Влияние генотипа крупного рогатого скота на химический состав говядины

Abstract

Purpose. To study the slaughter qualities of mixed young cattle and the chemical composition of beef obtained from it. Materials and Methods. The object of research is 18-month-old crossbred bulls, obtained as a result of industrial crossing of Kazakh white-headed cattle bulls with heifers of the Simmental breed (group I), Hereford bulls with heifers of the Simmental breed (group II) and Kalmyk bulls with heifers of red steppe cattle (group III). Purebred bulls of the Kazakh white-headed breed were used as a control group. Chemical analysis of beef samples was carried out according to the following methods and GOST standards: moisture content was determined by drying the sample to a constant mass at a temperature of 100-105 °C according to GOST 9793-2016; protein content – by the amount of protein nitrogen by the Kjeldahl method according to GOST 25011-2017; fat content – according to GOST 23042-2015; ash content – according to GOST 31727-2012; the amino acid and vitamin composition was determined according to the method of measuring the mass fraction of amino acids and vitamins by the KE method on the Kapel-105M system, the concentration of hydrogen ions (pH) according to GOST R 51478-99. Calorie content of 100 g / meat was calculated using the formula of V. M. Aleksandrov. Results. To assess the meat productivity of crossbred steers, their control slaughter was carried out, which showed that the largest slaughter weight and slaughter yield were possessed by steers of the II experimental group – 312.4 kg and 61.0%. Beef samples from young animals of the II experimental group had the highest content of dry matter. The difference with peers from the control, I and III groups was 0.27, 0.21 and 0.63%, respectively. It was also noted that the crossbred young of the II experimental group surpassed purebred Kazakh white-headed bulls in protein content by 1.67%. The difference with the crossbreeds from group I and III is 1.38 and 2.3% respectively. A study of the vitamin composition of the beef of experimental young animals showed that the resulting beef was relatively rich in vitamins of group B. beef obtained from crossbred bulls of the II experimental group has a higher biological value (Protein qualitative indicator = 5.86 compared with the control 5.59). The increase in protein qualitative indicator is mainly due to the higher content of tryptophan in beef of the experimental group II – by 9.0% (494.40 mg% compared with 453.86 mg% in the control). The pH value of the water-meat extract in bulls of different genotypes is almost the same and ranged from 5.41 to 5.49. Conclusion. It has been established that the crossing of bulls of meat breeds of cattle with heifers of dairy and combined breeds contributes to the production of young offspring with excellent slaughter qualities, and beef obtained from such offspring has a high biological value.