Agronomy


 

 


Private animal husbandry, feeding, technologies of feed preparation and production of livestock products


UDC 636.2.082.25:636.237.21
DOI 10.36461/NP.2022.63.3.004

MILKING OF FIRST-CALF COWS AS THE FACTOR TO DETERMINE PRODUCTIVITY AND LONGEVITY OF COWS
T.V. Shishkina, Candidate of Agricultural Sciences, Associate Professor; S.Yu. Dmitrieva, Associate Professor; A.Y. Kuznetsov, Candidate of Agricultural Sciences, Associate Professor
Federal State Budgetary Educational Institution of Higher Education "Penza State Agrarian University", Penza, Russia, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

To find out how the intensity of milking of the first-calf cows influences their productive longevity and lifelong milk yield, a study was conducted in the conditions of the Ramzai Educational and Farm of Penza State Agrarian University in a herd of Holstein black-and-white cattle. For this purpose, groups were formed according to the productivity level after the first lactation. Milk and lifetime productivity, duration of use of animals and life expectancy were evaluated according to the level of cow milking, as well as the correlation between milk yield of cows during the first lactation and lifetime milk productivity. As a result of the research, it was found that the average duration of animal use is 3.6 lactations; lifetime milk yield in the studied groups averages 22019.5 kg, the amount of milk fat is 861.0 kg, and the amount of milk protein is 598.6 kg. According to the milk productivity class of 7001 to 7500 kg in the first lactation, the group of animals significantly exceeded the other study groups in life expectancy (2663.62 days); in the duration of productive use (1385.38 days); in lifetime milk yield (27728.86 kg); in milk fat content (194.12 kg); in milk protein content (178.8 kg). The correlation coefficient between lifetime productivity and the first lactation milk yield had a weak positive connection and averaged 0.23. As a result of our research, we found that the most preferable periods of productive longevity are observed when milking first-calf heifers from 7001 to 7500 kg of milk per lactation.
Keywords: breed, milk productivity, milking, lactation, longevity, lifelong productivity.

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Technologies, machinery and equipment for the agro-industrial complex


UDC 633.63:631.171
DOI 10.36461/NP.2022.63.3.003

MODELLING THE STRESS-STRAIN STATE OF THE ROTARY PADDLE ORIENTING DEVICE SHAFT
V.A. Ovtov, Candidate of Technical Sciences, Associate Professor;
A.A. Orekhov, Candidate of Technical Sciences, Associate Professor;
A.V. Polikanov, Candidate of Technical Sciences, Associate Professor;
N.S. Chirkova, Student; D.A. Frolov, Student; N.N. Koldaev, Student;
A.S. Kostromitin, Student;R.I. Devlikamov Student
Federal State Budgetary Educational Institution of Higher Education "Penza State Agrarian University",
Penza, Russia, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

The article considers the construction and the operating principle of the rotary paddle orienting device for planting of sugar beet mother root crops of conical form, which high-quality operation largely determines the technological process of a piece-by-piece feeding of root crops into the planting cones of a planting apparatus with the following planting of root crops with a cone downward into the soil. The fulfillment of agro-technological requirements for planting works largely determines the obtaining of planned harvests of sugar beet seeds. We have determined the loads, which work upon the drive shaft of a paddle rotor of a rotary paddle orienting device, and carried out its stress-strain analysis, which showed that the strength and rigidity of a designed and modelled shaft will ensure reliable operation of a rotary paddle device. Thus, the rotary paddle orienting device of the planting machine will provide piece-by-piece orientation of root crops, regardless of their size and taper.
Keywords: sugar beet, planting, stress-strain analysis, modelling, shaft, rotary paddle device.

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