Dual-purpose Wheat Research Articles

Evaluation of dual-purpose wheat varieties in the Southeast United States

Evaluation of dual-purpose wheat varieties in the Southeast United States

Effect of Mowing on Wheat Growth at Seeding Stage.

Winter wheat is used as forage at the tillering stage in many countries; however, the regrowth pattern of wheat after mowing remains unclear. In this study, the growth patterns of wheat were revealed through cytological and physiological assessments as well as transcriptome sequencing. The results of agronomic traits and paraffin sections showed that the shoot growth rate increased, but root growth was inhibited after mowing. The submicroscopic structure revealed a decrease in heterochromatin in the tillering node cell and a change in mitochondrial shape in the tillering node and secondary root. Analysis of the transcriptome showed the number of differentially expressed genes (DEGs) involved in biological processes, cellular components, and molecular functions; 2492 upregulated DEGs and 1534 downregulated DEGs were identified. The results of the experimental study showed that mowing induced expression of DEGs in the phenylpropanoid biosynthesis pathway and increased the activity of PAL and 4CL. The upregulated DEGs in the starch and sucrose metabolism pathways and related enzyme activity alterations indicated that the sugar degradation rate increased. The DEGs in the nitrogen metabolism pathway biosynthesis of the amino acids, phenylpropanoid biosynthesis metabolism, and in the TCA pathway also changed after mowing. Hormone content and related gene expression was also altered in the tillering and secondary roots after mowing. When jasmonic acid and ethylene were used to treat the wheat after mowing, the regeneration rate increased, whereas abscisic acid inhibited regrowth. This study revealed the wheat growth patterns after mowing, which could lead to a better understanding of the development of dual-purpose wheat.

Wheat yield is not causally related to the duration of the growing season

A common conceptual model for crop growth analysis assumes biomass is proportional to the accumulation of radiation intercepted by the canopy during the growing season, and yield is the product of biomass and harvest index. This model assumes that biomass and harvest index are independent, and that biomass has the same value for yield across developmental stages; here we focus on the latter assumption. A corollary of this model is that yield and duration of the growing season are causally related. In this article, we analyse the evidence for and against this causal relationship. We use both a physiological perspective and agronomic evidence to challenge this causality. An alternative, phenology-focused model is outlined that is based on the following principles: crops accommodate environmental variation through grain number, grain number is defined in a species-specific critical developmental period, and grain number is a function of three traits in the critical period: duration, growth rate, and partitioning to reproduction. Against this framework, we analyse dual purpose wheat, where a substantial part of the biomass is removed, effectively shortening the growing season, with little or no effect on yield; timing of nitrogen fertilisation, where delayed application reduces the growth rate early in the season, with little or no effect on yield; and the correlation between season length and yield of winter wheat and spring wheat - wheat yield in Southern Chile, with a sowing-to-maturity season of ∼ 5 months, could be as high as that of winter wheat in the UK, with a sowing-to-maturity season of ∼ 10 months. Physiological principles and agronomic evidence support the conclusion that the duration of, and growth rate and partitioning during the critical period, rather than the duration of the growing season, are the drivers of wheat yield.

Dual use insurance for annual forage producers: comparing risk management alternatives

PurposeThe purpose of this paper is to evaluate the Dual Use (DU) Option – a crop insurance policy created by the 2018 Farm Bill – relative to other policies available to dual-purpose annual forage producers. The new policy combines existing rainfall-based policies for annual forage crops and multi-peril policies for grain, allowing coverage for multiple crop uses on the same acres during the same growing season.Design/methodology/approachThe paper uses a simulation model to examine crop insurance choices for a typical Texas dual-purpose wheat farm. The certainty equivalent (CE) of wealth is used to rank choices within and between three insurance plans and to analyze the effects of those choices over a range of producer risk aversion levels and for three cases of yield expectations.FindingsThe DU Option is more preferred as risk aversion increases, but it is not universally preferred. Therefore, while the policy can be a viable risk management tool, certain restrictions may be limiting its effectiveness.Practical implicationsThe findings of this paper can help explain farm-level decision making related to dual-purpose annual forage crop insurance program choices.Originality/valueThis paper contributes to the literature by documenting a new crop insurance program made available in the 2018 Farm Bill and provides insights into producers' possible choices by evaluating extensive scenarios.

Cutting management of dual purpose wheat and implications on seed quality

The nutritive value of a dual purpose forage, its structural and morphological composition, seed production capacity are determining characteristics in the selection of a genotype. The objective of this work was to evaluate the effect of cutting management on yield components, physiological quality of the seeds in the subsequent generation. Experiment I: the field cutting management was performed, and the yield components and the physiological quality of the seeds were evaluated. Experiment II: where the components of plant yield and physiological quality of the seeds were evaluated. The cutting managements affect the components of yield, such as thousand seed weight and seed mass per cob, as well as germination, first germination count and seedling dry mass of dual purpose wheat. In the generation that evaluates the quality of the seeds produced, the cuts do not influence the physiological quality of the seeds, however, they affect the yield components, number of cobs per plant, one thousand seed weight and seed mass per cob.

Management of dual-purpose wheat genotypes by rotatinuous stocking

The objective was to evaluate whether rotatinuous stocking management in dual-purpose wheat genotypes provides greater forage performance compared to the traditional rotational grazing management, which could become an alternative to ryegrass, once this new management strategy has been validated. Three dual-purpose wheat cultivars (BRS Pastoreio, BRS Tarumã and BRS Tarumaxi) and a black oat cultivar (Embrapa 139 Neblina) were used in the experiment, in traditional rotational and rotatinuous stocking. The experiment was carried out in a randomized complete blocks design, with treatments arranged in a 4 x 2 factorial scheme (cultivars x management strategies), with pre and post-harvest heights in traditional rotational management (RT) of 25 and 5 cm, and 25 and 15 in the rotatinuous stocking management (RN). The experiment was carried out at Embrapa Trigo, in Passo Fundo, Rio Grande do Sul state, southern Brazil. Nitrogen was applied after sowing and after cuts, according to the management strategies. Dry matter yield, percentage of leaf blades and forage accumulation per cut and total were evaluated. Wheat cultivars in rotatinuous stocking management showed higher numbers of cuts, greater cycle, percentage of leaves and average rate of forage accumulation, with smaller intervals between cycles. The total forage production showed no difference between the cultivars, however, BRS Tarumaxi was higher in the rotatinuous stocking management. Thus, responses between the genotypes in relation to the management strategies adopted are different.

Mixtures of rye cultivars to improve forage yield, distribution and nutritive value

The search for forage cultivars that provide higher yields with quality in periods of forage shortage, whether in isolated or mixed management, is essential for livestock stability. Thus, the objective was to evaluate the forage performance and nutritive value of rye cultivars mixtures (BRS Progresso, BRS Serrano and Temprano) from different production cycles compared to the isolated management of rye, dual-purpose wheat cvs. (BRS Tarumã and BRS Pastoreio) and black oat cv. Embrapa 139 Neblina as controls. The experiment was conducted at a randomized complete block design, with four rye associations and the isolated cultivation of wheat, oat, and rye. Dry matter (DM) yield and nutritive value, such as content of neutral detergent fiber (NDF), acid detergent fiber (ADF), and crude protein (CP) content were evaluated for each cut and total values. There was difference (P<0.001) in total DM, the highest yield was in single cultivation as well as mixtures with Temprano. BRS Serrano and BRS Progresso and their mixture had lower leaf blade percentage in the total DM. There were differences (P<0.05) in NDF concentration (55.1 to 70.60%), ADF (15.2 to 34.7%), and CP (27.4 to 36.8%) levels along harvests. Among cultivars, Temprano showed the highest proportion of leaf blades and total DM yield.

Effect of seed rate and fertilizer levels on fodder quality, yield and economics of dual purpose wheat in western zone of Haryana

Dual purpose wheat i.e., for grain as well as for green fodder purposes is a novel concept in the world. In view of this, the experiment was conducted on Research Farm of Agronomy, CCS Haryana Agricultural University, Hisar during rabi season of 2017–2018 and 2018–2019 to study the effect of different seed rates and fertilizer levels on green fodder, grain productivity and economics of dual purpose wheat in western Haryana. The field experiment was laid out in split plot design with two varieties i.e., C 306 and WH 1105 with cutting management practices in main plots and different seed rates with various fertilizer levels in sub plots. Significantly higher green fodder yield, yield attributes, NPK, protein and crude protein content of green fodder were observed in cultivar WH 1105 over C 306 and wheat supplied with 130% RDF over 115 and 100% RDF with either seed rate. Cultivation of C 306 under cut management practices sown at 125 kg/ha seed rate with 130% RDF was observed more economical with higher B-C ratio than WH 1105 and no cut management system.

Timing and Splitting of Nitrogen Compensated for the Loss in Grain Yield of Dual-Purpose Wheat Under Varied Cutting Heights

Timing and Splitting of Nitrogen Compensated for the Loss in Grain Yield of Dual-Purpose Wheat Under Varied Cutting Heights

Suitability of wheat (Triticum aestivum) varieties for dual purpose under varying seed rate and fertilizer levels

To meet the demand of grain and fodder, dual purpose crops can be a good alternative that can also reduce burden on the land. A field study was carried out during two consecutive rabi seasons of 2017–18 and 2018–19 on research farm of Agronomy, CCS HAU, Hisar, Haryana, to evaluate the performance of dual purpose wheat (Triticum aestivum L.). The experiment was laid out in split plot design with three replications. It comprised two varieties (C 306 and WH 1105) along with cut management in main plots, and two seed rates (100 kg/ha and 125 kg/ha) with three levels of fertilizer, viz. RDF, 115% of RDF and 130% of RDF in sub-plots. The findings revealed that significantly higher crop growth rate (CGR) up to 60 DAS was observed in C 306 over WH 1105, whereas, after 60 DAS, higher CGR was observed in WH 1105 over C 306. Maximum tillers/m2, dry matter accumulation, effective tillers, grain and biological yield, crude protein were obtained in WH 1105 without cut, closely followed by C 306 without cut. Among, seed and fertilizer rate combinations, significantly higher CGR, protein and crude protein content other growth parameters were observed in 125 kg/ha seed rate +130% RDF and 100 kg/ha seed rate + 130% RDF. It was concluded that C 306 may be a good choice for dual purpose wheat which can provide fodder in lean period without affecting its yield if supplied with slightly higher dose of fertilizers

20 Forage Production and Nutritive Quality of Dual-purpose Wheat Managed Under Three Different Grazing Frequencies in the Southeastern United States

Abstract Grazing of dual-purpose wheat is an established management system in the Great Plains regions of the United States. Varietal and climatic differences between regions has limited use of dual-purpose systems in the Southeast. The objective of this study was to evaluate four wheat varieties, [feed wheat (mixed variety, Feed), seed wheat (‘GA Gore’) and two forage varieties, ‘AGS 2024’ (AGS) and ‘Pioneer 26R41’ (Pioneer)], under three grazing treatments [no-grazing (NG), low frequency (LF), high frequency (HF)]. The experiment was a randomized complete block design (n = 4) using mob-grazing. Forage samples were taken using three 0.1m2-quadrats before (Pre) and after (Post) each grazing event. Crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) were determined on all Pre samples. Wheat grain yield was determined at the end of the season. Data were analyzed using PROC GLIMMIX of SAS (SAS Inst., Cary, NC), a < 0.05. Pre-grazed, AGS seasonal forage production was greater (P < 0.01) than all other varieties (1,517 kg/ha vs 1,031 kg/ha, respectively). Post-grazing biomass from AGS and Pioneer was greater than GA Gore (817 vs 512 kg DM/ha, respectively; P = 0.04). Pre-grazing, Feed, GA Gore and Pioneer had greater (P < 0.01) CP than AGS (31.6 vs. 30.1%, respectively). The concentration of NDF was greatest for AGS (39.1%) compared with all other varieties (34.9%, P < 0.01). Grazing frequency did not affect CP (P = 0.67). The NG plots had greater NDF and ADF than LF and HF (37.5 vs. 35.2% and 19.8 vs. 18.6%, respectively; P < 0.01). Pioneer had the greatest grain yield but was not different from AGS (57.6 and 52.4 kg/ha, respectively; P = 0.41). Management of wheat as a dual-purpose crop is feasible in the Southeast. More information is needed to determine the economic impact of this management practice.

Technological Quality of Dual-purpose Wheat Stored

Defoliation may interfere in the sink-source relationship and influence the technological quality of wheat flour. This study aimed to confirm the effects of plant cutting heights and number of cuttings on the technological wheat flour quality of BRS Umbu and BRS Tarumã cultivars after six months of storage. A completely randomized design was used and treatments consisted of a combination of cutting heights (20 and 30 cm) and number of cuttings (no cutting, 1, 2 and 3 cuttings), resulting in the following treatments: 20/1, 20/2, 20/3 30/1, 30/2, 30/3 and controls with no cuttings. Grain moisture, crude protein, hectoliter weight, gluten strength, falling number and wet gluten were determined. It was observed the behavior for both cultivars and number of cuts was similar, and it was found that the defoliation height of 30 cm resulted in greater decreases in PH and W values of 2.5 and 25.5% respectively. The results indicate that defoliation does not lead to the evolution of the stored wheat evaluated technological properties and with storage, properties such as W and WG of both cultivars showed a reduction.

176 Evaluating Dual-purpose Wheat Varieties in the Southeastern U.S

Abstract Dual-purpose wheat (Triticum aestivum L.) systems increase farm sustainability by diversifying on-farm income. While these systems are common in the Southern Great Plains of the United States, they are not often utilized in the Southeast. This study aimed to evaluate pre- and post-grazing herbage mass (HM) of four winter wheat varieties managed under a dual-purpose grazing and grain production system. The winter wheat varieties evaluated were generic feed-type wheat (mixed variety, Feed), seed-type wheat (‘GA Gore’) and two forage-type varieties, ‘AGS 2024’ (AGS) and ‘Pioneer 26R41’ (Pioneer). The experiment was a completely randomized block design with n = 4. Each plot was randomly assigned either as no-grazing (CON) or grazing (GF2). Plots were grazed with cow-calf pairs that were fasted 24 h before each grazing event. Grazing was considered complete when the average stubble height was 10 cm. Herbage mass was determined using three 0.1m2-quadrats per plot and clipping to a 10 cm stubble height before (PreG) and after (PostG) each grazing event. Forage samples were then dried at 45°C for 72 h. Data were analyzed using PROC GLIMMIX of SAS (SAS Inst., Cary, NC). Differences were declared at P < 0.05. Initial HM was greater for PreG than PostG (883 and 615 kg/ha, respectively; P < 0.01). Prior to grazing, AGS (1204 kg/ha) was greater (P < 0.02) than all other varieties. Pre-grazing, there were no differences among the other varieties (776 kg/ha; P > 0.14). Post-grazing, AGS had a greater HM than Seed (788 and 391 ka/ha, respectively; P = 0.04), while all other varieties were intermediate (642 kg/ha). Herbage mass was affected by grazing frequency with CON being greater (P < 0.01) than GF2 (993 and 691 kg/ha, respectively). These results indicate that both wheat variety and grazing treatment had an effect on dual-purpose wheat herbage mass.

RELATIONSHIPS OF PRIMARY AND SECONDARY WHEAT YIELD COMPONENTS

The aim is to improve production techniques, so the study aims to verify the change in the productivity dynamics of ears contained in the main stems and tillers related to the sowing densities and dual purpose wheat cultivars. The experiment was carried out in Frederico Westphalen, RS. The design used was randomized blocks organized in factorial scheme, with five wheat cultivars, five density managements, arranged in three repetitions. In the analysis of variance, interaction for cultivar and density was observed for all variables analyzed, except for ear length in the main plant, tiller ear length, grain mass per tiller indicating that the interaction between both collaborated to obtain the results. The cultivar BRS Taruma, BRS Figueira and BRS Guatambu showed to be able to compensate the production in higher densities, increasing the values of some variables analyzed. All yield components show positive correlations.

Towards an ideotype for food-fuel dual-purpose wheat in Argentina with focus on biogas production

BackgroundWheat straw, one of the most abundant agricultural residues worldwide, can be used to produce biogas, which is considered one of the most efficiently produced renewable energies. Wheat grown with the dual-purpose of producing food and biogas should display simultaneously high grain and straw yields, low lodging susceptibility and high conversion efficiency of straw into biogas. The aims of this study were to determine the best food-fuel dual-purpose wheat candidates among 36 wheat genotypes—including French, CIMMYT and local (Criollo) germplasm—used in breeding programs in Argentina and to gain some insights into the relationships between key traits relevant for dual-purpose wheat genotypes.ResultsHigh variability in individual key traits for dual-purpose wheat ideotype has been found. Genotypes of French origin displayed the highest grain yield, and those of CIMMYT origin, the lowest straw yield. Genotypes of Criollo origin showed the highest lodging susceptibility, and French ones, the lowest. Straw yield was positively correlated with grain yield in all genotypes, and negatively correlated with plant height in genotypes of Criollo origin. Straw conversion into biogas was measured in terms of the biogas potential production and kinetic parameters Bmax (maximum specific biogas production) and k (first-order kinetic constant) were analyzed. All key traits were analyzed together by a principal component analysis. Baguette 31 and SNR Nogal, two genotypes of French origin, showed high grain yield, high-to-very high straw yield, low lodging susceptibility, and moderate-to-high Bmax and k. Buck Guapo and Buck Baqueano, two genotypes of Criollo origin, displayed good values for grain yield, straw yield and Bmax and k. However, their high lodging susceptibility precludes their production in shallow soils or high-input systems. Lastly, some old genotypes (e.g. Klein Atlas) harbored a good combination of all key traits and could prove valuable to be included in future breeding programs for dual-purpose wheat.ConclusionsWhile none of the genotypes excelled in every key trait, a few candidates showed potential for dual-purpose ideotype, particularly Baguette 31 and SNR Nogal. The challenge lays in gathering all attributes for food and 2G fuel in the same genotype.

Plant arrangement and its effects on yield and bromatological quality of wheat submitted to different cutting systems

This was aimed to evaluate the effects of plant arrangements and cutting systems on the yield and quality of dual purpose wheat. The present study was conducted in the years 2015, 2016 and 2017 in Frederico Westphalen, belonging to the state of Rio Grande do Sul. The dual purpose wheat genotype used was BRS Tarumã. For this, five sowing densities were used, namely: 75, 150, 225, 300 and 375 seeds per square meter. The analysis of variance revealed significance for the interaction sowing density x cutting systems x chemical quality for the variables dry matter per hectare, lipids, digestible fiber in acid detergent, lignin, cellulose, mineral matter, total carbohydrates and non-fibrous carbohydrates. The positive effects on yield and bromatological quality of the forage are obtained by arranging plants and cutting systems through the sowing density of 300 to 375 seeds per meter with the practice of up to two cuts in dual purpose wheat. Superior dry matter per unit area was observed in the second cut, which was defined by the stimulation of tillering, regrowth and split nitrogen fertilization. Since, the superior bromatological quality is determined by the magnitude of non-fibrous carbohydrates in the forage.

Influence of seed rate and fertilizer levels on agro physiological parameters and yield of dual purpose wheat (Triticum aestivum)

The experiment was conducted at Research Farm of Agronomy, CCS HAU, Hisar during rabi season of the year 2017-18 and 2018-19 to study the influence of seed rate and fertilizer levels on agro-physiological parameters and yield of dual purpose wheat (Triticum aestivum L.). Four treatments, viz. C 306 without cut (M1), C 306 with cut at 60 DAS (M2), WH 1105 without cut (M3), WH 1105 with cut at 60 DAS (M4) in main plot and six seed rate and fertilizer combinations, viz: 100 kg/ha seed rate + 100% RDF (S1), 100 kg/ha seed rate + 115% RDF (S2), 100 kg/ha seed rate + 130% RDF (S3), 125 kg/ha seed rate + 100% RDF (S4), 125 kg/ha seed rate + 115% RDF (S5), 125 kg/ha seed rate + 130% RDF (S6) in subplot with three replications were laid out in split plot design. Results of this study indicate that wheat plant population was not influenced by different cultivars and different dose of fertilizers, but it was significantly affected by seed rate and fertilizer levels. Plant population was significantly higher (55.11/m.r.l.) in wheat sown at 125 kg/ha seed rate with 130% RDF over wheat sown at 100 kg/ha seed rate with either dose of fertilizer during both the years. Significantly higher dry matter accumulation (400.76 g/m.r.l. at harvest), LAI and total tillers were recorded in WH 1105 under without cut management, whereas, significantly taller plants (138.37 cm at harvest) was recorded in C 306 under without cut management. While comparing the seed rate and fertilizer combination treatments, significantly higher dry matter accumulation (308.38 g/m.r.l. at harvest), plant height (114.47 cm at harvest), LAI and total tillers were recorded in wheat sown at 125 kg/ha seed rate with 130% RDF. Significantly higher grain yield (6203 kg/ha) was recorded in WH 1105 under without cut management sown at 125 kg/ha seed rate with 130% RDF over C 306 under either cut management sown at either seed rate with either fertilizer levels during both years, which was statistically at par with WH 1105 sown at 125 kg/ha seed rate with 115% RDF and WH 1105 sown at 100 kg/ha seed rate with 130% RDF.

Utilising dual-purpose crops to produce prime lambs: comparison of White Dorper and Merino sheep on crops and pasture

Context Dual-purpose crops (for grazing and grain) are an important part of the feedbase in mixed farming systems in the medium-rainfall zone of southern Australia. On these farms, non-wool sheep breeds such as the Dorper may provide an opportunity to increase lamb production while reducing labour costs compared with traditional sheep breeds. Aims This study was designed to compare lamb production systems based on White Dorper and Merino ewes joined to a terminal sire, while exploiting a feedbase that included dual-purpose crops. Methods Two experiments were conducted at Wagga Wagga, New South Wales, during 2013 (Expt 1) and 2014 (Expt 2). In February in both experiments, White Dorper ewes were joined to either White Dorper or White Suffolk rams (lambs designated DD and WSD, respectively), and Merino ewes were joined to White Suffolk rams (lambs designated WSM). In Expt 1 a dual-purpose wheat (Triticum aestivum L.) crop was established and the paddock subdivided into nine plots (0.93 ha each). Pregnant ewes were allocated to plots on the basis of genotype (DD, WSD or WSM grazing separate plots) after blocking for number of fetuses identified at mid-pregnancy scanning, with three replicates based on genotype. Lambing commenced on 28 June, and ewes grazed the crop from 27 June to 14 August and then continued to graze in the same groups on a lucerne (Medicago sativa L.)–clover (Trifolium spp.) pasture subdivided into nine plots (2.1 ha), maintaining the same replicates until weaning on 2 October. In Expt 2, the cropping paddock was subdivided into six plots (1.86 ha each) sown to either dual-purpose wheat or canola (Brassica napus L.), with three replicates. Lambing commenced on 13 July. Merino and White Dorper ewes grazed the crops concurrently from 19 June to 12 August, and then lucerne–clover pasture until weaning on 29 September. In both experiments a mineral supplement was fed to ewes grazing wheat during the crop-grazing period. Key results Feed on offer was low (0.33 t/ha) in dual-purpose wheat crops at the start of grazing in Expt 1 and did not differ among genotypes at the cessation of grazing crops. Feed on offer was higher in wheat than canola at the commencement of grazing in Expt 2 (2.6 vs 2.3 t/ha; P = 0.009), and a higher stocking rate was maintained on wheat than canola from the start of lambing. White Dorper ewes maintained a higher body condition score than Merino ewes throughout both experiments. In Expt 2, some ewes had serum magnesium and calcium levels below the normal range, and a high number of ewes (20%) required assistance at lambing. Number of lambs weaned per ewe scanned pregnant was similar among genotypes in both experiments. WSD lambs were heaviest (P < 0.05) at weaning and DD lambs had greatest (P < 0.05) fat depth over the eye muscle at weaning. Conclusions and implications When grazed on a feedbase typical of mixed farms in the medium-rainfall zone of southern NSW, White Dorper ewes were in higher body condition than Merino ewes; however, reproductive rates were similar. Joining White Dorper ewes to a terminal sire may increase weaning weight of lambs compared with joining to a White Dorper ram, or a Merino maternal system.

Dual-purpose crops: the potential to increase cattle liveweight gains in winter across southern Australia

Context Dual-purpose wheat (Triticum aestivum L.) and canola (Brassica napus L.) crops have been extensively researched for grazing in Australian farming systems, with a focus on grazing by sheep. In some regions, dual-purpose crops have been grazed by cattle, but there have been reports of animal health problems. Aims This paper sought to collate all known experiments conducted throughout Australia of cattle grazing dual-purpose crops, in order to evaluate grazing management options for cattle on dual-purpose crops that result in high growth rates and good animal health outcomes. Methods There were six experiments. In Expts 1–3, cattle were grazed on wheat crops with and without available mineral supplementation of NaCl and MgO in a 1:1 ratio. In Expt 3, lime was also added to the mineral mix. In Expts 4 and 5, dual-purpose crops were grazed in combination with annual pastures to determine whether strategic use of dual-purpose crops could increase whole farm livestock productivity. In Expt 6, cattle were introduced to dual-purpose canola with different periods of adaptation (0, 4 and 7 days). Liveweight gain was monitored regularly to assess differences between adaptation treatments. Key results Liveweight gain was increased by 0–27% when cattle grazing high quality, dual-purpose wheat were provided with mineral supplement. Cattle had an initial lag in growth rate when introduced to dual-purpose canola for grazing and this was not affected by the adaptation strategy used. Cattle that experienced a shorter adaptation period achieved higher weight gains more quickly. After the lag phase, average daily gain (ADG) was ≥2 kg/head.day, with an ADG over the entire grazing period for all treatments of 1.75 kg/head.day. The effect on the farm system was determined by extending the length of the grazing period on the dual-purpose crops. Grazing periods of shorter duration did not increase overall liveweight gains compared with grazing only pasture, whereas extending the period of dual-purpose crop grazing resulted in increased cattle weights. Conclusions Cattle benefit from the addition of mineral supplements when grazing a dual-purpose wheat crop, with a response similar to that previously demonstrated in sheep. Cattle can safely graze dual-purpose canola and achieve high ADG. Inclusion of dual-purpose crops can improve overall cattle performance in the farming system. Implications The potential area for production of dual-purpose crops within the Australian mixed farming zone is large and there may be insufficient livestock numbers within the zone to utilise the potential forage production. Cattle from other regions could be introduced during autumn and winter to realise this large forage potential during a period that is commonly a feed deficit on grazing-only properties. Estimates suggest that up to two million young cattle could be supported for 60 days, increasing liveweight by 90 kg/head.

Utilising dual-purpose crops in an Australian high-rainfall livestock production system to increase meat and wool production. 2. Production from breeding-ewe flocks

Context The use of dual-purpose crops (for grazing and grain) has increased in the high-rainfall zone in southern Australia. Aim A systems experiment examined the impact on livestock production and supplementary feeding when dual-purpose crops were incorporated into a production system based on Merino ewes producing yearling lambs for sale. Methods The experimental site near Canberra, ACT, was subdivided into nine experimental units (‘farmlets’) with three replicate farmlets for each of three production-system treatments. Each farmlet was managed as a self-contained unit with six Merino ewes and their progeny during 2013–16 (4 years). Ewes were joined in February, lambed in July and shorn in spring; the original cohort of ewes (born 2009) was replaced by a new cohort (born 2012) at the midpoint of the experiment. Six weaners were retained after weaning in each farmlet and sold as yearlings. Control farmlets were sown to pasture based on phalaris (Phalaris aquatica L.) and subterranean clover (Trifolium subterraneum L.) and comprised sub-paddocks to allow rotational grazing. Farmlets in treatments that included dual-purpose crops comprised six sub-paddocks (0.231 ha), with two sown to permanent pasture, and four supporting a rotation of pasture–pasture–dual-purpose canola (Brassica napus L.)–dual-purpose wheat (Triticum aestivum L.). In one of the crop–pasture production system treatments, crop-grazing was prioritised for ewes (ECG treatment); in the other, crop-grazing was prioritised for their progeny weaners (WCG treatment). Key results Greasy fleece weight from ECG (5.3 kg) and WCG (5.1 kg) ewes was higher (P < 0.001) than from control ewes (4.7 kg) averaged over the 4 years. The final sale weight of yearling weaners from the WCG system (44.3 kg) was higher (P < 0.001) than from the control (39.2 kg) or ECG (39.1 kg) systems when averaged over the 4 years. The benefit was predominantly due to greater weight gain during the period when weaners grazed the crop during late autumn and winter. Sale weight of lamb per hectare was higher (P = 0.003) in the WCG treatment (216 kg) compared with the ECG treatment (186 kg) when averaged over the 4 years of the experiment but did not differ (P > 0.05) to the control (201 kg). Meat production over the 4 years was higher (P < 0.001) in the WCG system (226 kg/ha) than other treatments when weight gain from wethers in 2014 was included. The impact of including dual-purpose crops on supplementary feeding was variable and depended on seasonal conditions. Conclusions Incorporation of dual-purpose crops into the high-rainfall production system can increase meat and wool production, with the highest meat production being obtained when crop grazing was prioritised for young carry-over livestock. Implications Prioritising dual-purpose crops for young growing livestock can increase meat production from the system while allowing other livestock classes (wethers or ewes) to graze the crops in better seasons when there was excess forage that would otherwise have been under-utilised.