This article accelerates the development of selection methods for selecting the best genotypes that are acceptable from the similarity genotypes of imported Holstein cattle typical of Chinese, German and Slovenian selection. The genetic potential of reproduction and productivity of breeding breeds in genotype-environment interactions has been demonstrated. The results of the same feeding, storage and performance of Holstein cows in summer and winter, the productivity characteristics of the cattle are presented.
Reproductive biology of cultured common carp in Uzbekistan was studied. The ages, total lengths of the samples studied ranged 1-5 years, 5.0 - 87.0 cm in standard length. In spring, 1-year-old fish (8.0-25.0) cm had gonads at stage I; 2-years-old females (18.0 – 33.0 cm) had gonads at stage I (23 %) and II (77 %); 3-years-old females (25.6–47.1 cm) had ovaries at stage II (43 %) and III-IV (57 %); all 4-year-old and 5-year-old females were mature. Females mature when they reached 32 cm in standard length. Absolute fecundity varied 131–1830 thousand eggs, relative fecundity was 190.5–344.0 eggs/g of gutted fish body, real fecundity was 200.0–1300.0 thousand eggs. Average individual ripe egg size varied 1.32–1.52 mm. Positive correlation between maturation, absolute fecundity and growth was determined. For broodstock forming optimization, additional (to body size) fish characteristic should be entered to selection; fish growth could be recommended as such measure. Annual artificial selection of fishes with standard length at different ages (at least SL1 – 13 cm; SL2 - 25 cm; SL3 – 32 cm) would form broodstock which mature at 3-years-old age with real fecundity 800 – 1300 thousand eggs.
Studies have shown that the breeding cattle of the Swiss breed of different genotypes used in the selection in Uzbekistan are characterized by high breeding value. The cows obtained from them are distinguished by high milk productivity and fat-milk content, a high milk production coefficient, indicating a pronounced milk type. Cattle of Austrian breeding are characterized by a higher productivity potential. In some cattle cows, the milk yield by 191.3–417.1 kg, the milk yield of 4% milk by 212.6–472.6 kg, the milk yield coefficient by 26.1–45.8 kg exceeds the corresponding indicators of the cows of other cattle. The calves of the cattle nick-named Karan, Koster, Emil and Jordan had milk yield at 1,174.8, 1,219.4; 935.0 and 1,010.4 kg respectively; milk fat yield by 52.9; 55.3; 45.3, and 49.9 kg are higher than the requirements of the republican standard of the Swiss breed. Studies have confirmed that the use of semen from cattle -producers of the Swiss breed in breeding herds, regardless of origin, has a positive effect on the improvement of the main selection characteristics of cows of the Swiss breed of Uzbekistan.
The goal of present study was to examine gibel carp, Carassius gibelio (Bloch, 1782) growth, maturation, fecundity and ripe eggs size under pond fish culture conditions and conditions of natural water bodies of the River Syrdarya, Uzbekistan. Gibel carp originally came from the River Amur (Russia), it was introduced to Uzbekistan in 1950s. Recently, it is wide spread species in local ichthyofauna. Females matured for the first time at age 2 years: in ponds in 8-10 cm in standard length, in the river in 18-20 cm. The GSI increased to spawning up to 2.9 – 25%. In fish farm ponds absolute fecundity was 1,4 – 51,300 eggs, in the River Syrdarya - 9,2 – 91,400 eggs. Relative fecundity in all populations was 21 – 590 eggs/g in weight of gutted fish. In April, there were two peaks of ripe and yolk eggs size: 1st - 0.89 – 1.69 mm, 2nd – 0.69-0.9 mm.
Recently, in various countries of the world, in particular, the USA, Germany, Canada, India and Russia, tangible results have been achieved in the use of biological methods for combating zoophilic insects and ecoparasites, the use of microbiological and pyrethroid preparations with a plant base. Zoophilic insects and mites as ecto- and endoparasites parasitize on the body of animals and people cause infestation, that is, parasitosis (entomoses and acarosis), as a result of which the milk productivity of cattle decreases to 30-40 percent, meat productivity annually decreases by 10-12 kilograms, and also negatively affect the growth and development of young animals and lead to death.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.