Hematological profile and activity of blood aminotransferases in suckling lambs under the alimentary effect of yeast feed additives

Abstract

Goal. To study changes in the hematological profile, activity of blood aminotransferases, and growth rate of lambs by the alimentary effect of yeast feed additives made based on microscopic yeast fungi Kluyveromyces marxianus. Methods. The study was conducted during the winter-spring stall period in 2025 on hybrid lambs (1/2 by puriness) at the age of 2–4 months, bred as a result of crossing ewes of the Askanian meat-and-beef breed with rams of the Dorper meat breed. For this purpose, the following methods were used: zootechnical (determination of feed nutrition, gross and average daily increases in live weight of animals), hematological (determination of the hematological blood profile), enzymatic (determination of the activity of blood serum transaminases), analytical (analysis of literary sources), and mathematical statistics (use of standard computer programs for processing the data obtained). Results. It was established that the use of probiotic KluActive G and post-biotic NutriLys KM S and their mixture in the composition of mixed fodder for suckling lambs at the age of 2–4 months optimized hematological parameters, did not have a negative effect on the activity of alanine and aspartate aminotransferase of blood, and stimulated the intensity of growth of animals. Conclusions. It was experimentally proved that the alimentary use of domestic yeast feed additives stimulated metabolic activity and increased the productivity of lambs. The most significant effect on the hematological profile and growth intensity of suckling lambs at the age of 2–4 months in the stall period was provided by the use of feed additives based on yeast fungi Kluyveromyces marxianus, namely a mixture of pro-biotic KA G in a dose of 0.02% and post-biotic NL KM S in a dose of 0.2% of the feed weight.