Comparison of the effects of applying xylooligosaccharides alone or in combination with calcium acetate in broiler chickens

Abstract

Xylooligosaccharides (XOS) which are generally processed by the enzymatic hydrolysis of extracted xylan, constitute a class of feed additives with potential probiotic properties. Although the production of the XOS through a novel acetic acid catalysis is green and efficient, the removal of acetic acid is costly and tedious. To ease operation and save expenditure, the acetic acid should be chemically immobilized by adding CaO to form calcium acetate (CAS), which acts as a feed additive component in the XOS products. This study identified the biofunction of the acidolyzed XOS product and compared its effects to those of the immobilized XOS and calcium acetate (CXC) combination on the growth performance, carcass characteristics, meat quality and immunity functions during broilers breeding. A total of 180 1-day-old male Arbor Acres broilers were randomly allocated to three groups: a) control group; b) XOS group (0.2 g XOS /kg feed); c) CXC group (0.2 g XOS + 0.23 g CAS/kg feed). The results indicated that supplementation with XOS or CXC improved the body weight (BW) and average daily gain (ADG), decreased feed/gain (F/G) of the broilers (P < 0.05), and was the best for the XOS group. XOS and CXC increased the carcass weight of broilers, while CXC was found to increase the abdominal fat yield (P < 0.05). The addition of XOS or CXC was found to reduce the cooking losses in broilers (P < 0.05). XOS was found to decrease the concentrations of uric acid (UA) and urea, and improve the concentration of immunoglobulin (Ig) G, while CXC was found to lower the concentration of UA and increase the (Ig)A and IgG concentrations in the serum of broilers (P < 0.05). There was no difference in the content of short-chain fatty acids in the cecum among the groups (P > 0.05), but there was an increasing trend in both the test groups compared to that of the control group. In conclusion, supplementation of XOS either alone or in combination with CAS was found to improve the growth performance, meat quality and immunity of broilers. The group supplemented with XOS alone demonstrated improved growth performance, meat quality, and metabolism, more effectively while the group fed with XOS + CAS in combination demonstrated a promising improvement in immunity. Based on the cost, effectiveness of the process and other factors, the XOS products can be directly implemented for animal production without removing CAS.