Selection and genetic parameters in the selection of dairy cattle

Studies were conducted to study the variability and correlation of indicators of dairy productivity of cattle in the conditions of breeding enterprises of the Omsk region, as well as the optimal size of the breeding group was determined on the basis of the Pareto diagram. It was found that the coefficient of variation of milk yield in cows of the red steppe breed was 23.4 %, which is 4.3% more than in cows of the black-and-white breed. To form breeding groups in breeding farms in the region, they must have a milk yield of at least 7000 kg of milk.

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 impact of variability of the type of Siberian cedar by seed scale apophysis on the seed peel firmness

The seed peel firmness of Siberian cedar morphological forms (by seed scale apophysis) has been studies. The existence of differences on the seed peel firmness indicators between the forms is theoretically based by the nutcracker’s activity. The results of the experiments prove the given assumption. It is shown that nuts from the cones with plain apophysis type require the relatively less maximum power and tension, but more time on their cracking. To use the seeds of the given morphological trees’ forms is prospective for the production of cedar kernel.

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