AGRICULTURAL BIOLOGY, 2016, V. 51, ¹ 4, pp. 500-508 ISSN 2412-0324 (English ed. Online) (SEL’SKOKHOZYAISTVENNAYA BIOLOGIYA) ISSN 0131-6397 (Russian ed. Print) ISSN 2313-4836 (Russian ed. Online) Physiology of digestion in productive animals UDC 636.3:636.082.266:591.13:612.015.3 doi: 10.15389/agrobiology.2016.4.500rus doi: 10.15389/agrobiology.2016.4.500eng BIOLOGICAL PARAMETERS FOR DIGESTIVE AND METABOLIC PROCESSES IN INTERSPECIES HYBRIDS OF DOMESTIC SHEEP (Ovis aries) AND ARGALI (Ovis ammon polii) N.V. BOGOLYUBOVA, V.N. ROMANOV, V.A. DEVYATKIN, I.V. GUSEV, V.A. BAGIROV, N.A. ZINOVIEVA L.K. Ernst All-Russian Research Institute of Animal Husbandry, Federal Agency of Scientific Organizations, pos. <...> Dubrovitsy, Podolsk Region, Moscow Province, 142132 Russia, e-mail 652202@mail.ru Acknowledgements: Supported financially by Russian Scientific Foundation (project number 14-36-00039) Received April 30, 2016 A b s t r a c t Introduction of the allele pool of wild species, in particular, Argali (Ovis ammon polii) into the domestic sheep (Ovis aries) of the modern breeds is one of the promising approaches to enhancing genetic diversity and, consequently, biodiversity and nutrient availability. <...> Study of the processes of digestion, assimilation of nutrient substrates in the body and metabolism is the basis for developing the feeding systems for animals of the novel genetic variation. <...> The objective of this survey was to study and metabolism, digestibility, and nutrient requirements of hybrids of Romanov sheep and Argali. <...> The experiments were performed on the wethers fitted with rumen fistulas (Vivarium of the L.K. Ernst Institute for Animal Husbandry, Moscow Province, pos. <...> Group I (control) included the purebred Romanov sheep (ROM, n = 3), group II included the F3 hybrids (HYB1, n = 3) from crossing Romanov ewes with F2 hybrid Romanov ewes and Argali (87.5 % of the Romanov sheep blood and 12.5 % of the Argali blood), and group III included the F3 hybrids (HYB2, n = 3) from crossing F2 hybrids Romanov ewes and Argali with the Edilbaj sheep (50 % of the Edilbaj sheep blood, 37.5 % of the Romanov sheep blood, and 12.5 % of the Argali blood). <...> The rumen content and blood samples for the analysis were taken an hour before feeding and in three hours after feeding. <...> The production of volatile fatty <...>