Yield Fluctuations Research Articles

Влияние погодных рисков на урожайность кукурузы на зерно в Ростовской области

One of the reasons for the volatility of agricultural production is poorly predictable weather fluctuations that affect the food security of our country and are a serious problem for agricultural producers.
 Therefore, it is necessary to develop, justify and use measures that contribute to increasing the stability of agricultural crop yields throughout the territory of agricultural lands.
 The object of research was the yield of corn for grain and weather conditions during its growing season in the Rostov region. The purpose of the study was to analyze the impact on the stability of corn yield on grain of two main factors: natural and climatic changes represented by fluctuations in moisture supply, both interannual and during the growing season of corn for grain, and human economic activity considered in the aspect of reclamation measures, as well as the development and formulation of proposals to improve this stability.
 The main factors influencing the sustainable development of agricultural production as a whole are identified by the methods of system analysis and a scheme of relations in the agroindustrial complex is constructed, and the dependences of the corn yield on grain on the experimental fields of the Biryuchekut vegetable breeding experimental station are determined by the methods of statistical analysis –the branch of the Federal State Budgetary Scientific Institution ≪Federal Scientific Center of Vegetable Growing≫ depends on the amounts of precipitation and temperatures during the growing season, on the basis of which the main directions of land reclamation are formulated that allow optimal use of the agricultural opportunities of the land fund.
 The paper notes the connection of fluctuations in the yield of corn for grain with the heterogeneity of weather and climatic conditions and the results of human economic activity depending on the level of scientific and technical development in the agricultural sector, as well as with complex solutions to environmental management problems consisting in the rational use of natural resources and the use of various types of land reclamation. It was found that in the period from 2000 to 2019, depending on the amount of precipitation, the yield of corn on the bogar at the representative object varied from 11.8 to 39.5 c/ha, that is, by more than 3.3 times, whereas during irrigation in these years of observation, the yield was from 125.2 to 138 c/ha, respectively, that is, yield fluctuations did not exceed 10 %, irrigation of corn crops in acute arid years increased the yield by 8.6 times, in dry years –by 82.2 %, in favorable –by 71.7 %, and this indicates that in order to obtain a high yield of corn for grain, irrigation should be used not only in dry years, but also in years when 350–00 mm of precipitation falls during the growing season.

Modeling and optimization of bioethanol production planning under hybrid uncertainty: A heuristic multi-stage stochastic programming approach

When making planning decisions, fluctuation in both product demand and yield for the bioethanol plant denotes an important factor to affect the results. In this paper, a mixed multi-stage stochastic optimization model is proposed to solve the production planning problem of a bioethanol plant with multiple raw materials simultaneously considering uncertain demand and yield. The multi-source uncertainty is described as a multi-layer hybrid scenario tree model according to the historical statistics. Due to the diversity of pretreatment approach in the bioethanol production process, the yield of saccharification liquid is different. At each node of the scenario tree, the uncertainty of demand is expressed by probability. The uncertain scenarios of the yield are integrated at each node of demand to form a mixed scenario tree. To improve the solution efficiency, a heuristic algorithm based on fast forward selection is designed to simplify the decomposition of the large-scale hybrid scenario tree in the mixed multi-stage stochastic programming problem. The effectiveness of the proposed model is verified by a practical case. The results show that the proposed approach performs better than the two-stage stochastic programming and the deterministic approaches, and the algorithm can significantly reduce the computational efforts.

Impact of regional bans of highly hazardous pesticides on agricultural yields: the case of Kerala

BackgroundRemoving highly hazardous pesticides from agricultural practice in low- and middle-income countries is crucial to ensuring community and environmental health and occupational safety of farmers. However, the approach has been challenged as threatening food production, despite evidence from Asian countries that curbing agricultural use of highly hazardous pesticides does not affect crop yields. In 2011, the state of Kerala, India, banned 14 highly hazardous pesticides resulting in a marked reduction in deaths from pesticide poisoning.ObjectiveWe aimed to determine whether the Kerala pesticide bans impacted agricultural yields.MethodsWe collected data on agricultural production, area under cultivation, and rainfall, published by the Kerala state agricultural department from 2004 to 2018 for eight key crops that had been treated with the banned pesticides. Trends in crop yields (total production/area under cultivation) and rainfall across 14 districts in Kerala were aggregated and analysed using joinpoint regression. These trends were evaluated to ascertain possible associations with the pesticide bans.ResultsThe joinpoint regression analyses showed no evidence for any change in yield trends for any of the eight crops in the year of the pesticide bans (2011), or the subsequent year (2012), suggesting a negligible impact of the bans on crop yields. Steady trends of predominately reductions in overall rainfall, without any change around the time of the pesticide bans, was observed in Kerala throughout the period. No evidence of district-level changes in rainfall that might have offset any potential adverse impacts of the pesticide bans on crop yields was noted. Fluctuations in yield until 2018 could be explained by variation in rainfall, changes in land use, and agricultural policies.ConclusionWe found no evidence of an adverse effect on agricultural yields in Kerala that could be attributed to bans of highly hazardous pesticides. This work provides further evidence that such pesticides can be withdrawn from agricultural use without affecting yields. Further studies are required for the whole of India after the national bans of 12 pesticides in 2018 to identify state-level effects of the bans.

Management of macro and micro nutrients to suppress flower yield fluctuations in productive clove

Yield fluctuations in cloves are still an unsolved problem. This study aimed to increase vegetative and reproductive shoots to stimulate flowering by applying macro and micronutrients using 30 years old clove-plant. The treatments tested were: (p0) control, (p1) NPKMg (4:1:3:0,4), (p2) NPKMg (4:1:3:0,4) + 30 g B + 30 g Zn, and (p3) NPKMg (4:1:3:0,4) + 60 g B + 60 g Zn. The dose of NPKMg given was adjusted to the plant-based on the SOP for fertilizing cloves aged 34 years, namely 8.4 kg (N=4 kg, P2O5=1 kg, K2O=3 kg, and MgO=0.4 kg per tree per year). The results showed that fertilizer application could improve canopy and branch conditions after a large harvest season and increase the number of shoots. Meanwhile, micro fertilizers B and Zn (p3) application during the small harvest season can increase the production of fresh flowers 303.27-516.67% higher than the control. During the medium harvest season, it is only 122.37%. In the large harvest season, macro fertilizer (p1) increased the production of fresh flowers by 135.53%, higher than the control. This study indicates that clove plants aged >30 years can still increase their productivity through macro and micronutrient management and suppress yield fluctuations.

Flowering induction of clove to reduce its yield fluctuation by using a plant growth regulator

The main problem in clove cultivation is yield fluctuation which occurred every 2-4 years. It is usually caused by internal factors such as photosynthates, nutrition, and plant growth regulators that control the flowering process. The study was conducted from January to December 2015 on +30 years old-cloves at a farmer’s plantation in Sumedang, West Java. The trial was arranged in a randomized block design with three replications. The treatment consisted of 13 treatments of paclobutrazol application: (1) control, (2) 2500 ppm paclobutrazol, given eight weeks after harvest (WAH); (3) 2500 ppm paclobutrazol, 10 WAH, (4) Paclobutrazol 2500 ppm, 12 WAH. (5) 2500 ppm paclobutrazol, 14 WAH, (6) Paclobutrazol 2500 ppm, 16 WAH, (7) Paclobutrazol 2500 ppm, 18 WAH, (8) 5000 ppm paclobutrazol, 8 WAH, (9) Paclobutrazol 5000 ppm, 10 WAH, (10) 5000 ppm paclobutrazol, 12 WAH, (11) Paclobutrazol 5000 ppm, 14 WAH, (12) 5000 ppm paclobutrazol, 16 WAH, and (13) 5000 ppm paclobutrazol, 18 WAH. Results indicated that paclobutrazol 5000 ppm applied at 16 WAH gave a higher new shoot number and yield than control within three consecutive years (2014, 2015, and 2016). The range of chlorophyll content was 0.08-0.15%.

УПРАВЛЕНИЕ ВОДНЫМ РЕЖИМОМ ПОЧВЫ КУЛЬТУР СЕВООБОРОТНОГО УЧАСТКА В ЗАВИСИМОСТИ ОТ ПОГОДНЫХ УСЛОВИЙ НА ОРОШАЕМЫХ ЗЕМЛЯХ САРАТОВСКОЙ ОБЛАСТИ

Due to significant global climate change, which leads to a mismatch between the requirements of plants and environmental conditions, the most relevant at present is the placement of crops in places where the reclamation regime (culture requirements for environmental conditions) coincides with environmental conditions in a given place. The manifestations of global climate warming in the Saratov region are expressed in a decrease in the amount of precipitation falling during the main growing season of agricultural crops (May-July), which, against the background of rising air temperature, increases the discrepancy between moisture resources and the need for plants, which leads to large fluctuations in agricultural yields. cultures. Therefore, in the production of agricultural crops, farming systems and crop rotations should be based on agroecological principles, providing for high yields, reproduction of soil fertility, environmentally friendly products, efficient and rational use of irrigation water, which will provide economic efficiency, and serve to restore the ecological balance in the region. An analysis of the current state of irrigated agriculture shows that the possibility of increasing agricultural production is not fully used. Irrigation efficiency is largely reduced due to a violation of the complex of agrotechnical and agro-ameliorative measures, the lack of reasonable crop rotations, non-fulfillment of irrigation plans, insufficient application of organic and mineral fertilizers, as well as the current natural and climatic changes and a number of other reasons. Only the observance of a high culture of agriculture in combination with the whole complex of land reclamation measures will make it possible to obtain high yields of grain and other crops in the Saratov region.

Sources of Fluctuations in Short-Term Yields and Recession Probabilities

Sources of Fluctuations in Short-Term Yields and Recession Probabilities

Sources of fluctuations in short-term yields and recession probabilities

Sources of fluctuations in short-term yields and recession probabilities

Changes’ assessment in the interrelation of productive traits of holsteinized black pied cattle

Holstein black pied cattle with a high genetic potential of productivity are bred in the Sverdlovsk region. The study of the interrelation between the productive traits of modern domestic dairy black pied cattle of the Middle Urals zone with high thorough-bredness for the Holstein breed is relevant. The purpose of the work was to study the conjugation dynamics of productive traits by lactation depending on the line. According to the average milk yield indicators. There were no differences in MFF and MFP in milk from cows of different lines, yet the fluctuations in milk yield within the lines were significant. The highest indicators of the correlation coefficient are established between the qualitative indicators of milk, which means that an increase in one of the indicators invariably leads to an increase another. A positive low conjugacy was established between milk yield and MFP in milk, as well as milk yield and cows’ live weight for the first and second lactation in cows of both lines. In cows of the Vis Back Ideal 1013415 line, the conjugacy of productive traits for the third lactation turned into negative, except for milk yield and live weight. Thus, the linear affiliation of cows and their age (lactation) influence the interrelation of productive traits, which can be considered when further planning breeding work with the herd.

ABOUT THE INFLUENCE OF WEATHER AND CLIMATIC FACTORS ON THE GRAIN CROPS YIELD OF MINSK AND MOGILEV PROVINCES IN LATE 19th – EARLY 20th CENTURIES

A quantitative assessment of the influence of weather and climatic factors (average air temperature and the amount of precipitation by months of the growing season) on major agricultural crops yield was carried out using ‘weather – harvest’ regression models and available statistical and meteorological data for Minsk and Mogilev provinces in late 19th – early 20th centuries. On the basis of the established dependencies, the vulnerability of the main grain crops to the climatic conditions of the period under consideration is shown, and specific factors are identified that determine the climatic variability of their yield. Using the weather index on the example of Minsk province, the favorable weather conditions for the main grain crops growth (winter rye and oats) in the considered years were assessed. It is shown that fluctuations in yield of winter rye were determined by moisture storage on eve of sowing and the conditions of its conduction, the sizes of sowings death because of temperature and precipitation sums ratio, heat supply of a period of vegetation resumption, weather conditions of spring and summer vegetation, ripening and harvesting. The fluctuations in oat yield were conditioned by spring moisture storage, weather conditions of sowing and harvesting but mainly by temperature background of during a period of summer vegetation and crop ripening.

Study on the Formation Mechanism of the Pyrolysis Products of Lignite at Different Temperatures Based on ReaxFF-MD.

The internal part of coal that is not in contact with oxygen will undergo pyrolysis reaction due to heat conduction, and the active groups generated can reverse-aggravate the degree of coal spontaneous combustion. At present, a few studies have been conducted on the pyrolysis mechanism of coal at different temperatures by using mutually validated experimental and simulation methods, resulting in the mismatch between the microscopic mechanism and macroscopic characteristics. In this paper, DH lignite is taken as the research object, and its macromolecular model is established. The pyrolysis reaction of lignite is studied by the experimental methods of coal pyrolysis index gas collection and detection experimental and thermogravimetric analyses and the simulation method of ReaxFF-MD. The influence of temperature on lignite pyrolysis is explored by analyzing the distribution of products at different temperatures and the formation mechanism of typical products, so as revealing the microscopic mechanism of lignite pyrolysis. The results show that 110–500 K of experimental temperature corresponds to 1400–2400 K of simulation temperature. CO2 and C2H4 are the main gas products during pyrolysis simulation. Carboxyl and ester groups are the main source of CO2, which gradually increases with the rise of temperature. Since CO2 can be reduced to produce CO, H2O, and C2H2O at high temperatures, the yield decreases when the temperature is higher than 2000 K. C2H4 is derived from the decomposition of long-chain aliphatic hydrocarbons, and its yield fluctuation rises with the rise of temperature. The formation of H2O and H2 mainly occurs in the secondary pyrolysis stage. When 1400 K < T < 2100 K, the primary pyrolysis is the main reaction, where the weak bridge bonds and macromolecular structure undergo cleavage to form gas products and tar free radical fragments. When T > 2100 K, the secondary pyrolysis reactions were significant. Tar free radicals and char undergo decomposition, hydrogenation, and polymerization reaction, gas products and tar free radicals increase, and the char yield decreases compared with the primary pyrolysis stage, so 2100 K is the key temperature of the pyrolysis reaction. The research is of great importance in improving the accurate control of coal spontaneous combustion.

Tradeoffs of managing cod as a sustainable resource in fluctuating environments.

Sustainable human exploitation of living marine resources stems from a delicate balance between yield stability and population persistence to achieve socioeconomic and conservation goals. But our imperfect knowledge of how oceanic oscillations regulate temporal variation in an exploited species can obscure the risk of missing management targets. We illustrate how applying a management policy to suppress fluctuations in fishery yield in variable environments (prey density and regional climate) can present unintended outcomes in harvested predators and the sustainability of harvesting. Using Atlantic cod (Gadus morhua, an apex predatory fish) in the Barents Sea as a case study we simulate age-structured population and harvest dynamics through time-varying, density-dependent and density-independent processes with a stochastic, process-based model informed by 27-year monitoring data. In this model, capelin (Mallotus villosus, a pelagic forage fish), a primary prey of cod, fluctuations modulate the strength of density-dependent regulation primarily through cannibalistic pressure on juvenile cod survival; sea temperature fluctuations modulate thermal regulation of cod feeding, growth, maturation, and reproduction. We first explore how capelin and temperature fluctuations filtered through cod intrinsic dynamics modify catch stability and then evaluate how management to suppress short-term variability in catch targets alters overharvest risk. Analyses revealed that suppressing year-to-year catch variability impedes management responses to adjust fishing pressure, which becomes progressively out of sync with variations in cod abundance. This asynchrony becomes amplified in fluctuating environments, magnifying the amplitudes of both fishing pressure and cod abundance and then intensifying the density-dependent regulation of juvenile survival through cannibalism. Although these transient dynamics theoretically give higher average catches, emergent, quasicyclic behaviors of the population would increase long-term yield variability and elevate overharvest risk. Management strategies that overlook the interplay of extrinsic (fishing and environment) and intrinsic (life history and demography) fluctuations thus can inadvertently destabilize fish stocks, thereby jeopardizing the sustainability of harvesting. These policy implications underscore the value of ecosystem approaches to designing management measures to sustainably harvest ecologically connected resources while achieving socioeconomic security.

Monitoring of climatic changes and their impact on grain production in the Saratov region using remote sensing data

Differentiated development of climatic risks in agricultural regions leads to fluctuations in yields and agricultural production volumes, disruption of food chains and a decrease in food reserves, thereby endangering sustainable agricultural production and creating risks for ensuring the country's food security. In the period from 1991 to 2019 in the Saratov region, using satellite monitoring data, a number of unfavorable meteorological (weather) phenomena were identified. The dependence of the main indicators of grain production in the Saratov region on the growing influence of negative climatic factors has been investigated. The necessity of taking into account the impact of hazardous meteorological (weather) phenomena in the system of strategic priorities, as well as when making forecasts for the socio-economic development of the region, modeling the influence of negative climatic factors on the structural balance of the agro-industrial complex has been substantiated.

Impact of heat and drought stresses on grain nutrient content in chickpea: Genome-wide marker-trait associations for protein, Fe and Zn

Chickpea is a cheap source of protein and micronutrients to the poor and vegetarian population living in south-Asia and sub-Saharan Africa. Due to changes in climatic conditions and cropping systems, the crop is being exposed to severe drought and heat stress during its reproductive period, which leads to significant yield losses and fluctuations in grain nutrient accumulation. The study was conducted with 140 diverse genotypes under non-stress, drought, and heat stress conditions to estimate their effects on grain nutrient (protein, Fe and Zn) contents and identify the marker-trait associations. Analysis of variance revealed highly significant differences among genotypes for nutrient content under respective planting conditions. The seed yield was negatively associated with the grain Fe (r = −0.37, −0.25, 0.11) and Zn (r = −0.49, −0.35, −0.72) under respective planting conditions. The PCA indicated that PC1 was positively associated with grain Fe in non-stress and heat, while Zn in all planting conditions, whereas PC2 was positively influenced by protein content followed by grain yield. Cluster analysis identified eight clusters, of which cluster VI showed maximum cluster means for Fe (73 mg kg-1) and Zn (48.1 mg kg-1). The Genome-wide association study revealed, a total of 181 MTAs for grain Fe, Zn, and protein content in all three growing conditions. A total of 4, 2, and 48 SNPs for grain Fe and Zn content, whereas, 66, 46, 15 SNPs for grain protein content have shown significant association under non-stress, drought, and heat stress, respectively. One SNP each on chr1 (S1_35622241; P ≤ 3.47 ×10-6) and chr4 (S4_44607232; P ≤ 1.35 ×10-5) was co-associated under drought and non-stress conditions for protein and Fe, respectively. The identified robust MTAs will be validated and used in marker-assisted selection towards the rapid development of nutrient-rich varieties.

Vulnerability Assessment of Maize Yield Affected by Precipitation Fluctuations: A Northeastern United States Case Study

Crop yields are threatened by global climate change. Maize has high water requirements, and precipitation fluctuations can impact its yield. In this study, we used the Environmental Policy Integrated Climate (EPIC) model to simulate maize yields in eight northeastern U.S. states. We used precipitation fluctuations and the coefficient of variation (CV) of yield as indicators to construct a vulnerability curve for the CV of yield and precipitation fluctuations. We then evaluated the vulnerability of maize yields under precipitation fluctuations in the region. We obtained the following results: (1) the fitted vulnerability curves were classified into three categories (positive slope, negative slope, and insignificant fit), of which the first category accounted for about 92.7%, indicating that the CV of maize yield was positively correlated with precipitation fluctuations in most parts of the study area; and (2) the CV of maize yield under 11 precipitation fluctuation scenarios was mapped to express the CV at the spatial level, and the maize yield in Connecticut and Maryland proved to be the most sensitive to precipitation fluctuations. This study provided a theoretical and experimental basis for the prevention of maize yield risk under fluctuating precipitation conditions.

Developing Maize Yield Predictive Models from Sentinel-2 MSI Derived Vegetation Indices: An Approach to an Early Warning System on Yield Fluctuation and Food Security

Developing Maize Yield Predictive Models from Sentinel-2 MSI Derived Vegetation Indices: An Approach to an Early Warning System on Yield Fluctuation and Food Security

Prerequisites and prospects for sustainable development of grain production in Ukraine

Purpose. The aim of the article is to identify the benefits of the chosen strategy of agribusiness (profit maximization, or yield maximization) based on the statistical observations of yields and production factors (fertilizers, plant protection products).&#x0D; Methodology / approach. To analyze productivity growth in grain production under the influence of innovative technologies the data of long-term observations of winter wheat yield in Germany and the United States were selected. In this paper, to analyze the prerequisites and prospects for stabilizing of the crop production, mineral fertilizers and plant protection products were selected as production factors affecting the yield of wheat. Methods of time series analysis and nonlinear econometric analysis were used to assess the impact of these factors. Long-term trends of growth of wheat yields in Germany, the USA and Ukraine were analyzed using regression models. The general model of agrarian business profitability in grain production is based on non-linear correlations of individual factors of intensification and panel regression. In order to substantiate the conclusions of the calculation, the estimation of climatic risks is used. For this purpose, dispersion methods, nonlinear optimization methodology are used. &#x0D; Results. Estimates of wheat yield fluctuations due to climate risks show that they will not significantly affect the problem of food security, so there is no need to impose restrictions on the export of wheat. On the choice of optimal strategy, based on analysis using econometric model of decreasing marginal utility of production resources, it is proved that the maximization of yields is achieved at lower costs than profit maximization.&#x0D; Originality / scientific novelty. The main contribution of the article to the level of application is to analyze the impact of production factors on wheat yield, taking into account climatic risk and reducing the marginal utility of production factors. At the theoretical level of the study, it represents a contribution to the discussion of the vectors of the optimal path of wheat production in Ukraine. Analysis of data on wheat yield variability in Germany and the USA showed correlation of profitability and risk (indicators of expected yield and its variance). However, this means that an increase in wheat yields in Ukraine will also increase its variability and therefore requires the implementation of a long-term strategy that can ensure stable growth.&#x0D; Practical value / implications. Based on the above calculations, it should be emphasized that the Ukrainian agrarian business (in particular, crop production) is developing its own way, not following the development path of Germany or the USA. However, some peculiarities of the development can be highlighted. After a rather long recession, the agricultural sector has embarked on a path of stable growth with an annual increase in wheat yields of around 1 hundred kg/ha. Furthermore, the extremely low proportion of forested land in Ukraine by European standards significantly increases the impact of weather and climate risks. Therefore, a further intensification of crop production while increasing the share of forested land at the expense of less productive land is probably the way to an ecologically balanced development of agriculture.

Cultivation of microalgae for lipid production using municipal wastewater

The shortage of energy and the aggravation of eutrophication are two major problems in China. The use of municipal wastewater to cultivate lipid-producing microalgae for the production of biodiesel not only reduces the production cost of biodiesel and alleviates energy shortage, but also mitigates eutrophication and protects the water environment. This study explored the effects of light, pH, and nutrients on the growth and lipid production of Scenedesmus obliquus, as well as the lipid production and pollutant removal capabilities of algae during microalgae cultivation in municipal wastewater at different treatment stages. The optimal conditions for the growth and lipid production of S. obliquus were determined as light intensity of 14,500 lx, total nitrogen (TN) content of 97 mg L−1, total phosphorus (TP) content of 11 mg L−1, and CO2 content of 9.8%. Under these optimal conditions, the lipid yield from microalgae was 0.367 g L−1, which was superior to other optimisation results in the literature. The total lipid yields of S. obliquus cultivated in the wastewater from the primary and secondary settling tanks were 0.38 g L−1 and 0.33 g L−1, respectively. The TN and TP removal rates were 99.8% and 83.1% from the wastewater of the primary settling tank, and 98.9% and 97.6% from the wastewater of the secondary settling tank, respectively. In addition, fluctuations in the quality of raw wastewater may lead to fluctuations in the final lipid yield, and a regulating tank should be used when necessary. In short, these results indicate the feasibility of cultivating lipid-producing microalgae in municipal wastewater for the production of biodiesel.

Productive qualities of holsteinized black-and-white cattle

In Sverdlovsk region Holsteinized black-and-white cattle of Ural type are bred. This livestock is represented by highly productive animals with a high genetic potential for productivity. The aim of the research is to study the productive qualities of the Holsteinized black-and-white cattle with a high proportion of blood relationship to Holstein breed. Milk yield increases with age of cows. The difference between the first and second lactation amounts to 1.084 kg or 11.4%, and between the second and third lactation it is 326 kg (3.0%). In general, the milk yield of mature (full-aged) cows was higher by 1.410 kg or 14.9% than the milk yield of first-calves It is known that mature full-aged cows have a productivity 30% higher than the first-calves. I. e. the genetic potential of the farm broodstock of full-aged cows is within 12.595 kg, and this potential is not fully used. The farm uses cows that are quite different in terms of milk yield. The fluctuations in milk yield from lactation to lactation are 7.060 kg (1st lactation), 10.210 kg (2nd lactation) and 6.785 kg (3rd lactation). In terms of the milk quality indicators – MFF (mass fraction of fat) and MFP (mass fraction of protein) no significant differences in lactation were established, although a certain positive tendency was observed for increase of MFF with age gaining in reference to the first-calves.

Comparative assessment of productive qualities of holsteinized black-and-white cattle by lines

In Sverdlovsk region Holsteinized black-and-white cattle of the Ural type are bred. The herd is represented by large bodied, highly productive animals with a high genetic potential for milk productivity. The aim of the research was to study the productive qualities of Holsteinized black-and-white cattle with a high blood relationship to Holstein breed depending on the line, and correlation between milk yield and live weight of cows. The average milk yield for 305 days of lactation in cows of both lines was almost the same, and the difference between them was insignificant. However, when considering the change in milk yield within the groups, it was found that the group of Reflection Sovering cows featured higher performance indicators – from 8.376 to 14.706 kg of milk. The difference between low productive and high productive cows yield amounted to 6.333 kg or 43.1%. In Vis Back Ideal group of cows the difference was less expressed, and amounted to 5.367 kg or 40.4%. The coefficient of variability in the groups was within the range of 26-28%, which indicates significant fluctuations in milk yield. The yield of nutrients in milk (the amount of milk fat + milk protein) was at the equal level - 783 and 730 kg.