Evaluation of rendered animal protein sources on growth performance and blood chemistry in growing pigs

Abstract Text: A 6-wk growth assay was conducted to determine the effects of animal skin protein from swine and cattle on growth performance, body condition, and blood characteristics in growing pigs. A total of 96 pigs (23.5 kg) were allotted into pens with 4 pigs/pen and 6 pens/treatment. Treatments were: 1) a corn-soybean-meal based control and the control diet with 2) 1.5% hydrolyzed render meal (HRM), 3) 1.5% swine skin meal (SSM), or 4) 1.5% cattle hide meal (CHM). The HRM and enzyme-treated skin meal was obtained from the Woosin food company (Pocheon, Gyeonggi, Korea) and was produced using a dry processing method at 130°C and under 500 kPa of steam. Chromium oxide was added to the diet as an indigestible marker at 0.20% for 7 d prior to fecal collection during the 6^th week for calculating apparent total tract digestibility of dry matter (DM), nitrogen (N), and energy (E). The data obtained were analyzed using the General Linear Model procedure of SAS as a randomized complete block design by ANOVA. Pen was considered as the experimental unit. Variability in the data is expressed as the standard error and a probability level of P < 0.05 was considered to be statistically significant. Average daily gain (ADG) was improved in response to SSM treatment compared with other treatments (P < 0.05). Pigs fed with HRM, SSM and CHM diets showed increased (P < 0.05) average daily feed intake (ADFI) and decreased (P < 0.05) gain-to-feed ratio compared with pigs fed the control diet. There were no differences in DM, N, or E digestibilities among treatments. Neither backfat thickness nor lean percentage of pigs were affected by dietary treatment. No differences were observed in blood concentrations of creatinine or BUN, and activities of serum GOT and GPT did not differ among the dietary treatment groups. In conclusion, the supplementation of SSM in growing pig diets improved the growth rate and feed intake of pigs, but its usage in swine diets is limited by the poor protein quality.

Keywords: animal-derived protein, enzyme, growing pigs