Efficiency of two-phase piglet rearing with changes in different feeding sys-tems and their duration

The growth rate, survival rate, feed cost per unit of gain, and economic feasibility of rearing piglets using single-phase and two-phase technology, which involved changing the liquid feeding method during the suckling period to dry feeding in the first phase of rearing and returning to the liquid method in the second phase, were compared. It was found that piglets that were transferred to the second phase of rearing using a liquid feeding system immediately after weaning from sows had advantages in growth rate, survival rate, and feed efficiency compared to groups of peers that had a two-phase rearing and were transferred from the first phase (dry feeding) to the second phase (liquid feeding) at the age of 7, 14, and 21 days. They demonstrated, respectively, better survival during the growing period by 1.15, 0.39 and 0.69 %, higher average daily gains by 10.3, 7.1 and 13.9 %, higher relative gains by 5.03, 3.32 and 6.65 % and higher live weight of piglets at the end of growing by 8.3, 5.8 and 11.3 %. At the same time, the average weight of piglets that dropped out of the group in the first phase depended on the duration of this phase, while during the second phase, a clear pattern of dependence of the weight of dropped piglets on the duration of the phase was not observed. Considering that the largest share of the operating cost of growing one head falls on feed, it is logical that the lowest operating cost of growing one piglet was found in animals with the longest duration of the first growing phase. Their operating cost was 10.8 % lower compared to animals that did not have dry feeding, 9.4 % lower compared to animals that had a 7-day first growing phase, and 9.1 % lower compared to animals that were 14 days into growing with dry feeding. Due to different growth rates and, as a result, different absolute gains during the growing period, the cost of one kilogram of growth during this time was different. It was the lowest in animals with a single-phase growing phase, while in their counterparts that had a 7-day first growing phase, it was 9.8 % higher, in a 14-day first growing phase, 5.7 %, and in a 21-day growing phase, 3.6 % higher compared to single-phase growing. At the same time, animals on single-phase liquid feeding had the highest cost of one piglet upon completion of rearing, which was 0.3–4.3 % higher compared to animals on two-phase rearing. However, due to the higher weight of piglets upon completion of single-phase rearing, their sales value was 8.3 % higher compared to animals that had 7 days of dry feeding, 5.8 % higher compared to animals that had 14 days of dry feeding, and 11.3 % higher compared to animals that had 21 days of dry feeding. Due to the higher profit from rearing one animal at a similar cost, the profitability of rearing was also higher in animals that were kept on constant liquid feeding. It was 11.8 % higher compared to animals that had 7 days of dry feeding, 7.59 % higher compared to analogues that had 14 days of dry feeding, and 10.79 % higher compared to animals that had 21 days of dry feeding. Despite the highest operating cost of one piglet during its single-phase growing, the cost of 1 kg of live weight upon its completion was the lowest in them (8.7 %, 5.4 % and 7.9 % lower compared to animals that had a liquid feeding phase duration of 42, 35 and 28 days, respectively), while the profit from growing a kilogram of weight of these animals was 6.63 %, 18.20 % and 11.40 % higher, respectively.