This experiment was conducted to determine the effect of variety and planting year on the nutritive values of corn fed to growing pigs. Four corn varieties examined in this experiment were planted in the same village located in Longhua County, Heibei Province, China, in 2012, 2013, and 2014, respectively. During each year, corn was hand-harvested in early October and sun dried to about 14% moisture content. Three batches of twenty-four barrows (33.27±4.30, 31.88±2.93, 34.21±3.81 kg body wight [BW] in 2012, 2013, and 2014, respectively) were used and allotted to a complete block design with 4 diets and 6 replicate pigs per diet. Pigs were individually placed in metabolic crates. The four experimental diets were formulated by mixing each variety of corn and vitamins and minerals, respectively. A five-day collection period followed a seven-day diet acclimation period. The results indicated that variety of corn significantly influenced the available energy content (digestible energy [DE] on dry matter basis, p<0.05; metabolizable energy (ME) on dry matter basis, p<0.05, respectively), and the apparent total tract digestibility (ATTD) of organic matter (p<0.01), dry matter (p<0.05), gross energy (p<0.05), neutral detergent fiber (p<0.01), acid detergent fiber and ether extract (p<0.05). The planting year also significantly influenced the available energy contents (DE on dry matter basis, p<0.05; ME on dry matter basis, p<0.01, respectively) and the ATTD of neutral detergent fiber (p<0.01), acid detergent fiber (p<0.01), crude protein (p<0.01), and ether extract (p<0.01). No interaction was observed between the variety and planting year in DE and ME contents in corn. In conclusion, the variety and planting year significantly influenced the available energy and nutrient digestibility of corn fed to growing pigs.
Keywords: Corn; Digestible Energy; Pigs; Planting Year; Variety.