Effects of Different Crude Protein and Dietary Fiber Levels on the Comparative Energy and Nutrient Utilization in Sows and Growing Pigs

SIMPLE SUMMARY: Accurate evaluation of the nutritional values of ingredients fed to sows is highly valuable in swine production, and those values should be kept updated with the genetic improvement of sows. In the feedstuff tables of NRC (2012), the same available energy value was assigned for growing pigs and adult sows for the same ingredient, whereas two different values were used in the feedstuff tables published in China and France (INRA). More research and efforts are required to solve these conflicts, while data gained from animal trials are limited currently. Therefore, we determined and compared the nutritional values of eight ingredients fed to both growing pigs and adult sows, and found that sows had lower available energy and nutrient digestibility when fed soybean meal or cottonseed meal compared with growing pigs, and the crude protein content is a good predictor to estimate the available energy values of ingredients fed to sows based on the values measured from growing pigs. The results of the current study can facilitate the accurate formulation of sow diets. ABSTRACT: This study was conducted to determine and compare digestible energy (DE) and metabolizable energy (ME) values and the apparent total tract digestibility (ATTD) of energy and nutrients in eight ingredients fed to both growing pigs and sows. Two experiments with 48 crossbred barrows or six non-pregnant sows were allotted to eight treatments in a completely randomized design or a pseudo Latin square with six replicated pigs per dietary treatment. The dietary treatments were formulated with two cereal ingredients: corn and wheat; two ingredients with a high protein level and a low fiber level (HPLF): soybean meal (SBM) and cottonseed meal (CSM); two ingredients with medium protein level and medium fiber level (MPMF): corn distiller’ dried grains with solubles (DDGS) and corn germ meal (CGM); and two ingredients with a low protein level and a high fiber level (LPHF): wheat bran (WB) and palm kernel meal (PKM), respectively. Adult sows had greater DE and ME values and ATTD of energy and nutrients when fed cereal ingredients compared with growing pigs, and had lower DE and ME contents and ATTD of energy and nutrients except for acid detergent fiber (ADF) when fed HPLF ingredients compared with growing pigs. Moreover, no differences were observed between adult sows and growing pigs in DE and ME contents and ATTD of energy and nutrients when fed MPMF and LPHF ingredients, except that adult sows showed a greater ATTD of crude protein (CP) when fed MPMF ingredients compared with growing pigs. Our results indicate that sows had a lower available energy and nutrient digestibility when fed SBM or CSM compared with growing pigs. Crude protein contents in ingredients should be considered when predicting DE and ME values in sows based on the DE and ME values measured from growing pigs.