The productivity of first-calf heifers and technological properties of milk when use in rations of linseed and rapeseed press cakes

Abstract

Summary. Practical interest at the present stage in feeding highly productive cows is the use of fl axseed and rapeseed press cakes, which are sources of energy, high-grade protein and polyunsaturated fatty acids. Rapeseed and linseed press cakes are excellent protein feed for cattle. In concentrates for this animal species they may be the only high-protein components. The purpose of the work was to carry out comprehensive research on fi rst-calf heifers productivity traits, milk quality and its technological properties when using linseed and rapeseed press cakes in their rations. The research has been carried out in JSC “Uchkhoz Iyulskoe of Izhevsk State Agricultural Academy”. The object of research was fi rst-calf heifers of Black-and-White breed. In order to conduct research, four groups of fi rst-calf heifers have been formed – a control group and three experimental groups of 12 animals in each group. A comprehensive evaluation of productive traits, milk quality, its technological properties, as well as the quality of dairy products (cheese, cottage cheese, yogurt) when used in fi rst-calf heifers feeding various cakes (linseed and rapeseed). The lowest prime-cost of 1 kg of milk has been obtained with the simultaneous use of linseed and rapeseed cakes of 14,0 rubles, which was less than in the control group by 2,1 rubles, the 1st experimental group by 1,7 rubles and the 2nd experimental group by 0,7 rubles. The largest gross profi t from milk sales has been received in the 3rd and 2nd experimental groups of 55 744 and 48 202 rubles, respectively. The level of profi tability in all groups was high and ranged from 36,6 % in the control group and up to 57,1 % in the 3rd experimental group. The result of the conducted researches has proved the effi ciency when feeding lactating fi rst-calf heifers of Black-and-White breed of rapeseed press cake and a mixture of rapeseed and linseed press cake in 1 : 1 ratio when replacing 30 % (on crude protein content) of sunfl ower press cake in their rations.