Effects of lysine and protein intake over two consecutive lactations on lactation and subsequent reproductive performance in multiparous sows

Abstract The aim of the study was to evaluate that the effect of lysine and protein intake over two consecutive lactations on lactation and subsequent reproductive performance in multiparous sows. The experiment was designed in a 2×2 factorial arrangement with 2 levels of total lysine (0.95% and 1.10%) and 2 levels of crude protein (17.5% and 19.0%). The treatment diets were the same for all sows within each treatment combination during two consecutive lactations. The average ambient temperature of the semi-enclosed farrowing room during the first and second lactation were 28.3±1.7 °C and 23.4±2.2 °C, respectively. The results showed that the 19.0% CP diets increased the first and second lactating sow CP intake compared with the 17.5% CP diets ( P P P P P P >0.05). These results indicated that, at low levels of lysine intake, increasing lysine intake was beneficial for reducing sow lactation weight loss and culling rate of sow failing to display estrus within 21 d after weaning, while increasing lysine intake at high levels of lysine intake increased sow lactation weight loss and culling rate of sow failing to display estrus within 21 d after weaning.