THE ABILITY OF HOLSTEIN BREED SIRES TO TRANSMIT A HIGH IMMUNE RESPONSE TO THEIR OFFSPRING IN CASE OF DISEASE

Genomic selection allows animals to be selected based on their genetic information, which enables more accurate prediction of hereditary traits. This shortens the selection interval, improves reproductive efficiency, reduces the cost of raising unproductive individuals, and accelerates genetic progress in the population. The research was conducted at the dairy production complex LLC “Ostriykivske,” where 54 Holstein heifers were selected for genomic evaluation. Genomic testing revealed significant differences in immune indicators among the daughters of different sires, confirming the genetic influence of the father on the health of his offspring. The highest Immunity+ index (105.67 ± 1.39) was recorded in the daughters of the sire Elkhart 3148929453, from the Elevation 1491007.65 lineage of the Holstein breed. These daughters inherit a high immune response to disease, as evidenced by a 7.86% lower incidence rate according to genomic testing. This indicates high genetic resistance to infectious diseases, which is a crucial factor for improving herd health and productivity. In contrast, the sire Majordomo 13353511, which has a low Immunity Index, produces offspring that are more prone to diseases. This is supported by low immune resistance in his daughters, leading to increased cases of diseases such as paresis, retained placenta, and others. Using semen from sires with a high Immunity Index is an effective tool in breeding programs aimed at improving disease resistance in animals. Genomic evaluation enables the selection of sires with positive markers associated with immune response. The offspring of such animals show better health indicators, higher calf survival rates, and reduced veterinary costs. This is especially relevant in conditions of production intensification, when ensuring not only productivity but also animal welfare is critical. Immunity+ (I) – bull semen with the property of transmitting strong immunity. This is an innovative technology in cattle breeding that enables the selection and use of semen from bulls with a high immune index. It aims to improve immune resistance in offspring, reduce morbidity, and enhance cow productivity. This opens new opportunities for selection and herd health improvement through the choice of sires with high immune status.