key elements from soil to plants significantly differed with combinations of legumes and grasses compared to individual species. Elevated concentrations of P, K and S were recorded in clover when growing with grasses, although Ca uptake was lower. Expected reciprocal reduction of clover N or enhanced grass N were not recorded. Mass balance data (total extraction of key nutrients from the soil pool) showed that combination of grasses and legumes exploit soil nutrients (particularly P, Zn, Mn and Mo) more effectively than single species alone. In grasses, only tissue concentrations of K, S and Zn significantly increased when growing with legumes, but native tussock grass procured less nutrients when growing with the exotic legumes. Field sampling of clover from the more fertile lowland soil showed significantly higher foliar concentrations of K, Mn, Cu and B, but less Ca. Conclusions The findings are indicative of a mutualistic relationship: legumes derive nutritional benefits from growing with grasses. Native tussock grass contained less N when growing with the exotic legumes, suggesting less compatibility and a lack of adaptation to coexistence.

Objective The objective of these experiments was to determine how altering the proportion of ryegrass (Lolium perenne L.) to chicory (Cichorium intybus L.), alfalfa (Medicago sativa L.), or plantain (Plantago lanceolata L.) or a mixture (equal parts DM of chicory, alfalfa, and plantain) affects the in vitro fermentation rates and formation of fermentation products. Materials and Methods In vitro experiments were conducted using the ANKOM RF gas production modules (ANKOM). Experiment 1 examined increasing inclusion level (0, 50, 100%) of chicory, plantain, or alfalfa with ryegrass, and Exp. 2 examined increasing inclusion level (0, 25, 50, 75, 100%) of ryegrass to a mixture (equal parts DM of chicory, plantain, and alfalfa). Results and Discussion In Exp. 1, there was a positive linear effect for 24-h gas production per gram of DM as inclusion increased for chicory (P Implications and Applications Incorporating greater levels of chicory; plantain; or a mixture of chicory, plantain, and alfalfa with ryegrass increased gas production and reduced NH3 and branched-chain VFA in rumen fluid, which could imply a greater nutrient supply from the rumen to the host animal. Further research is required to evaluate whether these results translate to in vivo benefits on animal performance and reductions of urinary N excretion.

Background Experimental work using pot trials and mesocosm studies has indicated that species combinations are more effective in mitigating the soil nutrient constraints that limit pasture productivity in New Zealand’s hill country, but there is little field evidence to support this.Aim We question whether coexistence of species provides an opportunity to facilitate enhanced uptake and improved procurement of key soil nutrients by assemblages of plants in these mid-altitude grasslands. Methods Native and exotic legumes and co-occurring plant species were sampled according to whether they were growing together in close proximity or in single species patches. Foliar concentrations of nutrients were compared. Results Uptake of nutrients by a native broom, Carmichaelia petriei, was enhanced when it was growing in combination with native tussock grasses. Enhanced uptake of eight nutrients was recorded in foliage of an exotic legume, Lotus pedunculatus, when it was growing with native grasses or within the acuminate foliage of Aciphylla aurea (golden spaniard). Foliar concentrations of only P and Mn were elevated in white clover (Trifolium repens) foliage when it was growing in combination with grasses. Overall, mutual facilitation of nutrient uptake by combinations of species growing together was in evidence. Conclusions Some species that are less desirable from an agricultural perspective may improve acquisition of soil nutrients by the plant community. Novel native species assemblages represent an opportunity to refine pasture management. Exploiting combinations of plant species that facilitate optimal exploitation of nutrients could reduce fertiliser requirements, enhancing and protecting biodiversity in pastoral grasslands.

Intensive pastoral systems have moved away from diverse and varied diets towards overly simple monotonous diets. Feed choice through time is an obsolete way of providing forage to animals, as intensive management schemes generally allocate a single herbage or a dyad mixed sward. Monotonous feeding regimes impose nutritional repetition, which may impair animal performance and welfare. The objective of this experiment was to determine the impact of a diverse diet [DIV; free choice from perennial ryegrass (Lolium perenne L.), plantain (Plantago lanceolata L.), alfalfa (Medicago sativa L.), and chicory (Cichorium intybus L.) at all times], a varied diet [VAR; choice from ryegrass and plantain in the AM (0700–1600 h), and chicory and alfalfa in PM (1600–0700 h)], and a single forage diet of alfalfa [SFA; alfalfa at all times], on DMI, performance, and welfare of lambs. Six-month-old Coopworth ram lambs (n = 21) were offered their respective fresh-forage treatment (n = 7) diet indoors for 20 d. The DIV lambs consumed 1.64 ± 0.03 kg DM/d (mean ± SEm), which was 6% more (P < 0.05; 1.54 ± 0.03 kg DM/d) than the SFA and were not different (P > 0.05; 1.59 ± 0.03 kg DM/d) to the VAR lambs. Average daily gain (ADG) of DIV (296 g/d) and VAR (378 g/d) was 30% and 67% greater (P < 0.05) than that in the SFA lambs (227 g/d), respectively. The VAR lambs had 28% greater (P < 0.05) ADG than the DIV lambs. Differences among treatments were detected (P < 0.05) for the proportion of the day spent conducting the following behaviors: eating, ruminating, idling, lying, and standing. In addition, the number of bouts of stereotypic behaviors recorded from the SFA lambs (13.2 ± 2.2) was 150% greater (P < 0.05) than the DIV (5.1 ± 1.0) and VAR (5.5 ± 1.0) lambs. Our results suggest that the varied diet offered can improve animal performance and welfare compared to a monotonous SFA diet. Feeding management to provide a varied diet can improve performance relative to giving lambs free choice from taxonomically diverse forage options. Moreover, performance is affected by more than the primary chemical composition of the diet consumed, but how the diet is presented through time and the herbage species and quantities of each that are consumed to reach that chemical composition.

Good pasture management requires an accurate knowledge of whole-farm feedbase, yet most systems for measuring pasture growth are manually operated and time consuming. A newly developed pasture-measuring device enables remote measurement of pasture height on a regular basis. This study investigated the accuracy of such a device compared with a rising plate meter, then assessed the device on a pure perennial ryegrass paddock at a research farm, followed by field testing in a perennial ryegrass/white clover paddock on a commercial dairy farm. A strong correlation (R2 = 0.93) was obtained between collected DM yield and device-derived pasture height within the pure perennial ryegrass paddock but the correlation was weaker (R2 =0.68) with data from the dairy farm perennial ryegrass/white clover paddock. There is considerable potential to improve upon these initial data through the use of adjusted calibrations. Findings demonstrate the device has the potential to accurately estimate pasture growth.

Farm systems resilience in New Zealand pasture-based farming is influenced by external drivers such as environmental regulation, and internal drivers such as existence, expressed as profitability. We examine ten published case studies of farm systems change to provide insight into management interventions to these drivers and their impacts on pasture resilience. Nutrient supply was key to increasing pasture longevity, water use efficiency and animal feed supply. Manipulating water use efficiency through irrigation and legume (predominantly lucerne) use increased nitrogen use efficiency and added pasture supply for animal consumption. Monitoring the pasture supply and animal response ensured both animal feed requirements and pasture conditions for future growth were met. Theresilience of pastures was improved when monitoring guided adaptive management application to ensure whole-farm resilience.

The objective of this study was to determine the effect of offering animals a multiforage choice (MF) of fresh herbages on dry matter intake (DMI), live weight gain, and animal welfare, in comparison with a monotonous diet of ryegrass (Lolium perenne L.). Twenty ram lambs (30.5 ± 0.9 kg initial live weight; mean ± SEM), were randomly allocated to either a diet consisting of diverse MF choice or a single forage ryegrass (SF) diet (n = 10 per treatment) for 35 d. Both diets were fed ad libitum; however, the MF diet was composed of set dry matter ratios of 24% chicory (Cichorium intybus L.), 30% lucerne (Medicago sativa L.), 25% plantain (Plantago lanceolata L.), and 21% ryegrass. The DMI of the MF lambs was 48% greater (P < 0.01) and the within animal day-to-day coefficient of variation (CV) of intake was 26% lower (P < 0.01) than the SF lambs. The average daily gain (ADG) of lambs offered the MF diet was 92% greater (P < 0.01) than the lambs offered the SF diet. The within-animal day-to-day CV of intake was negatively related to ADG (r = −0.59; P < 0.01). The MF lamb’s urinary N concentration was 30% lower (P < 0.01) than that of the SF lambs. The SF lambs spent more time (P < 0.05) exhibiting stereotypic behaviors in the afternoon and spent more time observing other animals than the MF. Overall, allocating an MF choice of fresh herbages as opposed to a single forage diet of ryegrass increases DMI and thereby animal performance, while potentially reducing urinary N excretion.

Energy supplementation may reduce oxidative stress by correcting a negative energy balance, but in some contexts, it has been shown to increase oxidative stress, especially at peak lactation. The current experiment examined if a pelleted energy supplement with or without the addition of Lactobacillus-fermented seaweed or seaweed plus terrestrial plants extracts affected oxidative stress of ewes from late gestation through to weaning and ewe and lamb production from lambing to weaning. Treatments were either no supplement (CON−), a pelleted supplement only (CON+, 100 g/ewe per d), CON+ with seaweed extract only (SWO, 10 mL/ewe per day), or CON+ with seaweed plus an arrangement of terrestrial plant extract (SWP, 10 mL/ewe per d). Ewes (n = 160; mean initial BW = 72.3 ± 9.5 kg [mean ± SD]) were randomized to pastures (n = 4 pastures per treatment with 10 ewes each). After lambing, ewes with twins were reallocated to pastures (n = 3 pastures per treatment with 10 ewes each) according to lambing date. At 4 wk in milk, supplementation tended to reduce total antioxidant status (TAS; P = 0.10) and increased glutathione peroxidase (GPx) activity compared with nonsupplemented ewes (P = 0.04). The addition of seaweed and terrestrial plants extracts to the concentrate, that is, SWO and SWP, increased TAS and reduced GPx activity compared with CON+ (P < 0.01). Supplementation increased milk yield at weeks 4, 6, and 8 of lactation, and protein, lactose, and total milk solids yield at peak lactation (week 4; P < 0.05). The CON− ewes had greater somatic cell count than the supplemented ewes at weeks 4, 8, and 10 of lactation (P = 0.03). Our results suggest that energy supplementation, alone, increases oxidative stress of lactating ewes, which may relate to increased oxidative phosphorylation. Most importantly, these results indicate that in situations where energy supplementation is needed to increase animal performance, negative effects of energy supplementation around peak lactation can be offset by the addition of Lactobacillus-fermented plant extracts (SWO and SWP) to improve antioxidant status.

Chicory (Cichorium intybus L.) used in pastoral systems has the attributes required of a forage species to reduce animal urinary nitrogen loading to soil, increase milk production, and enhance milk fatty acid profile to improve pastoral farm systems for matching increasing global demand for dairy products and environmental standards of livestock systems. Greater adoption of chicory requires confidence in management decisions that can control risks to farm production, namely bolting after vernalisation or a decline in persistence of chicory swards, which have slowed its adoption in pastoral systems. We, therefore, measured functional traits, morphology and herbage production of chicory under irrigated field conditions before and after vernalisation in Canterbury, New Zealand. The experimental site was laid out in a complete randomized block design with four replications where two regrowth intervals and two defoliation heights were applied. Regrowth interval had a stronger influence over functional traits and herbage production than defoliation height, with more pronounced effects after vernalisation. Plants managed under shorter regrowth intervals had narrower roots with lower concentration of sugars than plants under longer intervals, which might compromise their longevity. In addition, plants managed under shorter intervals remained mostly vegetative with heavier and longer leaves, though with reduced photosynthetic capacity than those managed under longer intervals. The thermal time to initiate stem elongation in plants managed under longer intervals was ~274 growing degree-days, with a mean stem elongation rate increasing linearly at 1.4 &plusmn, 0.08 mm/growing degree-days. The key outcomes of this research quantify the growing degree-days to initiate stem elongation post vernalisation, which provides management directive for timing of defoliation of chicory in order to maintain feed quality for grazing livestock. Alternating frequent and infrequent defoliation regimes might be used to optimise vegetative growth, root reserves, and pasture persistence.

A long-term pasture persistence trial, consisting of repeated annual sowings, commenced in Canterbury in 2015 and is planned to continue until 2024. Preliminary results of the first 3 years sowings are reported. Each annual sowing used the same randomised block design of eight perennial ryegrass cultivars, one tall fescue and one cocksfoot cultivar, replicated four times. Grasses were drilled into a cultivated seedbed in autumn, with white clover broadcast-sown, then rolled with a Cambridge roller. Except for one 3-week spell in spring and in autumn to accumulate herbage to measure DM yield, botanical composition, morphology and sward density, plots were continuously stocked with sheep to maintain a 3-8 cm sward height from late-August to late-May. Results from the first 12 months following each of the three annual sowings (2015, 2016 and 2017) indicate establishment year had a greater influence on DM yield, botanical composition, grass leaf and stem proportions, and basal cover than did grass species or cultivar. Accumulating data from successive annual sowings and continued monitoring of each will help identify the long-term effect and difference between establishment years, as well as grass persistence traits for inclusion in the Forage Value Index ranking of perennial ryegrass cultivars.

Breeding cows for improved production and production efficiency may have led to indirect selection for behavioural traits including grazing and urination behavioural patterns. This study investigat...

Greenhouse gases emissions are considered one of the most important environmental issues of dairy farming systems. Nitrous oxide (N2O) has particular importance owing to its global warming potential and stratospheric ozone depletion. The objective of this study was to investigate the influence of two rotational grazing strategies characterized by two pre-grazing targets (95% and maximum canopy light interception; LI95% and LIMax, respectively) on milk production efficiency and N2O fluxes from soil in a tropical dairy farming system based on elephant grass (Pennisetum purpureum Schum. cv. Cameroon). Results indicated that LI95% pre-grazing target provided more frequent defoliations than LIMax.Water-filled pore space, soil and chamber temperatures were affected by sampling periods (P1 and P2). There was a significant pre-grazing target treatment × sampling period interaction effect on soil NH4 + concentration, which was most likely associated with urinary-N discharge. During P1, there was a greater urinary-N discharge for LI95% than LIMax (26.3 vs. 20.9 kg of urinary-N/paddock) caused by higher stocking rate, which resulted in greater N2O fluxes for LI95%. Inversely, during P2, the soil NH4 + and N2O fluxes were greater for LIMax than LI95%. During this period, the greater urinary-N discharge (46.8 vs. 44.8 kg of urinary N/paddock) was likely associated with longer stocking period for LIMax relative to LI95%, since both treatments had similar stocking rate. Converting hourly N2O fluxes to daily basis and relating to milk production efficiency, LI95% was 40% more efficient than LIMax (0.34 vs. 0.57 g N˗N2O/kg milk·ha). In addition, LI95% pre-grazing target decreased urea-N loading per milk production by 34%. Strategic grazing management represented by the LI95% pre-grazing target allows for intensification of tropical pasture-based dairy systems, enhanced milk production efficiency and decreased N-N2O emission intensity. Made available in DSpace on 2019-10-25T18:08:43Z (GMT). No. of bitstreams: 1 StrategicGrazingManagement.pdf: 919309 bytes, checksum: 86b425d4eed29c3fe7da37652bc030f3 (MD5) Previous issue date: 2019

Pasture mitigation strategies are needed to reduce the negative effects of nitrate (NO₃⁻) leaching from intensive pastoral livestock production systems. We explored the capability of pasture grasses with different cool season (winter–early spring) growth rates to reduce NO₃⁻ leaching and increase N uptake. Following a single urine application of 700 kg N ha⁻¹, NO₃⁻ leaching loss and N uptake by Italian ryegrass and four perennial ryegrass cultivars of varying seasonal growth (heading dates from –7 to +20 days), either undersown with/without Italian ryegrass, were quantified in a 12 month lysimeter study. Italian ryegrass cv. Tabu had lower NO₃⁻–N leaching loss and drainage, and greater N uptake and DM yield than perennial ryegrass varieties. Italian ryegrass total N leaching loss (143 kg N ha⁻¹ yr⁻¹) was 46–33% less (P

The objectives were to determine the effect of in utero and early-life dietary exposure to a diverse diet or a perennial ryegrass (Lolium perenne L.) diet on grazing behavior and dietary neophobia of lambs ~3.5 months post-weaning (weaned at 6 weeks of age). Sixty-four Coopworth lambs (152.5 ± 1.4 d of age; mean ± SEM,) were used. Sixteen lambs had previous in utero exposure to the diverse diet (INDIV) and another 16 had in utero and early life (from birth to weaning at 42 ± 2 d of age) exposure to the diverse diet (ELDIV) of ryegrass, red clover (Trifolium pratense L.), plantain (Plantago lanceolata L.), chicory (Cichorium intybus L.), and alfalfa (Medicago sativa L.). Sixteen lambs had only in utero exposure to ryegrass (INRYE) and the other 16 had early life exposure to ryegrass (ELRYE). Lambs were randomly allocated to one of 16 paddocks (n = 4 per treatment) with 4 lambs per paddock. All paddocks contained equal areas of spatially separated strips of red clover, chicory, alfalfa, plantain, and ryegrass, of which arrangement within the paddock was randomized. Every 5 min from 0620 to 2105 h, trained observers recorded the behavior (grazing, idle, and ruminating) and the location (pasture species) of each lamb. The INRYE and ELRYE lambs tended to (P ≤ 0.10) and spent more time (P

The objective of this experiment was to determine if supplementation with Lactobacillus fermented plant extracts will affect the livestock performance (BW change and reproduction) and antioxidant status of ewe lambs managed to lamb as yearlings (EWES). A further objective of this experiment was to determine how providing the Lactobacillus fermented plant extracts may influence their lambs’ (LAMBS) performance, rumen fermentation patterns, and antioxidant status following weaning. The EWES [n = 60; initial body weight (BW) = 29.6 ± 2.4] were provided a concentrate supplement (100 g/ewe/d) with either no extract (CON), a seaweed based extract (SWO; 10 mL/ewe/d), or a seaweed plus terrestrial plant extract (SWP; 10 mL/ewe/d), from their weaning through to the weaning of their lambs. Treatment did not influence EWES plasma total antioxidant status (TAS), whole blood glutathione peroxidase activity (GPx), or EWES or LAMBS body weight change. However, one day after weaning, the LAMBS born to SWO and SWP EWES had 13–14% greater (P = 0.02) TAS and had lower (P = 0.03) GPx activity than LAMBS born to CON EWES indicating greater antioxidant transmission to their offspring in SWO and SWP EWES. Overall, it was concluded BW changes did not appear to be great enough to elicit oxidative stress in EWES. Supplying SWO and SWP to sheep increased the maternal transmission of antioxidants to their offspring.

Grasslands are complex and heterogeneous ecosystems, and their health can be defined by the cumulative ability of their components to evolve, adapt, and maintain their integrity in the presence of stress/disturbance and provide ecosystem services. Herein, a design approach is used to generate alternative and multifunctional pastoral livestock production systems that enhance grassland health. As a way of understanding the complexity of grasslands and initiating the design process using systems thinking, rich pictures emerge as a useful method. As rich pictures are subjective views, geographic information systems (GIS) could be applied to improve the veracity of their outcomes, as both techniques are forms of an analytical process. This paper reports the application of GIS to a case study of a high-country farm to generate and combine different thematic maps to create a modern rich picture. The rich picture is a combination of remote sensing data (altitude, slope, aspects, and the Normalized Difference Vegetation Index (NDVI)), and on-the-ground data (plant species distribution and diversity and soil chemical, biological, and physical parameters). Layers were combined using a multi-criteria evaluation (MCE) based on the analytical hierarchy process (AHP) to create a final rich picture. The results highlight dissimilarities in perceptions of what underpins ‘grassland health’ between researchers in different fields and with different perspectives. The use of GIS produced a modern rich picture that enhanced the understanding of grassland health and allowed for the identification of gaps, values, and possibilities for future research work.

While grazing lands can offer a diverse range of forages, individuals within herds prefer to graze some habitats and not others. They can have consistent differences in grazing patterns and occupy specific spatial domains, whilst developing tactics and strategies for foraging that are specific to their grazing personalities. In this review, we explore the development of our understanding of grazing personalities, as we move away from the search for an "optimal animal" toward designing behavior-customized herds with an arrangement of individual grazing personalities that enhance ecosystem services and productivity. We present a "grazing personality model" that accounts for the personality of individual animals and for collective behaviors of herds. We argue that grazing personalities of grazing ruminants and other large herbivores are in part genetically determined, and that they can act at the individual and collective level. The social and biophysical environments as well as the emotional state of animals regulate the expression of "grazing genes" that are observed phenotypically as distinct grazing personalities. The reproductive and sexual successes of individuals and herds filter for allele variants of grazing genes and in turn determines their relative frequency. While the selection of one grazing personality may be adequate for homogeneous pastoral systems, the design of herds with a range of grazing personalities that are matched to the habitat diversity may be a better approach to improving the distribution of grazing animals, enhancing ecosystem services, and maximizing productivity.

The study investigated the effect of stage of lactation and Breeding Worth (BW) index on estimated dry matter intake (DMI), milk solids (MS) production, energy use efficiency (EUE) and feed conversion efficiency (FCE) of grazing cows. Two hundred crossbred cows with similar calving date (14 August ± 9.97 days), live weight (471.5 ± 44.02) and age (7.5 ± 1.25 years) were separated into five groups (n = 40) based on New Zealand BW index: Low BW (BW = 63.1); Medium Low BW (BW = 88.2); Medium BW (BW = 19.1); Medium High BW (BW = 128.9); and High BW (BW = 146.9). Milk samples were collected in early, mid and late lactation and herbage samples were taken the day before milk sampling. The DMI was estimated by back-calculation based on metabolizable energy requirement for maintenance and production. The MS production, herbage DMI, EUE and FCE declined from early to late lactation. The overall results suggest regardless of the stage of lactation, cows with higher BW had a higher DMI, MS production and FCE.

The European Commission (EC) is critical of palm oil production as it has a high indirect land-use change (ILUC) risk from industrial palm oil expansion pressuring landless/displaced farmers to clear tropical forests. Major palm oil-producing countries such as Indonesia and Malaysia are claiming that the EC’s decision will cause unwarranted obstacles to the adoption of sustainable practices in the palm oil industry and obstruct free trade. To date, in responding to the EC, both Indonesia and Malaysia have yet to develop a national strategy that mitigates the risks of ILUC caused by industrial palm oil expansion. Hence, we propose these major palm oil-producing countries reform their land policy by making it compulsory for plantation companies to share production land with landless/displaced farmers. This strategy could prevent farmers from clearing more tracts of tropical forest and encourage them to use immature and mature areas of palm oil stands for crop and cattle farming, respectively. To guide this strategy, we performed Monte Carlo simulations to predict palm oil production land area and then estimate the land which could be allocated for crop and cattle farming at global-, country-, and plantation-scales. Besides mitigating further deforestation in the tropics, the crop and livestock integration strategy can boost food security and reduce the use of chemical herbicides in palm oil-producing countries. The strategy is consistent with palm oil certification schemes in terms of ensuring social and environmental sustainability. Palm oil-producing countries should implement the strategy to address ILUC risk while consumer countries should demand producers use such strategy.

The objective of this experiment was to determine how early life exposure to plant extracts would influence grazing behavior and dietary preference. This experiment used ram lambs (n = 60; initial body weight = 41.8 ± 3.8 kg, mean ± standard deviation). Their dams were either provided no plant extract (CON), a seaweed (Ecklonia radiata) extract (10 mL/ram/d; SWE), or an extract of seaweed, chicory (Cichorium intybus), plantain (Plantago lanceolata), lucerne (Medicago sativa), and dock (Rumex obtusifolius; 10 mL/ram/d; SWP). Treatments were provided to the dams starting in late gestation (63.9 ± 6.5 d before lambing), through to weaning of the lambs. After weaning (94 ± 6.5 d old), lambs received the respective treatments of their dams until the initiation of the current experiment (66 d after weaning). At the initiation of the current experiment, the lambs were placed into a paddock containing spatially separated strips of ryegrass (Lolium perenne), chicory, plantain, lucerne, and dock, of which they received a fresh break, weekly. During week 1, SWP had more (P

With a view to increasing rangeland pasture legume abundance, the herbage biomass and seedling recruitment of four New Zealand naturalized annual clover species (haresfoot clover Trifolium arvense L., suckling clover T. dubium Sibth, cluster clover T. glomeratum L., and striated clover T. striatum L.) were measured in relation to spring grazing deferment versus continuous grazing and low versus high superphosphate fertilizer application (5 vs. 9 kg P · ha-1) at a midaltitude (700-m) hill site. Naturalized species were dominant over periodically sown white (T. repens L.) and subterranean clover (T. subterraneum L.), contributing N 90% to sward legume composition. Rainfall in spring-early summer varied greatly between years, driving the large variation in sward legume content (28% in the moist first year; 2% in the very dry second year). Grazing deferment in spring did not influence autumn seedling recruitment or the following spring herbage biomass of naturalized species. However, autumn recruitme...

Selective grazing of white clover (Trifolium repens) over grass species in temperate pastures results in reduced clover abundance and availability over time. Within sheep- and cattle-grazed dryland (

Agricultural systems are responsible for environmental impacts that can be mitigated through the adoption of more sustainable principles. Our objective was to investigate the influence of two pre-grazing targets (95% and maximum canopy light interception during pasture regrowth; LI95% and LIMax, respectively) on sward structure and herbage nutritive value of elephant grass cv. Cameroon, and dry matter intake (DMI), milk yield, stocking rate, enteric methane (CH4) emissions by Holstein × Jersey dairy cows. We hypothesized that grazing strategies modifying the sward structure of elephant grass (Pennisetum purpureum Schum.) improves nutritive value of herbage, increasing DMI and reducing intensity of enteric CH4 emissions, providing environmental and productivity benefits to tropical pasture-based dairy systems. Results indicated that pre-sward surface height was greater for LIMax (≈135 cm) than LI95% (≈100 cm) and can be used as a reliable field guide for monitoring sward structure. Grazing management based on LI95% criteria improved herbage nutritive value and grazing efficiency, allowing greater DMI, milk yield and stocking rate by dairy cows. Daily enteric CH4 emission was not affected; however, cows grazing elephant grass at LI95% were more efficient and emitted 21% less CH4/kg of milk yield and 18% less CH4/kg of DMI. The 51% increase in milk yield per hectare overcame the 29% increase in enteric CH4 emissions per hectare in LI95% grazing management. Thereby the same resource allocation resulted in a 16% mitigation of the main greenhouse gas from pasture-based dairy systems. Overall, strategic grazing management is an environmental friendly practice that improves use efficiency of allocated resources through optimization of processes evolving plant, ruminant and their interface, and enhances milk production efficiency of tropical pasture-based systems.

International audience; AbstractThe use of agrochemicals is expected to increase with the global expansion of oil palm plantations. In line with environmentally sustainable palm oil certification, targeted grazing can minimize the dependency on herbicides for controlling weeds in plantations. Here, we show for the first time that targeted grazing would control weeds and improve biodiversity of desired animal species. We sampled birds at 45 oil palm plantations in Peninsular Malaysia that were systematically grazed, non-systematically grazed, or herbicide-controlled plantations without cattle grazing. We found that bird species richness increased with size of grazing area, but decreased with number of cattle. Bird abundance was higher in the systematic grazing system, but negatively related to number of cattle. These factors explained 18.41 and 25.34% of the observed variations in bird species richness and abundance, respectively. Our findings suggest that targeted cattle grazing can be instrumental for transforming conventional oil palm agriculture into more biodiversity-friendly agroecosystems. Targeted grazing is likely to be practical under field conditions in major palm oil producing countries. In addition, the use of targeted grazing as a biological control method for weeds would be welcomed by palm oil consumers and encouraged by sustainable palm oil certification bodies such as the Roundtable on Sustainable Palm Oil (RSPO).

Naturalised annual clover (NAC) species (suckling clover, cluster clover, striated clover, and haresfoot clover) are commonly present to locally abundant in summer dry hill and high country areas where white and subterranean (sub) clover abundance is limited. This field trial investigated NAC species dry matter production and seedling regeneration compared to white and sub clover. Autumn seedling recruitment was measured in response to low (75 kg/ha) or high (200 kg/ ha) superphosphate (SP) application. Over two growing seasons, NAC species contributed >90% to pasture legume content while white and sub clover contributed

Maintaining and increasing legume abundance is a critical component of pastoral intensification, increasing nitrogen inputs to nitrogen deficient New Zealand high and hill country pastures and improving feed quality. Establishment and persistence of traditionally sown legume species white clover (Trifolium repens) and subterranean clover (T. subterraneum) is often limited in summer-dry high country. In contrast, naturalized, adventive annual pasture legume species such as cluster clover (T. glomeratum), haresfoot clover (T. arvense), striated clover (T. striatum) and suckling clover (T. dubium) persist on low fertility, summer-dry high and hill country slopes, although little is known about the edaphic requirements of these species. A glasshouse study was conducted to determine the response and efficiency of these four pasture legume species to increasing levels of available phosphorus (P) in a typical, low fertility, acidic New Zealand high country soil, comparing against white clover and subter...

Adventive annual clovers play a critical role in nitrogen (N) cycling and feed quality in extensive summer-dry hill country, where traditionally sown white and subterranean clovers often fail to persist. However, very little is known about the edaphic (e.g. soil fertility) requirements of these species. The growth response and nutrient uptake of four adventive annual clovers to applied sulphur (S) or lime, grown in a typical low-fertility South Island high country soil, were investigated under glasshouse conditions and compared with white and subterranean clovers as reference species. The annual species had yield responses of 12–17% or were unresponsive to S applications. Trifolium repens and T. striatum responded to liming at low lime rates, while all other species had negative yield responses to liming. Maximum yields were generally in the order of T. subterraneum≥T. arvense>T. striatum≥T. dubium>T. glomeratum>T. repens. For lime treatments, yields were strongly driven by phosphorus (P) availab...

7 páginas, 4 tablas., Ensiled king grass (Cenchrus purpureus (Schumach.) Morrone) is commonly used as feed in tropical ruminant production. However, ruminant performance can be limited by low nitrogen (N) content in tropical grass silage. A mixed feed of legume–king grass silage may be an option to improve ruminant production. We investigated the effects of feeding an ensiled mixture of king grass forage and foliage of a browse tree legume, either leucaena (Leucaena leucocephala (Lam.) de Wit) or gliricidia (Gliricidia sepium (Jacq.) Walp), on dry matter (DM) intake, DM digestibility, organic matter (OM) digestibility and N balance of Pelibuey sheep. Twelve male lambs 9–11 months old were blocked by initial bodyweight (33 ± 3 kg, mean ± s.d.) into three groups of four lambs and randomly assigned to one of three feed treatments: king grass silage (KS); mixed king grass and leucaena silage (KLS); and mixed king grass and gliricidia silage (KGS). Results showed that DM and OM were similar among silages. The N content was higher (P < 0.001) in KLS and KGS than in KS. DM intake and DM digestibility were higher (P < 0.001) in KLS and KGS than in KS. OM digestibility was higher (P < 0.001) in KLS than in KS. Nitrogen intake, faecal N, urine volume, urinary N, digested N, N digestibility, N retention and retained N : N intake ratio from KLS and KGS treatments were higher (P < 0.05) than from KS. A lower (P < 0.01) urinary N : N intake ratio was detected from KGS and KLS than from KS. This study demonstrated that, compared with silage made from king grass alone, legume–king grass silage mixtures can improve intake and nutrient digestibility in Pelibuey lambs. Further, N retention can be enhanced when legume–king grass silages are used as feed compared with king grass silage alone., The Startup Research Fund offered by Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, to Long Cheng is acknowledged to support this international collaboration. We thank Miss Jiawen Li (Chengdu University of Information Technology) for useful discussion and help with formatting the manuscript for submission.

Oil palm expansion has caused considerable biodiversity loss as rainforest has been converted to plantation. However, it is still possible to mitigate such biodiversity losses and increase agricultural sustainability by introducing sustainable oil palm farming practices. One such method is the use of biological control agents for understory weed management in place of herbicides. Integrating cattle into oil palm plantation management to control undergrowth is expected to improve biodiversity (including avian diversity) in oil palm plantations. This study investigated the association between cattle grazing and farmland bird species composition in oil palm plantations. We used point transect sampling to survey farmland birds in 45 oil palm plantations which were divided into systematically and non-systematically cattle grazed plantations and control plantations (without cattle grazing). We found that both oil palm plantations with systematic (P=0.001) and non-systematic (P=0.005) cattle grazing had greater avian diversity than plantations without cattle grazing. Based on feeding guild, avian insectivores made up the majority of farmland birds observed. Bird species composition was determined by four attributes in our model: number of cattle, selective weeding frequency, age of oil palm stand, and palm height. We conclude that systematic grazing can improve avian diversity in oil palm plantations. We stress, that cattle integration into oil palm agriculture can provide an excellent means of maximising agricultural land use efficiency as well as increasing biodiversity in agricultural landscapes by increasing habitat complexity.

The abundance of four naturalised annual clovers (striated, cluster, suckling, haresfoot) and two sown clovers (subterranean and white clover) was investigated in relation to topographical, soil fertility and management factors on two contrasting hill/high country stations in the South Island: Glenfalloch in inland Canterbury (1 665 mm annual rainfall), and Mt Grand in Central Otago (703 mm annual rainfall).

The effect of crop sequence pasture species mixture and nitrogen fertiliser on gorse establishment was monitored over 23 months in land converted from pine forest to a dryland sheep pasture There were fewer gorse plants in plots sown initially into the forage crop triticale and then into grasslegume pasture than plots sown directly into grass or grasslegume pasture Once the triticale was grazed undersowing grasslegume pasture beneath rape to establish clover rich pastures suppressed gorse more than sowing grasslegume pasture directly There was no effect of nitrogen fertiliser applied at 150 kg N/ha/year on gorse plant density or cover Appropriate management tools to control gorse in forest to pasture conversions include a combination of crop sequences where forage crops are followed by pasture and the establishment of pasture legume rich herbage This type of pasture is preferred by livestock and results in high grazing intensity of gorse seedlings growing in the pasture

Differential equations and advanced statistical models have been used to predict growth phenomena. In the present study, general nonlinear growth functions such as von Bertalanffy, Gompertz, logistic, and Brody, along with hierarchical modeling were applied to investigate the phenotypic growth pattern of Iranian Lori-Bakhtiari sheep. Growth data from 1410 Lori- Bakhtiari lambs were used in the present study. The results showed that the Brody function outperformed the other three nonlinear growth functions. In addition, including hierarchical growth modeling results allowed the adoption of many random effect structures, suggesting that hierarchical growth modeling has a useful role in growth data modeling. This method provides an estimation of growth parameters based on individual animals, improving individual growth selection. The results suggest this approach for growth modeling. Combining the strength of individual growth modeling with general growth modeling, e.g., von Bertalanffy, Gompertz, logistic, and Brody would be deeply appealing in the future. In this regard, dealing with sheep growth phenomenon using pure mathematical models, i.e. grey system theory models that could be new powerful prediction tools for breeders and experts, has not been done yet. However, running the analysis on large datasets will require significantly higher computational power than is ordinarily available.