Effects of storage time and exogenous xylanase supplementation of new season wheats on the performance of young male pigs

A series of experiments was conducted to investigate the influence of new season wheats on pig growth performance. Experiments were carried out on 10 different wheats at the time of harvest and 10 mo post-harvest. At harvest wheat, at a 65% level in the steam-pelleted diets, influenced (P < 0.01) feed intake and daily gain over a 21-d trial. Thus, feed intake and daily gain of pigs offered the lowest and highest quality wheats varied by 47 and 48%, respectively. There was, however, no effect on feed conversion ratio (FCR), even though dry matter (DM) digestibility and digestible energy (DE) values of different wheats differed significantly (P < 0.01 and P < 0.01, respectively). The non-starch carbohydrate (NSC) level of the wheats was measured as the sum of non-starch polysaccharides (NSP) and free sugars. The NSC level of the wheats negatively affected feed intake (r(2) = -0.556: P < 0.01) and daily gain (r(2) = -0.574: P < 0.01). After 10 mo of storage, the feed intake and daily gain of the pigs fed the same wheats were significantly (P < 0.01) higher, but not all the wheats responded to storage. A xylanase product was added to three of the 10 mo-old wheats, which were pre-characterized as low, medium and high intake wheats. The enzyme increased (P < 0.01) daily gain and feed intake of the pigs fed the low-quality wheat by 50.6 and 42.8%, respectively. It may be concluded that the nutritive value of wheat for weaner pigs varies widely and appears to be related to the level of NSC and the cell wall structure of the grain.