Сельскохозяйственные и ветеринарные науки

Influence of diatomaceous earth and its combinations with poultry manure on soil fertility and crop productivity

The effect and aftereffect of various norms of silicon-containing agricultural ore (diatomite) on the content of humus, nutrition elements, exchange acidity, the fractional composition of water-bearing aggregates in the arable layer of gray forest soil and the productivity of corn and spring wheat were studied. Studies have found that the most significant effect on the increase in the content of humus, alkaline hydrolyzable nitrogen, mobile phosphorus and potassium, a decrease in metabolic acidity was caused by the introduction of diatomite in combination with bird droppings.

Selection and genetic parameters of productive traits and exterior features of black-and-white cattle in Western Siberia

The article presents materials on the selection and genetic indicators of black-and-white cattle. The amount of repeatability allows for selection by productive qualities already in the first lactation. There was a significant negative moderate relationship between the mass fraction of fat and milk yield for 305 days of lactation (- 0.308; Р>0,999). There is a tendency of negative weak dependence between the milk yield and the mass fraction of protein, namely, the increase in milk yield is accompanied by a slight decrease in protein content.

The Influence of Agricultural Methods on Formation of Agrophytocenoses of Perennial Grasses of Intensive Use in the European North of Russia

The article presents the results of a four-year research on the study of agricultural methods for creating agrophytocenoses of perennial grasses for intensive use. According to the results of the studies, it has been found out that the content of seeded grass species in the grass stand has been high regardless of the species composition and method of sowing and has been 83-94.1% in the third year of use. The method of sowing has had an impact on the botanical composition of agrophytocenoses – the amount of weed vegetation has been higher with the subcover method by 1.2-1.4 times.

Influence of degrees of inbreeding on the economic and useful qualities of dairy cattle

Studies were conducted to determine the relationship between the method of breeding, the reproductive qualities of heifers and their subsequent milk productivity in the conditions of enterprises of the Omsk region. It was found that the best characteristics of reproductive qualities are heifers with an inbreeding coefficient of up to 6.25% or with moderate inbreeding and inseminated from 13 to 18 months of age. With increasing homozygosity of organisms, the level of milk productivity decreases.

The comparative characteristic of the fat content of milk in cows, taking into account the season of the year

In dairy farming, when breeding dairy breeds of cattle, milk quality is an important factor, milk fat content in particular. According to the results of the research, on 3 farms of the Vologda region for the period from 2017 to 2019, taking into account the season of the year and basing on the comparative characteristics, high values of the mass fraction of fat in milk samples of cows have been revealed in autumn. On average, the farms have established high quality values of the mass fraction of fat that meet the state standard requirements.

Histological diagnosis and morphological characteristics of pathological changes in chronic kidney disease in the Central Asian tortoise-Testudo horsfieldii (clinical case)

The article describes the pathological changes in the excretory system of the Central Asian turtle. The material of the study is a puncture biopsy of the kidneys obtained under ultrasound control, assessment of the morphological structure of kidneys using classical histological techniques, and biochemical analysis. As a result violations of mineral metabolism and kidney function are revealed.

Productivity and nutritional value of pasture agrophytocenoses based on cereals and legumes

The paper presents the results of studying the influence of the species of perennial legumes and cereals on the productivity and nutritional value of pasture agrophytocenoses of the European North of the Russian Federation. The field experiment was started in 2017 and is still continuing. In the course of the research, it has been found that the most nutritious and highly productive, in comparison with the control variant, are the mixtures of legumes and cereals with the inclusion of festulolium or perennial ryegrass.

Evaluating harvested feed in the Vologda Region for the presence of nitrate compounds

The improvement of agriculture is inextricably linked with the increase in feed production. The intensive feed production system involves using high doses of nitrogen fertilizers. This significantly increases the yield, but at the same time nitrates accumulate in soil, water and feed. Excessive amount of nitrates causes the wrong course of functioning in natural ecosystems and animal organisms, there is a decrease in the biological value of products. Meanwhile, the importance of nitrates and their impact on human health has increased recently.

Correlation relationships of economic characteristics in black-and-white cattle

The present study has been carried out for obtaining comparative correlation data between productive and reproductive characteristics of the daughters of domestic and foreign breeding bulls in the modern black-and-white population of the Vologda region. The research is based on the works of domestic and foreign scientists and information databases on 10250 black-and-white cows of the 1st calving in the Vologda breeding farms. The statistical data has been calculated in the Microsoft Excel program.

Growth and ontogenetic allometry of visceral organs in cross Loman Brown chicken embryos at different embryogenesis stages under a standard temperature-humidity incubation regime

The article presents the study results of growth and ontogenetic allometry of visceral organs in cross Loman Brown chicken embryos at different embryogenesis stages under a standard temperature-humidity incubation regime. The research has been carried out in the scientific laboratory of the Velikie Luki State Agricultural Academy in 2019-2020. The material for the research is Loman Brown embryos (n=200).


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