Various Levels of Milk By-Products in Weaning Pig Diet on Growth Performance, Blood Profiles, Intestinal Morphology, Muscle Fiber Diameter and Diarrhea Incidence in Weaning Pigs

This experiment was conducted to evaluate various levels of milk by-products in weaning pig diet on growth performance, blood profiles, intestinal morphology, muscle fiber diameter and diarrhea incidence on weaning pigs. A total of 160 weaning pigs ([Yorkshire × Landrace] × Duroc), average 5.97 ± 1.53 kg body weight (BW), were allotted to one of four treatments with five replicates with eight pigs per pen by BW and sex in a randomized complete block (RCB) design. Pigs were fed each treatment diet with various levels of milk by-product (phase1: 30, 20, 10 or 5%; phase2: 15, 10, 5 or 0%) for 5 weeks (phase1: 0-2 week and phase2: 3-5 week, respectively). Growth performance was decreased linearly as milk by-product level decreased during phase 2 and whole experimental period (0-5 week) (linear response, P<0.05). Average daily gain, ADFI and G:F ratio were also decreased linearly as milk by-product level decreased during phase 2 and whole experimental period (0-5 week) (linear response, P<0.05). However, pigs fed milk by-product 10%-5% diet had similar growth performance rather than pigs fed milk by-product 30%-15%. In blood profiles, supplementation of milk by-products by different levels was not affect in BUN, creatinine, IgA and IgG among treatments during whole experimental period (0-5 week). However, IGF-1 concentration was significantly lower than other treatments when pigs were fed a diet containing 10%-5% of milk by-product (quadratic response, P<0.05). The villus height and crypt depth of small intestine (proximal, mid and distal) had no significant difference among dietary treatments. In addition, muscle fiber diameter was not affected by dietary milk by-product levels. The incidence of diarrhea had no significant difference by dietary treatments. These results demonstrated that inclusion of milk by-product 10%-5% had no negative influence on growth performance and other measurements compared with inclusion of milk by-product 30%-15%.