Abstract

The article presents the results of research on the influence of winter grazing on the aftergrass of natural and seeded grass and linseed cake feeding on metabolism and energy indices in Yakutian horses in winter. It was found that the aftergrass of seeded grass (winter-green oat mass) was characterized by a high content of nutrients and energy-intensive substances. Reliable differences were found out for dry matter 63.7 ± 0.13 % and for protein - 9.0 ± 0.14 % (P ≥ 0.95). The carotene content of winter-green oats is 104.6 % higher than that of natural grass (28.4 ± 0.76 %) and amounted to 133.0 ± 0.44 % (P ≥ 0.999). The largest amounts of polyunsaturated fatty acids have been identified. Thus, the sum of polyunsaturated fatty acids in the aftergrass of seeded grass (winter-green oat mass) was 40.7%, which is 25.06% higher than the sum of fatty acids of natural grass (15.65 ± 0.18%). The high content of polyunsaturated fatty acids in winter-green oat mass contributed to higher digestion of dry (66.5%) and organic (66.1%) substance, raw protein (70.6%), raw fiber (65.4%), crude fat (51.5%) and nitrogen-free extractive substances (66.7%) than in the case of winter gazing horses on natural grass and, correspondingly, higher usege of metabolizable energy per head per day (145.4 ± 3.32 MJ) and per 100 kg of live weight (36.53 ± 2.48 MJ). The inclusion of linseed cake in the horse's winter diet had a positive effect on the digestibility of feed in the horse's body, and also had a positive effect on metabolizable energy. Reliably high digestibility ratesfor horses in the experimental group were recorded for raw protein for 3.34% (70.85 ± 0.19%) (P ≥ 0.99), for raw fat by 14.3% (68.59 ± 0.64%) and for nitrogen-free extractive substances by 3.09% (77.71 ± 1.13%) (P ≥ 0.999). The high digestibility of basic nutrients resulted in a high metabolizable energy content of 1 kg of dry matter when included in a linseed cake diet (10.1 MJ) than in a dry fodder-oat diet (9.5 MJ), (P ≥ 0.95). The results obtained by us testify to the necessity of wide application of seeded grass at winter grazing and inclusion of linseed cake as a source of polyunsaturated fatty acids in winter for Yakutian hosres.

Key words: The Republic of Sakha (Yakutia), Yakutian horses; aftergrass of natural grass; aftergrass of seeded grass; linseed cake; dry fodder-oat diet; coefficient of digestibility of feed nutrients; metabolizable energy; polyunsaturated fatty acids.