Milk yield, composition and cheese quality in German and Israeli Holstein cows reared in Azerbaijan

Determination of the complex index of breeding traits in cattle is becoming increasingly important both for selection and for preserving their local populations. Along with quantitative indicators of milk production, the milk quality indicators in the complex assessment of cattle are inclusion practiced. High-tech processes of industrial milk processing and a wide range of dairy products increase the requirements for the raw materials used. National selection indices of Holstein cattle differ in the specific weight of some productivity indicators, while there are significant differences between countries in the organization of the selection process. The selection index in Israel does not comprise the duration of productive use, while in Germany the contribution of this feature is 40 %. This determines the interest in the experimental comparison of quantitative and qualitative features of milk productivity in groups of cattle of different origin, including the seasonal dependence of indicators in local conditions. Here, for the first time we assessed the yield and quality of milk and the quality of mature cheese produced from seasonal milk in Holstein cows of German and Israeli selection under the conditions of Azerbaijan. The aim of the study was a comparative study of milk productivity indicators, composition, quality of milk and cheese obtained from Holstein cows of different origin. The studies were carried out at ASK Livestock (Sheki district, Azerbaijan) in 2023 on 2 groups of cows: first-calf cows of German selection with over 87.5% Holstein blood and first-calf cows of Israeli selection with 87.5%. Holstein blood. The indicators of milk productivity, milk composition and properties, vitamin C content, amino acid and fatty acid composition, and physicochemical composition of mature cheese were assessed. Cows of Israeli selection, compared to the control animals, had higher milk yields for 305-day lactation (8248 vs 6951 kg of milk at p ≤ 0.001), their milk had a higher protein content (3.39 vs 3.23 % at p ≤ 0.001), milk fat yield (317 vs 269 kg at p ≤ 0.001), protein (279 vs 224 kg at p ≤ 0.001), low content of saturated and high content of unsaturated fatty acids, an increase in the total amount of amino acids (92.26 vs 86.56% at p ≤ 0.001). The richest chemical, amino acid and fatty acid composition of milk obtained from animals of Israeli selection and optimal milk processing indicators made it possible to obtain a high-quality processed product in the form of cheese. The knowledge obtained may be useful in developing a selection index for evaluating pedigree dairy cattle of different origins.