The effect of nitrogen use efficiency on significant traits of potato starch production

The development of beef cattle breeding and obtaining high-quality beef in Russia is currently one of the important tasks. The results of investigations on the influence of a feed additive with a low degree of protein breakdown on the efficiency of nitrogen use in the body of fattening steers and their productivity traits have been presented in the paper. The ration of steers included the feed additive as the source of hard-to-break down protein, which includes components of animal origin (feather fl our, fi sh meal, poultry waste), which have the high biological value of protein and its low degradation in the rumen. The feed additive was introduced into the daily ration at a dose of 1,5 g/kg of live weight. The accounting period of the experiment was 92 days. The degree of protein breakdown in the feed additive was determined on fistula animals in sacco, which was 55,2 %. The feed additive contains (%): 40–43 crude protein, 20–25 crude fat, 2,2 lysine, 1,9 methionine, 2,6 tryptophan, 1,5 calcium, 6,5 phosphorus. It has been found that the introduction of the protein additive with the low protein breakdown in the dose of 1,5 g/kg of live weight into the ration of steers had the positive influence on the indicators of the biochemical composition of blood, digestion in rumen, promoted better use of feed nitrogen and increased the productivity of fattening steers. There were significant differences in the increase in nitrogen deposition in the body of the experimental group of steerls by 29,5 %; the coefficients of nitrogen use from the feed consumed and from the digested increased by 5,57 and 7,71 abs.%, respectively. The average daily weight gain of the steers in the experimental group was 1102,17 g, which was 11,79 % higher compared to the animals of the control group that did not receive the protein additive. The research results indicate the effectiveness of the use of protein feed additive in the ration of young cattle during fattening.

Estimation of genetic parameters for predicted nitrogen use efficiency and losses in early lactation of Holstein cows

Awareness and interest in the use of nitrogen in dairy production systems is intensifying. Cows with high nitrogen use efficiency (NUE; nitrogen used and stored divided by nitrogen available) are generally considered to have a lower nitrogen footprint. This, however, may not always be true on a per-animal basis. The objective of this study was to characterize lactating dairy cows based on the combination of NUE and nitrogen balance (Nbal; nitrogen available less the nitrogen used and stored). Data were available for 1,472 weekly NUE and Nbal estimates from 711 lactations of 278 Holstein-Friesian grazing dairy cows. Random solutions for each cow from separate mixed model analyses of NUE and Nbal were used to categorize each cow into 1 of 2 strata for NUE and separately for Nbal; cows were then categorized on a combination of strata for NUE and Nbal. Data from 248 cows were used. Marginal means for a range of production traits were computed for each of the 4 strata. The population mean (SD) for NUE and Nbal was 21.3% (4.4) and 436 (97) grams of nitrogen per day, respectively. The correlation coefficient between NUE and Nbal was -0.47 demonstrating that the relationship between efficiency (i.e., NUE) and excretion (i.e., Nbal) is, indeed, not perfect. Cows with high NUE and low Nbal were assumed more desirable cows because they had, on average, a higher (i.e., better) or similar NUE to the other 3 strata and excreted, on average, 53 g of nitrogen less per day (SE = 5.1 g N/d) compared with the cows stratified as high NUE and high Nbal. Nevertheless, cows with high NUE and low Nbal were, on average, in greater negative energy balance than cows with low NUE and high Nbal, with the former also having, on average, a lower BCS than both strata of cows with low NUE, suggesting potential poorer health or reproductive capabilities compared with their counterparts. In conclusion, it is important to consider both NUE (high is desirable) and Nbal (low is desirable) when defining nitrogen-efficient dairy cows.

Global warming and nutrient use efficiency are growing challenges that affect the dairy sector, and many strategies have been investigated to tackle these challenges. In dairy cattle breeding, the common strategy is to incorporate new traits, such as greenhouse gas emissions (GHG), nitrogen use efficiency (NUE), and resilience, into the breeding programs. However, this strategy, which has long prioritized profit, now reveals limitations in the face of these new breeding directions, since the existing methodologies struggle to balance the economic and environmental consequences with inclusion of these new traits of interest. This thesis provided potential solutions to these challenges by integrating theories of dairy cattle breeding with methodologies and knowledge from different disciplines. First, a bioeconomic model was developed as a basis for evaluating economic consequences of selecting different trait combinations. The economic values were derived for 17 traits including production, fertility, longevity and health traits. Second, the developed bio-economic model was extended with a life-cycle assessment module to quantify GHG emissions at production chain level, enabling the evaluation of environmental consequences of breeding objectives and the trade-offs between economic and environmental consequences. The designed breeding indices are predicted to mitigate GHG emissions while increasing the profit for the next generation. Third, proxies of nitrogen-related traits were predicted based on mid-infrared spectra of milk samples from late lactation. The coefficient of determination of the best prediction model ranged from 0.58 to 0.63, which indicates the possibility of selecting these traits for better NUE of animals. Fourth, the economic and environmental consequences were evaluated for including resilience traits in the breeding indices. The index predictions for the next generation indicate that selecting resilient animals can maintain profit and reduce GHG emissions. Fifth, fertility traits were evaluated by reaction norm models. The observed heterogeneous fertility performances under different climatic conditions can support the selection of heat-tolerant animals. Finally, mechanistic models were integrated with the breeding simulation program to simulate future populations after selection under global warming scenarios, using breeding objectives that either include or exclude resilience. The economic and environmental consequences were then assessed using the developed framework. The results show that cows selected for improved resilience can benefit both farm profit and environmental sustainability under climate change conditions. Collectively, this thesis contributes to the transformation of profit-driven breeding programs into an integrated framework that balances economic and environmental sustainability while improving resilience.

The root system is responsible for soil resources acquisition. Hence, optimizing crop root characteristics has considerable implications for agricultural production. This study evaluated a panel of twenty-eight European modern cultivars of oilseed rape (Brassica napus L.) cultivated in laboratory and field environments. Root morphology was screened using a high-throughput hydroponic growth system with two divergent nitrogen supplies. The panel showed an important diversity for biomass production and root morphological traits. Differences in root and shoot dry biomasses and lateral root length were mainly explained by the genotype, and differences in primary root length by nitrogen nutrition. The cultivars were tested in a pluriannual field trial. The field variation for yield and seed quality traits attributed to the genotype was more important than the year or the genotype × year interaction effects. The total root length measured at the seedling stage could predict the proportion of nitrogen taken up from the field and reallocated to seed organs, a component of the nitrogen use efficiency. The genetic interrelationship between cultivars, established with simple sequence repeat markers, indicated a very narrow genetic base. Positive correlations were found between the genetic distance measures, root morphological traits during nitrogen depletion and yield components. This study illustrates a root phenotyping screen in the laboratory with a proof of concept evaluation in the field. The results could assist future genetic improvements in oilseed rape for desirable root characteristics to reduce nutrient losses in the environment.

Разработка новых технологий, которые могут повысить эффективность использования азота у жвачных животных, имеет большое значение для развития молочного сектора животноводства. Одним из таких перспективных решений является использование N-карбамоилглутамата (NКГ) в качестве кормовой добавки. NКГ - неметаболизируемый аналог N-ацетилглутамата, аллостерического активатора карбамоилфосфатсинтетазы на первой стадии цикла мочевины. NКГ менее подвержен разрушению рубцовой микрофлорой, что делает его более эффективным для жвачных животных, он не является антибиотиком, не оказывает отрицательного воздействия на микрофлору рубца. Фармакодинамические эффекты NКГ ограничены действием на цикл мочевины, он не обладает генотоксичностью и безопасен для животных и человека. Цель обзора – систематизация и обобщение результатов исследований по изучению физиологических механизмов действия и эффктивности кормовой добавки NКГ у животных. Основные разделы обзора: механизм действия NКГ; роль аргинина в метаболизме у жвачных; влияние NКГ на продуктивность и здоровье коров; эффекты применения NКГ у сухостойных коров; эффекты NКГ по снижению эмиссии аммиака в окружающую среду; практические аспекты применения добавки NКГ. Применение кормовой добавки NКГ улучшает метаболическое состояние коров за счёт снижения концентрации аммиака в крови и повышения синтеза аргинина в орнитиновом цикле. Повышение продукции аргинина и его метаболитов, в том числе оксида азота, способствует поддержанию репродуктивного здоровья, снижению заболеваемости и повышению продуктивности животных. Заключили о необходимости детальных исследований влияния добавок NКГ на продуктивно-хозяйственные признаки и физиолого-биохимические показатели у коров при разных условиях кормления и содержания. Development of new technologies that can improve the efficiency of nitrogen use in ruminants is of great importance for the development of the dairy sector of animal husbandry. One of such promising solutions is the use of N-carbamoyl glutamate (NKG) as a feed additive. NKG is a non-metabolizable analogue of N-acetylglutamate, an allosteric activator of carbamoyl phosphate synthetase at the first stage of the urea cycle. NKG is less susceptible to destruction by rumen microflora, which makes it more effective for ruminants; it is not an antibiotic and has no negative effect on rumen microflora. The pharmacodynamic effects of NKG are limited to the effect on the urea cycle; it is not genotoxic and is safe for animals and humans. The objective of the review is to systematize and summarize the results of studies on the physiological mechanisms of action and efficiency of the NKG feed additive in animals. The main sections of the review: mechanism of action of NKG; the role of arginine in metabolism in ruminants; the effect of NKG on the productivity and health of cows; the effects of NKG use in dry cows; the effects of NKG on reducing ammonia emissions into the environment; practical aspects of using the NKG additive. The use of the NKG feed additive improves the metabolic state of cows by reducing the concentration of ammonia in the blood and increasing the synthesis of arginine in the ornithine cycle. Increased production of arginine and its metabolites, including nitric oxide, helps maintain reproductive health, reduce morbidity and increase animal productivity. Concluded that the detailed studies are needed of the effect of NKG supplements on productive and economic traits and physiological and biochemical parameters in cows under different feeding and housing conditions.

Improving nitrogen use efficiency (NUE) represents one of the main goals to reduce N input in maximizing crop yield for sustainable agriculture. A NUE key strategy is the exploitation of genetic variation in available germplasm together with the understanding of molecular mechanisms governing this complex trait. Thus, NUE, its components, nitrogen uptake efficiency (NUpE) and nitrogen utilization efficiency (NUtE), and NUE-related traits heritability were evaluated in ancient (Cappelli, Capeiti, Russello, and Mazzancoio) and modern (Messapia, Tiziana, Svevo, and Normanno) wheat genotypes for tackling nitrogen (N) and/or water limitation in both growth chamber and field experiments. Our results exhibited a reduction of NUE, NUpE, and NUtE under water and combined (nitrogen + water) stress in all the genotypes, as expected. The contribution of genetic variability on phenotypic variation was significant for NUtE, harvest index, post-anthesis nitrogen uptake (PANU), and biomass production traits. Moreover, the stress tolerance indexes, calculated and bi-plotted for N and water stresses, exhibited two distinct clusters for many traits as then confirmed by principal component analysis. Although modern varieties showed higher crop yield and NUE under conventional N and water regimes, ancient varieties exhibited best performances to cope with both stresses, mainly under water limitation. Finally, the usage index, which takes into account total biomass increase, underlined that old genotypes were less affected by both stresses during crop cycle. In particular, these genotypes showed the best performances for NUE and its components under both stresses at stem elongation and milk ripening as shown also by PANU. In addition, at these stages, nitrate and ammonium transporter gene expressions in the root were performed, showing the highest activity in ancient varieties. In conclusion, the identification of NUE traits during a specific crop cycle stage, under both N and water limitation, will help in the breeding of more resilient varieties in Mediterranean sustainable agriculture by reducing N supply.

SummaryAgriculture faces the considerable challenge of having to adapt to a progressively changing climate (including the increase in CO2 levels and temperatures); environmental impact must be reduced while at the same time crop yields need to be maintained or increased to ensure food security. Under this scenario, increasing plants’ nitrogen (N) use efficiency and minimizing the energy losses associated with photorespiration are two goals of crop breeding that are long sought after. The plastidic glutamine synthetase (GS2) enzyme stands at the crossroads of N assimilation and photorespiration, and is therefore a key candidate for the improvement of crop performance. The GS2 enzyme has long been considered essential for angiosperm survival under photorespiratory conditions. Surprisingly, in Arabidopsis GS2 is not essential for plant survival, and its absence confers tolerance towards ammonium stress, which is in conflict with the idea that NH4+ accumulation is one of the main causes of ammonium stress. Altogether, it appears that the ‘textbook’ view of this enzyme must be revisited, especially regarding the degree to which it is essential for plant growth under photorespiratory conditions, and the role of NH4+ assimilation during ammonium stress. In this article we open the debate on whether more or less GS2 is a desirable trait for plant productivity.

Genotype dependent responses to N-deficiency were investigated in vitro as well as in pots grown in a rain-out shelter with a set of 17 potato cultivars with the aim to identify genotypic differences in traits associated with nitrogen uptake and utilization and to compare results obtained in the two test environments. In vitro plantlets were grown under four nitrogen (N) levels (60, 30, 15 and 7.5 mmol/l) for 18 days and their respective traits were assessed after 7, 11, 14 and 18 days of culture (DoC). Considerable differences between genotypes were identified as early as seven DoC regarding N uptake, biomass production, root percentages of the total plant fresh and dry matter as well as chlorophyll (SPAD values) and crude protein concentrations. Significant differences were obtained for total biomass production between the 60, 30 and 15 mmol/l N-level as well as genotypic differences. Furthermore, significant variation between cultivars was identified for traits associated with efficient nitrogen use, e.g. the ability to maintain photosynthesis and N metabolization under N limitation as well as increased root development. No direct correlation was found between biomass production under in vitro conditions and tuber yields determined in pot trials. However, the stability of the plant performance under N-deficiency in the in vitro system as expressed by the membership function value of stress tolerance calculated from 11 traits correlated to the stability of the tuber yield of cultivars grown under limited N supply in pot trials (r = 0.70). The experimental system is thought to be useful for pre-screening of germplasm and investigations of physiological processes associated with nitrogen use efficiency.

Plant resource-use characteristics as predictors for species contribution to community biomass in experimental grasslands

Energy-efficient and environmentally friendly production of starch-rich duckweed biomass using nitrogen-limited cultivation

CHAPTER XIV - POTATO STARCH: PRODUCTION AND USES

Aim: To formulate biopolymer urea composites in pellet form and to test their efficacy on the release and leaching of nitrogen in northern coastal sandy soils of Kerala. Place and Duration of Study: Department of Agronomy, College of Agriculture, Padannakkad, Kasaragod, Kerala agricultural University, between May 2023 and March 2024. Methodology: Pellets of biopolymer urea composites (BUCs) were formulated by mixing prilled urea with coconut shell charcoal (C1), gypsum (C2), rice husk biochar (C3), and zeolite (C4) as coating materials and potato starch (S1) and tapioca starch (S2) as binding materials. The experiment was laid out in a Factorial Completely Randomised Design. Castor oil was uniformly sprayed on the composites after formulation. These composites were tested against urea for their nitrogen content and pH. Release behavior of nitrogen in soil and distilled water and leaching behavior in the soil were studied using CRD as the experimental design. The treatments were: T1: Urea, T2: BUC 1, T3: BUC 2, T4: BUC 3, T5: BUC 4, T6: BUC 5, T7: BUC 6, T8: BUC 7, T9: BUC 8 and T10: Control (Soil). Results: Total nitrogen content was not significantly varied across different treatments, but the increase in pH was significant for the treatment, C4. Release of nitrogen in distilled water revealed marked differences among the treatments. Urea exhibited significantly elevated nitrogen release on first day compared to other treatments, whereas T9 and T4 initially showed substantially lower values, which gradually increased, reaching significantly higher levels by day 30. The soil incubation study demonstrated that urea exhibited significantly higher values of ammoniacal and nitrate nitrogen release on the 7th day, reaching their maximum on 14th day and then decreased gradually till 30 days. All other treatments showed significantly lower release of ammonia into the soil, followed by a gradual increase, reaching a maximum at 90 days. Leaching of ammoniacal and nitrate nitrogen was maximum for T1 on day 8. Significantly lower nitrate nitrogen leaching values were recorded by T9 towards the end of the experiment. Conclusion: T9 showed initial release of nitrogen at significantly lower rates. Furthermore, it had a significantly higher pH compared to other treatments, rendering its suitability for acidic soil.

Potato starch production encountered drastic changes during the last years, in particular in economics and substrate supply. Because of economically required reductions in subsidisation, production of potato starch will decrease. Changes in technology are characterised by savings in wash water and process water streams that are effected by increased efficiency introduced with new machinery and changed technological concepts. From an ecological point of view, an early and maximum fruit water separation (up to 95 %) based on dilution of gratings with process water and decanter separation allowed to reduce the fresh water supply to 0.4 to 0.5 m3/t of processed potatoes. For economical isolation of potato protein a correspondingly high protein recovery rate (up to 90 %) is essential. Concerning starch extraction, a minimum of 95 % is reached in modern potato starch plants, but optimum engineering (rasping, decanting, sieving) gives recovery rates of 97 to 98 %. In starch refinement, three-phase nozzle separators equipped with wash water supply and constructed for efficient displacement washing allow to achieve a fine fibre removal of 98 % within three separation stages and a final concentration of purified starch milk of 22 to 23°Bé. Potato protein isolates (protein content 83 to 85 %) are produced by isoelectric precipitation combined with heat coagulation while stringent solutions for treatment of de-proteinised fruit water are still lacking.

Potato starch production encountered drastic changes during the last years, in particular in economics and substrate supply. Because of economically required reductions in subsidisation, production of potato starch will decrease. Changes in technology are characterised by savings in wash water and process water streams that are effected by increased efficiency introduced with new machinery and changed technological concepts. From an ecological point of view, an early and maximum fruit water separation (up to 95 %) based on dilution of gratings with process water and decanter separation allowed to reduce the fresh water supply to 0.4 to 0.5 m3/t of processed potatoes. For economical isolation of potato protein a correspondingly high protein recovery rate (up to 90 %) is essential. Concerning starch extraction, a minimum of 95 % is reached in modern potato starch plants, but optimum engineering (rasping, decanting, sieving) gives recovery rates of 97 to 98 %. In starch refinement, three-phase nozzle separators equipped with wash water supply and constructed for efficient displacement washing allow to achieve a fine fibre removal of 98 % within three separation stages and a final concentration of purified starch milk of 22 to 23°Bé. Potato protein isolates (protein content 83 to 85 %) are produced by isoelectric precipitation combined with heat coagulation while stringent solutions for treatment of de-proteinised fruit water are still lacking.