Influence of housing methods of young bulls of Hereford breed on their meat productivity and survival rate
The indicators of productivity, survival rate and behavior of young bulls of Hereford breed were studied in a comparative aspect when they were raised in winter in the northern part of Kolpashevsky district of the Tomsk region. During the housing period, low average air temperatures were observed: from 20°С in October to –50°С in December – January and –49°С in February. Bulls of the control group were kept in a unit of the "three-wall" type during wintering, while bulls of the experimental group – in a lightweight unit. The increase in live weight of bulls of experimental group was 2.2 times higher than that in the control group, the slaughter weight was by 68.3 kg and the weight of internal fat was by 6.0 kg more than in the control. In the experimental group, the survival rate of bulls before slaughtering was 2 times higher than that in the control. In terms of live weight, experimental animals from the age of 15 months to slaughter exceeded the control group by 19%. Ethological studies showed that different types of housing units had a significant impact on animal behavior. The feed intake of the bulls of the control group was shorter by 54 minutes, (15%) than that of the experimental group. Animals also spent 95 minutes (20.21%) less on chewing cud compared to the experimental bulls. When kept in a lightweight type of unit, bulls were in motion for a longer time, as a result of which they rested 45 minutes less, which contributed to the increase in the metabolic processes in the body. The animals of the experimental group spent 50 minutes longer on eating food in comparison with the bulls in the “three-wall” unit. The air temperature in a unit of the "three-wall" type was close to the ambient air temperature, wherein the bulls spent most of their time lying down. The profitability of growing bulls in the experimental group exceeded the control indicator by 1.6 times. In the light-type premises, the housing conditions of bulls in the winter period at extremely low air temperatures were most favorable.