Pub Date : 2023-05-03DOI: 10.33584/jnzg.2022.84.3599
D. Moot, Malcolm C. Smith, A. Mills
Yield differences between resident and improved pastures were quantified over a 3-4 yr period on three rainfed farms located in North Canterbury (Stockgrove, north of Amberley), Banks Peninsula (Willesden Farm) and the Mid-Canterbury foothills (Inverary Station). Improved pastures produced two- to three-times more feed annually than unimproved resident pastures at each property. At Stockgrove, improved chicory/white clover-based pastures produced 14.1±0.66 t DM/ha/yr compared with 4.36±0.41 t DM/ha/yr from unimproved pastures. Spring accounted for 85% (improved) and 72% (unimproved) of total annual DM production. At Willesden, lucerne monocultures produced 11.5±0.97t DM/ha/yr, which was more than the 4.44±0.45 t DM/ha/yr produced from resident pastures. Improved pastures at Inverary yielded 7.31±0.59 t DM/ha in summer/autumn of 2018/19, which was more than double the 3.34±0.43 t DM/ha from unimproved pastures. In 2019/2020, improved pastures produced 11.7±1.45 t DM/ha compared with 4.45±0.73 t DM/ha. In the third growth season (2020/2021) improved pastures produced 14.1±1.76 t DM/ha compared with 6.67±1.38 t DM/ha from unimproved pastures. In Year 4 (2021/22) the 12.6±1.29 t DM/ha from improved pastures was 56% more than the 8.07±0.85 t DM/ha from the unimproved pastures. Substantial increases in annual and seasonal feed supply patterns can be achieved through hill country pasture improvement.
在位于北坎特伯雷（安伯利北部的斯托克格罗夫）、班克斯半岛（Willesden农场）和中坎特伯雷山麓（Inverary站）的三个雨养农场，对居民牧场和改良牧场之间3-4年的产量差异进行了量化。改良牧场每年生产的饲料是未改良牧场的两到三倍。在Stockgrove，改良菊苣/白三叶草牧场的产量为14.1±0.66 t DM/ha/年，而未改良牧场的产量则为4.36±0.41 t DM/ha/年。春季占全年DM总产量的85%（改善）和72%（未改善）。在Willesden，单一种植的苜蓿产量为11.5±0.97t DM/ha/年，高于当地牧场的4.44±0.45 t DM/ha/年。2018/19年夏秋季，Inverary改良牧场的产量为7.31±0.59 t DM/公顷，是未改良牧场3.34±0.43 t DM/ha的两倍多。2019/2020年，改良牧场的产量为11.7±1.45吨DM/公顷，而同期为4.45±0.73吨DM/ha。在第三个生长季节（2020/2021），改良牧场的产量为14.1±1.76 t DM/ha，而未改良牧场的生产量为6.67±1.38 t DM/ha。在第4年（2021/22年），改良牧场的12.6±1.29 t DM/公顷比未改良牧场的8.07±0.85 t DM/ha多56%。通过改善山地牧场，可以大幅增加年度和季节性饲料供应模式。
{"title":"Total annual and seasonal DM production of improved and unimproved resident pastures at three farms in Canterbury","authors":"D. Moot, Malcolm C. Smith, A. Mills","doi":"10.33584/jnzg.2022.84.3599","DOIUrl":"https://doi.org/10.33584/jnzg.2022.84.3599","url":null,"abstract":"Yield differences between resident and improved pastures were quantified over a 3-4 yr period on three rainfed farms located in North Canterbury (Stockgrove, north of Amberley), Banks Peninsula (Willesden Farm) and the Mid-Canterbury foothills (Inverary Station). Improved pastures produced two- to three-times more feed annually than unimproved resident pastures at each property. At Stockgrove, improved chicory/white clover-based pastures produced 14.1±0.66 t DM/ha/yr compared with 4.36±0.41 t DM/ha/yr from unimproved pastures. Spring accounted for 85% (improved) and 72% (unimproved) of total annual DM production. At Willesden, lucerne monocultures produced 11.5±0.97t DM/ha/yr, which was more than the 4.44±0.45 t DM/ha/yr produced from resident pastures. Improved pastures at Inverary yielded 7.31±0.59 t DM/ha in summer/autumn of 2018/19, which was more than double the 3.34±0.43 t DM/ha from unimproved pastures. In 2019/2020, improved pastures produced 11.7±1.45 t DM/ha compared with 4.45±0.73 t DM/ha. In the third growth season (2020/2021) improved pastures produced 14.1±1.76 t DM/ha compared with 6.67±1.38 t DM/ha from unimproved pastures. In Year 4 (2021/22) the 12.6±1.29 t DM/ha from improved pastures was 56% more than the 8.07±0.85 t DM/ha from the unimproved pastures. Substantial increases in annual and seasonal feed supply patterns can be achieved through hill country pasture improvement.","PeriodicalId":36573,"journal":{"name":"Journal of New Zealand Grasslands","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44601529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-03DOI: 10.33584/jnzg.2022.84.3574
J. Kay, Chris Boom, Kim Robinson, Kerry Chestnut
A three-year farm-systems trial was conducted in Northland from 2018–2021 with three independent 28-ha farms: 1) PAST: 2.7 cows/ha, no imported feed; 2) PKE: 3.1 cows/ha, palm kernel to meet pasture deficits; 3) PKE-PLUS: 3.1 cows/ha, palm kernel plus other supplementary feeds to meet pasture deficits. On average, cows on the PKE-PLUS farm were fed more supplementary feed and produced more milksolids than cows in the PAST and PKE farms (1328, 916 and 1209 kg MS/ha, respectively). Due to large variability in climate, pasture grown, milk and feed prices, there was no significant difference in mean operating profit ($2,636, $3,053, and $2,939 for the PAST, PKE and PKE-PLUS farms, respectively). The PAST farm had least personnel and machinery hours, and lowest methane emissions per hectare (316, 386 and 412 kg methane/ha, for PAST, PKE and PKE-PLUS, respectively). The low-input system was more affected by climate, whereas supplementary-feed systems were affected by externalities (milk and feed prices). With increasing environmental challenges and the need to ensure appropriate staff, farm systems should be evaluated by considering environmental, personnel and profit, rather than just milk production. Greater production may lead to more hours worked and more methane emissions, without any increase in profit.
{"title":"A quantitative case study assessment of the biophysical and economic effects of three different feed management systems in a Northland farmlet trial","authors":"J. Kay, Chris Boom, Kim Robinson, Kerry Chestnut","doi":"10.33584/jnzg.2022.84.3574","DOIUrl":"https://doi.org/10.33584/jnzg.2022.84.3574","url":null,"abstract":"A three-year farm-systems trial was conducted in Northland from 2018–2021 with three independent 28-ha farms: 1) PAST: 2.7 cows/ha, no imported feed; 2) PKE: 3.1 cows/ha, palm kernel to meet pasture deficits; 3) PKE-PLUS: 3.1 cows/ha, palm kernel plus other supplementary feeds to meet pasture deficits. On average, cows on the PKE-PLUS farm were fed more supplementary feed and produced more milksolids than cows in the PAST and PKE farms (1328, 916 and 1209 kg MS/ha, respectively). Due to large variability in climate, pasture grown, milk and feed prices, there was no significant difference in mean operating profit ($2,636, $3,053, and $2,939 for the PAST, PKE and PKE-PLUS farms, respectively). The PAST farm had least personnel and machinery hours, and lowest methane emissions per hectare (316, 386 and 412 kg methane/ha, for PAST, PKE and PKE-PLUS, respectively). The low-input system was more affected by climate, whereas supplementary-feed systems were affected by externalities (milk and feed prices). With increasing environmental challenges and the need to ensure appropriate staff, farm systems should be evaluated by considering environmental, personnel and profit, rather than just milk production. Greater production may lead to more hours worked and more methane emissions, without any increase in profit.","PeriodicalId":36573,"journal":{"name":"Journal of New Zealand Grasslands","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42452054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-03DOI: 10.33584/jnzg.2022.84.3573
M. Dodd, Felix Rodriguez-Firpo, Philippa Hedley, Denise Chandler, A. Duker
Based on the published benefits of narrow-leaved plantain for reducing nitrogen leaching losses in grazed pasture systems, dairy farmers in the Tararua District implemented a development programme to increase plantain in the diet of cows. To address key establishment and management questions posed by dairy farmers, an associated pasture monitoring programme commenced in autumn 2019. The inclusionof plantain at levels of >30% of harvested dry matter (autumn-measured) in perennial ryegrass/white clover pastures significantly improved annual herbage accumulation (+12%). Herbage accumulation of pure plantain and plantain-white clover pastures was not significantly different from established perennial ryegrass/white clover pastures. Forage quality was high in all pasture that included plantain and decreased only slightly in swards with high plantain content. In grass-based pastures, the greatest plantain content after a year was achieved when sown in a new pasture mix in autumn. However, the plantain content of all pastures declined with time regardless of establishment method and was typically <10% after two years. Dairy farmers can have confidence that the use of plantain in pastures will be unlikely to result in a reduction inforage quantity or quality, but the need to find ways to maintain plantain content over time remains, in order to realise the benefits for forage supply and N leaching. Keywords: forage quality, herbage accumulation, pasture management, persistence, Plantago lanceolata
{"title":"Performance of plantain pastures on Tararua dairy farms","authors":"M. Dodd, Felix Rodriguez-Firpo, Philippa Hedley, Denise Chandler, A. Duker","doi":"10.33584/jnzg.2022.84.3573","DOIUrl":"https://doi.org/10.33584/jnzg.2022.84.3573","url":null,"abstract":"Based on the published benefits of narrow-leaved plantain for reducing nitrogen leaching losses in grazed pasture systems, dairy farmers in the Tararua District implemented a development programme to increase plantain in the diet of cows. To address key establishment and management questions posed by dairy farmers, an associated pasture monitoring programme commenced in autumn 2019. The inclusionof plantain at levels of >30% of harvested dry matter (autumn-measured) in perennial ryegrass/white clover pastures significantly improved annual herbage accumulation (+12%). Herbage accumulation of pure plantain and plantain-white clover pastures was not significantly different from established perennial ryegrass/white clover pastures. Forage quality was high in all pasture that included plantain and decreased only slightly in swards with high plantain content. In grass-based pastures, the greatest plantain content after a year was achieved when sown in a new pasture mix in autumn. However, the plantain content of all pastures declined with time regardless of establishment method and was typically <10% after two years. Dairy farmers can have confidence that the use of plantain in pastures will be unlikely to result in a reduction inforage quantity or quality, but the need to find ways to maintain plantain content over time remains, in order to realise the benefits for forage supply and N leaching. Keywords: forage quality, herbage accumulation, pasture management, persistence, Plantago lanceolata ","PeriodicalId":36573,"journal":{"name":"Journal of New Zealand Grasslands","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44616484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-03DOI: 10.33584/jnzg.2022.84.3614
Melanie Miller, G. Edwards, H. Hague, R. Bryant
The timing and frequency of exogenous gibberellic acid (GA) application was explored in a cut-and-carry small plot experiment using irrigated Canterbury swards. GA applications (8 g GA/ha/application) replaced urea applications (25 kg N/ha/application) over multiple harvests in late winter, early spring and autumn. Timing and number (1, 2 or 3 applications) of GA application occurred in combinations to test the effect of early (August and February), delayed (September and March) or late (October and April) application of GA. Annual herbage yield was 14.6, 18.3 and 18.3±0.40 t DM/ha/y for the three controls (0, 250 kg N/ha/y and 250 kg N/ha/y + 80g GA/ha/y respectively). Clover content varied with treatment and time of year and was more abundant in low N treatments. There was a positive relationship between N fertiliser rate and annual herbage yield. There was no relationship between increasing GA rate and annual yield, though there was evidence of annual yield improvements, associated with frequent GA application under low (100 kg N/ha/y) or moderate (150 kg N/ha/y) N fertiliser. In late winter, delaying a single application of GA into spring improved N use efficiency (P<0.01). Tactical use of GA, in place of N fertiliser, can be used to maintain herbage yield.
在坎特伯雷灌溉草地上进行了一个切块携带小区试验，探讨了外源赤霉酸（GA）施用的时间和频率。在冬末、早春和秋季的多次收获中，GA施用（8 g GA/ha/施用）取代了尿素施用（25 kg N/公顷施用）。为检验早（8月和2月）、晚（9月和3月）或晚（10月和4月）施用GA的效果，采用组合施用GA的时间和次数（1、2或3次）。三个对照组（分别为0、250 kg N/ha/y和250 kg N/ha/y+80g GA/ha/y）的年牧草产量分别为14.6、18.3和18.3±0.40t DM/ha/y。三叶草含量随处理和一年中的时间而变化，在低氮处理中含量更丰富。施氮量与牧草年产量呈正相关。增加GA速率与年产量之间没有关系，尽管有证据表明年产量有所提高，这与在低（100 kg N/ha/y）或中等（150 kg N/ha/y）氮肥下频繁施用GA有关。冬末春季单次施用GA提高了牧草的氮素利用效率（P<0.01）。
{"title":"Tactical use of gibberellic acid and nitrogen fertiliser to improve production of perennial ryegrass and white clover swards","authors":"Melanie Miller, G. Edwards, H. Hague, R. Bryant","doi":"10.33584/jnzg.2022.84.3614","DOIUrl":"https://doi.org/10.33584/jnzg.2022.84.3614","url":null,"abstract":"The timing and frequency of exogenous gibberellic acid (GA) application was explored in a cut-and-carry small plot experiment using irrigated Canterbury swards. GA applications (8 g GA/ha/application) replaced urea applications (25 kg N/ha/application) over multiple harvests in late winter, early spring and autumn. Timing and number (1, 2 or 3 applications) of GA application occurred in combinations to test the effect of early (August and February), delayed (September and March) or late (October and April) application of GA. Annual herbage yield was 14.6, 18.3 and 18.3±0.40 t DM/ha/y for the three controls (0, 250 kg N/ha/y and 250 kg N/ha/y + 80g GA/ha/y respectively). Clover content varied with treatment and time of year and was more abundant in low N treatments. There was a positive relationship between N fertiliser rate and annual herbage yield. There was no relationship between increasing GA rate and annual yield, though there was evidence of annual yield improvements, associated with frequent GA application under low (100 kg N/ha/y) or moderate (150 kg N/ha/y) N fertiliser. In late winter, delaying a single application of GA into spring improved N use efficiency (P<0.01). Tactical use of GA, in place of N fertiliser, can be used to maintain herbage yield.","PeriodicalId":36573,"journal":{"name":"Journal of New Zealand Grasslands","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44854556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-03DOI: 10.33584/jnzg.2022.84.3562
K. Tozer, G. Douglas, R. Greenfield, Caitlin Dawbin, C. Cameron
Tagasaste (tree lucerne) can be difficult to establish from seed due to its hard seed coat and high levels of seedling mortality. Three experiments were performed. Experiment 1: Effect of gibberellic acid, potassium nitrate, seed nicking + soaking in warm water (38oC for 24 hours), soaking seeds in boiling water and a coldwater control on germination. The highest germination percentage occurred from the warm and boiling water treatments. Experiment 2: Effect of slug bait, rhizobia and phosphorus fertiliser on establishment of tagasaste seed which had been hand sown into a herbicide-treated pasture. Of the 1600 hand-sown seeds, emergence was negligible, and no treatments varied significantly from the untreated control. Greater pasture suppression is required for successful establishment. Experiment 3: Examined removal of 20%, 40%, 60% or 80% of the height of a seedling on tagasaste branching. Branch number was similar for all treatments 83 days aftertrimming the main stem. Removing 20% or 40% of the seedling height produced three-fold greater edible dry matter than when 80% of the seedling height was removed (P<0.001). Although pruning treatments did not affect branch number, a less severe pruning regime resulted in the regrowth of the greatest amount of edible dry matter.
{"title":"Establishing tagasaste from seed in Waikato hill country","authors":"K. Tozer, G. Douglas, R. Greenfield, Caitlin Dawbin, C. Cameron","doi":"10.33584/jnzg.2022.84.3562","DOIUrl":"https://doi.org/10.33584/jnzg.2022.84.3562","url":null,"abstract":"Tagasaste (tree lucerne) can be difficult to establish from seed due to its hard seed coat and high levels of seedling mortality. Three experiments were performed. Experiment 1: Effect of gibberellic acid, potassium nitrate, seed nicking + soaking in warm water (38oC for 24 hours), soaking seeds in boiling water and a coldwater control on germination. The highest germination percentage occurred from the warm and boiling water treatments. Experiment 2: Effect of slug bait, rhizobia and phosphorus fertiliser on establishment of tagasaste seed which had been hand sown into a herbicide-treated pasture. Of the 1600 hand-sown seeds, emergence was negligible, and no treatments varied significantly from the untreated control. Greater pasture suppression is required for successful establishment. Experiment 3: Examined removal of 20%, 40%, 60% or 80% of the height of a seedling on tagasaste branching. Branch number was similar for all treatments 83 days aftertrimming the main stem. Removing 20% or 40% of the seedling height produced three-fold greater edible dry matter than when 80% of the seedling height was removed (P<0.001). Although pruning treatments did not affect branch number, a less severe pruning regime resulted in the regrowth of the greatest amount of edible dry matter.\u0000 ","PeriodicalId":36573,"journal":{"name":"Journal of New Zealand Grasslands","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41769373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-02-02DOI: 10.33584/jnzg.2021.83.3498
S. Olykan, R. Lucas, D. Moot
White clover (Trifolium repens) foliar ‘grab’ samples were taken pre-grazing from two irrigated experiments at Lincoln University at ~6 week intervals from August 2019 to May 2021. Clover leaves were divided into lamina and petiole before analysis. The results for nitrogen (N), phosphorous (P), potassium (K) and sulphur (S) foliar concentrations are reported. While there were seasonal variations, N% and S% were consistently higher in the white clover lamina than the petiole, K% was mostly higher in the petiole, and P% was higher in the lamina during the winter/early spring period. With increasing clover sward height, the lamina to petiole DW ratio declined from 4, at a sward height of 5 cm, to 1 at 20 cm. The lamina+petiole sample had lower concentrations of N and S than lamina alone. Over time, foliar N% was relatively stable but concentrations of P, K and S showed ~ two-fold variation and may have been affected by low soil moisture. The diagnosis of clover nutrient status should be based on lamina-only samples taken during spring, when plant growth is fastest, and just prior to grazing when there is sufficient herbage. Clover foliage sampling should routinely be used to inform fertiliser recommendations rather than relying on the development of visual symptoms of nutrient deficiency.
{"title":"Refining foliage sampling protocols for white clover","authors":"S. Olykan, R. Lucas, D. Moot","doi":"10.33584/jnzg.2021.83.3498","DOIUrl":"https://doi.org/10.33584/jnzg.2021.83.3498","url":null,"abstract":"White clover (Trifolium repens) foliar ‘grab’ samples were taken pre-grazing from two irrigated experiments at Lincoln University at ~6 week intervals from August 2019 to May 2021. Clover leaves were divided into lamina and petiole before analysis. The results for nitrogen (N), phosphorous (P), potassium (K) and sulphur (S) foliar concentrations are reported. \u0000While there were seasonal variations, N% and S% were consistently higher in the white clover lamina than the petiole, K% was mostly higher in the petiole, and P% was higher in the lamina during the winter/early spring period. With increasing clover sward height, the lamina to petiole DW ratio declined from 4, at a sward height of 5 cm, to 1 at 20 cm. The lamina+petiole sample had lower concentrations of N and S than lamina alone. Over time, foliar N% was relatively stable but concentrations of P, K and S showed ~ two-fold variation and may have been affected by low soil moisture. \u0000The diagnosis of clover nutrient status should be based on lamina-only samples taken during spring, when plant growth is fastest, and just prior to grazing when there is sufficient herbage. Clover foliage sampling should routinely be used to inform fertiliser recommendations rather than relying on the development of visual symptoms of nutrient deficiency.","PeriodicalId":36573,"journal":{"name":"Journal of New Zealand Grasslands","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47909603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-02-02DOI: 10.33584/jnzg.2021.83.3502
A. Griffiths, Grace Ehoche, S. Arojju, Anna Larking, R. Jáuregui, G. Cousins, J. O’Connor, Z. Jahufer
Genomic selection (GS) integrates DNA marker and trait data to develop a model that enables prediction of trait performance (genomic-estimated breeding values; GEBVs) based on genotype data alone. GS has been shown to improve the efficiency and effectiveness of breeding programmes, especially for complex traits such dry matter yield (DMY). DMY data were generated from a training population of 200 white clover half-sibling (HS) families assessed in multi-location field trials for two years. We generated a GS prediction model after integrating genotyping-by-sequencing marker data from parents of the HS families with the HS DMY data. We then compared two selection strategies: a conventional method where individuals were chosen randomly from the phenotypically top-ranked HS families (HSP); and another where GEBVs were used to select the best individual from the top-ranked HS families (APWFGS). The mean predicted DMY GEBVs of the selected plants, as well as the predicted response to selection, were compared with those of the base population. This study showed that, compared with conventional selection (HSP), incorporating genomic selection (APWGSHS) is predicted to double the increase in DMY and response to selection relative to the base population. Synthetic populations based on these selections have been generated and will be tested in a field trial to determine empirically the impact of genomic selection for a complex trait.
{"title":"Developing genomic selection for dry matter yield in white clover","authors":"A. Griffiths, Grace Ehoche, S. Arojju, Anna Larking, R. Jáuregui, G. Cousins, J. O’Connor, Z. Jahufer","doi":"10.33584/jnzg.2021.83.3502","DOIUrl":"https://doi.org/10.33584/jnzg.2021.83.3502","url":null,"abstract":"Genomic selection (GS) integrates DNA marker and trait data to develop a model that enables prediction of trait performance (genomic-estimated breeding values; GEBVs) based on genotype data alone. GS has been shown to improve the efficiency and effectiveness of breeding programmes, especially for complex traits such dry matter yield (DMY). DMY data were generated from a training population of 200 white clover half-sibling (HS) families assessed in multi-location field trials for two years. We generated a GS prediction model after integrating genotyping-by-sequencing marker data from parents of the HS families with the HS DMY data. We then compared two selection strategies: a conventional method where individuals were chosen randomly from the phenotypically top-ranked HS families (HSP); and another where GEBVs were used to select the best individual from the top-ranked HS families (APWFGS). The mean predicted DMY GEBVs of the selected plants, as well as the predicted response to selection, were compared with those of the base population. This study showed that, compared with conventional selection (HSP), incorporating genomic selection (APWGSHS) is predicted to double the increase in DMY and response to selection relative to the base population. Synthetic populations based on these selections have been generated and will be tested in a field trial to determine empirically the impact of genomic selection for a complex trait.","PeriodicalId":36573,"journal":{"name":"Journal of New Zealand Grasslands","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44467440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-02-02DOI: 10.33584/jnzg.2021.83.3510
B. Barrett, Z. Jahufer, S. Arojju, J. Sise, M. Faville
Simulation offers a way to explore questions about implementation, value and impacts of various breeding methodologies for pasture species in New Zealand (NZ). We present genetic modelling and farm system-based economic simulations demonstrating the potential of genomic selection (GS) and high-throughput phenotyping (HTP) to improve breeding outcomes in perennial ryegrass, and assess the potential value for farmers. Predicted genetic gain (∆G) from half-sibling family selection without GS ranged up to 4.9% per cycle, depending on selection pressure. Including GS for within-family selection, ∆G ranged up to 7.6% per cycle. Across 12 scenarios tested for a single cycle, increasing ∆G per cycle doubled cost-efficiency per unit gain, even though cost per cycle increased. Simulation of 10 cycles of selection within a population with and without GS showed higher levels of ∆G were maintained over multiple cycles for GS. Farm system-based economic analysis, focused on agronomic traits, indicated full commercialisation of GS and HTP technology harnessing increased ∆G in 2026 creates new value rising by 2040 to a range of $74M - $221M per annum for NZ red meat farmers, and $399M to $1,260M per annum for dairy farmers in NZ and Australia. This study indicated incorporating GS in pasture plant breeding can increase the rate and cost-efficiency of genetic improvement, with pasture performance and sector economic benefits realised through the value chain.
{"title":"Forecasting the genetic and economic impacts of genomic selection in perennial ryegrass","authors":"B. Barrett, Z. Jahufer, S. Arojju, J. Sise, M. Faville","doi":"10.33584/jnzg.2021.83.3510","DOIUrl":"https://doi.org/10.33584/jnzg.2021.83.3510","url":null,"abstract":"Simulation offers a way to explore questions about implementation, value and impacts of various breeding methodologies for pasture species in New Zealand (NZ). We present genetic modelling and farm system-based economic simulations demonstrating the potential of genomic selection (GS) and high-throughput phenotyping (HTP) to improve breeding outcomes in perennial ryegrass, and assess the potential value for farmers. Predicted genetic gain (∆G) from half-sibling family selection without GS ranged up to 4.9% per cycle, depending on selection pressure. Including GS for within-family selection, ∆G ranged up to 7.6% per cycle. Across 12 scenarios tested for a single cycle, increasing ∆G per cycle doubled cost-efficiency per unit gain, even though cost per cycle increased. Simulation of 10 cycles of selection within a population with and without GS showed higher levels of ∆G were maintained over multiple cycles for GS. Farm system-based economic analysis, focused on agronomic traits, indicated full commercialisation of GS and HTP technology harnessing increased ∆G in 2026 creates new value rising by 2040 to a range of $74M - $221M per annum for NZ red meat farmers, and $399M to $1,260M per annum for dairy farmers in NZ and Australia. This study indicated incorporating GS in pasture plant breeding can increase the rate and cost-efficiency of genetic improvement, with pasture performance and sector economic benefits realised through the value chain.","PeriodicalId":36573,"journal":{"name":"Journal of New Zealand Grasslands","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69455376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-02-02DOI: 10.33584/jnzg.2021.83.3489
G. Pitman
ABSTRACT A two-herd farmlet comparison was carried out on the DTT Stratford Demonstration Farm in Central Taranaki examined the profitability, environmental outcomes, animal welfare benefits and practicality of using a covered woodchip stand-off feed pad for wintering cows (Pad.) compared with wintering cows with no removal from pasture (Control). The two farmlets were set up and managed similarly in all aspects except that the non-lactating cows of one herd used the pad every night through the winter and over calving. Use of the covered pad limited winter pugging damage of pasture to minimal levels while the control farmlet had 6% of the area requiring rolling and some re-seeding. Pasture growth on these pugged areas was 24 to 30% lower than non-pugged areas over the spring to early summer period while estimated annual pasture growth was 2.2% higher on the Pad farmlet compared to the control over the two years. The mean difference in milksolids production across two years was 3%, (range :<1%- 5%) in favour of the Pad herd. Nutrient losses calculated using OverseerFM calculated a 9% reduction in nitrogen leached from the use of the covered pad. A cost benefit analysis suggests that at best the use of the covered stand-off in winter covered the annual operating cost of the stand-off pad but failed to contribute to the capital cost of providing this facility. Keywords –Pasture growth, pasture pugging, milksolids production, profit, Labour input, nitrogen leaching
{"title":"Comparing a covered stand-off pad for on/off grazing during winter with conventional winter block grazing 2017-19 at DTT Stratford Demonstration farm","authors":"G. Pitman","doi":"10.33584/jnzg.2021.83.3489","DOIUrl":"https://doi.org/10.33584/jnzg.2021.83.3489","url":null,"abstract":"ABSTRACT \u0000A two-herd farmlet comparison was carried out on the DTT Stratford Demonstration Farm in Central Taranaki examined the profitability, environmental outcomes, animal welfare benefits and practicality of using a covered woodchip stand-off feed pad for wintering cows (Pad.) compared with wintering cows with no removal from pasture (Control). The two farmlets were set up and managed similarly in all aspects except that the non-lactating cows of one herd used the pad every night through the winter and over calving. \u0000Use of the covered pad limited winter pugging damage of pasture to minimal levels while the control farmlet had 6% of the area requiring rolling and some re-seeding. Pasture growth on these pugged areas was 24 to 30% lower than non-pugged areas over the spring to early summer period while estimated annual pasture growth was 2.2% higher on the Pad farmlet compared to the control over the two years. The mean difference in milksolids production across two years was 3%, (range :<1%- 5%) in favour of the Pad herd. Nutrient losses calculated using OverseerFM calculated a 9% reduction in nitrogen leached from the use of the covered pad. \u0000A cost benefit analysis suggests that at best the use of the covered stand-off in winter covered the annual operating cost of the stand-off pad but failed to contribute to the capital cost of providing this facility. \u0000Keywords –Pasture growth, pasture pugging, milksolids production, profit, Labour input, nitrogen leaching","PeriodicalId":36573,"journal":{"name":"Journal of New Zealand Grasslands","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44800474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-02-02DOI: 10.33584/jnzg.2021.83.3507
M. Mangwe, R. Bryant
Chicory (Chicorum intybus L.) is a high moisture, low fibre forage, traits that have been identified to influence protein degradation and urea metabolism. Our recent study revealed that sole diets of chicory increased urinations and diluted the concentration of nitrogen in the urine. The purpose of this study was to compare the effect of feeding a lesser proportion of chicory in the diet, and the impact of the diurnal changes in chemical composition of chicory on urinations and urinary nitrogen concentration. Thirty-six dairy cows were evenly divided into nine groups, and randomly allocated either ryegrass/white clove only (RGWC), ryegrass/white clove plus morning allocation of chicory (CHAM) or ryegrass/white clove plus afternoon allocation of chicory (CHPM). Chicory inclusion increased urinations by up to 69%, resulting in a 33% mean decline in UN concentration, independently of time of allocation. While farmers are encouraged to adopt mitigation strategies to reduce urinary N losses, there is value in offering a range of forage options to improve adoption. These results show that low moistures forages including chicory have the potential to reduce nitrogen leaching through changes in urination behaviour and urinary nitrogen loading.
{"title":"Partial replacement of ryegrass and clover herbage with chicory to alter urination behaviour and soil nitrogen loading of grazing dairy cows","authors":"M. Mangwe, R. Bryant","doi":"10.33584/jnzg.2021.83.3507","DOIUrl":"https://doi.org/10.33584/jnzg.2021.83.3507","url":null,"abstract":"Chicory (Chicorum intybus L.) is a high moisture, low fibre forage, traits that have been identified to influence protein degradation and urea metabolism. Our recent study revealed that sole diets of chicory increased urinations and diluted the concentration of nitrogen in the urine. The purpose of this study was to compare the effect of feeding a lesser proportion of chicory in the diet, and the impact of the diurnal changes in chemical composition of chicory on urinations and urinary nitrogen concentration. Thirty-six dairy cows were evenly divided into nine groups, and randomly allocated either ryegrass/white clove only (RGWC), ryegrass/white clove plus morning allocation of chicory (CHAM) or ryegrass/white clove plus afternoon allocation of chicory (CHPM). Chicory inclusion increased urinations by up to 69%, resulting in a 33% mean decline in UN concentration, independently of time of allocation. While farmers are encouraged to adopt mitigation strategies to reduce urinary N losses, there is value in offering a range of forage options to improve adoption. These results show that low moistures forages including chicory have the potential to reduce nitrogen leaching through changes in urination behaviour and urinary nitrogen loading.","PeriodicalId":36573,"journal":{"name":"Journal of New Zealand Grasslands","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46811616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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