ПРОДУКТИВНОЕ ДОЛГОЛЕТИЕ КОРОВ РАЗНОГО ТИПА СТРЕССОУСТОЙЧИВОСТИ

Abstract

The research goal is to increase the duration of the period of productive use of cows in modern complexes for milk production. The object of research is cows of the newly created intra-breed middle Volga type of black-and-white breed, culled for various reasons from the herd in the period from 2016 to 2018. All animals for further statistical processing of the studied indicators were divided into four groups, taking into account the type of stress resistance according to the method of E. p. Kokorina in the modification described by E. N. Letyagina. It was found that all hematological indicators decrease with increasing stress resistance in cows, except for the content of white blood cells. An increase in the concentration of white blood cells in the blood by 6.8-41.9% is probably a protective reaction of the body. Different reactivity of cows to the action of stress factors has an impact on the natural resistance of their body. A decrease in BASC by 3.2-10.5% was found, LASC –
 by 3.5-9.0%, FUNK-by 1.8-7.3%. When stress resistance decreases, the concentration of immunoglobulins in the blood decreases: IgG-by 3.9 – 11.2%, IgM-by 1.1 – 22.5%, IgA-by 3.4 – 24.1%. Studies have shown that cows of the first type of stress was superior to their peers with high stress-STU life expectancy at 262,6-1264,8 day (11,6-100%; P<0,05-0,001); in the long-STI period of productive use – on 0,2-2,5 lactation (4,7-125%; P<0.001); the magnitude of the average milk yield per lactation on 487-2175 kg of milk (8,5-53.6 percent; P<0,05-0,001); the value of lifetime milk yield –
 for 3340-19924 kg of milk (13.5-245.5%; P<0.01-0.001); for milk yield per 1 day of life-0.2-4.7 kg
 (1,8-73,4%; P<0,001), on the 1st day of lactation – 2,3-5,5 kg (13,9-41,4%; P<0,001). It is recommended that the" breeding core " of the herd be equipped with animals of types I and II of stress resistance. When using type II stress resistance cows, additional attention should be paid to the milk productivity of their mothers when selecting breeding bulls.