Effectiveness of Rapeseed Press Cake (RPC) in Sow Feeding in Two Reproduction Cycles

The possibility of replacing soybean meal with rapeseed press cake (RPC) in feed was determined over two reproductive cycles in an experiment with 54 pregnant and lactating sows allocated to three groups with 18 gilts per group. Group I received the standard mixture, group II received RPC as the main protein source from insemination to 100 days of pregnancy, and the control diet during late pregnancy and lactation. In group III, RPC replaced all of soybean meal protein in early pregnancy and one-half of soybean meal protein during late pregnancy and lactation. Half of the sows in each group received a iodine supplement (1 mg/kg feed). Sows were weighed at mating, farrowing and weaning. Piglets were weighed at 1 and 28 days of age (weaning). Samples of milk were collected at 14 days postpartum to determine the content of protein, fat, lactose and iodine. After the first reproductive cycle sows were mated and allocated to the respective groups as in the first cycle. Neither RPC nor iodine had any effect on body weight of the sows. RPC had a beneficial effect on body weight of piglets at birth and weaning, which could be due to a higher content of fat and amino acids in sow RPC diets. RPC, especially when given throughout pregnancy and lactation significantly lowered iodine content in sow milk. Piglets grew significantly faster in the second compared to the first reproductive cycle (184 and 178 g per day, respectively). Iodine supplemented to sows reduced piglet daily weight gain from 185 to 177 g. It is concluded that rapeseed press cake can replace soybean meal in the diets for pregnant and lactating sows without a negative effect on their performance while improving piglet body weight.