Dynamics of energy and protein nutritional value of roughage in the Republic of Tatarstan

The aim of the research was to analyze the dynamics of the energy and protein nutritional value of hay from cereal and leguminous herbs produced in the Republic of Tatarstan in the period from 1993 to 2018. The results of analysis of 560 samples of hay from different agroclimatic zones of the republic are presented. It was found that in the dry matter of both cereal and leguminous hay, the content of metabolizable energy practically did not change. The average content of metabolic energy in 1 kg of dry matter of cereal hay was 7.92 MJ / kg. The average deviation from the norm was minus 2.62%. The average content of metabolizable energy in 1 kg of dry matter of legume hay was 9.65 MJ / kg, which is 21.84% higher than in cereal hay. The average excess of the norm for this indicator was 13.77%. The level of net energy of lactation in cereal hay remains unchanged throughout the study, and for legumes there is a slight tendency to increase this indicator. The average value of the net energy content of lactation in 1 kg of dry matter of cereal hay was 3.72 MJ / kg, which deviates from the norm by minus 23.95%. The average content of net energy of lactation in 1 kg of dry matter of legume hay was 4.51 MJ / kg, which is 21.24% higher than in cereal hay. The deviation from the norm for the entire studied period of time was minus 8.34%. In the period from 1993 to 2018, a tendency for an increase in the content of digestible protein in dry matter was established, more pronounced in legume hay. The average long-term content of digestible protein in 1 kg of dry matter of cereal hay was 62.64 g / kg, while in legume hay its content was 70.10% higher (106.55 g / kg). The average deviation of this indicator from the norm in cereal hay was 15.04%, and in legumes - 8.51%.