Recent research has shown that salt levels of minimal 3.5 g/kg diet result in best performance in piglets between 7 and 11 kg. In the US, pig diets tend to have higher salt levels and higher crude protein (CP) levels than in Europe. Higher CP levels may lead to higher protein breakdown, while higher salt levels may lead to increased water consumption, which might facilitate nitrogen clearance through the kidneys. Therefore, we hypothesized that high salt levels are more important when the pigs receive a high CP diet. For this experiment, 96 pens of 5 piglets were divided over 8 treatments in a 2 × 4 factorial design with 2 protein levels (189 vs 223 g/kg) and 4 salt levels (1.9, 2.5, 3.1, and 3.8 g/kg in the low protein diet and 1.9, 2.6, 3.2, and 3.9 g/kg in the high protein diet). Different salt levels were obtained by exchanging SiO₂ for NaCl. The low protein diet was formulated to contain 11.8 g SID lysine and 9.85 MJ net energy/kg diet, while the high protein diet had 12.5 g SID lysine and 10.40 MJ net energy/kg diet. Salt level did not affect performance nor did it interact with crude protein level. Fecal consistency worsened as salt levels increased during the first week after weaning. The latter might be a result of either increased water consumption or increased osmotic pressure in combination with the piglets’ limited absorption capacity shortly after weaning, especially when receiving diets without zinc oxide or antibiotics. The higher nutrient density in the high protein diet resulted in lower feed intake with similar growth, leading to improved feed efficiency per kg diet, but not per MJ of net energy consumed. Based on the present experiment, we could not confirm our hypothesis that increased protein levels lead to higher sodium requirements in weaned piglets.

最近的研究表明，最低日粮3.5 g / kg的食盐水平可使7至11 kg的仔猪表现最佳。在美国，与欧洲相比，猪日粮中的盐含量和粗蛋白（CP）含量较高。较高的CP水平可能导致较高的蛋白质分解，而较高的盐水平可能导致水消耗增加，这可能有助于通过肾脏清除氮。因此，我们假设当猪接受高CP饲料时，高盐含量更为重要。在本实验中，将96头5头仔猪的笔分成2×4因子设计的8种处理方法，其中2种蛋白质含量（189 vs 223 g / kg）和4种盐含量含量（1.9、2.5、3.1和3.8 g / kg）。低蛋白饮食，高蛋白饮食为1.9、2.6、3.2和3.9 g / kg）。通过交换SiO获得不同的盐含量_2个用于氯化钠。低蛋白饮食的配方中含有11.8 g SID赖氨酸和9.85 MJ净能量/ kg饮食，而高蛋白饮食则具有12.5 g SID赖氨酸和10.40 MJ净能量/ kg饮食。盐水平既不影响生产性能，也不与粗蛋白水平相互作用。断奶后第一周，由于盐含量增加，粪便的稠度变差。后者可能是由于断奶后不久，尤其是在接受不含氧化锌或抗生素的日粮时，耗水量增加或渗透压升高，加上仔猪吸收能力有限所致。高蛋白日粮中较高的养分密度导致较低的采食量和相似的生长，从而提高了每公斤日粮的饲料效率，但不是每MJ净能量消耗。根据目前的实验，