Effects of dietary lysozyme levels on growth performance, intestinal morphology, non‐specific immunity and mRNA expression in weanling piglets

Abstract

The aim of the present study was to determine the effect of dietary lysozyme levels on growth performance, gut health and non-specific immunity of weanling piglets. A total of 150 weanling piglets were allocated to six treatments. The piglets were fed the same basel diet supplemented with 0, 30, 60, 90 and 120 mg/kg lysozyme as well as antibiotics for 28 days. From day 14 to day 28 of dietary treatment, piglets fed 90 mg/kg lysozyme had greater average daily gain than piglets fed control diet. During the whole experimental period, piglets fed 120 mg/kg lysozyme tended to have greater average daily gain than piglets fed control diet. Compared with piglets fed control diet, piglets fed diets containing antibiotics and 90 mg/kg lysozyme had greater villus height to crypt depth ratio in duodenum and jejunum. Additionally, dietary supplementation of 60 and 90 mg/kg lysozyme as well as antibiotics enhanced the phagocytic activity of peritoneal macrophages in piglets. In conclusion, dietary lysozyme can accelerate the growth of weanling piglets by improving gut health and non-specific immunity and supplementing 90 mg/kg lysozyme is as effective as antibiotics (20 mg/kg colistin sulphate + 50 mg/kg kitasamycin) in improving the growth performance of weanling piglets.

Effects of dietary lysozyme levels on growth performance, intestinal morphology, immunity response and microbiota community of growing pigs

“…Antibiotics have been used as growth promoters by improving feed efficiency for more than 50 years. A series of studies have proven the beneficial effects of dietary supplementation of lysozyme on growth performance of pigs at different stages of growth, including 10‐day‐old pigs, nursery pigs, weaned pigs and 6‐week‐old pigs . The current study showed that growing pigs fed with 100 mg kg −1 lysozyme had a similar or even better feed efficiency than pigs fed with colistin sulfate ( P > 0.05).…”

“…Lysozyme can take part in the natural defence mechanism in Gram‐positive bacteria and perhaps indirectly affect Gram‐negative bacteria . It was proven that lysozyme could partially replace antibiotics as an important non‐specific immune component . Furthermore, Ginsburg found that lysozyme has many other biological functions, including regulation of inflammatory response, and antiviral and antitumor activities.…”

“…[3][4][5] It is well known that lysozyme, 1,4--N-acetylmuramidase, specifically catalyses the hydrolysis of bacterial cell wall by cleavage of -1,4 linkages between N-acetylmuramic acid and N-acetylglucosamine of peptidoglycan. 6 It is secreted by polymorphonuclear leukocytes and found in tissue and bodily fluids, including egg white, tears and milk. 7 Lysozyme is highly resistant to hydrolysis by acids and proteases, as well as to digestion in the gastrointestinal tract.…”

“…11 Nursery diets supplemented with lysozyme improved body weight, average daily gain and small intestinal morphology of 21-day-weaned pigs. 12 In addition, Long et al 6 reported that dietary supplementation with 90 mg kg −1 lysozyme is as effective as antibiotics in improving growth performance and non-specific immunity of weanling piglets. Lysozyme can take part in the natural defence mechanism in Gram-positive bacteria 13 and perhaps indirectly affect Gram-negative bacteria.…”

“…14 It was proven that lysozyme could partially replace antibiotics as an important non-specific immune component. 6,15 Furthermore, Ginsburg 16 found that lysozyme has many other biological functions, including regulation of inflammatory response, and antiviral and antitumor activities. However, the effect of dietary lysozyme on growth performance and gut health of growing pigs is unknown.…”