BULL-CALVES FATTENING TECHNOLOGY USING NANO IRON POWDER
Nanoparticles compared to metal salts, traditionally used in animal feeding, have low toxicity, but are able to activate physiological and biochemical processes in the body. To study the influence of iron nanoparticles during fattening on some morpho-biological parameters of the Kalmyk bull-calves the scientific-economic experiment was conducted between 2016-2017 in Ardonsky district of the Republic of North Ossetia-Alania. The objects of research were Kalmyk bull-calves, which at 6 months by analogue scale were divided into two groups of 10 animals each, with the initial live weight 154 kg. The experiment lasted 12 months. The bull-calves were in the same conditions of feeding and housing. A distinctive feature consisted in supplements of the nano iron powder at the rate of 0,08 mg/kg of live weight to the mixed feed of the animals in the test group. The inclusion of nano iron powder into the mixed feed of the test group contributed to an increase in live weight by 9,13%, and the average daily gain by 14,71%. This contributed to the reduction of feed costs per EFU production unit by 12,89% and digestible protein - by 12,82%. The bull-calves in the test group had the best indicators of meat productivity, i.e., exceeded the counterparts from the control group in pre-slaughter weight by 9,1%, in weight of fresh-killed and chilled carcass - by 20,45%, in weight of internal fat - by 35,3% and in slaughter yield - by 3,10%. Economic calculations showed that in the test group, the revenue from beef production was higher and amounted to 75735 roubles, which is more than that of the control counterparts by 9.1%. On the basis of the data obtained, it follows that the use of nano iron particles in bull-calves feeding at the rate of 0,08 mg/kg of live weight per day promotes the metabolic processes that increase fattening bull-calves' productivity: live weight by 9,1% and profitability - 2,37%.